Back out 6 changesets (bug 1186745) for cpptest failure in runnable_utils_unittest, nrappkit_unittest, test_nr_socket_unittest
authorPhil Ringnalda <philringnalda@gmail.com>
Mon, 28 Sep 2015 19:05:02 -0700
changeset 285607 00a507c0f66201e793e11b369a664421bbbef6bc
parent 285606 572c67f7b62c6ee23953b8bbf0e7b47d27cb4b32
child 285608 00a10127e2cebc68d3266dc76748e3d59406aa08
push idunknown
push userunknown
push dateunknown
bugs1186745
milestone44.0a1
backs outc6142b815de04b37c1b798b79729dbdb4e827330
d8f740ef24304bb4088be28ba1c0204962aeadf1
edc0b56d81faf04f67462221aaaa566319df8c39
383f8ac033ea6a9951779b06ee463c95d230a4ab
ce960a661987dacec560459797e720d442ccb912
3e9783023fb2091856dbe5407c5c0a3fc3220386
first release with
nightly linux32
nightly linux64
nightly mac
nightly win32
nightly win64
last release without
nightly linux32
nightly linux64
nightly mac
nightly win32
nightly win64
Back out 6 changesets (bug 1186745) for cpptest failure in runnable_utils_unittest, nrappkit_unittest, test_nr_socket_unittest Backed out changeset c6142b815de0 (bug 1186745) Backed out changeset d8f740ef2430 (bug 1186745) Backed out changeset edc0b56d81fa (bug 1186745) Backed out changeset 383f8ac033ea (bug 1186745) Backed out changeset ce960a661987 (bug 1186745) Backed out changeset 3e9783023fb2 (bug 1186745)
tools/profiler/tasktracer/GeckoTaskTracer.h
tools/profiler/tasktracer/TracedTaskCommon.cpp
tools/profiler/tasktracer/TracedTaskCommon.h
xpcom/glue/moz.build
xpcom/glue/nsThreadUtils.cpp
xpcom/glue/nsThreadUtils.h
xpcom/glue/standalone/moz.build
xpcom/glue/standalone/staticruntime/moz.build
xpcom/glue/staticruntime/moz.build
xpcom/threads/LeakRefPtr.h
xpcom/threads/nsIEventTarget.idl
xpcom/threads/nsThread.cpp
xpcom/threads/nsThread.h
xpcom/threads/nsThreadPool.cpp
xpcom/threads/nsThreadSyncDispatch.h
--- a/tools/profiler/tasktracer/GeckoTaskTracer.h
+++ b/tools/profiler/tasktracer/GeckoTaskTracer.h
@@ -70,18 +70,17 @@ nsTArray<nsCString>* GetLoggedData(TimeS
 const PRTime GetStartTime();
 
 /**
  * Internal functions.
  */
 
 Task* CreateTracedTask(Task* aTask);
 
-already_AddRefed<nsIRunnable>
-CreateTracedRunnable(already_AddRefed<nsIRunnable>&& aRunnable);
+already_AddRefed<nsIRunnable> CreateTracedRunnable(nsIRunnable* aRunnable);
 
 // Free the TraceInfo allocated on a thread's TLS. Currently we are wrapping
 // tasks running on nsThreads and base::thread, so FreeTraceInfo is called at
 // where nsThread and base::thread release themselves.
 void FreeTraceInfo();
 
 const char* GetJSLabelPrefix();
 
--- a/tools/profiler/tasktracer/TracedTaskCommon.cpp
+++ b/tools/profiler/tasktracer/TracedTaskCommon.cpp
@@ -85,19 +85,19 @@ TracedTaskCommon::ClearTLSTraceInfo()
   info->mCurTraceSourceId = 0;
   info->mCurTraceSourceType = SourceEventType::Unknown;
   info->mCurTaskId = 0;
 }
 
