public void Monitor_Enter_SetsLockTaken()
{
bool lockTaken = false;
var obj = new object();
Monitor.Enter(obj, ref lockTaken);
Assert.IsTrue(lockTaken);
Monitor.Exit(obj);
// The documentation does not specifies that lockTaken variable is
// set to false after Exit is called
// Assert.IsFalse(lockTaken);
}
public void Monitor_Enter_Invalid()
{
bool lockTaken = false;
var obj = new object();
AssertExtensions.Throws <ArgumentNullException>("obj", () => Monitor.Enter(null));
AssertExtensions.Throws <ArgumentNullException>("obj", () => Monitor.Enter(null, ref lockTaken));
Assert.IsFalse(lockTaken);
lockTaken = true;
AssertExtensions.Throws <ArgumentException>("lockTaken", () => Monitor.Enter(obj, ref lockTaken));
//Assert.IsFalse(lockTaken);
Assert.IsTrue(lockTaken);
}
public void Monitor_BasicRecursion()
{
var obj = new object();
Assert.IsTrue(Monitor.TryEnter(obj));
Assert.IsTrue(Monitor.TryEnter(obj));
Monitor.Exit(obj);
//Assert.IsTrue(Monitor.IsEntered(obj));
Monitor.Enter(obj);
//Assert.IsTrue(Monitor.IsEntered(obj));
Monitor.Exit(obj);
//Assert.IsTrue(Monitor.IsEntered(obj));
Monitor.Exit(obj);
//Assert.IsFalse(Monitor.IsEntered(obj));
}
public void Monitor_WaitTest()
{
var obj = new object();
var waitTests =
new Func <bool>[]
{
() => Monitor.Wait(obj, FailTimeoutMilliseconds),
() => Monitor.Wait(obj, FailTimeoutMilliseconds),
() => Monitor.Wait(obj, TimeSpan.FromMilliseconds(FailTimeoutMilliseconds)),
() => Monitor.Wait(obj, TimeSpan.FromMilliseconds(FailTimeoutMilliseconds)),
};
var t =
new Thread(() =>
{
Monitor.Enter(obj);
for (int i = 0; i < waitTests.Length; ++i)
{
Monitor.Pulse(obj);
Monitor.Wait(obj, FailTimeoutMilliseconds);
}
Monitor.Exit(obj);
});
t.IsBackground = true;
Monitor.Enter(obj);
t.Start();
int counter = 0;
foreach (var waitTest in waitTests)
{
Assert.IsTrue(waitTest(), "#" + counter.ToString());
Monitor.Pulse(obj);
counter++;
}
Monitor.Exit(obj);
}
/// <summary>
/// Blocks the current thread until it can enter the <see cref="SemaphoreSlim"/>,
/// 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 current thread successfully entered the <see cref="SemaphoreSlim"/>; otherwise, false.</returns>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="millisecondsTimeout"/> is a negative number other than -1,
/// which represents an infinite time-out.</exception>
/// <exception cref="System.OperationCanceledException"><paramref name="cancellationToken"/> was canceled.</exception>
public bool Wait(int millisecondsTimeout, CancellationToken cancellationToken)
{
CheckDispose();
// Validate input
if (millisecondsTimeout < -1)
{
throw new ArgumentOutOfRangeException(
"totalMilliSeconds", millisecondsTimeout, GetResourceString("SemaphoreSlim_Wait_TimeoutWrong"));
}
cancellationToken.ThrowIfCancellationRequested();
long startTimeTicks = 0;
if (millisecondsTimeout != Timeout.Infinite && millisecondsTimeout > 0)
{
startTimeTicks = DateTime.UtcNow.Ticks;
}
bool lockTaken = false;
//Register for cancellation outside of the main lock.
//NOTE: Register/deregister inside the lock can deadlock as different lock acquisition orders could
// occur for (1)this.m_lockObj and (2)cts.internalLock
CancellationTokenRegistration cancellationTokenRegistration = cancellationToken.Register(s_cancellationTokenCanceledEventHandler, this);
try
{
// Perf: first spin wait for the count to be positive, but only up to the first planned yield.
// This additional amount of spinwaiting in addition
// to Monitor2.Enter()’s spinwaiting has shown measurable perf gains in test scenarios.
//
SpinWait spin = new SpinWait();
while (m_currentCount == 0 && !spin.NextSpinWillYield)
{
spin.SpinOnce();
}
// entering the lock and incrementing waiters must not suffer a thread-abort, else we cannot
// clean up m_waitCount correctly, which may lead to deadlock due to non-woken waiters.
try { }
finally
{
Monitor2.Enter(m_lockObj, ref lockTaken);
if (lockTaken)
{
m_waitCount++;
}
}
// If the count > 0 we are good to move on.
// If not, then wait if we were given allowed some wait duration
if (m_currentCount == 0)
{
if (millisecondsTimeout == 0)
{
return(false);
}
// Prepare for the main wait...
// wait until the count become greater than zero or the timeout is expired
if (!WaitUntilCountOrTimeout(millisecondsTimeout, startTimeTicks, cancellationToken))
{
return(false);
}
}
// At this point the count should be greater than zero
Contract.Assert(m_currentCount > 0);
m_currentCount--;
// Exposing wait handle which is lazily initialized if needed
if (m_waitHandle != null && m_currentCount == 0)
{
m_waitHandle.Reset();
}
}
finally
{
// Release the lock
if (lockTaken)
{
m_waitCount--;
Monitor.Exit(m_lockObj);
}
// Unregister the cancellation callback.
cancellationTokenRegistration.Dispose();
}
return(true);
}
