public static void WaitNotificationTest() { ThreadTestHelpers.RunTestInBackgroundThread(() => { var tsc = new TestSynchronizationContext(); SynchronizationContext.SetSynchronizationContext(tsc); Assert.Same(tsc, SynchronizationContext.Current); var e = new ManualResetEvent(false); tsc.WaitAction = () => e.Set(); Assert.False(tsc.IsWaitNotificationRequired()); Assert.False(e.WaitOne(0)); tsc.SetWaitNotificationRequired(); Assert.True(tsc.IsWaitNotificationRequired()); Assert.True(e.WaitOne(0)); var mres = new ManualResetEventSlim(); tsc.WaitAction = () => mres.Set(); mres.Reset(); mres.CheckedWait(); e.Reset(); tsc.WaitAction = () => e.Set(); SynchronizationContext.SetSynchronizationContext(new TestSynchronizationContext()); Assert.False(e.WaitOne(0)); SynchronizationContext.SetSynchronizationContext(tsc); Assert.True(e.WaitOne(0)); e.Reset(); e.CheckedWait(); e.Reset(); var lockObj = new object(); var lockAcquiredFromBackground = new AutoResetEvent(false); Action waitForThread; Thread t = ThreadTestHelpers.CreateGuardedThread(out waitForThread, () => { lock (lockObj) { lockAcquiredFromBackground.Set(); e.CheckedWait(); } }); t.IsBackground = true; t.Start(); lockAcquiredFromBackground.CheckedWait(); Assert.True(Monitor.TryEnter(lockObj, ThreadTestHelpers.UnexpectedTimeoutMilliseconds)); Monitor.Exit(lockObj); waitForThread(); e.Reset(); var m = new Mutex(); t = ThreadTestHelpers.CreateGuardedThread(out waitForThread, () => { m.CheckedWait(); try { lockAcquiredFromBackground.Set(); e.CheckedWait(); } finally { m.ReleaseMutex(); } }); t.IsBackground = true; t.Start(); lockAcquiredFromBackground.CheckedWait(); m.CheckedWait(); m.ReleaseMutex(); waitForThread(); }); }