Bug 1669214 - Part 5: Construct regular EventQueue using TC forwarding for the main thread. r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D92454

xpcom/threads/ThreadEventQueue.cpp

@@ -52,7 +52,8 @@ ThreadEventQueue<InnerQueueT>::ThreadEventQueue(UniquePtr<InnerQueueT> aQueue,
                                                 bool aIsMainThread)
     : mBaseQueue(std::move(aQueue)),
       mLock("ThreadEventQueue"),
-      mEventsAvailable(mLock, "EventsAvail") {
+      mEventsAvailable(mLock, "EventsAvail"),
+      mIsMainThread(aIsMainThread) {
   if (aIsMainThread) {
     TaskController::Get()->SetConditionVariable(&mEventsAvailable);
   }
@@ -84,7 +85,7 @@ bool ThreadEventQueue<InnerQueueT>::PutEventInternal(
     // Check if the runnable wants to override the passed-in priority.
     // Do this outside the lock, so runnables implemented in JS can QI
     // (and possibly GC) outside of the lock.
-    if (InnerQueueT::SupportsPrioritization) {
+    if (mIsMainThread) {
       auto* e = event.get();  // can't do_QueryInterface on LeakRefPtr.
       if (nsCOMPtr<nsIRunnablePriority> runnablePrio = do_QueryInterface(e)) {
         uint32_t prio = nsIRunnablePriority::PRIORITY_NORMAL;

xpcom/threads/ThreadEventQueue.h

@@ -91,6 +91,7 @@ class ThreadEventQueue final : public SynchronizedEventQueue {
 
   bool mEventsAreDoomed = false;
   nsCOMPtr<nsIThreadObserver> mObserver;
+  bool mIsMainThread;
 };
 
 extern template class ThreadEventQueue<EventQueue>;

xpcom/threads/nsThreadManager.cpp

@@ -379,15 +379,12 @@ nsresult nsThreadManager::Init() {
   TaskController::Get()->SetIdleTaskManager(
       new IdleTaskManager(idlePeriod.forget()));
 
-  // Create main thread queue and construct main thread.
-  UniquePtr<PrioritizedEventQueue> queue = MakeUnique<PrioritizedEventQueue>();
+  // Create main thread queue that forwards events to TaskController and
+  // construct main thread.
+  UniquePtr<EventQueue> queue = MakeUnique<EventQueue>(true);
 
-  PrioritizedEventQueue* prioritized = queue.get();
-
-  RefPtr<ThreadEventQueue<PrioritizedEventQueue>> synchronizedQueue =
-      new ThreadEventQueue<PrioritizedEventQueue>(std::move(queue), true);
-
-  prioritized->SetMutexRef(synchronizedQueue->MutexRef());
+  RefPtr<ThreadEventQueue<EventQueue>> synchronizedQueue =
+      new ThreadEventQueue<EventQueue>(std::move(queue), true);
 
   mMainThread =
       new nsThread(WrapNotNull(synchronizedQueue), nsThread::MAIN_THREAD, 0);