private bool WaitForSignal(int timeoutMs)
{
Debug.Assert(timeoutMs > 0 || timeoutMs == -1);
_onWait();
while (true)
{
if (!WaitCore(timeoutMs))
{
// Unregister the waiter. The wait subsystem used above guarantees that a thread that wakes due to a timeout does
// not observe a signal to the object being waited upon.
_separated._counts.InterlockedDecrementWaiterCount();
return(false);
}
// Unregister the waiter if this thread will not be waiting anymore, and try to acquire the semaphore
Counts counts = _separated._counts;
while (true)
{
Debug.Assert(counts.WaiterCount != 0);
Counts newCounts = counts;
if (counts.SignalCount != 0)
{
newCounts.DecrementSignalCount();
newCounts.DecrementWaiterCount();
}
// This waiter has woken up and this needs to be reflected in the count of waiters signaled to wake
if (counts.CountOfWaitersSignaledToWake != 0)
{
newCounts.DecrementCountOfWaitersSignaledToWake();
}
Counts countsBeforeUpdate = _separated._counts.InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
if (counts.SignalCount != 0)
{
return(true);
}
break;
}
counts = countsBeforeUpdate;
}
}
}