public void Invoke(Action action)
{
// Execute now if already on the thread
if (Thread.CurrentThread == _thread)
{
action();
}
else
{
lock (action)
{
// Schedule action
InvokeLater(action);
// Wait for action to complete
ThreadMonitor.Wait(action);
}
}
}
public void TestComplexMonitor()
{
this.Test(async() =>
{
object syncObject = new object();
bool waiting = false;
List <string> log = new List <string>();
Task t1 = Task.Run(() =>
{
Monitor.Enter(syncObject);
log.Add("waiting");
waiting = true;
Monitor.Wait(syncObject);
log.Add("received pulse");
Monitor.Exit(syncObject);
});
Task t2 = Task.Run(async() =>
{
while (!waiting)
{
await Task.Delay(1);
}
Monitor.Enter(syncObject);
Monitor.Pulse(syncObject);
log.Add("pulsed");
Monitor.Exit(syncObject);
});
await Task.WhenAll(t1, t2);
string expected = "waiting, pulsed, received pulse";
string actual = string.Join(", ", log);
Specification.Assert(expected == actual, "ControlledMonitor out of order, '{0}' instead of '{1}'", actual, expected);
},
this.GetConfiguration());
}
public void DefaultTest() {
var messages = 0;
var warnings = 0;
var exceptions = 0;
var task = new Monitor();
task.Message += (sender, args) => {
messages++;
};
task.Exception += (sender, args) => {
exceptions++;
};
task.Warning += (sender, args) => {
warnings++;
};
task.Execute(token => {
task.OnMessage("m1");
task.OnMessage("m2");
task.OnMessage("m3");
Thread.Sleep(200);
task.OnWarning("w1");
task.OnWarning("w2");
task.OnException(new Exception());
});
Assert.AreEqual(true, task.IsRunning);
task.Wait();
Assert.AreEqual(3, messages);
Assert.AreEqual(2, warnings);
Assert.AreEqual(1, exceptions);
}
/// <summary> /// Releases the lock on an object and blocks the current thread until it reacquires /// the lock. If the specified time-out interval elapses, the thread enters the ready /// queue. /// </summary> /// <param name="timeout">A System.TimeSpan representing the amount of time to wait before the thread enters /// the ready queue.</param> /// <returns>True if the lock was reacquired before the specified time elapsed; false if the /// lock was reacquired after the specified time elapsed. The method does not return /// until the lock is reacquired.</returns> public virtual bool Wait(TimeSpan timeout) => SystemMonitor.Wait(this.SyncObject, timeout);
/// <summary> /// Releases the lock on an object and blocks the current thread until it reacquires /// the lock. If the specified time-out interval elapses, the thread enters the ready /// queue. /// </summary> /// <param name="millisecondsTimeout">The number of milliseconds to wait before the thread enters the ready queue.</param> /// <returns>True if the lock was reacquired before the specified time elapsed; false if the /// lock was reacquired after the specified time elapsed. The method does not return /// until the lock is reacquired.</returns> public virtual bool Wait(int millisecondsTimeout) => SystemMonitor.Wait(this.SyncObject, millisecondsTimeout);
/// <summary> /// Releases the lock on an object and blocks the current thread until it reacquires /// the lock. /// </summary> /// <returns>True if the call returned because the caller reacquired the lock for the specified /// object. This method does not return if the lock is not reacquired.</returns> public virtual bool Wait() => SystemMonitor.Wait(this.SyncObject);
/// <summary> /// Releases the lock on an object and blocks the current thread until it reacquires /// the lock. /// </summary> /// <returns>True if the call returned because the caller reacquired the lock for the specified /// object. This method does not return if the lock is not reacquired.</returns> internal virtual bool Wait() => SystemMonitor.Wait(this.SyncObject);
/// <summary>
/// Blocks the current thread until the current <see cref="ManualResetEventSlim"/> is set, using a
/// 32-bit signed integer to measure the time interval, while observing a <see
/// cref="T:System.Threading.CancellationToken"/>.