 /**
  * Implementation of class TracedRunnable.
  */
-TracedRunnable::TracedRunnable(already_AddRefed<nsIRunnable>&& aOriginalObj)
+TracedRunnable::TracedRunnable(nsIRunnable* aOriginalObj)
   : TracedTaskCommon()
-  , mOriginalObj(Move(aOriginalObj))
+  , mOriginalObj(aOriginalObj)
 {
   Init();
   LogVirtualTablePtr(mTaskId, mSourceEventId, *(int**)(aOriginalObj));
 }
 
 TracedRunnable::~TracedRunnable()
 {
 }
@@ -143,19 +143,19 @@ TracedTask::Run()
   ClearTLSTraceInfo();
 }
 
 /**
  * CreateTracedRunnable() returns a TracedRunnable wrapping the original
  * nsIRunnable object, aRunnable.
  */
 already_AddRefed<nsIRunnable>
-CreateTracedRunnable(already_AddRefed<nsIRunnable>&& aRunnable)
+CreateTracedRunnable(nsIRunnable* aRunnable)
 {
-  nsCOMPtr<nsIRunnable> runnable = new TracedRunnable(Move(aRunnable));
+  nsCOMPtr<nsIRunnable> runnable = new TracedRunnable(aRunnable);
   return runnable.forget();
 }
 
 /**
  * CreateTracedTask() returns a TracedTask wrapping the original Task object,
  * aTask.
  */
 Task*
--- a/tools/profiler/tasktracer/TracedTaskCommon.h
+++ b/tools/profiler/tasktracer/TracedTaskCommon.h
@@ -41,17 +41,17 @@ protected:
 };
 
 class TracedRunnable : public TracedTaskCommon
                      , public nsRunnable
 {
 public:
   NS_DECL_NSIRUNNABLE
 
-  TracedRunnable(already_AddRefed<nsIRunnable>&& aOriginalObj);
+  TracedRunnable(nsIRunnable* aOriginalObj);
 
 private:
   virtual ~TracedRunnable();
 
   nsCOMPtr<nsIRunnable> mOriginalObj;
 };
 
 class TracedTask : public TracedTaskCommon
--- a/xpcom/glue/moz.build
+++ b/xpcom/glue/moz.build
@@ -101,17 +101,16 @@ FORCE_STATIC_LIB = True
 if CONFIG['_MSC_VER']:
     DEFINES['_USE_ANSI_CPP'] = True
     # Don't include directives about which CRT to use
     CFLAGS += ['-Zl']
     CXXFLAGS += ['-Zl']
 
 LOCAL_INCLUDES += [
     '../build',
-    '../threads',
 ]
 
 if CONFIG['ENABLE_TESTS']:
     DIRS += ['tests/gtest']
 
 # Include fallible for third party code using the xpcom glue
 USE_LIBS += [
     'fallible',
--- a/xpcom/glue/nsThreadUtils.cpp
+++ b/xpcom/glue/nsThreadUtils.cpp
@@ -2,17 +2,16 @@
 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
 /* 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 "nsThreadUtils.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/Likely.h"
-#include "LeakRefPtr.h"
 
 #ifdef MOZILLA_INTERNAL_API
 # include "nsThreadManager.h"
 #else
 # include "nsXPCOMCIDInternal.h"
 # include "nsIThreadManager.h"
 # include "nsServiceManagerUtils.h"
 #endif
@@ -23,18 +22,16 @@
 using mozilla::IsVistaOrLater;
 #elif defined(XP_MACOSX)
 #include <sys/resource.h>
 #endif
 
 #include <pratom.h>
 #include <prthread.h>
 
-using namespace mozilla;
-
 #ifndef XPCOM_GLUE_AVOID_NSPR
 
 NS_IMPL_ISUPPORTS(nsRunnable, nsIRunnable)
 
 NS_IMETHODIMP
 nsRunnable::Run()
 {
   // Do nothing
@@ -137,69 +134,52 @@ NS_IsMainThread()
     do_GetService(NS_THREADMANAGER_CONTRACTID);
   if (mgr) {
     mgr->GetIsMainThread(&result);
   }
   return bool(result);
 }
 #endif
 
