commit 37c047a757209618976176c54ee5b2c9f0432cfb
parent 4b61512512f362895db9d670aa3d3712b214a69b
Author: Bastian Gruber <foreach@me.com>
Date: Tue, 2 Dec 2025 11:20:48 +0000
Bug 1983135 - Implement a Necko backend for viaduct. r=bdk,valentin,supply-chain-reviewers
Differential Revision: https://phabricator.services.mozilla.com/D271450
Diffstat:
44 files changed, 6507 insertions(+), 0 deletions(-)
diff --git a/Cargo.lock b/Cargo.lock
@@ -2659,6 +2659,7 @@ dependencies = [
"urlpattern",
"urlpattern_glue",
"viaduct",
+ "viaduct-necko",
"webext-storage",
"webrender_bindings",
"wgpu_bindings",
@@ -5232,6 +5233,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
[[package]]
+name = "oneshot"
+version = "0.1.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b4ce411919553d3f9fa53a0880544cda985a112117a0444d5ff1e870a893d6ea"
+
+[[package]]
name = "ordered-float"
version = "3.4.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -7675,6 +7682,17 @@ dependencies = [
]
[[package]]
+name = "viaduct-necko"
+version = "0.1.0"
+dependencies = [
+ "async-trait",
+ "error-support",
+ "oneshot",
+ "url",
+ "viaduct",
+]
+
+[[package]]
name = "void"
version = "1.0.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/Cargo.toml b/Cargo.toml
@@ -26,6 +26,7 @@ members = [
"toolkit/crashreporter/mozwer-rust",
"toolkit/library/gtest/rust",
"toolkit/library/rust/",
+ "services/application-services/components/viaduct-necko",
]
# Excluded crates may be built as dependencies, but won't be considered members
diff --git a/services/application-services/components/viaduct-necko/Cargo.toml b/services/application-services/components/viaduct-necko/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "viaduct-necko"
+version = "0.1.0"
+edition = "2021"
+rust-version.workspace = true
+
+[dependencies]
+async-trait = "0.1"
+error-support = "0.1"
+oneshot = "0.1.11"
+url = "2"
+viaduct = "0.1"
+
+[lib]
+path = "src/lib.rs"
diff --git a/services/application-services/components/viaduct-necko/backend.cpp b/services/application-services/components/viaduct-necko/backend.cpp
@@ -0,0 +1,670 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "backend.h"
+
+#include "mozilla/Logging.h"
+#include "mozilla/Span.h"
+#include "nsCOMPtr.h"
+#include "nsComponentManagerUtils.h"
+#include "nsContentUtils.h"
+#include "nsIChannel.h"
+#include "nsIHttpChannel.h"
+#include "nsIHttpChannelInternal.h"
+#include "nsIHttpHeaderVisitor.h"
+#include "nsIInputStream.h"
+#include "nsIStreamListener.h"
+#include "nsITimer.h"
+#include "nsIUploadChannel2.h"
+#include "nsIURI.h"
+#include "nsNetUtil.h"
+#include "nsPrintfCString.h"
+#include "nsStringStream.h"
+#include "nsThreadUtils.h"
+#include "nsTArray.h"
+
+#include <cinttypes>
+#include <utility>
+
+using namespace mozilla;
+
+// Logger for viaduct-necko backend
+static LazyLogModule gViaductLogger("viaduct");
+
+/**
+ * Manages viaduct Request/Result pointers
+ *
+ * This class ensures that we properly manage the `ViaductRequest` and
+ * `ViaductResult` pointers, avoiding use-after-free bugs. It ensures that
+ * either `viaduct_necko_result_complete` or
+ * `viaduct_necko_result_complete_error` will be called exactly once and the
+ * pointers won't be used after that.
+ *
+ * This class is designed to be created outside of NS_DispatchToMainThread and
+ * moved into the closure. This way, even if the closure never runs, the
+ * destructor will still be called and we'll complete with an error.
+ */
+class ViaductRequestGuard {
+ private:
+ const ViaductRequest* mRequest;
+ ViaductResult* mResult;
+
+ public:
+ // Constructor
+ ViaductRequestGuard(const ViaductRequest* aRequest, ViaductResult* aResult)
+ : mRequest(aRequest), mResult(aResult) {
+ MOZ_LOG(gViaductLogger, LogLevel::Debug,
+ ("ViaductRequestGuard: Created with request=%p, result=%p",
+ mRequest, mResult));
+ }
+
+ // Move Constructor
+ // Transfers ownership of the pointers from other to this.
+ ViaductRequestGuard(ViaductRequestGuard&& other) noexcept
+ : mRequest(std::exchange(other.mRequest, nullptr)),
+ mResult(std::exchange(other.mResult, nullptr)) {
+ MOZ_LOG(gViaductLogger, LogLevel::Debug,
+ ("ViaductRequestGuard: Move constructed, request=%p, result=%p",
+ mRequest, mResult));
+ }
+
+ // Move assignment operator
+ ViaductRequestGuard& operator=(ViaductRequestGuard&& other) noexcept {
+ if (this != &other) {
+ // If we already own pointers, complete with error before replacing
+ if (mResult) {
+ MOZ_LOG(gViaductLogger, LogLevel::Warning,
+ ("ViaductRequestGuard: Move assignment replacing existing "
+ "pointers, completing with error"));
+ viaduct_necko_result_complete_error(
+ mResult, static_cast<uint32_t>(NS_ERROR_ABORT),
+ "Request replaced by move assignment");
+ }
+ mRequest = std::exchange(other.mRequest, nullptr);
+ mResult = std::exchange(other.mResult, nullptr);
+ }
+ return *this;
+ }
+
+ // Disable copy constructor and assignment
+ // We prevent copying since we only want to complete the result once.
+ ViaductRequestGuard(const ViaductRequestGuard& other) = delete;
+ ViaductRequestGuard& operator=(const ViaductRequestGuard& other) = delete;
+
+ ~ViaductRequestGuard() {
+ // If mResult is non-null, the request was destroyed before completing.
+ // This can happen if the closure never runs (e.g., shutdown).
+ if (mResult) {
+ MOZ_LOG(gViaductLogger, LogLevel::Warning,
+ ("ViaductRequestGuard: Destructor called with non-null result, "
+ "completing with error"));
+ viaduct_necko_result_complete_error(
+ mResult, static_cast<uint32_t>(NS_ERROR_ABORT),
+ "Request destroyed without completion");
+ }
+ }
+
+ // Get the request pointer (for reading request data)
+ // Returns nullptr if already consumed.
+ const ViaductRequest* Request() const {
+ MOZ_ASSERT(mRequest,
+ "ViaductRequestGuard::Request called after completion");
+ return mRequest;
+ }
+
+ // Get the result pointer (for building up the response)
+ // Returns nullptr if already consumed.
+ ViaductResult* Result() const {
+ MOZ_ASSERT(mResult, "ViaductRequestGuard::Result called after completion");
+ return mResult;
+ }
+
+ // Check if the guard still owns valid pointers
+ bool IsValid() const { return mResult != nullptr; }
+
+ // Complete the result successfully and release ownership.
+ // After this call, the guard no longer owns the pointers.
+ void Complete() {
+ MOZ_ASSERT(mResult, "ViaductRequestGuard::Complete called twice");
+ MOZ_LOG(gViaductLogger, LogLevel::Debug,
+ ("ViaductRequestGuard: Completing successfully"));
+ viaduct_necko_result_complete(mResult);
+ mResult = nullptr;
+ mRequest = nullptr;
+ }
+
+ // Complete the result with an error and release ownership.
+ // After this call, the guard no longer owns the pointers.
+ void CompleteWithError(nsresult aError, const char* aMessage) {
+ MOZ_ASSERT(mResult, "ViaductRequestGuard::CompleteWithError called twice");
+ MOZ_LOG(gViaductLogger, LogLevel::Error,
+ ("ViaductRequestGuard: Completing with error: %s (0x%08x)",
+ aMessage, static_cast<uint32_t>(aError)));
+ viaduct_necko_result_complete_error(mResult, static_cast<uint32_t>(aError),
+ aMessage);
+ mResult = nullptr;
+ mRequest = nullptr;
+ }
+};
+
+// Listener that collects the complete HTTP response (headers and body)
+class ViaductResponseListener final : public nsIHttpHeaderVisitor,
+ public nsIStreamListener,
+ public nsITimerCallback,
+ public nsINamed {
+ public:
+ NS_DECL_THREADSAFE_ISUPPORTS
+ NS_DECL_NSIHTTPHEADERVISITOR
+ NS_DECL_NSIREQUESTOBSERVER
+ NS_DECL_NSISTREAMLISTENER
+ NS_DECL_NSITIMERCALLBACK
+ NS_DECL_NSINAMED
+
+ explicit ViaductResponseListener(ViaductRequestGuard&& aGuard,
+ uint32_t aTimeoutSecs)
+ : mGuard(std::move(aGuard)), mChannel(nullptr) {
+ MOZ_LOG(gViaductLogger, LogLevel::Info,
+ ("TRACE: ViaductResponseListener constructor called with timeout: "
+ "%u seconds, guard valid: %s",
+ aTimeoutSecs, mGuard.IsValid() ? "true" : "false"));
+
+ // Create timeout timer if timeout > 0
+ if (aTimeoutSecs > 0) {
+ MOZ_LOG(gViaductLogger, LogLevel::Debug,
+ ("Setting timeout timer for %u seconds", aTimeoutSecs));
+ nsresult rv =
+ NS_NewTimerWithCallback(getter_AddRefs(mTimeoutTimer), this,
+ aTimeoutSecs * 1000, nsITimer::TYPE_ONE_SHOT);
+ if (NS_WARN_IF(NS_FAILED(rv))) {
+ MOZ_LOG(gViaductLogger, LogLevel::Error,
+ ("Failed to create timeout timer: 0x%08x",
+ static_cast<uint32_t>(rv)));
+ }
+ }
+ }
+
+ void SetChannel(nsIChannel* aChannel) { mChannel = aChannel; }
+
+ private:
+ ~ViaductResponseListener() {
+ MOZ_LOG(gViaductLogger, LogLevel::Info,
+ ("TRACE: ViaductResponseListener destructor called"));
+
+ ClearTimer();
+
+ // The guard's destructor will handle completion if needed
+ }
+
+ void ClearTimer() {
+ if (mTimeoutTimer) {
+ mTimeoutTimer->Cancel();
+ mTimeoutTimer = nullptr;
+ }
+ }
+
+ // Error handling: logs error and completes the result with error via the
+ // guard.
+ void HandleError(nsresult aError, const char* aMessage);
+
+ // Wrapper methods that use the guard to safely access the result
+ void SetStatusCode(uint16_t aStatusCode);
+ void SetUrl(const char* aUrl, size_t aLength);
+ void AddHeader(const char* aKey, size_t aKeyLength, const char* aValue,
+ size_t aValueLength);
+ void ExtendBody(const uint8_t* aData, size_t aLength);
+ void Complete();
+
+ ViaductRequestGuard mGuard;
+ nsCOMPtr<nsITimer> mTimeoutTimer;
+ nsCOMPtr<nsIChannel> mChannel;
+};
+
+NS_IMPL_ISUPPORTS(ViaductResponseListener, nsIHttpHeaderVisitor,
+ nsIStreamListener, nsIRequestObserver, nsITimerCallback,
+ nsINamed)
+
+void ViaductResponseListener::HandleError(nsresult aError,
+ const char* aMessage) {
+ MOZ_LOG(gViaductLogger, LogLevel::Error,
+ ("TRACE: HandleError called with message: %s (0x%08x)", aMessage,
+ static_cast<uint32_t>(aError)));
+
+ if (mGuard.IsValid()) {
+ MOZ_LOG(gViaductLogger, LogLevel::Info,
+ ("TRACE: Calling CompleteWithError via guard"));
+ mGuard.CompleteWithError(aError, aMessage);
+ } else {
+ MOZ_LOG(gViaductLogger, LogLevel::Error,
+ ("TRACE: HandleError called but guard is invalid"));
+ }
+}
+
+void ViaductResponseListener::SetStatusCode(uint16_t aStatusCode) {
+ MOZ_LOG(gViaductLogger, LogLevel::Info,
+ ("TRACE: SetStatusCode called with code: %u", aStatusCode));
+ if (!mGuard.IsValid()) {
+ MOZ_LOG(gViaductLogger, LogLevel::Error,
+ ("SetStatusCode called but guard is invalid"));
+ return;
+ }
+ viaduct_necko_result_set_status_code(mGuard.Result(), aStatusCode);
+ MOZ_LOG(gViaductLogger, LogLevel::Debug,
+ ("Set status code: %u", aStatusCode));
+}
+
+void ViaductResponseListener::SetUrl(const char* aUrl, size_t aLength) {
+ MOZ_LOG(gViaductLogger, LogLevel::Info,
+ ("TRACE: SetUrl called with URL (length %zu)", aLength));
+ if (!mGuard.IsValid()) {
+ MOZ_LOG(gViaductLogger, LogLevel::Error,
+ ("SetUrl called but guard is invalid"));
+ return;
+ }
+ viaduct_necko_result_set_url(mGuard.Result(), aUrl, aLength);
+ MOZ_LOG(gViaductLogger, LogLevel::Debug, ("Set URL"));
+}
+
+void ViaductResponseListener::AddHeader(const char* aKey, size_t aKeyLength,
+ const char* aValue,
+ size_t aValueLength) {
+ MOZ_LOG(gViaductLogger, LogLevel::Info,
+ ("TRACE: AddHeader called - key length: %zu, value length: %zu",
+ aKeyLength, aValueLength));
+ if (!mGuard.IsValid()) {
+ MOZ_LOG(gViaductLogger, LogLevel::Error,
+ ("AddHeader called but guard is invalid"));
+ return;
+ }
+ viaduct_necko_result_add_header(mGuard.Result(), aKey, aKeyLength, aValue,
+ aValueLength);
+ MOZ_LOG(gViaductLogger, LogLevel::Debug, ("Added header"));
+}
+
+void ViaductResponseListener::ExtendBody(const uint8_t* aData, size_t aLength) {
+ MOZ_LOG(gViaductLogger, LogLevel::Info,
+ ("TRACE: ExtendBody called with %zu bytes", aLength));
+ if (!mGuard.IsValid()) {
+ MOZ_LOG(gViaductLogger, LogLevel::Error,
+ ("ExtendBody called but guard is invalid"));
+ return;
+ }
+ viaduct_necko_result_extend_body(mGuard.Result(), aData, aLength);
+ MOZ_LOG(gViaductLogger, LogLevel::Debug,
+ ("Extended body with %zu bytes", aLength));
+}
+
+void ViaductResponseListener::Complete() {
+ MOZ_LOG(gViaductLogger, LogLevel::Info,
+ ("TRACE: Complete called - marking request as successful"));
+ if (!mGuard.IsValid()) {
+ MOZ_LOG(gViaductLogger, LogLevel::Error,
+ ("Complete called but guard is invalid"));
+ return;
+ }
+ MOZ_LOG(gViaductLogger, LogLevel::Info,
+ ("TRACE: Calling Complete via guard"));
+ mGuard.Complete();
+}
+
+NS_IMETHODIMP
+ViaductResponseListener::VisitHeader(const nsACString& aHeader,
+ const nsACString& aValue) {
+ MOZ_LOG(gViaductLogger, LogLevel::Info,
+ ("TRACE: VisitHeader called for header: %s",
+ PromiseFlatCString(aHeader).get()));
+ AddHeader(aHeader.BeginReading(), aHeader.Length(), aValue.BeginReading(),
+ aValue.Length());
+ return NS_OK;
+}
+
+NS_IMETHODIMP
+ViaductResponseListener::OnStartRequest(nsIRequest* aRequest) {
+ MOZ_LOG(gViaductLogger, LogLevel::Info,
+ ("TRACE: ========== OnStartRequest called =========="));
+
+ nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(aRequest);
+ if (!httpChannel) {
+ HandleError(NS_ERROR_FAILURE, "Request is not an HTTP channel");
+ return NS_ERROR_FAILURE;
+ }
+
+ // Get status code from HTTP channel
+ uint32_t responseStatus;
+ nsresult rv = httpChannel->GetResponseStatus(&responseStatus);
+ if (NS_FAILED(rv)) {
+ HandleError(rv, "Failed to get response status");
+ return rv;
+ }
+ SetStatusCode(static_cast<uint16_t>(responseStatus));
+
+ // Get final URL
+ nsCOMPtr<nsIURI> uri;
+ rv = httpChannel->GetURI(getter_AddRefs(uri));
+ if (NS_FAILED(rv)) {
+ HandleError(rv, "Failed to get URI");
+ return rv;
+ }
+
+ if (!uri) {
+ HandleError(NS_ERROR_FAILURE, "HTTP channel has null URI");
+ return NS_ERROR_FAILURE;
+ }
+
+ nsAutoCString spec;
+ rv = uri->GetSpec(spec);
+ if (NS_FAILED(rv)) {
+ HandleError(rv, "Failed to get URI spec");
+ return rv;
+ }
+ SetUrl(spec.get(), spec.Length());
+
+ // Collect response headers - using 'this' since we implement
+ // nsIHttpHeaderVisitor
+ MOZ_LOG(gViaductLogger, LogLevel::Info,
+ ("TRACE: About to visit response headers"));
+ rv = httpChannel->VisitResponseHeaders(this);
+ if (NS_FAILED(rv)) {
+ HandleError(rv, "Failed to visit response headers");
+ return rv;
+ }
+
+ return NS_OK;
+}
+
+NS_IMETHODIMP
+ViaductResponseListener::OnDataAvailable(nsIRequest* aRequest,
+ nsIInputStream* aInputStream,
+ uint64_t aOffset, uint32_t aCount) {
+ MOZ_LOG(gViaductLogger, LogLevel::Debug,
+ ("OnDataAvailable called with %u bytes at offset %" PRIu64, aCount,
+ aOffset));
+
+ // Read the data from the input stream
+ nsTArray<uint8_t> buffer;
+ buffer.SetLength(aCount);
+
+ uint32_t bytesRead;
+ nsresult rv = aInputStream->Read(reinterpret_cast<char*>(buffer.Elements()),
+ aCount, &bytesRead);
+ if (NS_FAILED(rv)) {
+ HandleError(rv, "Failed to read from input stream");
+ return rv;
+ }
+
+ if (bytesRead > 0) {
+ ExtendBody(buffer.Elements(), bytesRead);
+ } else {
+ MOZ_LOG(gViaductLogger, LogLevel::Warning,
+ ("Read 0 bytes from input stream"));
+ }
+
+ return NS_OK;
+}
+
+NS_IMETHODIMP
+ViaductResponseListener::OnStopRequest(nsIRequest* aRequest, nsresult aStatus) {
+ MOZ_LOG(gViaductLogger, LogLevel::Debug,
+ ("OnStopRequest called with status: 0x%08x",
+ static_cast<uint32_t>(aStatus)));
+
+ // Cancel timer since request is complete
+ ClearTimer();
+
+ if (NS_SUCCEEDED(aStatus)) {
+ Complete();
+ } else {
+ HandleError(aStatus, "Request failed");
+ }
+
+ return NS_OK;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// nsITimerCallback implementation
+
+NS_IMETHODIMP
+ViaductResponseListener::Notify(nsITimer* aTimer) {
+ MOZ_LOG(gViaductLogger, LogLevel::Warning,
+ ("TRACE: Request timeout fired - cancelling request"));
+
+ ClearTimer();
+
+ // Cancel the channel, which will trigger OnStopRequest with an error
+ if (mChannel) {
+ mChannel->Cancel(NS_ERROR_NET_TIMEOUT_EXTERNAL);
+ mChannel = nullptr;
+ }
+
+ return NS_OK;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// nsINamed implementation
+
+NS_IMETHODIMP
+ViaductResponseListener::GetName(nsACString& aName) {
+ aName.AssignLiteral("ViaductResponseListener");
+ return NS_OK;
+}
+
+// Convert ViaductMethod to HTTP method string
+static const char* GetMethodString(ViaductMethod method) {
+ switch (method) {
+ case VIADUCT_METHOD_GET:
+ return "GET";
+ case VIADUCT_METHOD_HEAD:
+ return "HEAD";
+ case VIADUCT_METHOD_POST:
+ return "POST";
+ case VIADUCT_METHOD_PUT:
+ return "PUT";
+ case VIADUCT_METHOD_DELETE:
+ return "DELETE";
+ case VIADUCT_METHOD_CONNECT:
+ return "CONNECT";
+ case VIADUCT_METHOD_OPTIONS:
+ return "OPTIONS";
+ case VIADUCT_METHOD_TRACE:
+ return "TRACE";
+ case VIADUCT_METHOD_PATCH:
+ return "PATCH";
+ default:
+ MOZ_LOG(gViaductLogger, LogLevel::Warning,
+ ("Unknown ViaductMethod: %d, defaulting to GET", method));
+ return "GET";
+ }
+}
+
+extern "C" {
+
+void viaduct_necko_backend_init() {
+ MOZ_LOG(gViaductLogger, LogLevel::Info,
+ ("Viaduct Necko backend initialized"));
+}
+
+void viaduct_necko_backend_send_request(const ViaductRequest* request,
+ ViaductResult* result) {
+ MOZ_LOG(gViaductLogger, LogLevel::Debug, ("send_request called"));
+
+ MOZ_ASSERT(request, "Request pointer should not be null");
+ MOZ_ASSERT(result, "Result pointer should not be null");
+
+ // Create a guard to manage the request/result pointer lifetime.
+ // This ensures that either viaduct_necko_result_complete or
+ // viaduct_necko_result_complete_error is called exactly once,
+ // even if the closure never runs (e.g., during shutdown).
+ ViaductRequestGuard guard(request, result);
+
+ // This function is called from Rust on a background thread.
+ // We need to dispatch to the main thread to use Necko.
