commit 69ce3c1b9fafe4f0e77f498436e944e076d62e1c
parent 6e1dbd670bcf13e7884e74e897e33596474a1c32
Author: Atila Butkovits <abutkovits@mozilla.com>
Date: Fri, 28 Nov 2025 20:39:55 +0200
Revert "Bug 1997192, Bug 2002876, Bug 2002035, Bug 2002849 - Enable JS MicroTaskQueue by default r=smaug" for causing xpc failures at test_promise_job_across_sandbox.js.
This reverts commit 4c000c7022cf307cc781a54f14f71b8f1cb83ab9.
Revert "Bug 2002876 - Remove un-necessary copy & move root out of loop r=smaug"
This reverts commit ff03e52ebf738ece9bbe7d0bf9ed94a892b28f97.
Revert "Bug 2002035 - Remove unnecessary barriers in MustConsumeMicroTaskRunnable r=jonco"
This reverts commit 120f48b684865bbc169066d3236d4469026779e9.
Revert "Bug 2002849 - Revert "Bug 1997702 - Remove use of PersistentRooted on JSContext for MicroTaskQueues" r=jonco"
This reverts commit e78b98f730ecd5918e4ee804a70a21abbe478d04.
Diffstat:
5 files changed, 23 insertions(+), 16 deletions(-)
diff --git a/js/src/vm/JSContext.cpp b/js/src/vm/JSContext.cpp
@@ -1067,9 +1067,11 @@ void js::MicroTaskQueueElement::trace(JSTracer* trc) {
auto* queue = cx->jobQueue.ref();
if (!queue || value.isGCThing()) {
- TraceRoot(trc, &value, "microtask-queue-entry");
+ TraceEdge(trc, &value, "microtask-queue-entry");
} else {
- queue->traceNonGCThingMicroTask(trc, &value);
+ // It's OK to use unbarriered address here because this is not a GC thing
+ // and so there are no worthwhile barriers to consider here.
+ queue->traceNonGCThingMicroTask(trc, value.unbarrieredAddress());
}
}
@@ -1161,7 +1163,7 @@ JS_PUBLIC_API bool JS::HasDebuggerMicroTasks(JSContext* cx) {
struct SavedMicroTaskQueueImpl : public JS::SavedMicroTaskQueue {
explicit SavedMicroTaskQueueImpl(JSContext* cx) : savedQueues(cx) {
savedQueues = js::MakeUnique<js::MicroTaskQueueSet>(cx);
- std::swap(cx->microTaskQueues.get(), savedQueues.get());
+ std::swap(cx->microTaskQueues, savedQueues.get());
}
~SavedMicroTaskQueueImpl() override = default;
JS::PersistentRooted<js::UniquePtr<js::MicroTaskQueueSet>> savedQueues;
@@ -1184,7 +1186,7 @@ JS_PUBLIC_API void JS::RestoreMicroTaskQueue(
// There's only one impl, so we know this is safe.
SavedMicroTaskQueueImpl* savedQueueImpl =
static_cast<SavedMicroTaskQueueImpl*>(savedQueue.get());
- std::swap(savedQueueImpl->savedQueues.get(), cx->microTaskQueues.get());
+ std::swap(savedQueueImpl->savedQueues.get(), cx->microTaskQueues);
}
JS_PUBLIC_API size_t JS::GetRegularMicroTaskCount(JSContext* cx) {
@@ -1290,8 +1292,7 @@ JSContext::JSContext(JSRuntime* runtime, const JS::ContextOptions& options)
canSkipEnqueuingJobs(this, false),
promiseRejectionTrackerCallback(this, nullptr),
promiseRejectionTrackerCallbackData(this, nullptr),
- insideExclusiveDebuggerOnEval(this, nullptr),
- microTaskQueues(this) {
+ insideExclusiveDebuggerOnEval(this, nullptr) {
MOZ_ASSERT(static_cast<JS::RootingContext*>(this) ==
JS::RootingContext::get(this));
}
@@ -1537,6 +1538,12 @@ void JSContext::trace(JSTracer* trc) {
#ifdef ENABLE_WASM_JSPI
wasm().promiseIntegration.trace(trc);
#endif
+
+ // Skip tracing the microtask queues on minor GC as we will be updating
+ // nursery pointers through the store buffer instead.