/// </summary>
/// <param name="millisecondsTimeout">The number of milliseconds to wait, or <see
/// cref="Timeout.Infinite"/>(-1) to wait indefinitely.</param>
/// <param name="cancellationToken">The <see cref="T:System.Threading.CancellationToken"/> to
/// observe.</param>
/// <returns>true if the <see cref="System.Threading.ManualResetEventSlim"/> was set; otherwise,
/// false.</returns>
/// <exception cref="T:System.ArgumentOutOfRangeException"><paramref name="millisecondsTimeout"/> is a
/// negative number other than -1, which represents an infinite time-out.</exception>
/// <exception cref="T:System.InvalidOperationException">
/// The maximum number of waiters has been exceeded.
/// </exception>
/// <exception cref="T:System.Threading.OperationCanceledException"><paramref
/// name="cancellationToken"/> was canceled.</exception>
public bool Wait(int millisecondsTimeout, CancellationToken cancellationToken)
{
ThrowIfDisposed();
cancellationToken.ThrowIfCancellationRequested(); // an early convenience check
if (millisecondsTimeout < -1)
{
throw new ArgumentOutOfRangeException(nameof(millisecondsTimeout));
}
if (!IsSet)
{
if (millisecondsTimeout == 0)
{
// For 0-timeouts, we just return immediately.
return(false);
}
// We spin briefly before falling back to allocating and/or waiting on a true event.
uint startTime = 0;
bool bNeedTimeoutAdjustment = false;
int realMillisecondsTimeout = millisecondsTimeout; //this will be adjusted if necessary.
if (millisecondsTimeout != Timeout.Infinite)
{
// We will account for time spent spinning, so that we can decrement it from our
// timeout. In most cases the time spent in this section will be negligible. But
// we can't discount the possibility of our thread being switched out for a lengthy
// period of time. The timeout adjustments only take effect when and if we actually
// decide to block in the kernel below.
startTime = TimeoutHelper.GetTime();
bNeedTimeoutAdjustment = true;
}
// Spin
int spinCount = SpinCount;
var spinner = new SpinWait();
while (spinner.Count < spinCount)
{
spinner.SpinOnce(sleep1Threshold: -1);
if (IsSet)
{
return(true);
}
if (spinner.Count >= 100 && spinner.Count % 10 == 0) // check the cancellation token if the user passed a very large spin count
{
cancellationToken.ThrowIfCancellationRequested();
}
}
// Now enter the lock and wait.
EnsureLockObjectCreated();
// We must register and unregister the token outside of the lock, to avoid deadlocks.
using (cancellationToken.UnsafeRegister(s_cancellationTokenCallback, this))
{
lock (m_lock)
{
// Loop to cope with spurious wakeups from other waits being canceled
while (!IsSet)
{
// If our token was canceled, we must throw and exit.
cancellationToken.ThrowIfCancellationRequested();
//update timeout (delays in wait commencement are due to spinning and/or spurious wakeups from other waits being canceled)
if (bNeedTimeoutAdjustment)
{
realMillisecondsTimeout = TimeoutHelper.UpdateTimeOut(startTime, millisecondsTimeout);
if (realMillisecondsTimeout <= 0)
{
return(false);
}
}
// There is a race condition that Set will fail to see that there are waiters as Set does not take the lock,
// so after updating waiters, we must check IsSet again.
// Also, we must ensure there cannot be any reordering of the assignment to Waiters and the
// read from IsSet. This is guaranteed as Waiters{set;} involves an Interlocked.CompareExchange
// operation which provides a full memory barrier.
// If we see IsSet=false, then we are guaranteed that Set() will see that we are
// waiting and will pulse the monitor correctly.
Waiters = Waiters + 1;
if (IsSet) //This check must occur after updating Waiters.
{
Waiters--; //revert the increment.
return(true);
}
// Now finally perform the wait.
try
{
// ** the actual wait **
if (!Monitor.Wait(m_lock, realMillisecondsTimeout))
{
return(false); //return immediately if the timeout has expired.
}
}
finally
{
// Clean up: we're done waiting.
Waiters = Waiters - 1;
}
// Now just loop back around, and the right thing will happen. Either:
// 1. We had a spurious wake-up due to some other wait being canceled via a different cancellationToken (rewait)
// or 2. the wait was successful. (the loop will break)
}
}
}
} // automatically disposes (and unregisters) the callback
return(true); //done. The wait was satisfied.
}