+ NS_DispatchToMainThread(NS_NewRunnableFunction(
+ "ViaductNeckoRequest", [guard = std::move(guard)]() mutable {
+ MOZ_LOG(gViaductLogger, LogLevel::Debug,
+ ("Executing request on main thread"));
+
+ MOZ_ASSERT(guard.Request() && guard.Result(),
+ "Guard should have valid pointers");
+
+ nsresult rv;
+
+ // Parse the URL
+ nsCOMPtr<nsIURI> uri;
+ nsAutoCString urlSpec(guard.Request()->url);
+ MOZ_LOG(gViaductLogger, LogLevel::Debug,
+ ("Parsing URL: %s", urlSpec.get()));
+
+ rv = NS_NewURI(getter_AddRefs(uri), urlSpec);
+ if (NS_FAILED(rv)) {
+ guard.CompleteWithError(rv, "Failed to parse URL");
+ return;
+ }
+
+ // Create the channel
+ nsSecurityFlags secFlags =
+ nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL |
+ nsILoadInfo::SEC_COOKIES_OMIT;
+
+ nsCOMPtr<nsIChannel> channel;
+ rv = NS_NewChannel(getter_AddRefs(channel), uri,
+ nsContentUtils::GetSystemPrincipal(), secFlags,
+ nsIContentPolicy::TYPE_OTHER);
+
+ if (NS_FAILED(rv)) {
+ guard.CompleteWithError(rv, "Failed to create channel");
+ return;
+ }
+
+ if (!channel) {
+ guard.CompleteWithError(NS_ERROR_FAILURE,
+ "NS_NewChannel returned null channel");
+ return;
+ }
+
+ // Get the HTTP channel interface
+ nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(channel);
+ if (!httpChannel) {
+ guard.CompleteWithError(NS_ERROR_FAILURE,
+ "Channel is not an HTTP channel");
+ return;
+ }
+
+ // Set HTTP method
+ const char* methodStr = GetMethodString(guard.Request()->method);
+ MOZ_LOG(gViaductLogger, LogLevel::Debug,
+ ("Setting HTTP method: %s", methodStr));
+ rv = httpChannel->SetRequestMethod(nsDependentCString(methodStr));
+ if (NS_FAILED(rv)) {
+ guard.CompleteWithError(rv, "Failed to set request method");
+ return;
+ }
+
+ // Set request headers
+ MOZ_LOG(gViaductLogger, LogLevel::Debug,
+ ("Setting %zu request headers", guard.Request()->header_count));
+ for (size_t i = 0; i < guard.Request()->header_count; i++) {
+ nsAutoCString key(guard.Request()->headers[i].key);
+ nsAutoCString value(guard.Request()->headers[i].value);
+ rv = httpChannel->SetRequestHeader(key, value, false);
+ if (NS_FAILED(rv)) {
+ guard.CompleteWithError(rv, "Failed to set request header");
+ return;
+ }
+ }
+
+ // Set redirect limit
+ if (guard.Request()->redirect_limit == 0) {
+ // Disable redirects entirely
+ MOZ_LOG(gViaductLogger, LogLevel::Debug, ("Disabling redirects"));
+ nsCOMPtr<nsIHttpChannelInternal> httpInternal =
+ do_QueryInterface(httpChannel);
+ if (!httpInternal) {
+ guard.CompleteWithError(
+ NS_ERROR_FAILURE,
+ "Failed to get nsIHttpChannelInternal interface");
+ return;
+ }
+ rv = httpInternal->SetRedirectMode(
+ nsIHttpChannelInternal::REDIRECT_MODE_ERROR);
+ if (NS_FAILED(rv)) {
+ guard.CompleteWithError(rv, "Failed to set redirect mode");
+ return;
+ }
+ } else {
+ // Set a specific redirect limit
+ MOZ_LOG(
+ gViaductLogger, LogLevel::Debug,
+ ("Setting redirect limit: %u", guard.Request()->redirect_limit));
+ rv =
+ httpChannel->SetRedirectionLimit(guard.Request()->redirect_limit);
+ if (NS_FAILED(rv)) {
+ guard.CompleteWithError(rv, "Failed to set redirection limit");
+ return;
+ }
+ }
+
+ // Set request body if present
+ if (guard.Request()->body != nullptr && guard.Request()->body_len > 0) {
+ MOZ_LOG(
+ gViaductLogger, LogLevel::Debug,
+ ("Setting request body (%zu bytes)", guard.Request()->body_len));
+ nsCOMPtr<nsIUploadChannel2> uploadChannel =
+ do_QueryInterface(httpChannel);
+ if (!uploadChannel) {
+ guard.CompleteWithError(
+ NS_ERROR_FAILURE, "Failed to get nsIUploadChannel2 interface");
+ return;
+ }
+
+ nsCOMPtr<nsIInputStream> bodyStream;
+ rv = NS_NewByteInputStream(
+ getter_AddRefs(bodyStream),
+ Span(reinterpret_cast<const char*>(guard.Request()->body),
+ guard.Request()->body_len),
+ NS_ASSIGNMENT_COPY);
+ if (NS_FAILED(rv)) {
+ guard.CompleteWithError(rv, "Failed to create body stream");
+ return;
+ }
+
+ rv = uploadChannel->ExplicitSetUploadStream(
+ bodyStream, VoidCString(), guard.Request()->body_len,
+ nsDependentCString(methodStr), false);
+ if (NS_FAILED(rv)) {
+ guard.CompleteWithError(rv, "Failed to set upload stream");
+ return;
+ }
+ }
+
+ // Get timeout before moving the guard
+ uint32_t timeout = guard.Request()->timeout;
+
+ // Create listener with timeout support.
+ // Move the guard into the listener so it owns the request/result
+ // pointers.
+ RefPtr<ViaductResponseListener> listener =
+ new ViaductResponseListener(std::move(guard), timeout);
+
+ // Store the channel in the listener so it can cancel it on
+ // timeout
+ listener->SetChannel(channel);
+
+ MOZ_LOG(gViaductLogger, LogLevel::Debug, ("Opening HTTP channel"));
+ rv = httpChannel->AsyncOpen(listener);
+
+ if (NS_FAILED(rv)) {
+ MOZ_LOG(gViaductLogger, LogLevel::Error,
+ ("AsyncOpen failed: 0x%08x. Guard was moved to listener, "
+ "destructor will handle cleanup and complete with error.",
+ static_cast<uint32_t>(rv)));
+ return;
+ }
+
+ MOZ_LOG(gViaductLogger, LogLevel::Debug,
+ ("Request initiated successfully"));
+ // The request is now in progress. The listener will handle
+ // completion.
+ }));
+}
+
+} // extern "C"
diff --git a/services/application-services/components/viaduct-necko/backend.h b/services/application-services/components/viaduct-necko/backend.h
@@ -0,0 +1,72 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef VIADUCT_NECKO_H
+#define VIADUCT_NECKO_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// HTTP Method enumeration (must match Rust side)
+enum ViaductMethod : uint8_t {
+ VIADUCT_METHOD_GET = 0,
+ VIADUCT_METHOD_HEAD = 1,
+ VIADUCT_METHOD_POST = 2,
+ VIADUCT_METHOD_PUT = 3,
+ VIADUCT_METHOD_DELETE = 4,
+ VIADUCT_METHOD_CONNECT = 5,
+ VIADUCT_METHOD_OPTIONS = 6,
+ VIADUCT_METHOD_TRACE = 7,
+ VIADUCT_METHOD_PATCH = 8,
+};
+
+// Header structure
+struct ViaductHeader {
+ const char* key;
+ const char* value;
+};
+
+// Request structure
+struct ViaductRequest {
+ uint32_t timeout;
+ uint32_t redirect_limit;
+ ViaductMethod method;
+ const char* url;
+ const ViaductHeader* headers;
+ size_t header_count;
+ const uint8_t* body; // Body remains uint8_t* since it's binary data
+ size_t body_len;
+};
+
+// Opaque result pointer (points to Rust FfiResult)
+struct ViaductResult;
+
+// Functions that C++ must implement
+void viaduct_necko_backend_init();
+void viaduct_necko_backend_send_request(const ViaductRequest* request,
+ ViaductResult* result);
+
+// Functions that Rust provides for C++ to call
+void viaduct_necko_result_set_url(ViaductResult* result, const char* url,
+ size_t length);
+void viaduct_necko_result_set_status_code(ViaductResult* result, uint16_t code);
+void viaduct_necko_result_add_header(ViaductResult* result, const char* key,
+ size_t key_length, const char* value,
+ size_t value_length);
+void viaduct_necko_result_extend_body(ViaductResult* result,
+ const uint8_t* data, size_t length);
+void viaduct_necko_result_complete(ViaductResult* result);
+void viaduct_necko_result_complete_error(ViaductResult* result,
+ uint32_t error_code,
+ const char* message);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // VIADUCT_NECKO_H
diff --git a/services/application-services/components/viaduct-necko/moz.build b/services/application-services/components/viaduct-necko/moz.build
@@ -0,0 +1,16 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+FINAL_LIBRARY = "xul"
+
+with Files("**"):
+ BUG_COMPONENT = ("Application Services", "General")
+
+UNIFIED_SOURCES += [
+ "backend.cpp",
+]
+
+XPCSHELL_TESTS_MANIFESTS += ["tests/xpcshell.toml"]
diff --git a/services/application-services/components/viaduct-necko/src/lib.rs b/services/application-services/components/viaduct-necko/src/lib.rs
@@ -0,0 +1,350 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use error_support::{info, warn};
+use std::{ffi::{CStr, c_char}, ptr, slice, sync::Arc};
+use url::Url;
+use viaduct::{
+ init_backend, Backend, ClientSettings, Method, Request, Response, Result, ViaductError,
+};
+
+const NULL: char = '\0';
+
+/// Request for the C++ backend
+#[repr(C)]
+pub struct FfiRequest {
+ pub timeout: u32,
+ pub redirect_limit: u32,
+ pub method: Method,
+ pub url: *mut u8,
+ pub headers: *mut FfiHeader,
+ pub header_count: usize,
+ pub body: *mut u8,
+ pub body_len: usize,
+}
+
+#[repr(C)]
+pub struct FfiHeader {
+ pub key: *mut u8,
+ pub value: *mut u8,
+}
+
+/// Result from the backend
+///
+/// This is built-up piece by piece using the extern "C" API.
+pub struct FfiResult {
+ // oneshot sender that the Rust code is awaiting. If `Ok(())` is sent, then the Rust code
+ // should return the response. If an error is sent, then that should be returned instead.
+ sender: Option<oneshot::Sender<Result<Response>>>,
+ response: Response,
+ // Owned values stored in the [FfiRequest]. These are copied from the request. By storing
+ // them in the result, we ensure they stay alive while the C code may access them.
+ pub url: String,
+ pub headers: Vec<(String, String)>,
+ pub body: Option<Vec<u8>>,
+ // The request struct that we pass to C++. This must be kept alive as long as the C++ code is
+ // using it.
+ pub request: FfiRequest,
+ pub ffi_headers: Vec<FfiHeader>,
+}
+
+// Functions that the C++ library exports for us
+extern "C" {
+ fn viaduct_necko_backend_init();
+
+ #[allow(improper_ctypes)]
+ fn viaduct_necko_backend_send_request(request: *const FfiRequest, result: *mut FfiResult);
+}
+
+// Functions that we provide to the C++ library
+
+/// Set the URL for a result
+///
+/// # Safety
+///
+/// - `result` must be valid.
+/// - `url` and `length` must refer to a valid byte string.
+///
+/// Note: URLs are expected to be ASCII. Non-ASCII URLs will be logged and skipped.
+#[no_mangle]
+pub unsafe extern "C" fn viaduct_necko_result_set_url(
+ result: *mut FfiResult,
+ url: *const u8,
+ length: usize,
+) {
+ let result = unsafe { &mut *result };
+
+ // Safety: Creating a slice from raw parts is safe if the backend passes valid pointers and lengths
+ let url_bytes = unsafe { slice::from_raw_parts(url, length) };
+
+ // Validate that the URL is ASCII before converting to String
+ if !url_bytes.is_ascii() {
+ warn!(
+ "Non-ASCII URL received - length: {} - skipping URL update",
+ length
+ );
+ return;
+ }
+
+ // Safety: We just verified the bytes are ASCII, which is valid UTF-8
+ let url_str = unsafe { std::str::from_utf8_unchecked(url_bytes) };
+
+ match Url::parse(url_str) {
+ Ok(url) => {
+ result.response.url = url;
+ }
+ Err(e) => {
+ warn!("Error parsing URL from C backend: {e}")
+ }
+ }
+}
+
+/// Set the status code for a result
+///
+/// # Safety
+///
+/// `result` must be valid.
+#[no_mangle]
+pub unsafe extern "C" fn viaduct_necko_result_set_status_code(result: *mut FfiResult, code: u16) {
+ let result = unsafe { &mut *result };
+ result.response.status = code;
+}
+
+/// Set a header for a result
+///
+/// # Safety
+///
+/// - `result` must be valid.
+/// - `key` and `key_length` must refer to a valid byte string.
+/// - `value` and `value_length` must refer to a valid byte string.
+///
+/// Note: HTTP headers are expected to be ASCII. Non-ASCII headers will be logged and skipped.
+#[no_mangle]
+pub unsafe extern "C" fn viaduct_necko_result_add_header(
+ result: *mut FfiResult,
+ key: *const u8,
+ key_length: usize,
+ value: *const u8,
+ value_length: usize,
+) {
+ let result = unsafe { &mut *result };
+
+ // Safety: Creating slices from raw parts is safe if the backend passes valid pointers and lengths
+ let key_bytes = unsafe { slice::from_raw_parts(key, key_length) };
+ let value_bytes = unsafe { slice::from_raw_parts(value, value_length) };
+
+ // Validate that headers are ASCII before converting to String
+ // HTTP headers should be ASCII per best practices, though the spec technically allows other encodings
+ if !key_bytes.is_ascii() || !value_bytes.is_ascii() {
+ warn!(
+ "Non-ASCII HTTP header received - key_len: {}, value_len: {} - skipping header",
+ key_length, value_length
+ );
+ return;
+ }
+
+ // Safety: We just verified the bytes are ASCII, which is valid UTF-8
+ let (key, value) = unsafe {
+ (
+ String::from_utf8_unchecked(key_bytes.to_vec()),
+ String::from_utf8_unchecked(value_bytes.to_vec()),
+ )
+ };
+
+ let _ = result.response.headers.insert(key, value);
+}
+
+/// Append data to a result body
+///
+/// This method can be called multiple times to build up the body in chunks.
+///
+/// # Safety
+///
+/// - `result` must be valid.
+/// - `data` and `length` must refer to a binary string.
+#[no_mangle]
+pub unsafe extern "C" fn viaduct_necko_result_extend_body(
+ result: *mut FfiResult,
+ data: *const u8,
+ length: usize,
+) {
+ let result = unsafe { &mut *result };
+ // Safety: this is safe as long as the backend passes us valid data
+ result
+ .response
+ .body
+ .extend_from_slice(unsafe { slice::from_raw_parts(data, length) });
+}
+
+/// Complete a result
+///
+/// # Safety
+///
+/// `result` must be valid. After calling this function it must not be used again.
+#[no_mangle]
+pub unsafe extern "C" fn viaduct_necko_result_complete(result: *mut FfiResult) {
+ let mut result = unsafe { Box::from_raw(result) };
+ match result.sender.take() {
+ Some(sender) => {
+ // Ignore any errors when sending the result. This happens when the receiver is
+ // closed, which happens when a future is cancelled.
+ let _ = sender.send(Ok(result.response));
+ }
+ None => warn!("viaduct-necko: result completed twice"),
+ }
+}
+
+/// Complete a result with an error message
+///
+/// # Safety
+///
+/// - `result` must be valid. After calling this function it must not be used again.
+/// - `message` and `length` must refer to a valid UTF-8 string.
+#[no_mangle]
+pub unsafe extern "C" fn viaduct_necko_result_complete_error(
+ result: *mut FfiResult,
+ error_code: u32,
+ message: *const u8,
+) {
+ let mut result = unsafe { Box::from_raw(result) };
+ // Safety: this is safe as long as the backend passes us valid data
+ let msg_str = unsafe {
+ CStr::from_ptr(message as *const c_char)
+ .to_string_lossy()
+ .into_owned()
+ };
+ let msg = format!("{} (0x{:08x})", msg_str, error_code);
+ match result.sender.take() {
+ Some(sender) => {
+ // Ignore any errors when sending the result. This happens when the receiver is
+ // closed, which happens when a future is cancelled.
+ let _ = sender.send(Err(ViaductError::BackendError(msg)));
+ }
+ None => warn!("viaduct-necko: result completed twice"),
+ }
+}
+
+// The Necko backend is a zero-sized type, since all the backend functionality is statically linked
+struct NeckoBackend;
+
+/// Initialize the Necko backend
+///
+/// This should be called once at startup before any HTTP requests are made.
+pub fn init_necko_backend() -> Result<()> {
+ info!("Initializing viaduct Necko backend");
+ // Safety: this is safe as long as the C++ code is correct.
+ unsafe { viaduct_necko_backend_init() };
+ init_backend(Arc::new(NeckoBackend))
+}
+
+#[async_trait::async_trait]
+impl Backend for NeckoBackend {
+ async fn send_request(&self, request: Request, settings: ClientSettings) -> Result<Response> {
+ // Convert the request for the backend
+ let mut url = request.url.to_string();
+ url.push(NULL);
+
+ // Convert headers to null-terminated strings for C++
+ // Note: Headers iterates over Header objects, not tuples
+ let header_strings: Vec<(String, String)> = request
+ .headers
+ .iter()
+ .map(|h| {
+ let mut key_str = h.name().to_string();
+ key_str.push(NULL);
+ let mut value_str = h.value().to_string();
+ value_str.push(NULL);
+ (key_str, value_str)
+ })
+ .collect();
+
+ // Prepare an FfiResult with an empty response
+ let (sender, receiver) = oneshot::channel();
+ let mut result = Box::new(FfiResult {
+ sender: Some(sender),
+ response: Response {
+ request_method: request.method,
+ url: request.url.clone(),
+ status: 0,
+ headers: viaduct::Headers::new(),
+ body: Vec::default(),
+ },
+ url,
+ headers: header_strings,
+ body: request.body,
+ request: FfiRequest {
+ timeout: settings.timeout,
+ redirect_limit: settings.redirect_limit,
+ method: request.method,
+ url: ptr::null_mut(),
+ headers: ptr::null_mut(),
+ header_count: 0,
+ body: ptr::null_mut(),
+ body_len: 0,
+ },
+ ffi_headers: Vec::new(),
+ });
+
+ // Now that we have the result box, we can set up the pointers in the request.
+ // By doing this after creating the box, we minimize the chance that a value moves after a pointer is created.
+ result.ffi_headers = result
+ .headers
+ .iter_mut()
+ .map(|(key, value)| FfiHeader {
+ key: key.as_mut_ptr(),
+ value: value.as_mut_ptr(),
+ })
+ .collect();
+
+ let (body_ptr, body_len) = match &result.body {
+ Some(body) => (body.as_ptr() as *mut u8, body.len()),
+ None => (ptr::null_mut(), 0),
+ };
+
+ result.request.url = result.url.as_mut_ptr();
+ result.request.headers = result.ffi_headers.as_mut_ptr();
+ result.request.header_count = result.ffi_headers.len();
+ result.request.body = body_ptr;
+ result.request.body_len = body_len;
+
+ let request_ptr = &result.request as *const FfiRequest;
+
+ // Safety: this is safe if the C backend implements the API correctly.
+ unsafe {
+ viaduct_necko_backend_send_request(request_ptr, Box::into_raw(result));
+ };
+
+ receiver.await.unwrap_or_else(|_| {
+ Err(ViaductError::BackendError(
+ "Error receiving result from C++ backend".to_string(),
+ ))
+ })
+ }
+}
+
+// Mark FFI types as Send to allow them to be used across an await point. This is safe as long as
+// the backend code uses them correctly.
+unsafe impl Send for FfiRequest {}
+unsafe impl Send for FfiResult {}
+unsafe impl Send for FfiHeader {}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+
+ #[test]
+ fn test_method_layout() {
+ // Assert that the viaduct::Method enum matches the layout expected by the C++ backend.
