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TaskSignal.cpp (3472B)

      1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim:expandtab:shiftwidth=2:tabstop=2:
      3 */
      4 /* This Source Code Form is subject to the terms of the Mozilla Public
      5 * License, v. 2.0. If a copy of the MPL was not distributed with this
      6 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      7 
      8 #include "TaskSignal.h"
      9 
     10 #include "WebTaskScheduler.h"
     11 
     12 namespace mozilla::dom {
     13 
     14 NS_IMPL_CYCLE_COLLECTION_INHERITED(TaskSignal, AbortSignal,
     15                                   mDependentTaskSignals)
     16 
     17 NS_IMPL_ISUPPORTS_CYCLE_COLLECTION_INHERITED_0(TaskSignal, AbortSignal)
     18 
     19 already_AddRefed<TaskSignal> TaskSignal::Create(nsIGlobalObject* aGlobalObject,
     20                                                TaskPriority aPriority) {
     21  return do_AddRef(new TaskSignal(aGlobalObject, aPriority));
     22 }
     23 
     24 void TaskSignal::RunPriorityChangeAlgorithms() {
     25  for (const WeakPtr<WebTaskScheduler>& scheduler : mSchedulers) {
     26    if (scheduler) {
     27      scheduler->RunTaskSignalPriorityChange(this);
     28    }
     29  }
     30 }
     31 void TaskSignal::SetWebTaskScheduler(WebTaskScheduler* aScheduler) {
     32  mSchedulers.AppendElement(aScheduler);
     33 }
     34 
     35 // https://wicg.github.io/scheduling-apis/#create-a-dependent-task-signal
     36 /* static */
     37 already_AddRefed<TaskSignal> TaskSignal::Any(
     38    GlobalObject& aGlobal, const Sequence<OwningNonNull<AbortSignal>>& aSignals,
     39    const TaskSignalAnyInit& aInit) {
     40  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports());
     41  // 1. Let resultSignal be the result of creating a dependent signal from
     42  // signals using the TaskSignal interface and realm.
     43  RefPtr<AbortSignal> abortSignal =
     44      AbortSignal::Any(global, aSignals, [](nsIGlobalObject* aGlobal) {
     45        // Use User_visible as a temporary priority for now, it'll alwasy be set
     46        // again later.
     47        RefPtr<TaskSignal> signal =
     48            new TaskSignal(aGlobal, TaskPriority::User_visible);
     49        return signal.forget();
     50      });
     51 
     52  if (!abortSignal) {
     53    return nullptr;
     54  }
     55 
     56  RefPtr<TaskSignal> resultSignal = static_cast<TaskSignal*>(abortSignal.get());
     57 
     58  // 2. Set resultSignal’s dependent to true.
     59  resultSignal->mDependent = true;
     60 
     61  // 3. If init["priority"] is a TaskPriority, then:
     62  if (aInit.mPriority.IsTaskPriority()) {
     63    // 3.1 Set resultSignal’s priority to init["priority"].
     64    resultSignal->SetPriority(aInit.mPriority.GetAsTaskPriority());
     65    return resultSignal.forget();
     66  }
     67 
     68  // 4. Otherwise:
     69  // 4.1. Let sourceSignal be init["priority"].
     70  OwningNonNull<TaskSignal> sourceSignal = aInit.mPriority.GetAsTaskSignal();
     71 
     72  // 4.2. Set resultSignal’s priority to sourceSignal’s priority.
     73  resultSignal->SetPriority(sourceSignal->Priority());
     74 
     75  // 4.3 If sourceSignal does not have fixed priority, then:
     76  if (!sourceSignal->HasFixedPriority()) {
     77    // 4.3.1 If sourceSignal’s dependent is true, then set sourceSignal to
     78    // sourceSignal’s source signal
     79    if (sourceSignal->mDependent) {
     80      sourceSignal = sourceSignal->mSourceTaskSignal;
     81    }
     82    // 4.3.2. Assert: sourceSignal is not dependent.
     83    MOZ_ASSERT(!sourceSignal->mDependent);
     84    // 4.3.3. Set resultSignal’s source signal to a weak reference to
     85    // sourceSignal.
     86    resultSignal->mSourceTaskSignal = sourceSignal;
     87    // 4.3.4. Append resultSignal to sourceSignal’s dependent signals.
     88    sourceSignal->mDependentTaskSignals.AppendElement(resultSignal);
     89  }
     90  return resultSignal.forget();
     91 }
     92 }  // namespace mozilla::dom