diff -r 000000000000 -r 6474c204b198 xpcom/tests/TestTimers.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/tests/TestTimers.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,186 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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 "TestHarness.h"
+
+#include "nsIThread.h"
+#include "nsITimer.h"
+
+#include "nsCOMPtr.h"
+#include "nsComponentManagerUtils.h"
+#include "nsServiceManagerUtils.h"
+#include "nsThreadUtils.h"
+#include "prinrval.h"
+#include "prmon.h"
+#include "prthread.h"
+#include "mozilla/Attributes.h"
+
+#include "mozilla/ReentrantMonitor.h"
+using namespace mozilla;
+
+typedef nsresult(*TestFuncPtr)();
+
+class AutoTestThread
+{
+public:
+  AutoTestThread() {
+    nsCOMPtr<nsIThread> newThread;
+    nsresult rv = NS_NewThread(getter_AddRefs(newThread));
+    if (NS_FAILED(rv))
+      return;
+
+    newThread.swap(mThread);
+  }
+
+  ~AutoTestThread() {
+    mThread->Shutdown();
+  }
+
+  operator nsIThread*() const {
+    return mThread;
+  }
+
+  nsIThread* operator->() const {
+    return mThread;
+  }
+
+private:
+  nsCOMPtr<nsIThread> mThread;
+};
+
+class AutoCreateAndDestroyReentrantMonitor
+{
+public:
+  AutoCreateAndDestroyReentrantMonitor() {
+    mReentrantMonitor = new ReentrantMonitor("TestTimers::AutoMon");
+    NS_ASSERTION(mReentrantMonitor, "Out of memory!");
+  }
+
+  ~AutoCreateAndDestroyReentrantMonitor() {
+    delete mReentrantMonitor;
+  }
+
+  operator ReentrantMonitor* () {
+    return mReentrantMonitor;
+  }
+
+private:
+  ReentrantMonitor* mReentrantMonitor;
+};
+
+class TimerCallback MOZ_FINAL : public nsITimerCallback
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  TimerCallback(nsIThread** aThreadPtr, ReentrantMonitor* aReentrantMonitor)
+  : mThreadPtr(aThreadPtr), mReentrantMonitor(aReentrantMonitor) { }
+
+  NS_IMETHOD Notify(nsITimer* aTimer) {
+    NS_ASSERTION(mThreadPtr, "Callback was not supposed to be called!");
+    nsCOMPtr<nsIThread> current(do_GetCurrentThread());
+
+    ReentrantMonitorAutoEnter mon(*mReentrantMonitor);
+
+    NS_ASSERTION(!*mThreadPtr, "Timer called back more than once!");
+    *mThreadPtr = current;
+
+    mon.Notify();
+
+    return NS_OK;
+  }
+private:
+  nsIThread** mThreadPtr;
+  ReentrantMonitor* mReentrantMonitor;
+};
+
+NS_IMPL_ISUPPORTS(TimerCallback, nsITimerCallback)
+
+nsresult
+TestTargetedTimers()
+{
+  AutoCreateAndDestroyReentrantMonitor newMon;
+  NS_ENSURE_TRUE(newMon, NS_ERROR_OUT_OF_MEMORY);
+
+  AutoTestThread testThread;
+  NS_ENSURE_TRUE(testThread, NS_ERROR_OUT_OF_MEMORY);
+
+  nsresult rv;
+  nsCOMPtr<nsITimer> timer = do_CreateInstance(NS_TIMER_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsIEventTarget* target = static_cast<nsIEventTarget*>(testThread);
+
+  rv = timer->SetTarget(target);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsIThread* notifiedThread = nullptr;
+
+  nsCOMPtr<nsITimerCallback> callback =
+    new TimerCallback(&notifiedThread, newMon);
+  NS_ENSURE_TRUE(callback, NS_ERROR_OUT_OF_MEMORY);
+
+  rv = timer->InitWithCallback(callback, PR_MillisecondsToInterval(2000),
+                               nsITimer::TYPE_ONE_SHOT);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  ReentrantMonitorAutoEnter mon(*newMon);
+  while (!notifiedThread) {
+    mon.Wait();
+  }
+  NS_ENSURE_TRUE(notifiedThread == testThread, NS_ERROR_FAILURE);
+
+  return NS_OK;
+}
+
+nsresult
+TestTimerWithStoppedTarget()
+{
+  AutoTestThread testThread;
+  NS_ENSURE_TRUE(testThread, NS_ERROR_OUT_OF_MEMORY);
+
+  nsresult rv;
+  nsCOMPtr<nsITimer> timer = do_CreateInstance(NS_TIMER_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsIEventTarget* target = static_cast<nsIEventTarget*>(testThread);
+
+  rv = timer->SetTarget(target);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // If this is called, we'll assert
+  nsCOMPtr<nsITimerCallback> callback =
+    new TimerCallback(nullptr, nullptr);
+  NS_ENSURE_TRUE(callback, NS_ERROR_OUT_OF_MEMORY);
+
+  rv = timer->InitWithCallback(callback, PR_MillisecondsToInterval(100),
+                               nsITimer::TYPE_ONE_SHOT);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  testThread->Shutdown();
+
+  PR_Sleep(400);
+
+  return NS_OK;
+}
+
+int main(int argc, char** argv)
+{
+  ScopedXPCOM xpcom("TestTimers");
+  NS_ENSURE_FALSE(xpcom.failed(), 1);
+
+  static TestFuncPtr testsToRun[] = {
+    TestTargetedTimers,
+    TestTimerWithStoppedTarget
+  };
+  static uint32_t testCount = sizeof(testsToRun) / sizeof(testsToRun[0]);
+
+  for (uint32_t i = 0; i < testCount; i++) {
+    nsresult rv = testsToRun[i]();
+    NS_ENSURE_SUCCESS(rv, 1);
+  }
+
+  return 0;
+}