+ // See ViaductMethod in backend.h
+ assert_eq!(Method::Get as u8, 0);
+ assert_eq!(Method::Head as u8, 1);
+ assert_eq!(Method::Post as u8, 2);
+ assert_eq!(Method::Put as u8, 3);
+ assert_eq!(Method::Delete as u8, 4);
+ assert_eq!(Method::Connect as u8, 5);
+ assert_eq!(Method::Options as u8, 6);
+ assert_eq!(Method::Trace as u8, 7);
+ assert_eq!(Method::Patch as u8, 8);
+ }
+}
diff --git a/services/application-services/components/viaduct-necko/tests/test_viaduct_necko_backend.js b/services/application-services/components/viaduct-necko/tests/test_viaduct_necko_backend.js
@@ -0,0 +1,318 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* global add_setup, add_task, Assert, info, do_get_profile, do_timeout, registerCleanupFunction, Services */
+
+const { HttpServer } = ChromeUtils.importESModule(
+ "resource://testing-common/httpd.sys.mjs"
+);
+
+const { NetUtil } = ChromeUtils.importESModule(
+ "resource://gre/modules/NetUtil.sys.mjs"
+);
+
+// Create a test HTTP server
+let gHttpServer = null;
+let gServerPort = -1;
+let gServerURL = "";
+
+// Track requests received by the server
+let gRequestsReceived = [];
+
+/**
+ * Helper to decode potentially gzipped request body
+ */
+function decodeRequestBody(request) {
+ let bodyStream = request.bodyInputStream;
+ let avail = bodyStream.available();
+ if (avail === 0) {
+ return "";
+ }
+
+ if (
+ request.hasHeader("content-encoding") &&
+ request.getHeader("content-encoding") === "gzip"
+ ) {
+ // For gzipped content, we'd need to decompress
+ // For now, just note it was gzipped
+ return "[gzipped content]";
+ }
+
+ return NetUtil.readInputStreamToString(bodyStream, avail);
+}
+
+/**
+ * Setup function to initialize the HTTP server
+ */
+add_setup(async function () {
+ info("Setting up viaduct-necko test environment");
+
+ // FOG needs a profile directory to store its data
+ do_get_profile();
+
+ // Create and start the HTTP server
+ gHttpServer = new HttpServer();
+
+ // Register various test endpoints
+ setupTestEndpoints();
+
+ gHttpServer.start(-1);
+ gServerPort = gHttpServer.identity.primaryPort;
+ gServerURL = `http://localhost:${gServerPort}`;
+
+ info(`Test HTTP server started on port ${gServerPort}`);
+
+ // Set the telemetry port preference to use our test server
+ Services.prefs.setIntPref("telemetry.fog.test.localhost_port", gServerPort);
+
+ // Enable telemetry upload (needed for viaduct to be used)
+ Services.prefs.setBoolPref("datareporting.healthreport.uploadEnabled", true);
+
+ // Initialize FOG/Glean which should trigger viaduct-necko initialization
+ // This internally calls init_necko_backend() through GkRust_Init
+ Services.fog.testResetFOG();
+
+ registerCleanupFunction(async () => {
+ Services.prefs.clearUserPref("telemetry.fog.test.localhost_port");
+ Services.prefs.clearUserPref("datareporting.healthreport.uploadEnabled");
+ await new Promise(resolve => gHttpServer.stop(resolve));
+ });
+});
+
+/**
+ * Setup test endpoints on the HTTP server
+ */
+function setupTestEndpoints() {
+ // Glean telemetry submission endpoints
+ gHttpServer.registerPrefixHandler("/submit/", (request, response) => {
+ const path = request.path;
+ info(`Viaduct request received: ${request.method} ${path}`);
+
+ // Read the request body
+ const body = decodeRequestBody(request);
+
+ // Extract ping type from path
+ // Path format: /submit/firefox-desktop/{ping-type}/1/{uuid}
+ const pathParts = path.split("/");
+ const pingType = pathParts[3] || "unknown";
+
+ gRequestsReceived.push({
+ path,
+ method: request.method,
+ pingType,
+ body,
+ bodySize: request.hasHeader("content-length")
+ ? parseInt(request.getHeader("content-length"), 10)
+ : body.length,
+ headers: {
+ "content-type": request.hasHeader("content-type")
+ ? request.getHeader("content-type")
+ : null,
+ "content-encoding": request.hasHeader("content-encoding")
+ ? request.getHeader("content-encoding")
+ : null,
+ "user-agent": request.hasHeader("user-agent")
+ ? request.getHeader("user-agent")
+ : null,
+ },
+ });
+
+ // Return a response similar to what a telemetry server would return
+ // Using 501 to match your test scenario
+ response.setStatusLine(request.httpVersion, 501, "Not Implemented");
+ response.setHeader("Server", "TestServer/1.0 (Viaduct Backend)");
+ response.setHeader("Date", new Date().toUTCString());
+ response.setHeader("Connection", "close");
+ response.setHeader("Content-Type", "application/json");
+
+ const responseBody = JSON.stringify({
+ status: "not_implemented",
+ message: "Test server response",
+ });
+ response.setHeader("Content-Length", responseBody.length.toString());
+ response.write(responseBody);
+ });
+}
+
+/**
+ * Test that the viaduct-necko backend was initialized and is processing requests
+ */
+add_task(async function test_viaduct_backend_working() {
+ info("Testing viaduct-necko backend initialization and request processing");
+
+ // Clear previous requests (though some health pings may have already been sent)
+ const initialRequestCount = gRequestsReceived.length;
+ info(
+ `Already received ${initialRequestCount} requests during initialization`
+ );
+
+ // Wait for any pending requests to complete using do_timeout
+ // This ensures we capture the health pings that are automatically sent
+ await new Promise(resolve => do_timeout(500, resolve));
+
+ // Check that we've received requests through viaduct
+ Assert.ok(
+ !!gRequestsReceived.length,
+ `Viaduct-necko backend is processing requests. Received ${gRequestsReceived.length} requests.`
+ );
+
+ // Verify the requests are health pings (as shown in your logs)
+ const healthPings = gRequestsReceived.filter(r => r.pingType === "health");
+ info(`Received ${healthPings.length} health pings through viaduct-necko`);
+
+ // All telemetry submissions should be POST requests
+ for (const request of gRequestsReceived) {
+ Assert.equal(
+ request.method,
+ "POST",
+ `Request to ${request.path} should be POST`
+ );
+ }
+
+ // Log summary of what was processed
+ const pingTypes = [...new Set(gRequestsReceived.map(r => r.pingType))];
+ info(
+ `Test successful: Viaduct-necko backend processed ${gRequestsReceived.length} requests`
+ );
+ info(`Ping types received: ${pingTypes.join(", ")}`);
+ info(
+ `The C++ backend successfully handled requests from Rust through the FFI layer`
+ );
+});
+
+/**
+ * Test different HTTP parameters and methods
+ * We verify different body sizes and headers are handled correctly
+ */
+add_task(async function test_different_parameters() {
+ info("Testing different HTTP parameters through viaduct-necko");
+
+ // Clear request tracking
+ gRequestsReceived = [];
+
+ // Submit different types of pings with varying sizes
+ // This will test different body sizes and headers
+
+ // Reset FOG to trigger new pings
+ Services.fog.testResetFOG();
+
+ // Wait to collect the requests
+ await new Promise(resolve => do_timeout(1000, resolve));
+
+ const requestsAfterReset = gRequestsReceived.length;
+ info(`Received ${requestsAfterReset} requests after FOG reset`);
+
+ // Verify different content types and encodings were handled
+ const contentTypes = new Set();
+ const contentEncodings = new Set();
+ const bodySizes = new Set();
+
+ for (const request of gRequestsReceived) {
+ if (request.headers["content-type"]) {
+ contentTypes.add(request.headers["content-type"]);
+ }
+ if (request.headers["content-encoding"]) {
+ contentEncodings.add(request.headers["content-encoding"]);
+ }
+ if (request.bodySize) {
+ bodySizes.add(request.bodySize);
+ }
+ }
+
+ info(`Content types seen: ${Array.from(contentTypes).join(", ")}`);
+ info(`Content encodings seen: ${Array.from(contentEncodings).join(", ")}`);
+ info(
+ `Body sizes seen: ${Array.from(bodySizes)
+ .sort((a, b) => a - b)
+ .join(", ")}`
+ );
+
+ Assert.ok(
+ !!gRequestsReceived.length,
+ "Different parameters were processed successfully"
+ );
+
+ // Verify we're seeing variation in body sizes (different ping types have different sizes)
+ Assert.ok(
+ bodySizes.size > 1,
+ `Multiple body sizes handled: ${Array.from(bodySizes).join(", ")}`
+ );
+});
+
+/**
+ * Test that headers are properly passed through the FFI layer
+ */
+add_task(async function test_header_handling() {
+ info("Testing header handling through viaduct-necko");
+
+ // Check the headers that were sent in previous requests
+ let hasHeaders = false;
+ let headerCount = 0;
+
+ for (const request of gRequestsReceived) {
+ if (request.headers && Object.keys(request.headers).length) {
+ hasHeaders = true;
+ const nonNullHeaders = Object.entries(request.headers).filter(
+ ([_, value]) => value !== null
+ );
+
+ if (nonNullHeaders.length) {
+ headerCount++;
+ info(
+ `Request headers found: ${JSON.stringify(Object.fromEntries(nonNullHeaders))}`
+ );
+ }
+ }
+ }
+
+ Assert.ok(
+ hasHeaders,
+ "Headers are properly transmitted through viaduct-necko"
+ );
+
+ Assert.ok(headerCount > 0, `Found ${headerCount} requests with headers`);
+
+ // Verify specific headers we expect to see
+ const hasContentType = gRequestsReceived.some(
+ r => r.headers && r.headers["content-type"] !== null
+ );
+ const hasContentEncoding = gRequestsReceived.some(
+ r => r.headers && r.headers["content-encoding"] !== null
+ );
+ const hasUserAgent = gRequestsReceived.some(
+ r => r.headers && r.headers["user-agent"] !== null
+ );
+
+ Assert.ok(hasContentType, "Content-Type header is present");
+ Assert.ok(hasContentEncoding, "Content-Encoding header is present");
+ Assert.ok(hasUserAgent, "User-Agent header is present");
+
+ info("Headers are properly handled through the Rust → C++ → Necko chain");
+});
+
+/**
+ * Test configuration validation
+ * While we can't directly test redirects and timeouts, we can verify
+ * that the configuration is being passed correctly from logs
+ */
+add_task(async function test_configuration_validation() {
+ info("Validating viaduct-necko configuration");
+
+ // We can verify at least that requests are completing successfully
+ // which means the configuration isn't breaking anything
+ const successfulRequests = gRequestsReceived.filter(
+ r => r.method === "POST" && r.path.includes("/submit/")
+ );
+
+ Assert.ok(
+ !!successfulRequests.length,
+ `Configuration is valid: ${successfulRequests.length} successful requests processed`
+ );
+
+ info(
+ "Viaduct-necko backend configuration validated through successful request processing"
+ );
+});
diff --git a/services/application-services/components/viaduct-necko/tests/xpcshell.toml b/services/application-services/components/viaduct-necko/tests/xpcshell.toml
@@ -0,0 +1,5 @@
+[DEFAULT]
+head = ""
+firefox-appdir = "browser"
+
+["test_viaduct_necko_backend.js"]
diff --git a/services/moz.build b/services/moz.build
@@ -32,6 +32,7 @@ if not CONFIG["RELEASE_OR_BETA"] or CONFIG["MOZ_DEBUG"]:
if CONFIG["MOZ_WIDGET_TOOLKIT"] != "android":
DIRS += [
"fxaccounts",
+ "application-services/components/viaduct-necko",
]
if CONFIG["MOZ_SERVICES_SYNC"]:
diff --git a/supply-chain/audits.toml b/supply-chain/audits.toml
@@ -4623,6 +4623,11 @@ The git branch is my fork of the official code that removes the `loom` target to
This doesn't change any of the functionality -- the `loom` target is only used for testing.
"""
+[[audits.oneshot]]
+who = "Bastian Gruber <foreach@me.com>"
+criteria = "safe-to-deploy"
+version = "0.1.11"
+
[[audits.oneshot-uniffi]]
who = "Ben Dean-Kawamura <bdk@mozilla.com>"
criteria = "safe-to-deploy"
diff --git a/supply-chain/imports.lock b/supply-chain/imports.lock
@@ -2807,6 +2807,7 @@ criteria = "safe-to-deploy"
user-id = 213776 # divviup-github-automation
start = "2020-09-28"
end = "2026-01-07"
+renew = false
[[audits.isrg.audits.base64]]
who = "Tim Geoghegan <timg@letsencrypt.org>"
diff --git a/third_party/rust/oneshot/.cargo-checksum.json b/third_party/rust/oneshot/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{"CHANGELOG.md":"1e0a210e4c51ac6c7ddd08d8653fd81154569c9198ef2db2c7e1396434484937","Cargo.lock":"f8bfc4b346998db9bd5ab75351e51b988990378f85dc3a3be04102d3f4b226a9","Cargo.toml":"edeea486c050740833cdcaf23b0b23acc900cef59d676cb5f3e5d5bfe18879d8","LICENSE-APACHE":"62c7a1e35f56406896d7aa7ca52d0cc0d272ac022b5d2796e7d6905db8a3636a","LICENSE-MIT":"23f18e03dc49df91622fe2a76176497404e46ced8a715d9d2b67a7446571cca3","README.md":"811ea1c958d5a65583d0223b7ab09bb282e7a51ed60f9a2cb90ef6d555325a68","benches/benches.rs":"f60be1b186d362e84fb6cbb52119733706824833c8c4433e071d97d57544f5f5","check_mem_leaks.sh":"c1ab6ef27997c7f971352ab1c86a184004843c499bc24925da953aefcf1c624c","examples/recv_before_send.rs":"9a3cabcc2878990b61787d0048061b382555a8cd1a08b1ddec63a6e8a4a31e56","examples/recv_before_send_then_drop_sender.rs":"14706c6b4308a690662ceaa47f1699588bd833b3ec020eb9f42f220f3ffc7ae7","examples/recv_ref_before_send.rs":"43699f4720c46b5f138c260b866eb708ddf616e2b442ffa74a97373f4f48d4d0","examples/recv_ref_before_send_then_drop_sender.rs":"a190ed220cb4288d4965485365c9afaed30535cbfad5f8cb7389071b82d67cac","examples/recv_timeout_before_send.rs":"2262aa6531afce7816d43182ad9cbec2c04f3dc129064e11e89452278ce8b163","examples/recv_timeout_before_send_then_drop_sender.rs":"4cc8eade4c211f52f5b9be0f72a5906689b894490f4cb5255525e44106e7a4a8","examples/recv_with_dropped_sender.rs":"7906685053ce1c53ff6c26ce11d3221d4bf5ca3429d1d4d2c28de9237cb151c6","examples/send_before_recv.rs":"5555bd61ad52273b663007794128d8f012fc54272bd3225259b5546221bcd591","examples/send_then_drop_receiver.rs":"c3612de207309098404b057468687a2d2311d07f354b7e046398e35e93c4cdcf","examples/send_with_dropped_receiver.rs":"f5a7762b231a24a0db4397c5139437cba155d09b9dbb59872d662c7923080706","src/errors.rs":"7c1a1e5c4c0215f01c273d294fa5db0dd4720456485bca0c021edecd0e221786","src/lib.rs":"1cc6b6f73321187f9e4a304eb4d86815586fd03a037265d78d24d62fe9f7fa7d","src/loombox.rs":"231b922504bd2be5e00dd21fe14392e7c34e66a4c2e23d598ffd9845dc0dd755","tests/assert_mem.rs":"b1e5190af01af22e55c7c1cd1ff2711807591f788e4eb8b6c6d89123e146105e","tests/async.rs":"843370475eefd741bd2d05231e054a1f6dbb2e26c03efb64cbcc18aca287d94f","tests/future.rs":"c42982570863ac13dfe97bfd0ba6f5266eac840a907b65877db27de8b8010eb9","tests/helpers/mod.rs":"1c597bcdd7cea357c91f36bf9f93acd83c7345233940916e6c6711e12e193ae4","tests/helpers/waker.rs":"77494d49f62d0d320df3830643c306e06e6e20751d210cf6fa58b238bd96c3f9","tests/loom.rs":"38f44782aa42106f58b04a1640cb4d14e4637bbad2cdcccbeafb80a4b6339f5b","tests/raw.rs":"04d8c0e5a0dba9018bc2ad6bfaf1c713b873a94dac79d84e57b86e05c3bf3312","tests/sync.rs":"2434bf7ec4206e528004fe4c02edc09db15c3cfb154bfb8836c9e9eda2f3b064"},"package":"b4ce411919553d3f9fa53a0880544cda985a112117a0444d5ff1e870a893d6ea"}
+\ No newline at end of file
diff --git a/third_party/rust/oneshot/CHANGELOG.md b/third_party/rust/oneshot/CHANGELOG.md
@@ -0,0 +1,106 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
+and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
+
+### Categories each change fall into
+
+* **Added**: for new features.
+* **Changed**: for changes in existing functionality.
+* **Deprecated**: for soon-to-be removed features.
+* **Removed**: for now removed features.
+* **Fixed**: for any bug fixes.
+* **Security**: in case of vulnerabilities.
+
+
+## [Unreleased]
+
+
+## [0.1.11] - 2025-02-22
+### Fixed
+- Handle the `UNPARKING` state correctly in `Receiver::drop()`. Fixes a panic that could
+ occur if a `Receiver` had been first polled as a future and then was being dropped
+ in parallel with the `Sender` sending a message.
+
+
+## [0.1.10] - 2025-02-04
+### Added
+- Add `is_closed` and `has_message` to the `Receiver`. Allows polling for the channel
+ state without modifying the channel or pulling the message from it.
+- Make the cargo features show up on docs.rs for better discoverability.
+
+
+## [0.1.9] - 2025-02-02
+### Added
+- Implement `Sync` for `Sender`. There is not a whole lot someone can do with a `&Sender`,
+ but this allows storing the sender in places that are overly conservative and require
+ a `Sync` bound on the content.
+
+
+## [0.1.8] - 2024-06-13
+### Changed
+- Change how loom concurrency testing is triggered. To get rid of `loom` in the dependency tree
+ `oneshot` pulls in, it has in addition to being gated behind `cfg(oneshot_loom)` also been made
+ an optional dependency. This makes this library way smaller for downstream consumers.
+ This has the downside that the crate now exposes a `loom` feature.
+ DOWNSTREAM USERS ARE NOT SUPPOSED TO EVER ENABLE THIS. No stability or semver
+ guarantees exist around the `loom` feature.
+ This change ultimately makes no difference for any user of `oneshot` in regular usage.
+
+
+## [0.1.7] - 2024-05-24
+### Added
+* Add `is_closed` method to the `Sender`.
+
+
+## [0.1.6] - 2023-09-14
+### Added
+* Add `into_raw` and `from_raw` methods on both `Sender` and `Receiver`. Allows passing `oneshot`
+ channels over FFI without an extra layer of heap allocation.
+
+
+## [0.1.5] - 2022-09-01
+### Fixed
+- Handle the UNPARKING state correctly in all recv methods. `try_recv` will now not panic
+ if used on a `Receiver` that is being unparked from an async wait. The other `recv` methods
+ will still panic (as they should), but with a better error message.
+
+
+## [0.1.4] - 2022-08-30
+### Changed
+- Upgrade to Rust edition 2021. Also increases the MSRV to Rust 1.60.
+- Add null-pointer optimization to `Sender`, `Receiver` and `SendError`.
+ This reduces the call stack size of Sender::send and it makes
+ `Option<Sender>` and `Option<Receiver>` pointer sized (#18).
+- Relax the memory ordering of all atomic operations from `SeqCst` to the most appropriate
+ lower ordering (#17 + #20).
+
+### Fixed
+- Fix undefined behavior due to multiple mutable references to the same channel instance (#18).
+- Fix race condition that could happen during unparking of a receiving `Receiver` (#17 + #20).
+
+
+## [0.1.3] - 2021-11-23
+### Fixed
+- Keep the *last* `Waker` in `Future::poll`, not the *first* one. Stops breaking the contract
+ on how futures should work.
+
+
+## [0.1.2] - 2020-08-11
+### Fixed
+- Fix unreachable code panic that happened if the `Receiver` of an empty but open channel was
+ polled and then dropped.
+
+
+## [0.1.1] - 2020-05-10
+Initial implementation. Supports basically all the (for now) intended functionality.
+Sender is as lock-free as I think it can get and the receiver can both do thread blocking
+and be awaited asynchronously. The receiver also has a wait-free `try_recv` method.
+
+The crate has two features. They are activated by default, but the user can opt out of async
+support as well as usage of libstd (making the crate `no_std` but still requiring liballoc)
+
+
+## [0.1.0] - 2019-05-30
+Name reserved on crate.io by someone other than the author of this crate.
diff --git a/third_party/rust/oneshot/Cargo.lock b/third_party/rust/oneshot/Cargo.lock
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diff --git a/third_party/rust/oneshot/Cargo.toml b/third_party/rust/oneshot/Cargo.toml
@@ -0,0 +1,159 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2021"
+rust-version = "1.60.0"
+name = "oneshot"
+version = "0.1.11"
+authors = ["Linus Färnstrand <faern@faern.net>"]
+build = false
+autolib = false
+autobins = false
+autoexamples = false
+autotests = false
+autobenches = false
+description = """
+Oneshot spsc channel with (potentially) lock-free non-blocking send, and a receiver supporting
+both thread blocking receive operations as well as Future based async polling.
+"""
+readme = "README.md"
+keywords = [
+ "oneshot",
+ "spsc",
+ "async",
+ "sync",
+ "channel",
+]
+categories = [
+ "asynchronous",
+ "concurrency",
+]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/faern/oneshot"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = [
+ "--cfg",
+ "docsrs",
+]
+
+[features]
+async = []
+default = [
+ "std",
+ "async",
+]
+std = []
+
+[lib]
+name = "oneshot"
+path = "src/lib.rs"
+
+[[example]]
+name = "recv_before_send"
+path = "examples/recv_before_send.rs"
+
+[[example]]
+name = "recv_before_send_then_drop_sender"
+path = "examples/recv_before_send_then_drop_sender.rs"
+
+[[example]]
+name = "recv_ref_before_send"
+path = "examples/recv_ref_before_send.rs"
+
+[[example]]
+name = "recv_ref_before_send_then_drop_sender"
+path = "examples/recv_ref_before_send_then_drop_sender.rs"
+
+[[example]]
+name = "recv_timeout_before_send"
+path = "examples/recv_timeout_before_send.rs"
+
+[[example]]
+name = "recv_timeout_before_send_then_drop_sender"
+path = "examples/recv_timeout_before_send_then_drop_sender.rs"
+
+[[example]]
+name = "recv_with_dropped_sender"
+path = "examples/recv_with_dropped_sender.rs"
+
+[[example]]
+name = "send_before_recv"
+path = "examples/send_before_recv.rs"
+
+[[example]]
+name = "send_then_drop_receiver"
+path = "examples/send_then_drop_receiver.rs"
+
+[[example]]
+name = "send_with_dropped_receiver"
+path = "examples/send_with_dropped_receiver.rs"
+
+[[test]]
+name = "assert_mem"
+path = "tests/assert_mem.rs"
+
+[[test]]
+name = "async"
+path = "tests/async.rs"
+
+[[test]]
+name = "future"
+path = "tests/future.rs"
+
+[[test]]
+name = "loom"
+path = "tests/loom.rs"
+
+[[test]]
+name = "raw"
+path = "tests/raw.rs"
+
+[[test]]
+name = "sync"
+path = "tests/sync.rs"
+
+[[bench]]
+name = "benches"
+path = "benches/benches.rs"
+harness = false
+
+[dev-dependencies.async-std]
+version = "1"
+features = ["attributes"]
+
+[dev-dependencies.tokio]
+version = "1"
+features = [
+ "rt",
+ "rt-multi-thread",
+ "macros",
+ "time",
+]
+
+[target."cfg(criterion)".dev-dependencies.criterion]
+version = "0.5.1"
+
+[target."cfg(oneshot_loom)".dependencies.loom]
+version = "0.7.2"
+features = ["futures"]
+optional = true
+
+[lints.rust.unexpected_cfgs]
+level = "deny"
+priority = 0
+check-cfg = [
+ "cfg(oneshot_loom)",
+ "cfg(oneshot_test_delay)",
+ "cfg(criterion)",
+]
diff --git a/third_party/rust/oneshot/LICENSE-APACHE b/third_party/rust/oneshot/LICENSE-APACHE
@@ -0,0 +1,176 @@
+ Apache License
+ Version 2.0, January 2004
+ http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+ "License" shall mean the terms and conditions for use, reproduction,
+ and distribution as defined by Sections 1 through 9 of this document.
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+ direction or management of such entity, whether by contract or
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+
+ "You" (or "Your") shall mean an individual or Legal Entity
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+5. Submission of Contributions. Unless You explicitly state otherwise,
+ any Contribution intentionally submitted for inclusion in the Work
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+ Notwithstanding the above, nothing herein shall supersede or modify
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+
+8. Limitation of Liability. In no event and under no legal theory,
+ whether in tort (including negligence), contract, or otherwise,
+ unless required by applicable law (such as deliberate and grossly
+ negligent acts) or agreed to in writing, shall any Contributor be
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+
+END OF TERMS AND CONDITIONS
diff --git a/third_party/rust/oneshot/LICENSE-MIT b/third_party/rust/oneshot/LICENSE-MIT
@@ -0,0 +1,23 @@
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/third_party/rust/oneshot/README.md b/third_party/rust/oneshot/README.md
@@ -0,0 +1,94 @@
+# oneshot
+
+Oneshot spsc (single producer, single consumer) channel. Meaning each channel instance
+can only transport a single message. This has a few nice outcomes. One thing is that
+the implementation can be very efficient, utilizing the knowledge that there will
+only be one message. But more importantly, it allows the API to be expressed in such
+a way that certain edge cases that you don't want to care about when only sending a
+single message on a channel does not exist. For example: The sender can't be copied
+or cloned, and the send method takes ownership and consumes the sender.
+So you are guaranteed, at the type level, that there can only be one message sent.
+
+The sender's send method is non-blocking, and potentially lock- and wait-free.
+See documentation on [Sender::send] for situations where it might not be fully wait-free.
+The receiver supports both lock- and wait-free `try_recv` as well as indefinite and time
+limited thread blocking receive operations. The receiver also implements `Future` and
+supports asynchronously awaiting the message.
+
+
+## Examples
+
+This example sets up a background worker that processes requests coming in on a standard
+mpsc channel and replies on a oneshot channel provided with each request. The worker can
+be interacted with both from sync and async contexts since the oneshot receiver
+can receive both blocking and async.
+
+```rust
+use std::sync::mpsc;
+use std::thread;
+use std::time::Duration;
+
+type Request = String;
+
+// Starts a background thread performing some computation on requests sent to it.
