Bug 1300118 P3 Fix TaskQueue sCurrentThread TLS handling for nsIEventTarget targets. r=jwwang

xpcom/threads/AbstractThread.cpp

@@ -70,7 +70,6 @@ public:
     PRThread* thread = nullptr;
     mTarget->GetPRThread(&thread);
     bool in = PR_GetCurrentThread() == thread;
-    MOZ_ASSERT(in == (GetCurrent() == this));
     return in;
   }
 

xpcom/threads/TaskQueue.cpp

@@ -191,7 +191,6 @@ bool
 TaskQueue::IsCurrentThreadIn()
 {
   bool in = NS_GetCurrentThread() == mRunningThread;
-  MOZ_ASSERT(in == (GetCurrent() == this));
   return in;
 }
 

xpcom/threads/TaskQueue.h

@@ -148,13 +148,14 @@ protected:
   public:
     explicit AutoTaskGuard(TaskQueue* aQueue)
       : AutoTaskDispatcher(/* aIsTailDispatcher = */ true), mQueue(aQueue)
+      , mLastCurrentThread(nullptr)
     {
       // NB: We don't hold the lock to aQueue here. Don't do anything that
       // might require it.
       MOZ_ASSERT(!mQueue->mTailDispatcher);
       mQueue->mTailDispatcher = this;
 
-      MOZ_ASSERT(sCurrentThreadTLS.get() == nullptr);
+      mLastCurrentThread = sCurrentThreadTLS.get();
       sCurrentThreadTLS.set(aQueue);
 
       MOZ_ASSERT(mQueue->mRunningThread == nullptr);
@@ -168,12 +169,13 @@ protected:
       MOZ_ASSERT(mQueue->mRunningThread == NS_GetCurrentThread());
       mQueue->mRunningThread = nullptr;
 
-      sCurrentThreadTLS.set(nullptr);
+      sCurrentThreadTLS.set(mLastCurrentThread);
       mQueue->mTailDispatcher = nullptr;
     }
 
   private:
   TaskQueue* mQueue;
+  AbstractThread* mLastCurrentThread;
   };
 
   TaskDispatcher* mTailDispatcher;