+// It is common to call NS_DispatchToCurrentThread with a newly
+// allocated runnable with a refcount of zero. To keep us from leaking
+// the runnable if the dispatch method fails, we take a death grip.
 NS_METHOD
-NS_DispatchToCurrentThread(already_AddRefed<nsIRunnable>&& aEvent)
+NS_DispatchToCurrentThread(nsIRunnable* aEvent)
 {
-  nsresult rv;
-  nsCOMPtr<nsIRunnable> event(aEvent);
+  nsCOMPtr<nsIRunnable> deathGrip = aEvent;
 #ifdef MOZILLA_INTERNAL_API
   nsIThread* thread = NS_GetCurrentThread();
   if (!thread) {
     return NS_ERROR_UNEXPECTED;
   }
 #else
   nsCOMPtr<nsIThread> thread;
-  rv = NS_GetCurrentThread(getter_AddRefs(thread));
+  nsresult rv = NS_GetCurrentThread(getter_AddRefs(thread));
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
 #endif
-  // To keep us from leaking the runnable if dispatch method fails,
-  // we grab the reference on failures and release it.
-  nsIRunnable* temp = event.get();
-  rv = thread->Dispatch(event.forget(), NS_DISPATCH_NORMAL);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    // Dispatch() leaked the reference to the event, but due to caller's
-    // assumptions, we shouldn't leak here. And given we are on the same
-    // thread as the dispatch target, it's mostly safe to do it here.
-    NS_RELEASE(temp);
-  }
-  return rv;
-}
-
-// It is common to call NS_DispatchToCurrentThread with a newly
-// allocated runnable with a refcount of zero. To keep us from leaking
-// the runnable if the dispatch method fails, we take a death grip.
-NS_METHOD
-NS_DispatchToCurrentThread(nsIRunnable* aEvent)
-{
-  nsCOMPtr<nsIRunnable> event(aEvent);
-  return NS_DispatchToCurrentThread(event.forget());
+  return thread->Dispatch(aEvent, NS_DISPATCH_NORMAL);
 }
 
 NS_METHOD
 NS_DispatchToMainThread(already_AddRefed<nsIRunnable>&& aEvent, uint32_t aDispatchFlags)
 {
-  LeakRefPtr<nsIRunnable> event(Move(aEvent));
+  nsCOMPtr<nsIRunnable> event(aEvent);
   nsCOMPtr<nsIThread> thread;
   nsresult rv = NS_GetMainThread(getter_AddRefs(thread));
   if (NS_WARN_IF(NS_FAILED(rv))) {
     NS_ASSERTION(false, "Failed NS_DispatchToMainThread() in shutdown; leaking");
     // NOTE: if you stop leaking here, adjust Promise::MaybeReportRejected(),
     // which assumes a leak here, or split into leaks and no-leaks versions
-    return rv;
+    nsIRunnable* temp = event.forget().take(); // leak without using "unused <<" due to Windows (boo)
+    return temp ? rv : rv; // to make compiler not bletch on us
   }
-  return thread->Dispatch(event.take(), aDispatchFlags);
+  return thread->Dispatch(event.forget(), aDispatchFlags);
 }
 
 // In the case of failure with a newly allocated runnable with a
 // refcount of zero, we intentionally leak the runnable, because it is
 // likely that the runnable is being dispatched to the main thread
 // because it owns main thread only objects, so it is not safe to
 // release them here.
 NS_METHOD
--- a/xpcom/glue/nsThreadUtils.h
+++ b/xpcom/glue/nsThreadUtils.h
@@ -101,18 +101,16 @@ extern NS_METHOD NS_GetCurrentThread(nsI
  *
  * @param aEvent
  *   The event to dispatch.
  *
  * @returns NS_ERROR_INVALID_ARG
  *   If event is null.
  */
 extern NS_METHOD NS_DispatchToCurrentThread(nsIRunnable* aEvent);
-extern NS_METHOD
-NS_DispatchToCurrentThread(already_AddRefed<nsIRunnable>&& aEvent);
 