+// Delivers the response back over a oneshot channel.
+fn spawn_processing_thread() -> mpsc::Sender<(Request, oneshot::Sender<usize>)> {
+ let (request_sender, request_receiver) = mpsc::channel::<(Request, oneshot::Sender<usize>)>();
+ thread::spawn(move || {
+ for (request_data, response_sender) in request_receiver.iter() {
+ let compute_operation = || request_data.len();
+ let _ = response_sender.send(compute_operation()); // <- Send on the oneshot channel
+ }
+ });
+ request_sender
+}
+
+let processor = spawn_processing_thread();
+
+// If compiled with `std` the library can receive messages with timeout on regular threads
+#[cfg(feature = "std")] {
+ let (response_sender, response_receiver) = oneshot::channel();
+ let request = Request::from("data from sync thread");
+
+ processor.send((request, response_sender)).expect("Processor down");
+ match response_receiver.recv_timeout(Duration::from_secs(1)) { // <- Receive on the oneshot channel
+ Ok(result) => println!("Processor returned {}", result),
+ Err(oneshot::RecvTimeoutError::Timeout) => eprintln!("Processor was too slow"),
+ Err(oneshot::RecvTimeoutError::Disconnected) => panic!("Processor exited"),
+ }
+}
+
+// If compiled with the `async` feature, the `Receiver` can be awaited in an async context
+#[cfg(feature = "async")] {
+ tokio::runtime::Runtime::new()
+ .unwrap()
+ .block_on(async move {
+ let (response_sender, response_receiver) = oneshot::channel();
+ let request = Request::from("data from sync thread");
+
+ processor.send((request, response_sender)).expect("Processor down");
+ match response_receiver.await { // <- Receive on the oneshot channel asynchronously
+ Ok(result) => println!("Processor returned {}", result),
+ Err(_e) => panic!("Processor exited"),
+ }
+ });
+}
+```
+
+## Sync vs async
+
+The main motivation for writing this library was that there were no (known to me) channel
+implementations allowing you to seamlessly send messages between a normal thread and an async
+task, or the other way around. If message passing is the way you are communicating, of course
+that should work smoothly between the sync and async parts of the program!
+
+This library achieves that by having a fast and cheap send operation that can
+be used in both sync threads and async tasks. The receiver has both thread blocking
+receive methods for synchronous usage, and implements `Future` for asynchronous usage.
+
+The receiving endpoint of this channel implements Rust's `Future` trait and can be waited on
+in an asynchronous task. This implementation is completely executor/runtime agnostic. It should
+be possible to use this library with any executor.
+
+
+License: MIT OR Apache-2.0
diff --git a/third_party/rust/oneshot/benches/benches.rs b/third_party/rust/oneshot/benches/benches.rs
@@ -0,0 +1,138 @@
+#[cfg(not(criterion))]
+pub fn main() {
+ eprintln!(
+ "!!!!!! WARNING
+To run benches, you neet to run with RUSTFLAGS=\"--cfg criterion\"
+!!!!!! WARNING
+ "
+ );
+}
+
+#[cfg(criterion)]
+criterion::criterion_group!(benches, imp::bench);
+#[cfg(criterion)]
+criterion::criterion_main!(benches);
+
+#[cfg(criterion)]
+mod imp {
+ macro_rules! bench_send_and_recv {
+ ($c:expr, $($type:ty => $value:expr);+) => {
+ // Sanity check that all $values are of $type.
+ $(let _: $type = $value;)*
+ {
+ let mut group = $c.benchmark_group("create_channel");
+ $(group.bench_function(stringify!($type), |b| {
+ b.iter(oneshot::channel::<$type>)
+ });)*
+ group.finish();
+ }
+ {
+ let mut group = $c.benchmark_group("create_and_send");
+ $(group.bench_function(stringify!($type), |b| {
+ b.iter(|| {
+ let (sender, _receiver) = oneshot::channel();
+ sender.send(criterion::black_box($value)).unwrap()
+ });
+ });)*
+ group.finish();
+ }
+ {
+ let mut group = $c.benchmark_group("create_and_send_on_closed");
+ $(group.bench_function(stringify!($type), |b| {
+ b.iter(|| {
+ let (sender, _) = oneshot::channel();
+ sender.send(criterion::black_box($value)).unwrap_err()
+ });
+ });)*
+ group.finish();
+ }
+ #[cfg(feature = "std")]
+ {
+ let mut group = $c.benchmark_group("create_send_and_recv");
+ $(group.bench_function(stringify!($type), |b| {
+ b.iter(|| {
+ let (sender, receiver) = oneshot::channel();
+ sender.send(criterion::black_box($value)).unwrap();
+ receiver.recv().unwrap()
+ });
+ });)*
+ group.finish();
+ }
+ #[cfg(feature = "std")]
+ {
+ let mut group = $c.benchmark_group("create_send_and_recv_ref");
+ $(group.bench_function(stringify!($type), |b| {
+ b.iter(|| {
+ let (sender, receiver) = oneshot::channel();
+ sender.send(criterion::black_box($value)).unwrap();
+ receiver.recv_ref().unwrap()
+ });
+ });)*
+ group.finish();
+ }
+ };
+ }
+
+ pub fn bench(c: &mut criterion::Criterion) {
+ bench_send_and_recv!(c,
+ () => ();
+ u8 => 7u8;
+ u128 => 1234567u128;
+ [u8; 64] => [0b10101010u8; 64];
+ [u8; 4096] => [0b10101010u8; 4096]
+ );
+
+ bench_try_recv(c);
+ #[cfg(feature = "std")]
+ bench_recv_deadline_now(c);
+ #[cfg(feature = "std")]
+ bench_recv_timeout_zero(c);
+ }
+
+ fn bench_try_recv(c: &mut criterion::Criterion) {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ c.bench_function("try_recv_empty", |b| {
+ b.iter(|| receiver.try_recv().unwrap_err())
+ });
+ drop(sender);
+ c.bench_function("try_recv_empty_closed", |b| {
+ b.iter(|| receiver.try_recv().unwrap_err())
+ });
+ }
+
+ #[cfg(feature = "std")]
+ fn bench_recv_deadline_now(c: &mut criterion::Criterion) {
+ let now = std::time::Instant::now();
+ {
+ let (_sender, receiver) = oneshot::channel::<u128>();
+ c.bench_function("recv_deadline_now", |b| {
+ b.iter(|| receiver.recv_deadline(now).unwrap_err())
+ });
+ }
+ {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ drop(sender);
+ c.bench_function("recv_deadline_now_closed", |b| {
+ b.iter(|| receiver.recv_deadline(now).unwrap_err())
+ });
+ }
+ }
+
+ #[cfg(feature = "std")]
+ fn bench_recv_timeout_zero(c: &mut criterion::Criterion) {
+ let zero = std::time::Duration::from_nanos(0);
+ {
+ let (_sender, receiver) = oneshot::channel::<u128>();
+ c.bench_function("recv_timeout_zero", |b| {
+ b.iter(|| receiver.recv_timeout(zero).unwrap_err())
+ });
+ }
+ {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ drop(sender);
+ c.bench_function("recv_timeout_zero_closed", |b| {
+ b.iter(|| receiver.recv_timeout(zero).unwrap_err())
+ });
+ }
+ }
+}
diff --git a/third_party/rust/oneshot/check_mem_leaks.sh b/third_party/rust/oneshot/check_mem_leaks.sh
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+set -eu
+
+SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+cd "$SCRIPT_DIR"
+
+for example_path in examples/*.rs; do
+ example_filename=$(basename -- $example_path)
+ example=${example_filename%.*}
+ echo $example
+ cargo valgrind run --example "$example"
+done
diff --git a/third_party/rust/oneshot/examples/recv_before_send.rs b/third_party/rust/oneshot/examples/recv_before_send.rs
@@ -0,0 +1,18 @@
+#[cfg(feature = "std")]
+fn main() {
+ use std::thread;
+ use std::time::Duration;
+
+ let (sender, receiver) = oneshot::channel();
+ let t = thread::spawn(move || {
+ thread::sleep(Duration::from_millis(2));
+ sender.send(9u128).unwrap();
+ });
+ assert_eq!(receiver.recv(), Ok(9));
+ t.join().unwrap();
+}
+
+#[cfg(not(feature = "std"))]
+fn main() {
+ panic!("This example is only for when the \"sync\" feature is used");
+}
diff --git a/third_party/rust/oneshot/examples/recv_before_send_then_drop_sender.rs b/third_party/rust/oneshot/examples/recv_before_send_then_drop_sender.rs
@@ -0,0 +1,18 @@
+#[cfg(feature = "std")]
+fn main() {
+ use std::thread;
+ use std::time::Duration;
+
+ let (sender, receiver) = oneshot::channel::<u128>();
+ let t = thread::spawn(move || {
+ thread::sleep(Duration::from_millis(2));
+ std::mem::drop(sender);
+ });
+ assert!(receiver.recv().is_err());
+ t.join().unwrap();
+}
+
+#[cfg(not(feature = "std"))]
+fn main() {
+ panic!("This example is only for when the \"sync\" feature is used");
+}
diff --git a/third_party/rust/oneshot/examples/recv_ref_before_send.rs b/third_party/rust/oneshot/examples/recv_ref_before_send.rs
@@ -0,0 +1,18 @@
+#[cfg(feature = "std")]
+fn main() {
+ use std::thread;
+ use std::time::Duration;
+
+ let (sender, receiver) = oneshot::channel();
+ let t = thread::spawn(move || {
+ thread::sleep(Duration::from_millis(2));
+ sender.send(9u128).unwrap();
+ });
+ assert_eq!(receiver.recv_ref(), Ok(9));
+ t.join().unwrap();
+}
+
+#[cfg(not(feature = "std"))]
+fn main() {
+ panic!("This example is only for when the \"sync\" feature is used");
+}
diff --git a/third_party/rust/oneshot/examples/recv_ref_before_send_then_drop_sender.rs b/third_party/rust/oneshot/examples/recv_ref_before_send_then_drop_sender.rs
@@ -0,0 +1,18 @@
+#[cfg(feature = "std")]
+fn main() {
+ use std::thread;
+ use std::time::Duration;
+
+ let (sender, receiver) = oneshot::channel::<u128>();
+ let t = thread::spawn(move || {
+ thread::sleep(Duration::from_millis(2));
+ std::mem::drop(sender);
+ });
+ assert!(receiver.recv_ref().is_err());
+ t.join().unwrap();
+}
+
+#[cfg(not(feature = "std"))]
+fn main() {
+ panic!("This example is only for when the \"sync\" feature is used");
+}
diff --git a/third_party/rust/oneshot/examples/recv_timeout_before_send.rs b/third_party/rust/oneshot/examples/recv_timeout_before_send.rs
@@ -0,0 +1,18 @@
+#[cfg(feature = "std")]
+fn main() {
+ use std::thread;
+ use std::time::Duration;
+
+ let (sender, receiver) = oneshot::channel();
+ let t = thread::spawn(move || {
+ thread::sleep(Duration::from_millis(2));
+ sender.send(9u128).unwrap();
+ });
+ assert_eq!(receiver.recv_timeout(Duration::from_millis(100)), Ok(9));
+ t.join().unwrap();
+}
+
+#[cfg(not(feature = "std"))]
+fn main() {
+ panic!("This example is only for when the \"sync\" feature is used");
+}
diff --git a/third_party/rust/oneshot/examples/recv_timeout_before_send_then_drop_sender.rs b/third_party/rust/oneshot/examples/recv_timeout_before_send_then_drop_sender.rs
@@ -0,0 +1,18 @@
+#[cfg(feature = "std")]
+fn main() {
+ use std::thread;
+ use std::time::Duration;
+
+ let (sender, receiver) = oneshot::channel::<u128>();
+ let t = thread::spawn(move || {
+ thread::sleep(Duration::from_millis(2));
+ std::mem::drop(sender);
+ });
+ assert!(receiver.recv_timeout(Duration::from_millis(100)).is_err());
+ t.join().unwrap();
+}
+
+#[cfg(not(feature = "std"))]
+fn main() {
+ panic!("This example is only for when the \"sync\" feature is used");
+}
diff --git a/third_party/rust/oneshot/examples/recv_with_dropped_sender.rs b/third_party/rust/oneshot/examples/recv_with_dropped_sender.rs
@@ -0,0 +1,11 @@
+#[cfg(feature = "std")]
+fn main() {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ std::mem::drop(sender);
+ receiver.recv().unwrap_err();
+}
+
+#[cfg(not(feature = "std"))]
+fn main() {
+ panic!("This example is only for when the \"sync\" feature is used");
+}
diff --git a/third_party/rust/oneshot/examples/send_before_recv.rs b/third_party/rust/oneshot/examples/send_before_recv.rs
@@ -0,0 +1,11 @@
+#[cfg(feature = "std")]
+fn main() {
+ let (sender, receiver) = oneshot::channel();
+ assert!(sender.send(19i128).is_ok());
+ assert_eq!(receiver.recv(), Ok(19i128));
+}
+
+#[cfg(not(feature = "std"))]
+fn main() {
+ panic!("This example is only for when the \"sync\" feature is used");
+}
diff --git a/third_party/rust/oneshot/examples/send_then_drop_receiver.rs b/third_party/rust/oneshot/examples/send_then_drop_receiver.rs
@@ -0,0 +1,7 @@
+use std::mem;
+
+fn main() {
+ let (sender, receiver) = oneshot::channel();
+ assert!(sender.send(19i128).is_ok());
+ mem::drop(receiver);
+}
diff --git a/third_party/rust/oneshot/examples/send_with_dropped_receiver.rs b/third_party/rust/oneshot/examples/send_with_dropped_receiver.rs
@@ -0,0 +1,8 @@
+use std::mem;
+
+fn main() {
+ let (sender, receiver) = oneshot::channel();
+ mem::drop(receiver);
+ let send_error = sender.send(5u128).unwrap_err();
+ assert_eq!(send_error.into_inner(), 5);
+}
diff --git a/third_party/rust/oneshot/src/errors.rs b/third_party/rust/oneshot/src/errors.rs
@@ -0,0 +1,151 @@
+use super::{dealloc, Channel};
+use core::fmt;
+use core::mem;
+use core::ptr::NonNull;
+
+/// An error returned when trying to send on a closed channel. Returned from
+/// [`Sender::send`](crate::Sender::send) if the corresponding [`Receiver`](crate::Receiver)
+/// has already been dropped.
+///
+/// The message that could not be sent can be retreived again with [`SendError::into_inner`].
+pub struct SendError<T> {
+ channel_ptr: NonNull<Channel<T>>,
+}
+
+unsafe impl<T: Send> Send for SendError<T> {}
+unsafe impl<T: Sync> Sync for SendError<T> {}
+
+impl<T> SendError<T> {
+ /// # Safety
+ ///
+ /// By calling this function, the caller semantically transfers ownership of the
+ /// channel's resources to the created `SendError`. Thus the caller must ensure that the
+ /// pointer is not used in a way which would violate this ownership transfer. Moreover,
+ /// the caller must assert that the channel contains a valid, initialized message.
+ pub(crate) const unsafe fn new(channel_ptr: NonNull<Channel<T>>) -> Self {
+ Self { channel_ptr }
+ }
+
+ /// Consumes the error and returns the message that failed to be sent.
+ #[inline]
+ pub fn into_inner(self) -> T {
+ let channel_ptr = self.channel_ptr;
+
+ // Don't run destructor if we consumed ourselves. Freeing happens here.
+ mem::forget(self);
+
+ // SAFETY: we have ownership of the channel
+ let channel: &Channel<T> = unsafe { channel_ptr.as_ref() };
+
+ // SAFETY: we know that the message is initialized according to the safety requirements of
+ // `new`
+ let message = unsafe { channel.take_message() };
+
+ // SAFETY: we own the channel
+ unsafe { dealloc(channel_ptr) };
+
+ message
+ }
+
+ /// Get a reference to the message that failed to be sent.
+ #[inline]
+ pub fn as_inner(&self) -> &T {
+ unsafe { self.channel_ptr.as_ref().message().assume_init_ref() }
+ }
+}
+
+impl<T> Drop for SendError<T> {
+ fn drop(&mut self) {
+ // SAFETY: we have ownership of the channel and require that the message is initialized
+ // upon construction
+ unsafe {
+ self.channel_ptr.as_ref().drop_message();
+ dealloc(self.channel_ptr);
+ }
+ }
+}
+
+impl<T> fmt::Display for SendError<T> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ "sending on a closed channel".fmt(f)
+ }
+}
+
+impl<T> fmt::Debug for SendError<T> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ write!(f, "SendError<{}>(_)", stringify!(T))
+ }
+}
+
+#[cfg(feature = "std")]
+impl<T> std::error::Error for SendError<T> {}
+
+/// An error returned from receiving methods that block/wait until a message is available.
+///
+/// The receive operation can only fail if the corresponding [`Sender`](crate::Sender) was dropped
+/// before sending any message, or if a message has already been received on the channel.
+#[cfg(any(feature = "std", feature = "async"))]
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+pub struct RecvError;
+
+#[cfg(any(feature = "std", feature = "async"))]
+impl fmt::Display for RecvError {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ "receiving on a closed channel".fmt(f)
+ }
+}
+
+#[cfg(feature = "std")]
+impl std::error::Error for RecvError {}
+
+/// An error returned when failing to receive a message in the non-blocking
+/// [`Receiver::try_recv`](crate::Receiver::try_recv).
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+pub enum TryRecvError {
+ /// The channel is still open, but there was no message present in it.
+ Empty,
+
+ /// The channel is closed. Either the sender was dropped before sending any message, or the
+ /// message has already been extracted from the receiver.
+ Disconnected,
+}
+
+impl fmt::Display for TryRecvError {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ let msg = match self {
+ TryRecvError::Empty => "receiving on an empty channel",
+ TryRecvError::Disconnected => "receiving on a closed channel",
+ };
+ msg.fmt(f)
+ }
+}
+
+#[cfg(feature = "std")]
+impl std::error::Error for TryRecvError {}
+
+/// An error returned when failing to receive a message in a method that block/wait for a message
+/// for a while, but has a timeout after which it gives up.
+#[cfg(feature = "std")]
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+pub enum RecvTimeoutError {
+ /// No message arrived on the channel before the timeout was reached. The channel is still open.
+ Timeout,
+
+ /// The channel is closed. Either the sender was dropped before sending any message, or the
+ /// message has already been extracted from the receiver.
+ Disconnected,
+}
+
+#[cfg(feature = "std")]
+impl fmt::Display for RecvTimeoutError {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ let msg = match self {
+ RecvTimeoutError::Timeout => "timed out waiting on channel",
+ RecvTimeoutError::Disconnected => "channel is empty and sending half is closed",
+ };
+ msg.fmt(f)
+ }
+}
+
+#[cfg(feature = "std")]
+impl std::error::Error for RecvTimeoutError {}
diff --git a/third_party/rust/oneshot/src/lib.rs b/third_party/rust/oneshot/src/lib.rs
@@ -0,0 +1,1343 @@
+//! Oneshot spsc (single producer, single consumer) channel. Meaning each channel instance
+//! can only transport a single message. This has a few nice outcomes. One thing is that
+//! the implementation can be very efficient, utilizing the knowledge that there will
+//! only be one message. But more importantly, it allows the API to be expressed in such
+//! a way that certain edge cases that you don't want to care about when only sending a
+//! single message on a channel does not exist. For example: The sender can't be copied
+//! or cloned, and the send method takes ownership and consumes the sender.
+//! So you are guaranteed, at the type level, that there can only be one message sent.
+//!
+//! The sender's send method is non-blocking, and potentially lock- and wait-free.
+//! See documentation on [Sender::send] for situations where it might not be fully wait-free.
+//! The receiver supports both lock- and wait-free `try_recv` as well as indefinite and time
+//! limited thread blocking receive operations. The receiver also implements `Future` and
+//! supports asynchronously awaiting the message.
+//!
+//!
+//! # Examples
+//!
+//! This example sets up a background worker that processes requests coming in on a standard
+//! mpsc channel and replies on a oneshot channel provided with each request. The worker can
+//! be interacted with both from sync and async contexts since the oneshot receiver
+//! can receive both blocking and async.
+//!
+//! ```rust
+//! # #[cfg(not(feature = "loom"))] {
+//! use std::sync::mpsc;
+//! use std::thread;
+//! use std::time::Duration;
+//!
+//! type Request = String;
+//!
+//! // Starts a background thread performing some computation on requests sent to it.
+//! // Delivers the response back over a oneshot channel.
+//! fn spawn_processing_thread() -> mpsc::Sender<(Request, oneshot::Sender<usize>)> {
+//! let (request_sender, request_receiver) = mpsc::channel::<(Request, oneshot::Sender<usize>)>();
+//! thread::spawn(move || {
+//! for (request_data, response_sender) in request_receiver.iter() {
+//! let compute_operation = || request_data.len();
+//! let _ = response_sender.send(compute_operation()); // <- Send on the oneshot channel
+//! }
+//! });
+//! request_sender
+//! }
+//!
+//! let processor = spawn_processing_thread();
+//!
+//! // If compiled with `std` the library can receive messages with timeout on regular threads
+//! #[cfg(feature = "std")] {
+//! let (response_sender, response_receiver) = oneshot::channel();
+//! let request = Request::from("data from sync thread");
+//!
+//! processor.send((request, response_sender)).expect("Processor down");
+//! match response_receiver.recv_timeout(Duration::from_secs(1)) { // <- Receive on the oneshot channel
+//! Ok(result) => println!("Processor returned {}", result),
+//! Err(oneshot::RecvTimeoutError::Timeout) => eprintln!("Processor was too slow"),
+//! Err(oneshot::RecvTimeoutError::Disconnected) => panic!("Processor exited"),
+//! }
+//! }
+//!
+//! // If compiled with the `async` feature, the `Receiver` can be awaited in an async context
+//! #[cfg(feature = "async")] {
+//! tokio::runtime::Runtime::new()
+//! .unwrap()
+//! .block_on(async move {
+//! let (response_sender, response_receiver) = oneshot::channel();
+//! let request = Request::from("data from sync thread");
+//!
+//! processor.send((request, response_sender)).expect("Processor down");
+//! match response_receiver.await { // <- Receive on the oneshot channel asynchronously
+//! Ok(result) => println!("Processor returned {}", result),
+//! Err(_e) => panic!("Processor exited"),
+//! }
+//! });
+//! }
+//! # }
+//! ```
+//!
+//! # Sync vs async
+//!
+//! The main motivation for writing this library was that there were no (known to me) channel
+//! implementations allowing you to seamlessly send messages between a normal thread and an async
+//! task, or the other way around. If message passing is the way you are communicating, of course
+//! that should work smoothly between the sync and async parts of the program!
+//!
+//! This library achieves that by having a fast and cheap send operation that can
+//! be used in both sync threads and async tasks. The receiver has both thread blocking
+//! receive methods for synchronous usage, and implements `Future` for asynchronous usage.
+//!