+ if (!trc->isTenuringTracer() && microTaskQueues) {
+ microTaskQueues->trace(trc);
+ }
}
JS::NativeStackLimit JSContext::stackLimitForJitCode(JS::StackKind kind) {
diff --git a/js/src/vm/JSContext.h b/js/src/vm/JSContext.h
@@ -166,7 +166,7 @@ struct MicroTaskQueueElement {
void trace(JSTracer* trc);
private:
- JS::Value value;
+ js::HeapPtr<JS::Value> value;
};
// Use TempAllocPolicy to report OOM
@@ -1070,7 +1070,7 @@ struct JS_PUBLIC_API JSContext : public JS::RootingContext,
bool hasExecutionTracer() { return false; }
#endif
- JS::PersistentRooted<js::UniquePtr<js::MicroTaskQueueSet>> microTaskQueues;
+ js::UniquePtr<js::MicroTaskQueueSet> microTaskQueues;
}; /* struct JSContext */
inline JSContext* JSRuntime::mainContextFromOwnThread() {
diff --git a/modules/libpref/init/StaticPrefList.yaml b/modules/libpref/init/StaticPrefList.yaml
@@ -9424,9 +9424,11 @@
do_not_use_directly: true
# Use the JS microtask queue for Promise jobs and other microtasks.
+# DO NOT TURN THIS ON BY DEFAULT WITHOUT THE BUGS BLOCKING
+# BUG 1990841 being fixed (especially Bug 1990842).
- name: javascript.options.use_js_microtask_queue
type: RelaxedAtomicBool
- value: true
+ value: false
# Changing this mid process will break invariants and crash, however
# making this mirror: once, and set_spidermonkey_pref: startup is
# broken: See Bug 1989094
diff --git a/xpcom/base/CycleCollectedJSContext.cpp b/xpcom/base/CycleCollectedJSContext.cpp
@@ -1197,7 +1197,7 @@ bool CycleCollectedJSContext::PerformMicroTaskCheckPoint(bool aForce) {
while (JS::HasAnyMicroTasks(cx)) {
MOZ_ASSERT(mDebuggerMicroTaskQueue.empty());
MOZ_ASSERT(mPendingMicroTaskRunnables.empty());
- job.set(DequeueNextMicroTask(cx));
+ job = DequeueNextMicroTask(cx);
// To avoid us accidentally re-enqueing a SuppressionMicroTaskList in
// itself, we determine here if the job is actually the suppression task
@@ -1327,11 +1327,11 @@ void CycleCollectedJSContext::PerformDebuggerMicroTaskCheckpoint() {
JSContext* cx = Context();
if (StaticPrefs::javascript_options_use_js_microtask_queue()) {
- JS::Rooted<MustConsumeMicroTask> job(cx);
while (JS::HasDebuggerMicroTasks(cx)) {
MOZ_ASSERT(mDebuggerMicroTaskQueue.empty());
MOZ_ASSERT(mPendingMicroTaskRunnables.empty());
+ JS::Rooted<MustConsumeMicroTask> job(cx);
job.set(DequeueNextDebuggerMicroTask(cx));
RunMicroTask(cx, &job);
diff --git a/xpcom/base/CycleCollectedJSContext.h b/xpcom/base/CycleCollectedJSContext.h
@@ -109,9 +109,7 @@ class SuppressedMicroTasks : public MicroTaskRunnable {
// A gecko wrapper for the JS::MicroTask type. Used to enforce both
// that this is handled move only, but also that we have succesfully
// consumed this microtask before destruction.
-//
-// This type must be rooted, it holds onto a JS reference.
-class MOZ_STACK_CLASS MustConsumeMicroTask {
+class MustConsumeMicroTask {
public:
// We need a public constructor to allow forward declared Rooted
MustConsumeMicroTask() = default;
@@ -255,14 +253,14 @@ class MOZ_STACK_CLASS MustConsumeMicroTask {
}
void trace(JSTracer* aTrc) {
- TraceRoot(aTrc, &mMicroTask, "MustConsumeMicroTask value");
+ TraceEdge(aTrc, &mMicroTask, "MustConsumeMicroTask value");
}
private:
explicit MustConsumeMicroTask(JS::GenericMicroTask&& aMicroTask)
: mMicroTask(aMicroTask) {}
- JS::GenericMicroTask mMicroTask;
+ JS::Heap<JS::GenericMicroTask> mMicroTask;
};
class SuppressedMicroTaskList final : public MicroTaskRunnable {