 /**
  * Dispatch the given event to the main thread.
  *
  * @param aEvent
  *   The event to dispatch.
  * @param aDispatchFlags
  *   The flags to pass to the main thread's dispatch method.
--- a/xpcom/glue/standalone/moz.build
+++ b/xpcom/glue/standalone/moz.build
@@ -33,17 +33,16 @@ if CONFIG['_MSC_VER']:
     # Don't include directives about which CRT to use
     CFLAGS += ['-Zl']
     CXXFLAGS += ['-Zl']
 
 DEFINES['XPCOM_GLUE'] = True
 
 LOCAL_INCLUDES += [
     '../../build',
-    '../../threads',
 ]
 
 # Don't use STL wrappers here (i.e. wrapped <new>); they require mozalloc
 DISABLE_STL_WRAPPING = True
 
 if CONFIG['GNU_CXX']:
     CXXFLAGS += ['-Wshadow']
 
--- a/xpcom/glue/standalone/staticruntime/moz.build
+++ b/xpcom/glue/standalone/staticruntime/moz.build
@@ -25,17 +25,16 @@ if CONFIG['_MSC_VER']:
     # Don't include directives about which CRT to use
     CFLAGS += ['-Zl']
     CXXFLAGS += ['-Zl']
 
 DEFINES['XPCOM_GLUE'] = True
 
 LOCAL_INCLUDES += [
     '../../../build',
-    '../../../threads',
 ]
 
 # Statically link to the CRT on Windows
 USE_STATIC_LIBS = True
 
 # Don't use STL wrappers here (i.e. wrapped <new>); they require mozalloc
 DISABLE_STL_WRAPPING = True
 
--- a/xpcom/glue/staticruntime/moz.build
+++ b/xpcom/glue/staticruntime/moz.build
@@ -23,17 +23,16 @@ FORCE_STATIC_LIB = True
 if CONFIG['_MSC_VER']:
     DEFINES['_USE_ANSI_CPP'] = True
     # Don't include directives about which CRT to use
     CFLAGS += ['-Zl']
     CXXFLAGS += ['-Zl']
 
 LOCAL_INCLUDES += [
     '../../build',
-    '../../threads',
 ]
 
 # Statically link to the CRT on Windows
 USE_STATIC_LIBS = True
 
 # Don't use STL wrappers here (i.e. wrapped <new>); they require mozalloc
 DISABLE_STL_WRAPPING = True
 
deleted file mode 100644
--- a/xpcom/threads/LeakRefPtr.h
+++ /dev/null
@@ -1,48 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* 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/. */
-
-/* Smart pointer which leaks its owning refcounted object by default. */
-
-#ifndef LeakRefPtr_h
-#define LeakRefPtr_h
-
-#include "mozilla/AlreadyAddRefed.h"
-
-namespace mozilla {
-
-/**
- * Instance of this class behaves like a raw pointer which leaks the
- * resource its owning if not explicitly released.
- */
-template<class T>
-class LeakRefPtr
-{
-public:
-  explicit LeakRefPtr(already_AddRefed<T>&& aPtr)
-    : mRawPtr(aPtr.take()) { }
-
-  explicit operator bool() const { return !!mRawPtr; }
-
-  LeakRefPtr<T>& operator=(already_AddRefed<T>&& aPtr)
-  {
-    mRawPtr = aPtr.take();
-    return *this;
-  }
-
-  already_AddRefed<T> take()
-  {
-    T* rawPtr = mRawPtr;
-    mRawPtr = nullptr;
-    return already_AddRefed<T>(rawPtr);
-  }
-
-private:
-  T* mRawPtr;
-};
-
-} // namespace mozilla
-
-#endif // LeakRefPtr_h
--- a/xpcom/threads/nsIEventTarget.idl
+++ b/xpcom/threads/nsIEventTarget.idl
@@ -55,20 +55,17 @@ interface nsIEventTarget : nsISupports
    */
   boolean isOnCurrentThread();
 