+//! The receiving endpoint of this channel implements Rust's `Future` trait and can be waited on
+//! in an asynchronous task. This implementation is completely executor/runtime agnostic. It should
+//! be possible to use this library with any executor, or even pass messages between tasks running
+//! in different executors.
+//!
+
+// # Implementation description
+//
+// When a channel is created via the `channel` function, it creates a single heap allocation
+// containing:
+// * A one byte atomic integer that represents the current channel state,
+// * Uninitialized memory to fit the message,
+// * Uninitialized memory to fit the waker that can wake the receiving task or thread up.
+//
+// The size of the waker depends on which features are activated, it ranges from 0 to 24 bytes[1].
+// So with all features enabled each channel allocates 25 bytes plus the size of the
+// message, plus any padding needed to get correct memory alignment.
+//
+// The Sender and Receiver only holds a raw pointer to the heap channel object. The last endpoint
+// to be consumed or dropped is responsible for freeing the heap memory. The first endpoint to
+// be consumed or dropped signal via the state that it is gone. And the second one see this and
+// frees the memory.
+//
+// ## Footnotes
+//
+// [1]: Mind that the waker only takes zero bytes when all features are disabled, making it
+// impossible to *wait* for the message. `try_recv` is the only available method in this scenario.
+
+#![deny(rust_2018_idioms)]
+#![cfg_attr(not(feature = "std"), no_std)]
+// Enables this nightly only feature for the documentation build on docs.rs.
+// To test this locally, build the docs with:
+// `RUSTDOCFLAGS="--cfg docsrs" cargo +nightly doc --all-features`
+#![cfg_attr(docsrs, feature(doc_cfg))]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+
+#[cfg(not(oneshot_loom))]
+extern crate alloc;
+
+use core::{
+ marker::PhantomData,
+ mem::{self, MaybeUninit},
+ ptr::{self, NonNull},
+};
+
+#[cfg(not(oneshot_loom))]
+use core::{
+ cell::UnsafeCell,
+ sync::atomic::{fence, AtomicU8, Ordering::*},
+};
+#[cfg(oneshot_loom)]
+use loom::{
+ cell::UnsafeCell,
+ sync::atomic::{fence, AtomicU8, Ordering::*},
+};
+
+#[cfg(all(any(feature = "std", feature = "async"), not(oneshot_loom)))]
+use core::hint;
+#[cfg(all(any(feature = "std", feature = "async"), oneshot_loom))]
+use loom::hint;
+
+#[cfg(feature = "async")]
+use core::{
+ pin::Pin,
+ task::{self, Poll},
+};
+#[cfg(feature = "std")]
+use std::time::{Duration, Instant};
+
+#[cfg(feature = "std")]
+mod thread {
+ #[cfg(not(oneshot_loom))]
+ pub use std::thread::{current, park, park_timeout, Thread};
+
+ #[cfg(oneshot_loom)]
+ pub use loom::thread::{current, park, Thread};
+
+ // loom does not support parking with a timeout. So we just
+ // yield. This means that the "park" will "spuriously" wake up
+ // way too early. But the code should properly handle this.
+ // One thing to note is that very short timeouts are needed
+ // when using loom, since otherwise the looping will cause
+ // an overflow in loom.
+ #[cfg(oneshot_loom)]
+ pub fn park_timeout(_timeout: std::time::Duration) {
+ loom::thread::yield_now()
+ }
+}
+
+#[cfg(oneshot_loom)]
+mod loombox;
+#[cfg(not(oneshot_loom))]
+use alloc::boxed::Box;
+#[cfg(oneshot_loom)]
+use loombox::Box;
+
+mod errors;
+// Wildcard imports are not nice. But since multiple errors have various conditional compilation,
+// this is easier than doing three different imports.
+pub use errors::*;
+
+/// Creates a new oneshot channel and returns the two endpoints, [`Sender`] and [`Receiver`].
+pub fn channel<T>() -> (Sender<T>, Receiver<T>) {
+ // Allocate the channel on the heap and get the pointer.
+ // The last endpoint of the channel to be alive is responsible for freeing the channel
+ // and dropping any object that might have been written to it.
+ let channel_ptr = NonNull::from(Box::leak(Box::new(Channel::new())));
+
+ (
+ Sender {
+ channel_ptr,
+ _invariant: PhantomData,
+ },
+ Receiver { channel_ptr },
+ )
+}
+
+/// Sending end of a oneshot channel.
+///
+/// Created and returned from the [`channel`] function.
+///
+/// Can be used to send a message to the corresponding [`Receiver`].
+#[derive(Debug)]
+pub struct Sender<T> {
+ channel_ptr: NonNull<Channel<T>>,
+ // In reality we want contravariance, however we can't obtain that.
+ //
+ // Consider the following scenario:
+ // ```
+ // let (mut tx, rx) = channel::<&'short u8>();
+ // let (tx2, rx2) = channel::<&'long u8>();
+ //
+ // tx = tx2;
+ //
+ // // Pretend short_ref is some &'short u8
+ // tx.send(short_ref).unwrap();
+ // let long_ref = rx2.recv().unwrap();
+ // ```
+ //
+ // If this type were covariant then we could safely extend lifetimes, which is not okay.
+ // Hence, we enforce invariance.
+ _invariant: PhantomData<fn(T) -> T>,
+}
+
+/// Receiving end of a oneshot channel.
+///
+/// Created and returned from the [`channel`] function.
+///
+/// Can be used to receive a message from the corresponding [`Sender`]. How the message
+/// can be received depends on what features are enabled.
+///
+/// This type implement [`IntoFuture`](core::future::IntoFuture) when the `async` feature is enabled.
+/// This allows awaiting it directly in an async context.
+#[derive(Debug)]
+pub struct Receiver<T> {
+ // Covariance is the right choice here. Consider the example presented in Sender, and you'll
+ // see that if we replaced `rx` instead then we would get the expected behavior
+ channel_ptr: NonNull<Channel<T>>,
+}
+
+unsafe impl<T: Send> Send for Sender<T> {}
+
+// SAFETY: The only methods that assumes there is only a single reference to the sender
+// takes `self` by value, guaranteeing that there is only one reference to the sender at
+// the time it is called.
+unsafe impl<T: Sync> Sync for Sender<T> {}
+
+unsafe impl<T: Send> Send for Receiver<T> {}
+impl<T> Unpin for Receiver<T> {}
+
+impl<T> Sender<T> {
+ /// Sends `message` over the channel to the corresponding [`Receiver`].
+ ///
+ /// Returns an error if the receiver has already been dropped. The message can
+ /// be extracted from the error.
+ ///
+ /// This method is lock-free and wait-free when sending on a channel that the
+ /// receiver is currently not receiving on. If the receiver is receiving during the send
+ /// operation this method includes waking up the thread/task. Unparking a thread involves
+ /// a mutex in Rust's standard library at the time of writing this.
+ /// How lock-free waking up an async task is
+ /// depends on your executor. If this method returns a `SendError`, please mind that dropping
+ /// the error involves running any drop implementation on the message type, and freeing the
+ /// channel's heap allocation, which might or might not be lock-free.
+ pub fn send(self, message: T) -> Result<(), SendError<T>> {
+ let channel_ptr = self.channel_ptr;
+
+ // Don't run our Drop implementation if send was called, any cleanup now happens here
+ mem::forget(self);
+
+ // SAFETY: The channel exists on the heap for the entire duration of this method and we
+ // only ever acquire shared references to it. Note that if the receiver disconnects it
+ // does not free the channel.
+ let channel = unsafe { channel_ptr.as_ref() };
+
+ // Write the message into the channel on the heap.
+ // SAFETY: The receiver only ever accesses this memory location if we are in the MESSAGE
+ // state, and since we're responsible for setting that state, we can guarantee that we have
+ // exclusive access to this memory location to perform this write.
+ unsafe { channel.write_message(message) };
+
+ // Set the state to signal there is a message on the channel.
+ // ORDERING: we use release ordering to ensure the write of the message is visible to the
+ // receiving thread. The EMPTY and DISCONNECTED branches do not observe any shared state,
+ // and thus we do not need acquire ordering. The RECEIVING branch manages synchronization
+ // independent of this operation.
+ //
+ // EMPTY + 1 = MESSAGE
+ // RECEIVING + 1 = UNPARKING
+ // DISCONNECTED + 1 = invalid, however this state is never observed
+ match channel.state.fetch_add(1, Release) {
+ // The receiver is alive and has not started waiting. Send done.
+ EMPTY => Ok(()),
+ // The receiver is waiting. Wake it up so it can return the message.
+ RECEIVING => {
+ // ORDERING: Synchronizes with the write of the waker to memory, and prevents the
+ // taking of the waker from being ordered before this operation.
+ fence(Acquire);
+
+ // Take the waker, but critically do not unpark it. If we unparked now, then the
+ // receiving thread could still observe the UNPARKING state and re-park, meaning
+ // that after we change to the MESSAGE state, it would remain parked indefinitely
+ // or until a spurious wakeup.
+ // SAFETY: at this point we are in the UNPARKING state, and the receiving thread
+ // does not access the waker while in this state, nor does it free the channel
+ // allocation in this state.
+ let waker = unsafe { channel.take_waker() };
+
+ // ORDERING: this ordering serves two-fold: it synchronizes with the acquire load
+ // in the receiving thread, ensuring that both our read of the waker and write of
+ // the message happen-before the taking of the message and freeing of the channel.
+ // Furthermore, we need acquire ordering to ensure the unparking of the receiver
+ // happens after the channel state is updated.
+ channel.state.swap(MESSAGE, AcqRel);
+
+ // Note: it is possible that between the store above and this statement that
+ // the receiving thread is spuriously unparked, takes the message, and frees
+ // the channel allocation. However, we took ownership of the channel out of
+ // that allocation, and freeing the channel does not drop the waker since the
+ // waker is wrapped in MaybeUninit. Therefore this data is valid regardless of
+ // whether or not the receive has completed by this point.
+ waker.unpark();
+
+ Ok(())
+ }
+ // The receiver was already dropped. The error is responsible for freeing the channel.
+ // SAFETY: since the receiver disconnected it will no longer access `channel_ptr`, so
+ // we can transfer exclusive ownership of the channel's resources to the error.
+ // Moreover, since we just placed the message in the channel, the channel contains a
+ // valid message.
+ DISCONNECTED => Err(unsafe { SendError::new(channel_ptr) }),
+ _ => unreachable!(),
+ }
+ }
+
+ /// Returns true if the associated [`Receiver`] has been dropped.
+ ///
+ /// If true is returned, a future call to send is guaranteed to return an error.
+ pub fn is_closed(&self) -> bool {
+ // SAFETY: The channel exists on the heap for the entire duration of this method and we
+ // only ever acquire shared references to it. Note that if the receiver disconnects it
+ // does not free the channel.
+ let channel = unsafe { self.channel_ptr.as_ref() };
+
+ // ORDERING: We *chose* a Relaxed ordering here as it sufficient to
+ // enforce the method's contract: "if true is returned, a future
+ // call to send is guaranteed to return an error."
+ channel.state.load(Relaxed) == DISCONNECTED
+ }
+
+ /// Consumes the Sender, returning a raw pointer to the channel on the heap.
+ ///
+ /// This is intended to simplify using oneshot channels with some FFI code. The only safe thing
+ /// to do with the returned pointer is to later reconstruct the Sender with [Sender::from_raw].
+ /// Memory will leak if the Sender is never reconstructed.
+ pub fn into_raw(self) -> *mut () {
+ let raw = self.channel_ptr.as_ptr() as *mut ();
+ mem::forget(self);
+ raw
+ }
+
+ /// Consumes a raw pointer from [Sender::into_raw], recreating the Sender.
+ ///
+ /// # Safety
+ ///
+ /// This pointer must have come from [`Sender<T>::into_raw`] with the same message type, `T`.
+ /// At most one Sender must exist for a channel at any point in time.
+ /// Constructing multiple Senders from the same raw pointer leads to undefined behavior.
+ pub unsafe fn from_raw(raw: *mut ()) -> Self {
+ Self {
+ channel_ptr: NonNull::new_unchecked(raw as *mut Channel<T>),
+ _invariant: PhantomData,
+ }
+ }
+}
+
+impl<T> Drop for Sender<T> {
+ fn drop(&mut self) {
+ // SAFETY: The receiver only ever frees the channel if we are in the MESSAGE or
+ // DISCONNECTED states. If we are in the MESSAGE state, then we called
+ // mem::forget(self), so we should not be in this function call. If we are in the
+ // DISCONNECTED state, then the receiver either received a MESSAGE so this statement is
+ // unreachable, or was dropped and observed that our side was still alive, and thus didn't
+ // free the channel.
+ let channel = unsafe { self.channel_ptr.as_ref() };
+
+ // Set the channel state to disconnected and read what state the receiver was in
+ // ORDERING: we don't need release ordering here since there are no modifications we
+ // need to make visible to other thread, and the Err(RECEIVING) branch handles
+ // synchronization independent of this cmpxchg
+ //
+ // EMPTY ^ 001 = DISCONNECTED
+ // RECEIVING ^ 001 = UNPARKING
+ // DISCONNECTED ^ 001 = EMPTY (invalid), but this state is never observed
+ match channel.state.fetch_xor(0b001, Relaxed) {
+ // The receiver has not started waiting, nor is it dropped.
+ EMPTY => (),
+ // The receiver is waiting. Wake it up so it can detect that the channel disconnected.
+ RECEIVING => {
+ // See comments in Sender::send
+
+ fence(Acquire);
+
+ let waker = unsafe { channel.take_waker() };
+
+ // We still need release ordering here to make sure our read of the waker happens
+ // before this, and acquire ordering to ensure the unparking of the receiver
+ // happens after this.
+ channel.state.swap(DISCONNECTED, AcqRel);
+
+ // The Acquire ordering above ensures that the write of the DISCONNECTED state
+ // happens-before unparking the receiver.
+ waker.unpark();
+ }
+ // The receiver was already dropped. We are responsible for freeing the channel.
+ DISCONNECTED => {
+ // SAFETY: when the receiver switches the state to DISCONNECTED they have received
+ // the message or will no longer be trying to receive the message, and have
+ // observed that the sender is still alive, meaning that we're responsible for
+ // freeing the channel allocation.
+ unsafe { dealloc(self.channel_ptr) };
+ }
+ _ => unreachable!(),
+ }
+ }
+}
+
+impl<T> Receiver<T> {
+ /// Checks if there is a message in the channel without blocking. Returns:
+ /// * `Ok(message)` if there was a message in the channel.
+ /// * `Err(Empty)` if the [`Sender`] is alive, but has not yet sent a message.
+ /// * `Err(Disconnected)` if the [`Sender`] was dropped before sending anything or if the
+ /// message has already been extracted by a previous receive call.
+ ///
+ /// If a message is returned, the channel is disconnected and any subsequent receive operation
+ /// using this receiver will return an error.
+ ///
+ /// This method is completely lock-free and wait-free. The only thing it does is an atomic
+ /// integer load of the channel state. And if there is a message in the channel it additionally
+ /// performs one atomic integer store and copies the message from the heap to the stack for
+ /// returning it.
+ pub fn try_recv(&self) -> Result<T, TryRecvError> {
+ // SAFETY: The channel will not be freed while this method is still running.
+ let channel = unsafe { self.channel_ptr.as_ref() };
+
+ // ORDERING: we use acquire ordering to synchronize with the store of the message.
+ match channel.state.load(Acquire) {
+ MESSAGE => {
+ // It's okay to break up the load and store since once we're in the message state
+ // the sender no longer modifies the state
+ // ORDERING: at this point the sender has done its job and is no longer active, so
+ // we don't need to make any side effects visible to it
+ channel.state.store(DISCONNECTED, Relaxed);
+
+ // SAFETY: we are in the MESSAGE state so the message is present
+ Ok(unsafe { channel.take_message() })
+ }
+ EMPTY => Err(TryRecvError::Empty),
+ DISCONNECTED => Err(TryRecvError::Disconnected),
+ #[cfg(feature = "async")]
+ RECEIVING | UNPARKING => Err(TryRecvError::Empty),
+ _ => unreachable!(),
+ }
+ }
+
+ /// Attempts to wait for a message from the [`Sender`], returning an error if the channel is
+ /// disconnected.
+ ///
+ /// This method will always block the current thread if there is no data available and it is
+ /// still possible for the message to be sent. Once the message is sent to the corresponding
+ /// [`Sender`], then this receiver will wake up and return that message.
+ ///
+ /// If the corresponding [`Sender`] has disconnected (been dropped), or it disconnects while
+ /// this call is blocking, this call will wake up and return `Err` to indicate that the message
+ /// can never be received on this channel.
+ ///
+ /// If a sent message has already been extracted from this channel this method will return an
+ /// error.
+ ///
+ /// # Panics
+ ///
+ /// Panics if called after this receiver has been polled asynchronously.
+ #[cfg(feature = "std")]
+ pub fn recv(self) -> Result<T, RecvError> {
+ // Note that we don't need to worry about changing the state to disconnected or setting the
+ // state to an invalid value at any point in this function because we take ownership of
+ // self, and this function does not exit until the message has been received or both side
+ // of the channel are inactive and cleaned up.
+
+ let channel_ptr = self.channel_ptr;
+
+ // Don't run our Drop implementation. This consuming recv method is responsible for freeing.
+ mem::forget(self);
+
+ // SAFETY: the existence of the `self` parameter serves as a certificate that the receiver
+ // is still alive, meaning that even if the sender was dropped then it would have observed
+ // the fact that we're still alive and left the responsibility of deallocating the
+ // channel to us, so channel_ptr is valid
+ let channel = unsafe { channel_ptr.as_ref() };
+
+ // ORDERING: we use acquire ordering to synchronize with the write of the message in the
+ // case that it's available
+ match channel.state.load(Acquire) {
+ // The sender is alive but has not sent anything yet. We prepare to park.
+ EMPTY => {
+ // Conditionally add a delay here to help the tests trigger the edge cases where
+ // the sender manages to be dropped or send something before we are able to store
+ // our waker object in the channel.
+ #[cfg(all(oneshot_test_delay, not(oneshot_loom)))]
+ std::thread::sleep(std::time::Duration::from_millis(10));
+
+ // Write our waker instance to the channel.
+ // SAFETY: we are not yet in the RECEIVING state, meaning that the sender will not
+ // try to access the waker until it sees the state set to RECEIVING below
+ unsafe { channel.write_waker(ReceiverWaker::current_thread()) };
+
+ // Switch the state to RECEIVING. We need to do this in one atomic step in case the
+ // sender disconnected or sent the message while we wrote the waker to memory. We
+ // don't need to do a compare exchange here however because if the original state
+ // was not EMPTY, then the sender has either finished sending the message or is
+ // being dropped, so the RECEIVING state will never be observed after we return.
+ // ORDERING: we use release ordering so the sender can synchronize with our writing
+ // of the waker to memory. The individual branches handle any additional
+ // synchronizaton
+ match channel.state.swap(RECEIVING, Release) {
+ // We stored our waker, now we park until the sender has changed the state
+ EMPTY => loop {
+ thread::park();
+
+ // ORDERING: synchronize with the write of the message
+ match channel.state.load(Acquire) {
+ // The sender sent the message while we were parked.
+ MESSAGE => {
+ // SAFETY: we are in the message state so the message is valid
+ let message = unsafe { channel.take_message() };
+
+ // SAFETY: the Sender delegates the responsibility of deallocating
+ // the channel to us upon sending the message
+ unsafe { dealloc(channel_ptr) };
+
+ break Ok(message);
+ }
+ // The sender was dropped while we were parked.
+ DISCONNECTED => {
+ // SAFETY: the Sender doesn't deallocate the channel allocation in
+ // its drop implementation if we're receiving
+ unsafe { dealloc(channel_ptr) };
+
+ break Err(RecvError);
+ }
+ // State did not change, spurious wakeup, park again.
+ RECEIVING | UNPARKING => (),
+ _ => unreachable!(),
+ }
+ },
+ // The sender sent the message while we prepared to park.
+ MESSAGE => {
+ // ORDERING: Synchronize with the write of the message. This branch is
+ // unlikely to be taken, so it's likely more efficient to use a fence here
+ // instead of AcqRel ordering on the RMW operation
+ fence(Acquire);
+
+ // SAFETY: we started in the empty state and the sender switched us to the
+ // message state. This means that it did not take the waker, so we're
+ // responsible for dropping it.
+ unsafe { channel.drop_waker() };
+
+ // SAFETY: we are in the message state so the message is valid
+ let message = unsafe { channel.take_message() };
+
+ // SAFETY: the Sender delegates the responsibility of deallocating the
+ // channel to us upon sending the message
+ unsafe { dealloc(channel_ptr) };
+
+ Ok(message)
+ }
+ // The sender was dropped before sending anything while we prepared to park.
+ DISCONNECTED => {
+ // SAFETY: we started in the empty state and the sender switched us to the
+ // disconnected state. It does not take the waker when it does this so we
+ // need to drop it.
+ unsafe { channel.drop_waker() };
+
+ // SAFETY: the sender does not deallocate the channel if it switches from
+ // empty to disconnected so we need to free the allocation
+ unsafe { dealloc(channel_ptr) };
+
+ Err(RecvError)
+ }
+ _ => unreachable!(),
+ }
+ }
+ // The sender already sent the message.
+ MESSAGE => {
+ // SAFETY: we are in the message state so the message is valid
+ let message = unsafe { channel.take_message() };
+
+ // SAFETY: we are already in the message state so the sender has been forgotten
+ // and it's our job to clean up resources
+ unsafe { dealloc(channel_ptr) };
+
+ Ok(message)
+ }
+ // The sender was dropped before sending anything, or we already received the message.
+ DISCONNECTED => {
+ // SAFETY: the sender does not deallocate the channel if it switches from empty to
+ // disconnected so we need to free the allocation
+ unsafe { dealloc(channel_ptr) };
+
+ Err(RecvError)
+ }
+ // The receiver must have been `Future::poll`ed prior to this call.
+ #[cfg(feature = "async")]
+ RECEIVING | UNPARKING => panic!("{}", RECEIVER_USED_SYNC_AND_ASYNC_ERROR),
+ _ => unreachable!(),
+ }
+ }
+
+ /// Attempts to wait for a message from the [`Sender`], returning an error if the channel is
+ /// disconnected. This is a non consuming version of [`Receiver::recv`], but with a bit
+ /// worse performance. Prefer `[`Receiver::recv`]` if your code allows consuming the receiver.
+ ///
+ /// If a message is returned, the channel is disconnected and any subsequent receive operation
+ /// using this receiver will return an error.
+ ///
+ /// # Panics
+ ///
+ /// Panics if called after this receiver has been polled asynchronously.
+ #[cfg(feature = "std")]
+ pub fn recv_ref(&self) -> Result<T, RecvError> {
+ self.start_recv_ref(RecvError, |channel| {
+ loop {
+ thread::park();
+
+ // ORDERING: we use acquire ordering to synchronize with the write of the message
+ match channel.state.load(Acquire) {
+ // The sender sent the message while we were parked.
+ // We take the message and mark the channel disconnected.
+ MESSAGE => {
+ // ORDERING: the sender is inactive at this point so we don't need to make
+ // any reads or writes visible to the sending thread
+ channel.state.store(DISCONNECTED, Relaxed);
+
+ // SAFETY: we were just in the message state so the message is valid
+ break Ok(unsafe { channel.take_message() });
+ }
+ // The sender was dropped while we were parked.
+ DISCONNECTED => break Err(RecvError),
+ // State did not change, spurious wakeup, park again.
+ RECEIVING | UNPARKING => (),
+ _ => unreachable!(),
+ }
+ }
+ })
+ }
+
+ /// Like [`Receiver::recv`], but will not block longer than `timeout`. Returns:
+ /// * `Ok(message)` if there was a message in the channel before the timeout was reached.
+ /// * `Err(Timeout)` if no message arrived on the channel before the timeout was reached.
+ /// * `Err(Disconnected)` if the sender was dropped before sending anything or if the message
+ /// has already been extracted by a previous receive call.
+ ///
+ /// If a message is returned, the channel is disconnected and any subsequent receive operation
+ /// using this receiver will return an error.
+ ///
+ /// If the supplied `timeout` is so large that Rust's `Instant` type can't represent this point
+ /// in the future this falls back to an indefinitely blocking receive operation.
+ ///
+ /// # Panics
+ ///
+ /// Panics if called after this receiver has been polled asynchronously.
+ #[cfg(feature = "std")]
+ pub fn recv_timeout(&self, timeout: Duration) -> Result<T, RecvTimeoutError> {
+ match Instant::now().checked_add(timeout) {
+ Some(deadline) => self.recv_deadline(deadline),
+ None => self.recv_ref().map_err(|_| RecvTimeoutError::Disconnected),
+ }
+ }
+
+ /// Like [`Receiver::recv`], but will not block longer than until `deadline`. Returns:
+ /// * `Ok(message)` if there was a message in the channel before the deadline was reached.
+ /// * `Err(Timeout)` if no message arrived on the channel before the deadline was reached.
+ /// * `Err(Disconnected)` if the sender was dropped before sending anything or if the message
+ /// has already been extracted by a previous receive call.
+ ///
+ /// If a message is returned, the channel is disconnected and any subsequent receive operation
+ /// using this receiver will return an error.
+ ///
+ /// # Panics
+ ///
+ /// Panics if called after this receiver has been polled asynchronously.
+ #[cfg(feature = "std")]
+ pub fn recv_deadline(&self, deadline: Instant) -> Result<T, RecvTimeoutError> {
+ /// # Safety
+ ///
+ /// If the sender is unparking us after a message send, the message must already have been
+ /// written to the channel and an acquire memory barrier issued before calling this function
+ #[cold]
+ unsafe fn wait_for_unpark<T>(channel: &Channel<T>) -> Result<T, RecvTimeoutError> {
+ loop {
+ thread::park();
+
+ // ORDERING: The callee has already synchronized with any message write
+ match channel.state.load(Relaxed) {
+ MESSAGE => {
+ // ORDERING: the sender has been dropped, so this update only
+ // needs to be visible to us
+ channel.state.store(DISCONNECTED, Relaxed);
+ break Ok(channel.take_message());
+ }
+ DISCONNECTED => break Err(RecvTimeoutError::Disconnected),
+ // The sender is still unparking us. We continue on the empty state here since
+ // the current implementation eagerly sets the state to EMPTY upon timeout.
+ EMPTY => (),
+ _ => unreachable!(),
+ }
+ }
+ }
+
+ self.start_recv_ref(RecvTimeoutError::Disconnected, |channel| {
+ loop {
+ match deadline.checked_duration_since(Instant::now()) {
+ Some(timeout) => {
+ thread::park_timeout(timeout);
+
+ // ORDERING: synchronize with the write of the message
+ match channel.state.load(Acquire) {
+ // The sender sent the message while we were parked.
+ MESSAGE => {
+ // ORDERING: the sender has been `mem::forget`-ed so this update
+ // only needs to be visible to us.
+ channel.state.store(DISCONNECTED, Relaxed);
+
+ // SAFETY: we either are in the message state or were just in the
+ // message state
+ break Ok(unsafe { channel.take_message() });
+ }
+ // The sender was dropped while we were parked.
+ DISCONNECTED => break Err(RecvTimeoutError::Disconnected),
+ // State did not change, spurious wakeup, park again.
+ RECEIVING | UNPARKING => (),
+ _ => unreachable!(),
+ }
+ }
+ None => {
+ // ORDERING: synchronize with the write of the message
+ match channel.state.swap(EMPTY, Acquire) {
+ // We reached the end of the timeout without receiving a message
+ RECEIVING => {
+ // SAFETY: we were in the receiving state and are now in the empty
+ // state, so the sender has not and will not try to read the waker,
+ // so we have exclusive access to drop it.
+ unsafe { channel.drop_waker() };
+
+ break Err(RecvTimeoutError::Timeout);
+ }
+ // The sender sent the message while we were parked.
+ MESSAGE => {
+ // Same safety and ordering as the Some branch
+
+ channel.state.store(DISCONNECTED, Relaxed);
+ break Ok(unsafe { channel.take_message() });
+ }
+ // The sender was dropped while we were parked.
+ DISCONNECTED => {
+ // ORDERING: we were originally in the disconnected state meaning
+ // that the sender is inactive and no longer observing the state,
+ // so we only need to change it back to DISCONNECTED for if the
+ // receiver is dropped or a recv* method is called again
+ channel.state.store(DISCONNECTED, Relaxed);
+
+ break Err(RecvTimeoutError::Disconnected);
+ }
+ // The sender sent the message and started unparking us
+ UNPARKING => {
+ // We were in the UNPARKING state and are now in the EMPTY state.
+ // We wait to be properly unparked and to observe if the sender
+ // sets MESSAGE or DISCONNECTED state.
+ // SAFETY: The load above has synchronized with any message write.
+ break unsafe { wait_for_unpark(channel) };
+ }
+ _ => unreachable!(),
+ }
+ }
+ }
+ }
+ })
+ }
+
+ /// Returns true if the associated [`Sender`] was dropped before sending a message. Or if
+ /// the message has already been received.
+ ///
+ /// If `true` is returned, all future calls to receive methods are guaranteed to return
+ /// a disconnected error. And future calls to this method is guaranteed to also return `true`.
+ pub fn is_closed(&self) -> bool {
+ // SAFETY: the existence of the `self` parameter serves as a certificate that the receiver
+ // is still alive, meaning that even if the sender was dropped then it would have observed
+ // the fact that we're still alive and left the responsibility of deallocating the
+ // channel to us, so `self.channel` is valid
+ let channel = unsafe { self.channel_ptr.as_ref() };
+
+ // ORDERING: We *chose* a Relaxed ordering here as it is sufficient to
+ // enforce the method's contract. Once true has been observed, it will remain true.
+ // However, if false is observed, the sender might have just disconnected but this thread
+ // has not observed it yet.
+ channel.state.load(Relaxed) == DISCONNECTED
+ }
+
+ /// Returns true if there is a message in the channel, ready to be received.
+ ///
+ /// If `true` is returned, the next call to a receive method is guaranteed to return
+ /// a message.
+ pub fn has_message(&self) -> bool {
+ // SAFETY: the existence of the `self` parameter serves as a certificate that the receiver
+ // is still alive, meaning that even if the sender was dropped then it would have observed
+ // the fact that we're still alive and left the responsibility of deallocating the
+ // channel to us, so `self.channel` is valid
+ let channel = unsafe { self.channel_ptr.as_ref() };
+
+ // ORDERING: An acquire ordering is used to guarantee no subsequent loads is reordered
+ // before this one. This upholds the contract that if true is returned, the next call to
+ // a receive method is guaranteed to also abserve the `MESSAGE` state and return a message.
+ channel.state.load(Acquire) == MESSAGE
+ }
+
+ /// Begins the process of receiving on the channel by reference. If the message is already
+ /// ready, or the sender has disconnected, then this function will return the appropriate
+ /// Result immediately. Otherwise, it will write the waker to memory, check to see if the
+ /// sender has finished or disconnected again, and then will call `finish`. `finish` is
+ /// thus responsible for cleaning up the channel's resources appropriately before it returns,
+ /// such as destroying the waker, for instance.
+ #[cfg(feature = "std")]
+ #[inline]
+ fn start_recv_ref<E>(
+ &self,
+ disconnected_error: E,
+ finish: impl FnOnce(&Channel<T>) -> Result<T, E>,
+ ) -> Result<T, E> {
+ // SAFETY: the existence of the `self` parameter serves as a certificate that the receiver
+ // is still alive, meaning that even if the sender was dropped then it would have observed
+ // the fact that we're still alive and left the responsibility of deallocating the
+ // channel to us, so `self.channel` is valid
+ let channel = unsafe { self.channel_ptr.as_ref() };
+
+ // ORDERING: synchronize with the write of the message
+ match channel.state.load(Acquire) {
+ // The sender is alive but has not sent anything yet. We prepare to park.
+ EMPTY => {
+ // Conditionally add a delay here to help the tests trigger the edge cases where
+ // the sender manages to be dropped or send something before we are able to store
+ // our waker object in the channel.
+ #[cfg(all(oneshot_test_delay, not(oneshot_loom)))]
+ std::thread::sleep(std::time::Duration::from_millis(10));
+
+ // Write our waker instance to the channel.
+ // SAFETY: we are not yet in the RECEIVING state, meaning that the sender will not
+ // try to access the waker until it sees the state set to RECEIVING below
+ unsafe { channel.write_waker(ReceiverWaker::current_thread()) };
+
+ // ORDERING: we use release ordering on success so the sender can synchronize with
+ // our write of the waker. We use relaxed ordering on failure since the sender does
+ // not need to synchronize with our write and the individual match arms handle any
+ // additional synchronization
+ match channel
+ .state
+ .compare_exchange(EMPTY, RECEIVING, Release, Relaxed)
+ {
+ // We stored our waker, now we delegate to the callback to finish the receive
+ // operation
+ Ok(_) => finish(channel),
+ // The sender sent the message while we prepared to finish
+ Err(MESSAGE) => {
+ // See comments in `recv` for ordering and safety
+
+ fence(Acquire);
+
+ unsafe { channel.drop_waker() };
+
+ // ORDERING: the sender has been `mem::forget`-ed so this update only
+ // needs to be visible to us
+ channel.state.store(DISCONNECTED, Relaxed);
+
+ // SAFETY: The MESSAGE state tells us there is a correctly initialized
+ // message
+ Ok(unsafe { channel.take_message() })
+ }
+ // The sender was dropped before sending anything while we prepared to park.
+ Err(DISCONNECTED) => {
+ // See comments in `recv` for safety
+ unsafe { channel.drop_waker() };
+ Err(disconnected_error)
+ }
+ _ => unreachable!(),
+ }
+ }
+ // The sender sent the message. We take the message and mark the channel disconnected.
+ MESSAGE => {
+ // ORDERING: the sender has been `mem::forget`-ed so this update only needs to be
+ // visible to us
+ channel.state.store(DISCONNECTED, Relaxed);
+
+ // SAFETY: we are in the message state so the message is valid
+ Ok(unsafe { channel.take_message() })
+ }
+ // The sender was dropped before sending anything, or we already received the message.
+ DISCONNECTED => Err(disconnected_error),
+ // The receiver must have been `Future::poll`ed prior to this call.
+ #[cfg(feature = "async")]
+ RECEIVING | UNPARKING => panic!("{}", RECEIVER_USED_SYNC_AND_ASYNC_ERROR),
+ _ => unreachable!(),
+ }
+ }
+
+ /// Consumes the Receiver, returning a raw pointer to the channel on the heap.
+ ///
+ /// This is intended to simplify using oneshot channels with some FFI code. The only safe thing
+ /// to do with the returned pointer is to later reconstruct the Receiver with
+ /// [Receiver::from_raw]. Memory will leak if the Receiver is never reconstructed.
+ pub fn into_raw(self) -> *mut () {
+ let raw = self.channel_ptr.as_ptr() as *mut ();
+ mem::forget(self);
+ raw
+ }
+
+ /// Consumes a raw pointer from [Receiver::into_raw], recreating the Receiver.
+ ///
+ /// # Safety
+ ///
+ /// This pointer must have come from [`Receiver<T>::into_raw`] with the same message type, `T`.
+ /// At most one Receiver must exist for a channel at any point in time.
+ /// Constructing multiple Receivers from the same raw pointer leads to undefined behavior.
+ pub unsafe fn from_raw(raw: *mut ()) -> Self {
+ Self {
+ channel_ptr: NonNull::new_unchecked(raw as *mut Channel<T>),
+ }
+ }
+}
+
+#[cfg(feature = "async")]
+impl<T> core::future::Future for Receiver<T> {
+ type Output = Result<T, RecvError>;
+
+ fn poll(self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
+ // SAFETY: the existence of the `self` parameter serves as a certificate that the receiver
+ // is still alive, meaning that even if the sender was dropped then it would have observed
+ // the fact that we're still alive and left the responsibility of deallocating the
+ // channel to us, so `self.channel` is valid
+ let channel = unsafe { self.channel_ptr.as_ref() };
+
+ // ORDERING: we use acquire ordering to synchronize with the store of the message.
+ match channel.state.load(Acquire) {
+ // The sender is alive but has not sent anything yet.
+ EMPTY => {
+ // SAFETY: We can't be in the forbidden states, and no waker in the channel.
+ unsafe { channel.write_async_waker(cx) }
+ }
+ // We were polled again while waiting for the sender. Replace the waker with the new one.
+ RECEIVING => {
+ // ORDERING: We use relaxed ordering on both success and failure since we have not
+ // written anything above that must be released, and the individual match arms
+ // handle any additional synchronization.
+ match channel
+ .state
+ .compare_exchange(RECEIVING, EMPTY, Relaxed, Relaxed)
+ {
+ // We successfully changed the state back to EMPTY. Replace the waker.
+ // This is the most likely branch to be taken, which is why we don't use any
+ // memory barriers in the compare_exchange above.
+ Ok(_) => {
+ // SAFETY: We wrote the waker in a previous call to poll. We do not need
+ // a memory barrier since the previous write here was by ourselves.
+ unsafe { channel.drop_waker() };
+ // SAFETY: We can't be in the forbidden states, and no waker in the channel.
+ unsafe { channel.write_async_waker(cx) }
+ }
+ // The sender sent the message while we prepared to replace the waker.
+ // We take the message and mark the channel disconnected.
+ // The sender has already taken the waker.
+ Err(MESSAGE) => {
+ // ORDERING: Synchronize with the write of the message. This branch is
+ // unlikely to be taken.
+ channel.state.swap(DISCONNECTED, Acquire);
+ // SAFETY: The state tells us the sender has initialized the message.
+ Poll::Ready(Ok(unsafe { channel.take_message() }))
+ }
+ // The sender was dropped before sending anything while we prepared to park.
+ // The sender has taken the waker already.
+ Err(DISCONNECTED) => Poll::Ready(Err(RecvError)),
+ // The sender is currently waking us up.
+ Err(UNPARKING) => {
+ // We can't trust that the old waker that the sender has access to
+ // is honored by the async runtime at this point. So we wake ourselves
+ // up to get polled instantly again.
+ cx.waker().wake_by_ref();
+ Poll::Pending
+ }
+ _ => unreachable!(),
+ }
+ }
+ // The sender sent the message.
+ MESSAGE => {
+ // ORDERING: the sender has been dropped so this update only needs to be
+ // visible to us
+ channel.state.store(DISCONNECTED, Relaxed);
+ Poll::Ready(Ok(unsafe { channel.take_message() }))
+ }
+ // The sender was dropped before sending anything, or we already received the message.
+ DISCONNECTED => Poll::Ready(Err(RecvError)),
+ // The sender has observed the RECEIVING state and is currently reading the waker from
+ // a previous poll. We need to loop here until we observe the MESSAGE or DISCONNECTED
+ // state. We busy loop here since we know the sender is done very soon.
+ UNPARKING => loop {
+ hint::spin_loop();
+ // ORDERING: The load above has already synchronized with the write of the message.
+ match channel.state.load(Relaxed) {
+ MESSAGE => {
+ // ORDERING: the sender has been dropped, so this update only
+ // needs to be visible to us
+ channel.state.store(DISCONNECTED, Relaxed);
+ // SAFETY: We observed the MESSAGE state
+ break Poll::Ready(Ok(unsafe { channel.take_message() }));
+ }
+ DISCONNECTED => break Poll::Ready(Err(RecvError)),
+ UNPARKING => (),
+ _ => unreachable!(),
+ }
+ },
+ _ => unreachable!(),
+ }
+ }
+}
+
+impl<T> Drop for Receiver<T> {
+ fn drop(&mut self) {
+ // SAFETY: since the receiving side is still alive the sender would have observed that and
+ // left deallocating the channel allocation to us.
+ let channel = unsafe { self.channel_ptr.as_ref() };
+
+ // Set the channel state to disconnected and read what state the receiver was in
+ match channel.state.swap(DISCONNECTED, Acquire) {
+ // The sender has not sent anything, nor is it dropped.
+ EMPTY => (),
+ // The sender already sent something. We must drop it, and free the channel.
+ MESSAGE => {
+ // SAFETY: we are in the message state so the message is initialized
+ unsafe { channel.drop_message() };
+
+ // SAFETY: see safety comment at top of function
+ unsafe { dealloc(self.channel_ptr) };
+ }
+ // The receiver has been polled.
+ #[cfg(feature = "async")]
+ RECEIVING => {
+ // TODO: figure this out when async is fixed
+ unsafe { channel.drop_waker() };
+ }
+ // The sender was already dropped. We are responsible for freeing the channel.
+ DISCONNECTED => {
+ // SAFETY: see safety comment at top of function
+ unsafe { dealloc(self.channel_ptr) };
+ }
+ // This receiver was previously polled, so the channel was in the RECEIVING state.
+ // But the sender has observed the RECEIVING state and is currently reading the waker
+ // to wake us up. We need to loop here until we observe the MESSAGE or DISCONNECTED state.
+ // We busy loop here since we know the sender is done very soon.
+ #[cfg(any(feature = "std", feature = "async"))]
+ UNPARKING => {
+ loop {
+ hint::spin_loop();
+ // ORDERING: The swap above has already synchronized with the write of the message.
+ match channel.state.load(Relaxed) {
+ MESSAGE => {
+ // SAFETY: we are in the message state so the message is initialized
+ unsafe { channel.drop_message() };
+ break;
+ }
+ DISCONNECTED => break,
+ UNPARKING => (),
+ _ => unreachable!(),
+ }
+ }
+ // SAFETY: see safety comment at top of function
+ unsafe { dealloc(self.channel_ptr) };
+ }
+ _ => unreachable!(),
+ }
+ }
+}
+
+/// All the values that the `Channel::state` field can have during the lifetime of a channel.
+mod states {
+ // These values are very explicitly chosen so that we can replace some cmpxchg calls with
+ // fetch_* calls.
+
+ /// The initial channel state. Active while both endpoints are still alive, no message has been
+ /// sent, and the receiver is not receiving.
+ pub const EMPTY: u8 = 0b011;
+ /// A message has been sent to the channel, but the receiver has not yet read it.
+ pub const MESSAGE: u8 = 0b100;
+ /// No message has yet been sent on the channel, but the receiver is currently receiving.
+ pub const RECEIVING: u8 = 0b000;
+ #[cfg(any(feature = "std", feature = "async"))]
+ pub const UNPARKING: u8 = 0b001;
+ /// The channel has been closed. This means that either the sender or receiver has been dropped,
+ /// or the message sent to the channel has already been received. Since this is a oneshot
+ /// channel, it is disconnected after the one message it is supposed to hold has been
+ /// transmitted.
+ pub const DISCONNECTED: u8 = 0b010;
+}
+use states::*;
+
+/// Internal channel data structure structure. the `channel` method allocates and puts one instance
+/// of this struct on the heap for each oneshot channel instance. The struct holds:
+/// * The current state of the channel.
+/// * The message in the channel. This memory is uninitialized until the message is sent.
+/// * The waker instance for the thread or task that is currently receiving on this channel.
+/// This memory is uninitialized until the receiver starts receiving.
+struct Channel<T> {
+ state: AtomicU8,
+ message: UnsafeCell<MaybeUninit<T>>,
+ waker: UnsafeCell<MaybeUninit<ReceiverWaker>>,
+}
+
+impl<T> Channel<T> {
+ pub fn new() -> Self {
+ Self {
+ state: AtomicU8::new(EMPTY),
+ message: UnsafeCell::new(MaybeUninit::uninit()),
+ waker: UnsafeCell::new(MaybeUninit::uninit()),
+ }
+ }
+
+ #[inline(always)]
+ unsafe fn message(&self) -> &MaybeUninit<T> {
+ #[cfg(oneshot_loom)]
+ {
+ self.message.with(|ptr| &*ptr)
+ }
+
+ #[cfg(not(oneshot_loom))]
+ {
+ &*self.message.get()
+ }
+ }
+
+ #[inline(always)]
+ unsafe fn with_message_mut<F>(&self, op: F)
+ where
+ F: FnOnce(&mut MaybeUninit<T>),
+ {
+ #[cfg(oneshot_loom)]
+ {
+ self.message.with_mut(|ptr| op(&mut *ptr))
+ }
+
+ #[cfg(not(oneshot_loom))]
+ {
+ op(&mut *self.message.get())
+ }
+ }
+
+ #[inline(always)]
+ #[cfg(any(feature = "std", feature = "async"))]
+ unsafe fn with_waker_mut<F>(&self, op: F)
+ where
+ F: FnOnce(&mut MaybeUninit<ReceiverWaker>),
+ {
+ #[cfg(oneshot_loom)]
+ {
+ self.waker.with_mut(|ptr| op(&mut *ptr))
+ }
+
+ #[cfg(not(oneshot_loom))]
+ {
+ op(&mut *self.waker.get())
+ }
+ }
+
+ #[inline(always)]
+ unsafe fn write_message(&self, message: T) {
+ self.with_message_mut(|slot| slot.as_mut_ptr().write(message));
+ }
+
+ #[inline(always)]
+ unsafe fn take_message(&self) -> T {
+ #[cfg(oneshot_loom)]
+ {
+ self.message.with(|ptr| ptr::read(ptr)).assume_init()
+ }
+
+ #[cfg(not(oneshot_loom))]
+ {
+ ptr::read(self.message.get()).assume_init()
+ }
+ }
+
+ #[inline(always)]
+ unsafe fn drop_message(&self) {
+ self.with_message_mut(|slot| slot.assume_init_drop());
+ }
+
+ #[cfg(any(feature = "std", feature = "async"))]
+ #[inline(always)]
+ unsafe fn write_waker(&self, waker: ReceiverWaker) {
+ self.with_waker_mut(|slot| slot.as_mut_ptr().write(waker));
+ }
+
+ #[inline(always)]
+ unsafe fn take_waker(&self) -> ReceiverWaker {
+ #[cfg(oneshot_loom)]
+ {
+ self.waker.with(|ptr| ptr::read(ptr)).assume_init()
+ }
+
+ #[cfg(not(oneshot_loom))]
+ {
+ ptr::read(self.waker.get()).assume_init()
+ }
+ }
+
+ #[cfg(any(feature = "std", feature = "async"))]
+ #[inline(always)]
+ unsafe fn drop_waker(&self) {
+ self.with_waker_mut(|slot| slot.assume_init_drop());
+ }
+
+ /// # Safety
+ ///
+ /// * `Channel::waker` must not have a waker stored in it when calling this method.