   /**
    * Dispatch an event to this event target.  This function may be called from
    * any thread, and it may be called re-entrantly.
    *
    * @param event
-   *   The alreadyAddRefed<> event to dispatch.
-   *   NOTE that the event will be leaked if it fails to dispatch. Also note
-   *   that if "flags" includes DISPATCH_SYNC, it may return error from Run()
-   *   after a successful dispatch. In that case, the event is not leaked.
+   *   The alreadyAddRefed<> event to dispatch
    * @param flags
    *   The flags modifying event dispatch.  The flags are described in detail
    *   below.
    *
    * @throws NS_ERROR_INVALID_ARG
    *   Indicates that event is null.
    * @throws NS_ERROR_UNEXPECTED
    *   Indicates that the thread is shutting down and has finished processing
--- a/xpcom/threads/nsThread.cpp
+++ b/xpcom/threads/nsThread.cpp
@@ -31,18 +31,16 @@
 #include "mozilla/IOInterposer.h"
 #include "mozilla/ipc/MessageChannel.h"
 #include "mozilla/ipc/BackgroundChild.h"
 #endif // defined(MOZILLA_XPCOMRT_API)
 #include "mozilla/Services.h"
 #include "nsXPCOMPrivate.h"
 #include "mozilla/ChaosMode.h"
 #include "mozilla/TimeStamp.h"
-#include "nsThreadSyncDispatch.h"
-#include "LeakRefPtr.h"
 
 #ifdef MOZ_CRASHREPORTER
 #include "nsServiceManagerUtils.h"
 #include "nsICrashReporter.h"
 #endif
 
 #ifdef MOZ_NUWA_PROCESS
 #include "private/pprthred.h"
@@ -538,35 +536,34 @@ nsThread::PutEvent(nsIRunnable* aEvent, 
 {
   nsCOMPtr<nsIRunnable> event(aEvent);
   return PutEvent(event.forget(), aTarget);
 }
 
 nsresult
 nsThread::PutEvent(already_AddRefed<nsIRunnable>&& aEvent, nsNestedEventTarget* aTarget)
 {
-  // We want to leak the reference when we fail to dispatch it, so that
-  // we won't release the event in a wrong thread.
-  LeakRefPtr<nsIRunnable> event(Move(aEvent));
   nsCOMPtr<nsIThreadObserver> obs;
 
 #ifdef MOZ_NUWA_PROCESS
   // On debug build or when tests are enabled, assert that we are not about to
   // create a deadlock in the Nuwa process.
   NuwaAssertNotFrozen(PR_GetThreadID(mThread), PR_GetThreadName(mThread));
 #endif
 
   {
     MutexAutoLock lock(mLock);
     nsChainedEventQueue* queue = aTarget ? aTarget->mQueue : &mEventsRoot;
     if (!queue || (queue == &mEventsRoot && mEventsAreDoomed)) {
       NS_WARNING("An event was posted to a thread that will never run it (rejected)");
-      return NS_ERROR_UNEXPECTED;
+      nsCOMPtr<nsIRunnable> temp(aEvent);
+      nsIRunnable* temp2 = temp.forget().take(); // can't use unused << aEvent here due to Windows (boo)
+      return temp2 ? NS_ERROR_UNEXPECTED : NS_ERROR_UNEXPECTED; // to make compiler not bletch on us
     }
-    queue->PutEvent(event.take(), lock);
+    queue->PutEvent(Move(aEvent), lock);
 
     // Make sure to grab the observer before dropping the lock, otherwise the
     // event that we just placed into the queue could run and eventually delete
     // this nsThread before the calling thread is scheduled again. We would then
     // crash while trying to access a dead nsThread.
     obs = mObserver;
   }
 