+ /// * Channel state must not be RECEIVING or UNPARKING when calling this method.
+ #[cfg(feature = "async")]
+ unsafe fn write_async_waker(&self, cx: &mut task::Context<'_>) -> Poll<Result<T, RecvError>> {
+ // Write our thread instance to the channel.
+ // SAFETY: we are not yet in the RECEIVING state, meaning that the sender will not
+ // try to access the waker until it sees the state set to RECEIVING below
+ self.write_waker(ReceiverWaker::task_waker(cx));
+
+ // ORDERING: we use release ordering on success so the sender can synchronize with
+ // our write of the waker. We use relaxed ordering on failure since the sender does
+ // not need to synchronize with our write and the individual match arms handle any
+ // additional synchronization
+ match self
+ .state
+ .compare_exchange(EMPTY, RECEIVING, Release, Relaxed)
+ {
+ // We stored our waker, now we return and let the sender wake us up
+ Ok(_) => Poll::Pending,
+ // The sender sent the message while we prepared to park.
+ // We take the message and mark the channel disconnected.
+ Err(MESSAGE) => {
+ // ORDERING: Synchronize with the write of the message. This branch is
+ // unlikely to be taken, so it's likely more efficient to use a fence here
+ // instead of AcqRel ordering on the compare_exchange operation
+ fence(Acquire);
+
+ // SAFETY: we started in the EMPTY state and the sender switched us to the
+ // MESSAGE state. This means that it did not take the waker, so we're
+ // responsible for dropping it.
+ self.drop_waker();
+
+ // ORDERING: sender does not exist, so this update only needs to be visible to us
+ self.state.store(DISCONNECTED, Relaxed);
+
+ // SAFETY: The MESSAGE state tells us there is a correctly initialized message
+ Poll::Ready(Ok(self.take_message()))
+ }
+ // The sender was dropped before sending anything while we prepared to park.
+ Err(DISCONNECTED) => {
+ // SAFETY: we started in the EMPTY state and the sender switched us to the
+ // DISCONNECTED state. This means that it did not take the waker, so we're
+ // responsible for dropping it.
+ self.drop_waker();
+ Poll::Ready(Err(RecvError))
+ }
+ _ => unreachable!(),
+ }
+ }
+}
+
+enum ReceiverWaker {
+ /// The receiver is waiting synchronously. Its thread is parked.
+ #[cfg(feature = "std")]
+ Thread(thread::Thread),
+ /// The receiver is waiting asynchronously. Its task can be woken up with this `Waker`.
+ #[cfg(feature = "async")]
+ Task(task::Waker),
+ /// A little hack to not make this enum an uninhibitable type when no features are enabled.
+ #[cfg(not(any(feature = "async", feature = "std")))]
+ _Uninhabited,
+}
+
+impl ReceiverWaker {
+ #[cfg(feature = "std")]
+ pub fn current_thread() -> Self {
+ Self::Thread(thread::current())
+ }
+
+ #[cfg(feature = "async")]
+ pub fn task_waker(cx: &task::Context<'_>) -> Self {
+ Self::Task(cx.waker().clone())
+ }
+
+ pub fn unpark(self) {
+ match self {
+ #[cfg(feature = "std")]
+ ReceiverWaker::Thread(thread) => thread.unpark(),
+ #[cfg(feature = "async")]
+ ReceiverWaker::Task(waker) => waker.wake(),
+ #[cfg(not(any(feature = "async", feature = "std")))]
+ ReceiverWaker::_Uninhabited => unreachable!(),
+ }
+ }
+}
+
+#[cfg(not(oneshot_loom))]
+#[test]
+#[ignore = "Unstable test. Different Rust versions have different sizes for Thread"]
+fn receiver_waker_size() {
+ let expected: usize = match (cfg!(feature = "std"), cfg!(feature = "async")) {
+ (false, false) => 0,
+ (false, true) => 16,
+ (true, false) => 16,
+ (true, true) => 24,
+ };
+ assert_eq!(mem::size_of::<ReceiverWaker>(), expected);
+}
+
+#[cfg(all(feature = "std", feature = "async"))]
+const RECEIVER_USED_SYNC_AND_ASYNC_ERROR: &str =
+ "Invalid to call a blocking receive method on oneshot::Receiver after it has been polled";
+
+#[inline]
+pub(crate) unsafe fn dealloc<T>(channel: NonNull<Channel<T>>) {
+ drop(Box::from_raw(channel.as_ptr()))
+}
diff --git a/third_party/rust/oneshot/src/loombox.rs b/third_party/rust/oneshot/src/loombox.rs
@@ -0,0 +1,158 @@
+use core::{borrow, fmt, hash, mem, ptr};
+use loom::alloc;
+
+pub struct Box<T: ?Sized> {
+ ptr: *mut T,
+}
+
+impl<T> Box<T> {
+ pub fn new(value: T) -> Self {
+ let layout = alloc::Layout::new::<T>();
+ let ptr = unsafe { alloc::alloc(layout) } as *mut T;
+ unsafe { ptr::write(ptr, value) };
+ Self { ptr }
+ }
+}
+
+impl<T: ?Sized> Box<T> {
+ pub fn leak<'a>(b: Self) -> &'a mut T
+ where
+ T: 'a,
+ {
+ unsafe { &mut *Box::into_raw(b) }
+ }
+
+ #[inline]
+ pub fn into_raw(b: Box<T>) -> *mut T {
+ let ptr = b.ptr;
+ mem::forget(b);
+ ptr
+ }
+
+ pub const unsafe fn from_raw(ptr: *mut T) -> Box<T> {
+ Self { ptr }
+ }
+}
+
+impl<T: ?Sized> Drop for Box<T> {
+ fn drop(&mut self) {
+ unsafe {
+ let size = mem::size_of_val(&*self.ptr);
+ let align = mem::align_of_val(&*self.ptr);
+ let layout = alloc::Layout::from_size_align(size, align).unwrap();
+ ptr::drop_in_place(self.ptr);
+ alloc::dealloc(self.ptr as *mut u8, layout);
+ }
+ }
+}
+
+unsafe impl<T: Send> Send for Box<T> {}
+unsafe impl<T: Sync> Sync for Box<T> {}
+
+impl<T: ?Sized> core::ops::Deref for Box<T> {
+ type Target = T;
+
+ fn deref(&self) -> &T {
+ unsafe { &*self.ptr }
+ }
+}
+
+impl<T: ?Sized> core::ops::DerefMut for Box<T> {
+ fn deref_mut(&mut self) -> &mut T {
+ unsafe { &mut *self.ptr }
+ }
+}
+
+impl<T: ?Sized> borrow::Borrow<T> for Box<T> {
+ fn borrow(&self) -> &T {
+ self
+ }
+}
+
+impl<T: ?Sized> borrow::BorrowMut<T> for Box<T> {
+ fn borrow_mut(&mut self) -> &mut T {
+ self
+ }
+}
+
+impl<T: ?Sized> AsRef<T> for Box<T> {
+ fn as_ref(&self) -> &T {
+ self
+ }
+}
+
+impl<T: ?Sized> AsMut<T> for Box<T> {
+ fn as_mut(&mut self) -> &mut T {
+ self
+ }
+}
+
+impl<T: fmt::Display + ?Sized> fmt::Display for Box<T> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ fmt::Display::fmt(&**self, f)
+ }
+}
+
+impl<T: fmt::Debug + ?Sized> fmt::Debug for Box<T> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ fmt::Debug::fmt(&**self, f)
+ }
+}
+
+impl<T: Clone> Clone for Box<T> {
+ #[inline]
+ fn clone(&self) -> Box<T> {
+ Self::new(self.as_ref().clone())
+ }
+}
+
+impl<T: ?Sized + PartialEq> PartialEq for Box<T> {
+ #[inline]
+ fn eq(&self, other: &Box<T>) -> bool {
+ PartialEq::eq(&**self, &**other)
+ }
+
+ #[allow(clippy::partialeq_ne_impl)]
+ #[inline]
+ fn ne(&self, other: &Box<T>) -> bool {
+ PartialEq::ne(&**self, &**other)
+ }
+}
+
+impl<T: ?Sized + Eq> Eq for Box<T> {}
+
+impl<T: ?Sized + PartialOrd> PartialOrd for Box<T> {
+ #[inline]
+ fn partial_cmp(&self, other: &Box<T>) -> Option<core::cmp::Ordering> {
+ PartialOrd::partial_cmp(&**self, &**other)
+ }
+ #[inline]
+ fn lt(&self, other: &Box<T>) -> bool {
+ PartialOrd::lt(&**self, &**other)
+ }
+ #[inline]
+ fn le(&self, other: &Box<T>) -> bool {
+ PartialOrd::le(&**self, &**other)
+ }
+ #[inline]
+ fn ge(&self, other: &Box<T>) -> bool {
+ PartialOrd::ge(&**self, &**other)
+ }
+ #[inline]
+ fn gt(&self, other: &Box<T>) -> bool {
+ PartialOrd::gt(&**self, &**other)
+ }
+}
+
+impl<T: ?Sized + Ord> Ord for Box<T> {
+ #[inline]
+ fn cmp(&self, other: &Box<T>) -> core::cmp::Ordering {
+ Ord::cmp(&**self, &**other)
+ }
+}
+
+impl<T: ?Sized + hash::Hash> hash::Hash for Box<T> {
+ fn hash<H: hash::Hasher>(&self, state: &mut H) {
+ (**self).hash(state);
+ }
+}
diff --git a/third_party/rust/oneshot/tests/assert_mem.rs b/third_party/rust/oneshot/tests/assert_mem.rs
@@ -0,0 +1,37 @@
+use oneshot::{Receiver, Sender};
+use std::mem;
+
+/// Just sanity check that both channel endpoints stay the size of a single pointer.
+#[test]
+fn channel_endpoints_single_pointer() {
+ const PTR_SIZE: usize = mem::size_of::<*const ()>();
+
+ assert_eq!(mem::size_of::<Sender<()>>(), PTR_SIZE);
+ assert_eq!(mem::size_of::<Receiver<()>>(), PTR_SIZE);
+
+ assert_eq!(mem::size_of::<Sender<u8>>(), PTR_SIZE);
+ assert_eq!(mem::size_of::<Receiver<u8>>(), PTR_SIZE);
+
+ assert_eq!(mem::size_of::<Sender<[u8; 1024]>>(), PTR_SIZE);
+ assert_eq!(mem::size_of::<Receiver<[u8; 1024]>>(), PTR_SIZE);
+
+ assert_eq!(mem::size_of::<Option<Sender<[u8; 1024]>>>(), PTR_SIZE);
+ assert_eq!(mem::size_of::<Option<Receiver<[u8; 1024]>>>(), PTR_SIZE);
+}
+
+/// Check that the `SendError` stays small. Useful to automatically detect if it is refactored
+/// to become large. We do not want the stack requirement for calling `Sender::send` to grow.
+#[test]
+fn error_sizes() {
+ const PTR_SIZE: usize = mem::size_of::<usize>();
+
+ assert_eq!(mem::size_of::<oneshot::SendError<()>>(), PTR_SIZE);
+ assert_eq!(mem::size_of::<oneshot::SendError<u8>>(), PTR_SIZE);
+ assert_eq!(mem::size_of::<oneshot::SendError<[u8; 1024]>>(), PTR_SIZE);
+
+ // The type returned from `Sender::send` is also just pointer sized
+ assert_eq!(
+ mem::size_of::<Result<(), oneshot::SendError<[u8; 1024]>>>(),
+ PTR_SIZE
+ );
+}
diff --git a/third_party/rust/oneshot/tests/async.rs b/third_party/rust/oneshot/tests/async.rs
@@ -0,0 +1,128 @@
+#![cfg(all(feature = "async", not(oneshot_loom)))]
+
+use core::mem;
+use core::time::Duration;
+
+mod helpers;
+use helpers::DropCounter;
+
+#[tokio::test]
+async fn send_before_await_tokio() {
+ let (sender, receiver) = oneshot::channel();
+ assert!(sender.send(19i128).is_ok());
+ assert_eq!(receiver.await, Ok(19i128));
+}
+
+#[async_std::test]
+async fn send_before_await_async_std() {
+ let (sender, receiver) = oneshot::channel();
+ assert!(sender.send(19i128).is_ok());
+ assert_eq!(receiver.await, Ok(19i128));
+}
+
+#[tokio::test]
+async fn await_with_dropped_sender_tokio() {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ mem::drop(sender);
+ receiver.await.unwrap_err();
+}
+
+#[async_std::test]
+async fn await_with_dropped_sender_async_std() {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ mem::drop(sender);
+ receiver.await.unwrap_err();
+}
+
+#[tokio::test]
+async fn await_before_send_tokio() {
+ let (sender, receiver) = oneshot::channel();
+ let (message, counter) = DropCounter::new(79u128);
+ let t = tokio::spawn(async move {
+ tokio::time::sleep(Duration::from_millis(10)).await;
+ sender.send(message)
+ });
+ let returned_message = receiver.await.unwrap();
+ assert_eq!(counter.count(), 0);
+ assert_eq!(*returned_message.value(), 79u128);
+ mem::drop(returned_message);
+ assert_eq!(counter.count(), 1);
+ t.await.unwrap().unwrap();
+}
+
+#[async_std::test]
+async fn await_before_send_async_std() {
+ let (sender, receiver) = oneshot::channel();
+ let (message, counter) = DropCounter::new(79u128);
+ let t = async_std::task::spawn(async move {
+ async_std::task::sleep(Duration::from_millis(10)).await;
+ sender.send(message)
+ });
+ let returned_message = receiver.await.unwrap();
+ assert_eq!(counter.count(), 0);
+ assert_eq!(*returned_message.value(), 79u128);
+ mem::drop(returned_message);
+ assert_eq!(counter.count(), 1);
+ t.await.unwrap();
+}
+
+#[tokio::test]
+async fn await_before_send_then_drop_sender_tokio() {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ let t = tokio::spawn(async {
+ tokio::time::sleep(Duration::from_millis(10)).await;
+ mem::drop(sender);
+ });
+ assert!(receiver.await.is_err());
+ t.await.unwrap();
+}
+
+#[async_std::test]
+async fn await_before_send_then_drop_sender_async_std() {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ let t = async_std::task::spawn(async {
+ async_std::task::sleep(Duration::from_millis(10)).await;
+ mem::drop(sender);
+ });
+ assert!(receiver.await.is_err());
+ t.await;
+}
+
+// Tests that the Receiver handles being used synchronously even after being polled
+#[tokio::test]
+async fn poll_future_and_then_try_recv() {
+ use core::future::Future;
+ use core::pin::Pin;
+ use core::task::{self, Poll};
+
+ struct StupidReceiverFuture(oneshot::Receiver<()>);
+
+ impl Future for StupidReceiverFuture {
+ type Output = Result<(), oneshot::RecvError>;
+
+ fn poll(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
+ let poll_result = Future::poll(Pin::new(&mut self.0), cx);
+ self.0.try_recv().expect_err("Should never be a message");
+ poll_result
+ }
+ }
+
+ let (sender, receiver) = oneshot::channel();
+ let t = tokio::spawn(async {
+ tokio::time::sleep(Duration::from_millis(20)).await;
+ mem::drop(sender);
+ });
+ StupidReceiverFuture(receiver).await.unwrap_err();
+ t.await.unwrap();
+}
+
+#[tokio::test]
+async fn poll_receiver_then_drop_it() {
+ let (sender, receiver) = oneshot::channel::<()>();
+ // This will poll the receiver and then give up after 100 ms.
+ tokio::time::timeout(Duration::from_millis(100), receiver)
+ .await
+ .unwrap_err();
+ // Make sure the receiver has been dropped by the runtime.
+ assert!(sender.send(()).is_err());
+}
diff --git a/third_party/rust/oneshot/tests/future.rs b/third_party/rust/oneshot/tests/future.rs
@@ -0,0 +1,65 @@
+#![cfg(feature = "async")]
+
+use core::{future, mem, pin, task};
+
+#[cfg(oneshot_loom)]
+pub use loom::sync::{Arc, Mutex};
+#[cfg(not(oneshot_loom))]
+pub use std::sync::{Arc, Mutex};
+
+mod helpers;
+use helpers::maybe_loom_model;
+
+#[test]
+fn multiple_receiver_polls_keeps_only_latest_waker() {
+ #[derive(Default)]
+ struct MockWaker {
+ cloned: usize,
+ dropped: usize,
+ }
+
+ fn clone_mock_waker(waker: *const ()) -> task::RawWaker {
+ let mock_waker = unsafe { Arc::from_raw(waker as *const Mutex<MockWaker>) };
+ mock_waker.lock().unwrap().cloned += 1;
+ let new_waker =
+ task::RawWaker::new(Arc::into_raw(mock_waker.clone()) as *const (), &VTABLE);
+ mem::forget(mock_waker);
+ new_waker
+ }
+
+ fn drop_mock_waker(waker: *const ()) {
+ let mock_waker = unsafe { Arc::from_raw(waker as *const Mutex<MockWaker>) };
+ mock_waker.lock().unwrap().dropped += 1;
+ }
+
+ const VTABLE: task::RawWakerVTable =
+ task::RawWakerVTable::new(clone_mock_waker, |_| (), |_| (), drop_mock_waker);
+
+ maybe_loom_model(|| {
+ let mock_waker1 = Arc::new(Mutex::new(MockWaker::default()));
+ let raw_waker1 =
+ task::RawWaker::new(Arc::into_raw(mock_waker1.clone()) as *const (), &VTABLE);
+ let waker1 = unsafe { task::Waker::from_raw(raw_waker1) };
+ let mut context1 = task::Context::from_waker(&waker1);
+
+ let (_sender, mut receiver) = oneshot::channel::<()>();
+
+ let poll_result = future::Future::poll(pin::Pin::new(&mut receiver), &mut context1);
+ assert_eq!(poll_result, task::Poll::Pending);
+ assert_eq!(mock_waker1.lock().unwrap().cloned, 1);
+ assert_eq!(mock_waker1.lock().unwrap().dropped, 0);
+
+ let mock_waker2 = Arc::new(Mutex::new(MockWaker::default()));
+ let raw_waker2 =
+ task::RawWaker::new(Arc::into_raw(mock_waker2.clone()) as *const (), &VTABLE);
+ let waker2 = unsafe { task::Waker::from_raw(raw_waker2) };
+ let mut context2 = task::Context::from_waker(&waker2);
+
+ let poll_result = future::Future::poll(pin::Pin::new(&mut receiver), &mut context2);
+ assert_eq!(poll_result, task::Poll::Pending);
+ assert_eq!(mock_waker2.lock().unwrap().cloned, 1);
+ assert_eq!(mock_waker2.lock().unwrap().dropped, 0);
+ assert_eq!(mock_waker1.lock().unwrap().cloned, 1);
+ assert_eq!(mock_waker1.lock().unwrap().dropped, 1);
+ });
+}
diff --git a/third_party/rust/oneshot/tests/helpers/mod.rs b/third_party/rust/oneshot/tests/helpers/mod.rs
@@ -0,0 +1,63 @@
+#![allow(dead_code)]
+
+extern crate alloc;
+
+#[cfg(not(oneshot_loom))]
+use alloc::sync::Arc;
+#[cfg(not(oneshot_loom))]
+use core::sync::atomic::{AtomicUsize, Ordering::SeqCst};
+#[cfg(oneshot_loom)]
+use loom::sync::{
+ atomic::{AtomicUsize, Ordering::SeqCst},
+ Arc,
+};
+
+#[cfg(oneshot_loom)]
+pub mod waker;
+
+pub fn maybe_loom_model(test: impl Fn() + Sync + Send + 'static) {
+ #[cfg(oneshot_loom)]
+ loom::model(test);
+ #[cfg(not(oneshot_loom))]
+ test();
+}
+
+pub struct DropCounter<T> {
+ drop_count: Arc<AtomicUsize>,
+ value: Option<T>,
+}
+
+pub struct DropCounterHandle(Arc<AtomicUsize>);
+
+impl<T> DropCounter<T> {
+ pub fn new(value: T) -> (Self, DropCounterHandle) {
+ let drop_count = Arc::new(AtomicUsize::new(0));
+ (
+ Self {
+ drop_count: drop_count.clone(),
+ value: Some(value),
+ },
+ DropCounterHandle(drop_count),
+ )
+ }
+
+ pub fn value(&self) -> &T {
+ self.value.as_ref().unwrap()
+ }
+
+ pub fn into_value(mut self) -> T {
+ self.value.take().unwrap()
+ }
+}
+
+impl DropCounterHandle {
+ pub fn count(&self) -> usize {
+ self.0.load(SeqCst)
+ }
+}
+
+impl<T> Drop for DropCounter<T> {
+ fn drop(&mut self) {
+ self.drop_count.fetch_add(1, SeqCst);
+ }
+}
diff --git a/third_party/rust/oneshot/tests/helpers/waker.rs b/third_party/rust/oneshot/tests/helpers/waker.rs
@@ -0,0 +1,64 @@
+//! Creates a Waker that can be observed from tests.