@@ -576,68 +573,59 @@ nsThread::PutEvent(already_AddRefed<nsIR
 
   return NS_OK;
 }
 
 nsresult
 nsThread::DispatchInternal(already_AddRefed<nsIRunnable>&& aEvent, uint32_t aFlags,
                            nsNestedEventTarget* aTarget)
 {
-  // We want to leak the reference when we fail to dispatch it, so that
-  // we won't release the event in a wrong thread.
-  LeakRefPtr<nsIRunnable> event(Move(aEvent));
+  nsCOMPtr<nsIRunnable> event(aEvent);
   if (NS_WARN_IF(!event)) {
     return NS_ERROR_INVALID_ARG;
   }
 
   if (gXPCOMThreadsShutDown && MAIN_THREAD != mIsMainThread && !aTarget) {
     NS_ASSERTION(false, "Failed Dispatch after xpcom-shutdown-threads");
     return NS_ERROR_ILLEGAL_DURING_SHUTDOWN;
   }
 
 #ifdef MOZ_TASK_TRACER
-  nsCOMPtr<nsIRunnable> tracedRunnable = CreateTracedRunnable(event.take());
+  nsCOMPtr<nsIRunnable> tracedRunnable = CreateTracedRunnable(event); // adds a ref
   (static_cast<TracedRunnable*>(tracedRunnable.get()))->DispatchTask();
-  // XXX tracedRunnable will always leaked when we fail to disptch.
   event = tracedRunnable.forget();
 #endif
 
   if (aFlags & DISPATCH_SYNC) {
     nsThread* thread = nsThreadManager::get()->GetCurrentThread();
     if (NS_WARN_IF(!thread)) {
       return NS_ERROR_NOT_AVAILABLE;
     }
 
     // XXX we should be able to do something better here... we should
     //     be able to monitor the slot occupied by this event and use
     //     that to tell us when the event has been processed.
 
     nsRefPtr<nsThreadSyncDispatch> wrapper =
-      new nsThreadSyncDispatch(thread, event.take());
+      new nsThreadSyncDispatch(thread, event.forget());
     nsresult rv = PutEvent(wrapper, aTarget); // hold a ref
     // Don't wait for the event to finish if we didn't dispatch it...
     if (NS_FAILED(rv)) {
-      // PutEvent leaked the wrapper runnable object on failure, so we
-      // explicitly release this object once for that. Note that this
-      // object will be released again soon because it exits the scope.
-      wrapper.get()->Release();
       return rv;
     }
 
     // Allows waiting; ensure no locks are held that would deadlock us!
     while (wrapper->IsPending()) {
       NS_ProcessNextEvent(thread, true);
     }
-    // NOTE that, unlike the behavior above, the event is not leaked by
-    // this place, while it is possible that the result is an error.
     return wrapper->Result();
   }
 
   NS_ASSERTION(aFlags == NS_DISPATCH_NORMAL, "unexpected dispatch flags");
-  return PutEvent(event.take(), aTarget);
+  return PutEvent(event.forget(), aTarget);
 }
 
 //-----------------------------------------------------------------------------
 // nsIEventTarget
 
 NS_IMETHODIMP
 nsThread::DispatchFromScript(nsIRunnable* aEvent, uint32_t aFlags)
 {
@@ -1177,16 +1165,30 @@ nsThread::SetScriptObserver(mozilla::Cyc
   }
 
   MOZ_ASSERT(!mScriptObserver);
   mScriptObserver = aScriptObserver;
 }
 
 //-----------------------------------------------------------------------------
 
+NS_IMETHODIMP
+nsThreadSyncDispatch::Run()
+{
+  if (mSyncTask) {
+    mResult = mSyncTask->Run();
+    mSyncTask = nullptr;
+    // unblock the origin thread
+    mOrigin->Dispatch(this, NS_DISPATCH_NORMAL);
+  }
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+
 NS_IMPL_ISUPPORTS(nsThread::nsNestedEventTarget, nsIEventTarget)
 