+
+use std::mem::forget;
+use std::sync::atomic::{AtomicU32, Ordering};
+use std::sync::Arc;
+use std::task::{RawWaker, RawWakerVTable, Waker};
+
+#[derive(Default)]
+pub struct WakerHandle {
+ clone_count: AtomicU32,
+ drop_count: AtomicU32,
+ wake_count: AtomicU32,
+}
+
+impl WakerHandle {
+ pub fn clone_count(&self) -> u32 {
+ self.clone_count.load(Ordering::Relaxed)
+ }
+
+ pub fn drop_count(&self) -> u32 {
+ self.drop_count.load(Ordering::Relaxed)
+ }
+
+ pub fn wake_count(&self) -> u32 {
+ self.wake_count.load(Ordering::Relaxed)
+ }
+}
+
+pub fn waker() -> (Waker, Arc<WakerHandle>) {
+ let waker_handle = Arc::new(WakerHandle::default());
+ let waker_handle_ptr = Arc::into_raw(waker_handle.clone());
+ let raw_waker = RawWaker::new(waker_handle_ptr as *const _, waker_vtable());
+ (unsafe { Waker::from_raw(raw_waker) }, waker_handle)
+}
+
+pub(super) fn waker_vtable() -> &'static RawWakerVTable {
+ &RawWakerVTable::new(clone_raw, wake_raw, wake_by_ref_raw, drop_raw)
+}
+
+unsafe fn clone_raw(data: *const ()) -> RawWaker {
+ let handle: Arc<WakerHandle> = Arc::from_raw(data as *const _);
+ handle.clone_count.fetch_add(1, Ordering::Relaxed);
+ forget(handle.clone());
+ forget(handle);
+ RawWaker::new(data, waker_vtable())
+}
+
+unsafe fn wake_raw(data: *const ()) {
+ let handle: Arc<WakerHandle> = Arc::from_raw(data as *const _);
+ handle.wake_count.fetch_add(1, Ordering::Relaxed);
+ handle.drop_count.fetch_add(1, Ordering::Relaxed);
+}
+
+unsafe fn wake_by_ref_raw(data: *const ()) {
+ let handle: Arc<WakerHandle> = Arc::from_raw(data as *const _);
+ handle.wake_count.fetch_add(1, Ordering::Relaxed);
+ forget(handle)
+}
+
+unsafe fn drop_raw(data: *const ()) {
+ let handle: Arc<WakerHandle> = Arc::from_raw(data as *const _);
+ handle.drop_count.fetch_add(1, Ordering::Relaxed);
+ drop(handle)
+}
diff --git a/third_party/rust/oneshot/tests/loom.rs b/third_party/rust/oneshot/tests/loom.rs
@@ -0,0 +1,249 @@
+#![cfg(oneshot_loom)]
+
+use oneshot::TryRecvError;
+
+use loom::hint;
+use loom::thread;
+#[cfg(feature = "async")]
+use std::future::Future;
+#[cfg(feature = "async")]
+use std::pin::Pin;
+#[cfg(feature = "async")]
+use std::task::{self, Poll};
+#[cfg(feature = "std")]
+use std::time::Duration;
+
+mod helpers;
+
+#[test]
+fn try_recv() {
+ loom::model(|| {
+ let (sender, receiver) = oneshot::channel::<u128>();
+
+ let t = thread::spawn(move || loop {
+ match receiver.try_recv() {
+ Ok(msg) => break msg,
+ Err(TryRecvError::Empty) => hint::spin_loop(),
+ Err(TryRecvError::Disconnected) => panic!("Should not be disconnected"),
+ }
+ });
+
+ assert!(sender.send(19).is_ok());
+ assert_eq!(t.join().unwrap(), 19);
+ })
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn send_recv_different_threads() {
+ loom::model(|| {
+ let (sender, receiver) = oneshot::channel();
+ let t2 = thread::spawn(move || {
+ assert_eq!(receiver.recv_timeout(Duration::from_millis(1)), Ok(9));
+ });
+ let t1 = thread::spawn(move || {
+ sender.send(9u128).unwrap();
+ });
+ t1.join().unwrap();
+ t2.join().unwrap();
+ })
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn recv_drop_sender_different_threads() {
+ loom::model(|| {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ let t2 = thread::spawn(move || {
+ assert!(receiver.recv_timeout(Duration::from_millis(0)).is_err());
+ });
+ let t1 = thread::spawn(move || {
+ drop(sender);
+ });
+ t1.join().unwrap();
+ t2.join().unwrap();
+ })
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn async_recv() {
+ loom::model(|| {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ let t1 = thread::spawn(move || {
+ sender.send(987).unwrap();
+ });
+ assert_eq!(loom::future::block_on(receiver), Ok(987));
+ t1.join().unwrap();
+ })
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn send_then_poll() {
+ loom::model(|| {
+ let (sender, mut receiver) = oneshot::channel::<u128>();
+ sender.send(1234).unwrap();
+
+ let (waker, waker_handle) = helpers::waker::waker();
+ let mut context = task::Context::from_waker(&waker);
+
+ assert_eq!(
+ Pin::new(&mut receiver).poll(&mut context),
+ Poll::Ready(Ok(1234))
+ );
+ assert_eq!(waker_handle.clone_count(), 0);
+ assert_eq!(waker_handle.drop_count(), 0);
+ assert_eq!(waker_handle.wake_count(), 0);
+ })
+}
+
+// Make sure the receiver can be dropped while a send is happening in parallel
+#[cfg(feature = "async")]
+#[test]
+fn poll_then_drop_receiver_during_send() {
+ loom::model(|| {
+ let (sender, mut receiver) = oneshot::channel::<u128>();
+
+ let (waker, _waker_handle) = helpers::waker::waker();
+ let mut context = task::Context::from_waker(&waker);
+
+ // Put the channel into the receiving state
+ assert_eq!(Pin::new(&mut receiver).poll(&mut context), Poll::Pending);
+
+ // Spawn a separate thread that sends in parallel
+ let t = thread::spawn(move || {
+ let _ = sender.send(1234);
+ });
+
+ // Drop the receiver. Loom will make sure all thread interleavings with the send are tested
+ drop(receiver);
+
+ // The send operation should also not have panicked
+ t.join().unwrap();
+ })
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn poll_then_send() {
+ loom::model(|| {
+ let (sender, mut receiver) = oneshot::channel::<u128>();
+
+ let (waker, waker_handle) = helpers::waker::waker();
+ let mut context = task::Context::from_waker(&waker);
+
+ assert_eq!(Pin::new(&mut receiver).poll(&mut context), Poll::Pending);
+ assert_eq!(waker_handle.clone_count(), 1);
+ assert_eq!(waker_handle.drop_count(), 0);
+ assert_eq!(waker_handle.wake_count(), 0);
+
+ sender.send(1234).unwrap();
+ assert_eq!(waker_handle.clone_count(), 1);
+ assert_eq!(waker_handle.drop_count(), 1);
+ assert_eq!(waker_handle.wake_count(), 1);
+
+ assert_eq!(
+ Pin::new(&mut receiver).poll(&mut context),
+ Poll::Ready(Ok(1234))
+ );
+ assert_eq!(waker_handle.clone_count(), 1);
+ assert_eq!(waker_handle.drop_count(), 1);
+ assert_eq!(waker_handle.wake_count(), 1);
+ })
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn poll_with_different_wakers() {
+ loom::model(|| {
+ let (sender, mut receiver) = oneshot::channel::<u128>();
+
+ let (waker1, waker_handle1) = helpers::waker::waker();
+ let mut context1 = task::Context::from_waker(&waker1);
+
+ assert_eq!(Pin::new(&mut receiver).poll(&mut context1), Poll::Pending);
+ assert_eq!(waker_handle1.clone_count(), 1);
+ assert_eq!(waker_handle1.drop_count(), 0);
+ assert_eq!(waker_handle1.wake_count(), 0);
+
+ let (waker2, waker_handle2) = helpers::waker::waker();
+ let mut context2 = task::Context::from_waker(&waker2);
+
+ assert_eq!(Pin::new(&mut receiver).poll(&mut context2), Poll::Pending);
+ assert_eq!(waker_handle1.clone_count(), 1);
+ assert_eq!(waker_handle1.drop_count(), 1);
+ assert_eq!(waker_handle1.wake_count(), 0);
+
+ assert_eq!(waker_handle2.clone_count(), 1);
+ assert_eq!(waker_handle2.drop_count(), 0);
+ assert_eq!(waker_handle2.wake_count(), 0);
+
+ // Sending should cause the waker from the latest poll to be woken up
+ sender.send(1234).unwrap();
+ assert_eq!(waker_handle1.clone_count(), 1);
+ assert_eq!(waker_handle1.drop_count(), 1);
+ assert_eq!(waker_handle1.wake_count(), 0);
+
+ assert_eq!(waker_handle2.clone_count(), 1);
+ assert_eq!(waker_handle2.drop_count(), 1);
+ assert_eq!(waker_handle2.wake_count(), 1);
+ })
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn poll_then_try_recv() {
+ loom::model(|| {
+ let (_sender, mut receiver) = oneshot::channel::<u128>();
+
+ let (waker, waker_handle) = helpers::waker::waker();
+ let mut context = task::Context::from_waker(&waker);
+
+ assert_eq!(Pin::new(&mut receiver).poll(&mut context), Poll::Pending);
+ assert_eq!(waker_handle.clone_count(), 1);
+ assert_eq!(waker_handle.drop_count(), 0);
+ assert_eq!(waker_handle.wake_count(), 0);
+
+ assert_eq!(receiver.try_recv(), Err(TryRecvError::Empty));
+
+ assert_eq!(Pin::new(&mut receiver).poll(&mut context), Poll::Pending);
+ assert_eq!(waker_handle.clone_count(), 2);
+ assert_eq!(waker_handle.drop_count(), 1);
+ assert_eq!(waker_handle.wake_count(), 0);
+ })
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn poll_then_try_recv_while_sending() {
+ loom::model(|| {
+ let (sender, mut receiver) = oneshot::channel::<u128>();
+
+ let (waker, waker_handle) = helpers::waker::waker();
+ let mut context = task::Context::from_waker(&waker);
+
+ assert_eq!(Pin::new(&mut receiver).poll(&mut context), Poll::Pending);
+ assert_eq!(waker_handle.clone_count(), 1);
+ assert_eq!(waker_handle.drop_count(), 0);
+ assert_eq!(waker_handle.wake_count(), 0);
+
+ let t = thread::spawn(move || {
+ sender.send(1234).unwrap();
+ });
+
+ let msg = loop {
+ match receiver.try_recv() {
+ Ok(msg) => break msg,
+ Err(TryRecvError::Empty) => hint::spin_loop(),
+ Err(TryRecvError::Disconnected) => panic!("Should not be disconnected"),
+ }
+ };
+ assert_eq!(msg, 1234);
+ assert_eq!(waker_handle.clone_count(), 1);
+ assert_eq!(waker_handle.drop_count(), 1);
+ assert_eq!(waker_handle.wake_count(), 1);
+
+ t.join().unwrap();
+ })
+}
diff --git a/third_party/rust/oneshot/tests/raw.rs b/third_party/rust/oneshot/tests/raw.rs
@@ -0,0 +1,46 @@
+#![cfg(not(oneshot_loom))]
+
+use oneshot::{channel, Receiver, Sender};
+
+#[test]
+fn test_raw_sender() {
+ let (sender, receiver) = channel::<u32>();
+ let raw = sender.into_raw();
+ let recreated = unsafe { Sender::<u32>::from_raw(raw) };
+ recreated
+ .send(100)
+ .unwrap_or_else(|e| panic!("error sending after into_raw/from_raw roundtrip: {e}"));
+ assert_eq!(receiver.try_recv(), Ok(100))
+}
+
+#[test]
+fn test_raw_receiver() {
+ let (sender, receiver) = channel::<u32>();
+ let raw = receiver.into_raw();
+ sender.send(100).unwrap();
+ let recreated = unsafe { Receiver::<u32>::from_raw(raw) };
+ assert_eq!(
+ recreated
+ .try_recv()
+ .unwrap_or_else(|e| panic!("error receiving after into_raw/from_raw roundtrip: {e}")),
+ 100
+ )
+}
+
+#[test]
+fn test_raw_sender_and_receiver() {
+ let (sender, receiver) = channel::<u32>();
+ let raw_receiver = receiver.into_raw();
+ let raw_sender = sender.into_raw();
+
+ let recreated_sender = unsafe { Sender::<u32>::from_raw(raw_sender) };
+ recreated_sender.send(100).unwrap();
+
+ let recreated_receiver = unsafe { Receiver::<u32>::from_raw(raw_receiver) };
+ assert_eq!(
+ recreated_receiver
+ .try_recv()
+ .unwrap_or_else(|e| panic!("error receiving after into_raw/from_raw roundtrip: {e}")),
+ 100
+ )
+}
diff --git a/third_party/rust/oneshot/tests/sync.rs b/third_party/rust/oneshot/tests/sync.rs
@@ -0,0 +1,369 @@
+use core::mem;
+use oneshot::TryRecvError;
+
+#[cfg(feature = "std")]
+use oneshot::{RecvError, RecvTimeoutError};
+#[cfg(feature = "std")]
+use std::time::{Duration, Instant};
+
+#[cfg(feature = "std")]
+mod thread {
+ #[cfg(oneshot_loom)]
+ pub use loom::thread::spawn;
+ #[cfg(not(oneshot_loom))]
+ pub use std::thread::{sleep, spawn};
+
+ #[cfg(oneshot_loom)]
+ pub fn sleep(_timeout: core::time::Duration) {
+ loom::thread::yield_now()
+ }
+}
+
+mod helpers;
+use helpers::{maybe_loom_model, DropCounter};
+
+#[test]
+fn send_before_try_recv() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel();
+ assert!(!receiver.has_message());
+ assert!(sender.send(19i128).is_ok());
+
+ assert!(receiver.has_message());
+ assert_eq!(receiver.try_recv(), Ok(19i128));
+ assert!(!receiver.has_message());
+ assert_eq!(receiver.try_recv(), Err(TryRecvError::Disconnected));
+ #[cfg(feature = "std")]
+ {
+ assert_eq!(receiver.recv_ref(), Err(RecvError));
+ assert!(receiver.recv_timeout(Duration::from_secs(1)).is_err());
+ }
+ })
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn send_before_recv() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel::<()>();
+ assert!(sender.send(()).is_ok());
+ assert_eq!(receiver.recv(), Ok(()));
+ });
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel::<u8>();
+ assert!(sender.send(19).is_ok());
+ assert_eq!(receiver.recv(), Ok(19));
+ });
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel::<u64>();
+ assert!(sender.send(21).is_ok());
+ assert_eq!(receiver.recv(), Ok(21));
+ });
+ // FIXME: This test does not work with loom. There is something that happens after the
+ // channel object becomes larger than ~500 bytes and that makes an atomic read from the state
+ // result in "signal: 10, SIGBUS: access to undefined memory"
+ #[cfg(not(oneshot_loom))]
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel::<[u8; 4096]>();
+ assert!(sender.send([0b10101010; 4096]).is_ok());
+ assert!(receiver.recv().unwrap()[..] == [0b10101010; 4096][..]);
+ });
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn send_before_recv_ref() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel();
+ assert!(sender.send(19i128).is_ok());
+
+ assert_eq!(receiver.recv_ref(), Ok(19i128));
+ assert_eq!(receiver.recv_ref(), Err(RecvError));
+ assert_eq!(receiver.try_recv(), Err(TryRecvError::Disconnected));
+ assert!(receiver.recv_timeout(Duration::from_secs(1)).is_err());
+ })
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn send_before_recv_timeout() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel();
+ assert!(sender.send(19i128).is_ok());
+
+ let start = Instant::now();
+ let timeout = Duration::from_secs(1);
+ assert_eq!(receiver.recv_timeout(timeout), Ok(19i128));
+ assert!(start.elapsed() < Duration::from_millis(100));
+
+ assert!(receiver.recv_timeout(timeout).is_err());
+ assert!(receiver.try_recv().is_err());
+ assert!(receiver.recv().is_err());
+ })
+}
+
+#[test]
+fn send_then_drop_receiver() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel();
+ assert!(sender.send(19i128).is_ok());
+ mem::drop(receiver);
+ })
+}
+
+#[test]
+fn send_with_dropped_receiver() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel();
+ mem::drop(receiver);
+ let send_error = sender.send(5u128).unwrap_err();
+ assert_eq!(*send_error.as_inner(), 5);
+ assert_eq!(send_error.into_inner(), 5);
+ })
+}
+
+#[test]
+fn try_recv_with_dropped_sender() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ mem::drop(sender);
+ assert!(!receiver.has_message());
+ receiver.try_recv().unwrap_err();
+ })
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn recv_with_dropped_sender() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ mem::drop(sender);
+ receiver.recv().unwrap_err();
+ })
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn recv_before_send() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel();
+ let t = thread::spawn(move || {
+ thread::sleep(Duration::from_millis(2));
+ sender.send(9u128).unwrap();
+ });
+ assert_eq!(receiver.recv(), Ok(9));
+ t.join().unwrap();
+ })
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn recv_timeout_before_send() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel();
+ let t = thread::spawn(move || {
+ thread::sleep(Duration::from_millis(2));
+ sender.send(9u128).unwrap();
+ });
+ assert_eq!(receiver.recv_timeout(Duration::from_secs(1)), Ok(9));
+ t.join().unwrap();
+ })
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn recv_before_send_then_drop_sender() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ let t = thread::spawn(move || {
+ thread::sleep(Duration::from_millis(10));
+ mem::drop(sender);
+ });
+ assert!(receiver.recv().is_err());
+ t.join().unwrap();
+ })
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn recv_timeout_before_send_then_drop_sender() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ let t = thread::spawn(move || {
+ thread::sleep(Duration::from_millis(10));
+ mem::drop(sender);
+ });
+ assert!(receiver.recv_timeout(Duration::from_secs(1)).is_err());
+ t.join().unwrap();
+ })
+}
+
+#[test]
+fn try_recv() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ assert_eq!(receiver.try_recv(), Err(TryRecvError::Empty));
+ mem::drop(sender)
+ })
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn try_recv_then_drop_receiver() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel::<u128>();
+ let t1 = thread::spawn(move || {
+ let _ = sender.send(42);
+ });
+ let t2 = thread::spawn(move || {
+ assert!(matches!(
+ receiver.try_recv(),
+ Ok(42) | Err(TryRecvError::Empty)
+ ));
+ mem::drop(receiver);
+ });
+ t1.join().unwrap();
+ t2.join().unwrap();
+ })
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn recv_deadline_and_timeout_no_time() {
+ maybe_loom_model(|| {
+ let (_sender, receiver) = oneshot::channel::<u128>();
+
+ let start = Instant::now();
+ assert_eq!(
+ receiver.recv_deadline(start),
+ Err(RecvTimeoutError::Timeout)
+ );
+ assert!(start.elapsed() < Duration::from_millis(200));
+
+ let start = Instant::now();
+ assert_eq!(
+ receiver.recv_timeout(Duration::from_millis(0)),
+ Err(RecvTimeoutError::Timeout)
+ );
+ assert!(start.elapsed() < Duration::from_millis(200));
+ })
+}
+
+// This test doesn't give meaningful results when run with oneshot_test_delay and loom
+#[cfg(all(feature = "std", not(all(oneshot_test_delay, oneshot_loom))))]
+#[test]
+fn recv_deadline_time_should_elapse() {
+ maybe_loom_model(|| {
+ let (_sender, receiver) = oneshot::channel::<u128>();
+
+ let start = Instant::now();
+ #[cfg(not(oneshot_loom))]
+ let timeout = Duration::from_millis(100);
+ #[cfg(oneshot_loom)]
+ let timeout = Duration::from_millis(1);
+ assert_eq!(
+ receiver.recv_deadline(start + timeout),
+ Err(RecvTimeoutError::Timeout)
+ );
+ assert!(start.elapsed() > timeout);
+ assert!(start.elapsed() < timeout * 3);
+ })
+}
+
+#[cfg(all(feature = "std", not(all(oneshot_test_delay, oneshot_loom))))]
+#[test]
+fn recv_timeout_time_should_elapse() {
+ maybe_loom_model(|| {
+ let (_sender, receiver) = oneshot::channel::<u128>();
+
+ let start = Instant::now();
+ #[cfg(not(oneshot_loom))]
+ let timeout = Duration::from_millis(100);
+ #[cfg(oneshot_loom)]
+ let timeout = Duration::from_millis(1);
+
+ assert_eq!(
+ receiver.recv_timeout(timeout),
+ Err(RecvTimeoutError::Timeout)
+ );
+ assert!(start.elapsed() > timeout);
+ assert!(start.elapsed() < timeout * 3);
+ })
+}
+
+#[cfg(not(oneshot_loom))]
+#[test]
+fn non_send_type_can_be_used_on_same_thread() {
+ use std::ptr;
+
+ #[derive(Debug, Eq, PartialEq)]
+ struct NotSend(*mut ());
+
+ let (sender, receiver) = oneshot::channel();
+ sender.send(NotSend(ptr::null_mut())).unwrap();
+ let reply = receiver.try_recv().unwrap();
+ assert_eq!(reply, NotSend(ptr::null_mut()));
+}
+
+#[test]
+fn message_in_channel_dropped_on_receiver_drop() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel();
+ let (message, counter) = DropCounter::new(());
+ assert_eq!(counter.count(), 0);
+ sender.send(message).unwrap();
+ assert_eq!(counter.count(), 0);
+ mem::drop(receiver);
+ assert_eq!(counter.count(), 1);
+ })
+}
+
+#[test]
+fn send_error_drops_message_correctly() {
+ maybe_loom_model(|| {
+ let (sender, _) = oneshot::channel();
+ let (message, counter) = DropCounter::new(());
+
+ let send_error = sender.send(message).unwrap_err();
+ assert_eq!(counter.count(), 0);
+ mem::drop(send_error);
+ assert_eq!(counter.count(), 1);
+ });
+}
+
+#[test]
+fn send_error_drops_message_correctly_on_into_inner() {
+ maybe_loom_model(|| {
+ let (sender, _) = oneshot::channel();
+ let (message, counter) = DropCounter::new(());
+
+ let send_error = sender.send(message).unwrap_err();
+ assert_eq!(counter.count(), 0);
+ let message = send_error.into_inner();
+ assert_eq!(counter.count(), 0);
+ mem::drop(message);
+ assert_eq!(counter.count(), 1);
+ });
+}
+
+#[test]
+fn dropping_receiver_disconnects_sender() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel::<()>();
+ assert!(!sender.is_closed());
+ assert!(!receiver.is_closed());
+ drop(receiver);
+ assert!(sender.is_closed());
+ });
+}
+
+#[test]
+fn dropping_sender_disconnects_receiver() {
+ maybe_loom_model(|| {
+ let (sender, receiver) = oneshot::channel::<()>();
+ assert!(!sender.is_closed());
+ assert!(!receiver.is_closed());
+ drop(sender);
+ assert!(receiver.is_closed());
+ });
+}
diff --git a/toolkit/library/rust/shared/Cargo.toml b/toolkit/library/rust/shared/Cargo.toml
@@ -125,6 +125,7 @@ osclientcerts = { path = "../../../../security/manager/ssl/osclientcerts" }
gkrust-uniffi-components = { path = "../../../components/uniffi-bindgen-gecko-js/components/", features = ["xpcom"] }
uniffi-bindgen-gecko-js-test-fixtures = { path = "../../../components/uniffi-bindgen-gecko-js/test-fixtures/", optional = true }
viaduct = "0.1"
+viaduct-necko = { path = "../../../../services/application-services/components/viaduct-necko" }
webext-storage = "0.1"
[target.'cfg(target_os = "windows")'.dependencies]
diff --git a/toolkit/library/rust/shared/lib.rs b/toolkit/library/rust/shared/lib.rs
@@ -107,6 +107,8 @@ extern crate uniffi_bindgen_gecko_js_test_fixtures;
#[cfg(not(target_os = "android"))]
extern crate viaduct;
+#[cfg(not(target_os = "android"))]
+extern crate viaduct_necko;
extern crate gecko_logger;
extern crate gecko_tracing;
@@ -162,6 +164,10 @@ pub extern "C" fn GkRust_Init() {
let _ = GeckoLogger::init();
// Initialize tracing.
gecko_tracing::initialize_tracing();
+ #[cfg(not(target_os = "android"))]
+ if let Err(e) = viaduct_necko::init_necko_backend() {
+ log::warn!("Failed to initialize viaduct-necko backend: {:?}", e);
+ }
}
#[no_mangle]