 NS_IMETHODIMP
 nsThread::nsNestedEventTarget::DispatchFromScript(nsIRunnable* aEvent, uint32_t aFlags)
 {
   nsCOMPtr<nsIRunnable> event(aEvent);
   return Dispatch(event.forget(), aFlags);
 }
--- a/xpcom/threads/nsThread.h
+++ b/xpcom/threads/nsThread.h
@@ -202,16 +202,46 @@ protected:
   nsTArray<nsAutoPtr<struct nsThreadShutdownContext>> mRequestedShutdownContexts;
 
   bool mShutdownRequired;
   // Set to true when events posted to this thread will never run.
   bool mEventsAreDoomed;
   MainThreadFlag mIsMainThread;
 };
 
+//-----------------------------------------------------------------------------
+
+class nsThreadSyncDispatch : public nsRunnable
+{
+public:
+  nsThreadSyncDispatch(nsIThread* aOrigin, already_AddRefed<nsIRunnable>&& aTask)
+    : mOrigin(aOrigin)
+    , mSyncTask(aTask)
+    , mResult(NS_ERROR_NOT_INITIALIZED)
+  {
+  }
+
+  bool IsPending()
+  {
+    return mSyncTask != nullptr;
+  }
+
+  nsresult Result()
+  {
+    return mResult;
+  }
+
+private:
+  NS_DECL_NSIRUNNABLE
+
+  nsCOMPtr<nsIThread> mOrigin;
+  nsCOMPtr<nsIRunnable> mSyncTask;
+  nsresult mResult;
+};
+
 #if defined(XP_UNIX) && !defined(ANDROID) && !defined(DEBUG) && HAVE_UALARM \
   && defined(_GNU_SOURCE)
 # define MOZ_CANARY
 
 extern int sCanaryOutputFD;
 #endif
 
 #endif  // nsThread_h__
--- a/xpcom/threads/nsThreadPool.cpp
+++ b/xpcom/threads/nsThreadPool.cpp
@@ -7,17 +7,16 @@
 #include "nsIClassInfoImpl.h"
 #include "nsThreadPool.h"
 #include "nsThreadManager.h"
 #include "nsThread.h"
 #include "nsMemory.h"
 #include "nsAutoPtr.h"
 #include "prinrval.h"
 #include "mozilla/Logging.h"
-#include "nsThreadSyncDispatch.h"
 
 using namespace mozilla;
 
 static PRLogModuleInfo*
 GetThreadPoolLog()
 {
   static PRLogModuleInfo* sLog;
   if (!sLog) {
deleted file mode 100644
--- a/xpcom/threads/nsThreadSyncDispatch.h
+++ /dev/null
@@ -1,51 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* 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 nsThreadSyncDispatch_h_
-#define nsThreadSyncDispatch_h_
-
-#include "nsThreadUtils.h"
-#include "LeakRefPtr.h"
-
-class nsThreadSyncDispatch : public nsRunnable
-{
-public:
-  nsThreadSyncDispatch(nsIThread* aOrigin, already_AddRefed<nsIRunnable>&& aTask)
-    : mOrigin(aOrigin)
-    , mSyncTask(mozilla::Move(aTask))
-    , mResult(NS_ERROR_NOT_INITIALIZED)
-  {
-  }
-
-  bool IsPending()
-  {
-    return !!mSyncTask;
-  }
-
-  nsresult Result()
-  {
-    return mResult;
-  }
-
-private:
-  NS_IMETHOD Run() override
-  {
-    if (nsCOMPtr<nsIRunnable> task = mSyncTask.take()) {
-      mResult = task->Run();
-      // unblock the origin thread
-      mOrigin->Dispatch(this, NS_DISPATCH_NORMAL);
-    }
-    return NS_OK;
-  }
-
-  nsCOMPtr<nsIThread> mOrigin;
-  // The task is leaked by default when Run() is not called, because
-  // otherwise we may release it in an incorrect thread.
-  mozilla::LeakRefPtr<nsIRunnable> mSyncTask;
-  nsresult mResult;
-};
-
-#endif // nsThreadSyncDispatch_h_