/// <summary>Tries to enter the lock in read mode, with an optional integer time-out.</summary>
/// <returns>true if the calling thread entered read mode, otherwise, false.</returns>
/// <param name="millisecondsTimeout">The number of milliseconds to wait, or -1 (<see cref="F:System.Threading.Timeout.Infinite" />) to wait indefinitely.</param>
/// <exception cref="T:System.Threading.LockRecursionException">The <see cref="P:System.Threading.ReaderWriterLockSlim.RecursionPolicy" /> property is <see cref="F:System.Threading.LockRecursionPolicy.NoRecursion" /> and the current thread has already entered the lock. -or-The recursion number would exceed the capacity of the counter. The limit is so large that applications should never encounter it.</exception>
/// <exception cref="T:System.ArgumentOutOfRangeException">The value of <paramref name="millisecondsTimeout" /> is negative, but it is not equal to <see cref="F:System.Threading.Timeout.Infinite" /> (-1), which is the only negative value allowed. </exception>
public bool TryEnterReadLock(int millisecondsTimeout)
{
if (millisecondsTimeout < -1)
{
throw new ArgumentOutOfRangeException("millisecondsTimeout");
}
if (this.read_locks == null)
{
throw new ObjectDisposedException(null);
}
if (Thread.CurrentThread == this.write_thread)
{
throw new LockRecursionException("Read lock cannot be acquired while write lock is held");
}
this.EnterMyLock();
ReaderWriterLockSlim.LockDetails readLockDetails = this.GetReadLockDetails(Thread.CurrentThread.ManagedThreadId, true);
if (readLockDetails.ReadLocks != 0)
{
this.ExitMyLock();
throw new LockRecursionException("Recursive read lock can only be aquired in SupportsRecursion mode");
}
readLockDetails.ReadLocks++;
while (this.owners < 0 || this.numWriteWaiters != 0u)
{
if (millisecondsTimeout == 0)
{
this.ExitMyLock();
return(false);
}
if (this.readEvent == null)
{
this.LazyCreateEvent(ref this.readEvent, false);
}
else if (!this.WaitOnEvent(this.readEvent, ref this.numReadWaiters, millisecondsTimeout))
{
return(false);
}
}
this.owners++;
this.ExitMyLock();
return(true);
}
/// <summary>Tries to enter the lock in write mode, with an optional time-out.</summary>
/// <returns>true if the calling thread entered write mode, otherwise, false.</returns>
/// <param name="millisecondsTimeout">The number of milliseconds to wait, or -1 (<see cref="F:System.Threading.Timeout.Infinite" />) to wait indefinitely.</param>
/// <exception cref="T:System.Threading.LockRecursionException">The <see cref="P:System.Threading.ReaderWriterLockSlim.RecursionPolicy" /> property is <see cref="F:System.Threading.LockRecursionPolicy.NoRecursion" /> and the current thread has already entered the lock. -or-The current thread initially entered the lock in read mode, and therefore trying to enter write mode would create the possibility of a deadlock. -or-The recursion number would exceed the capacity of the counter. The limit is so large that applications should never encounter it.</exception>
/// <exception cref="T:System.ArgumentOutOfRangeException">The value of <paramref name="millisecondsTimeout" /> is negative, but it is not equal to <see cref="F:System.Threading.Timeout.Infinite" /> (-1), which is the only negative value allowed. </exception>
public bool TryEnterWriteLock(int millisecondsTimeout)
{
if (millisecondsTimeout < -1)
{
throw new ArgumentOutOfRangeException("millisecondsTimeout");
}
if (this.read_locks == null)
{
throw new ObjectDisposedException(null);
}
if (this.IsWriteLockHeld)
{
throw new LockRecursionException();
}
this.EnterMyLock();
ReaderWriterLockSlim.LockDetails readLockDetails = this.GetReadLockDetails(Thread.CurrentThread.ManagedThreadId, false);
if (readLockDetails != null && readLockDetails.ReadLocks > 0)
{
this.ExitMyLock();
throw new LockRecursionException("Write lock cannot be acquired while read lock is held");
}
while (this.owners != 0)
{
if (this.owners == 1 && this.upgradable_thread == Thread.CurrentThread)
{
this.owners = -1;
this.write_thread = Thread.CurrentThread;
IL_178:
this.ExitMyLock();
return(true);
}
if (millisecondsTimeout == 0)
{
this.ExitMyLock();
return(false);
}
if (this.upgradable_thread == Thread.CurrentThread)
{
if (this.upgradeEvent == null)
{
this.LazyCreateEvent(ref this.upgradeEvent, false);
}
else
{
if (this.numUpgradeWaiters > 0u)
{
this.ExitMyLock();
throw new ApplicationException("Upgrading lock to writer lock already in process, deadlock");
}
if (!this.WaitOnEvent(this.upgradeEvent, ref this.numUpgradeWaiters, millisecondsTimeout))
{
return(false);
}
}
}
else if (this.writeEvent == null)
{
this.LazyCreateEvent(ref this.writeEvent, true);
}
else if (!this.WaitOnEvent(this.writeEvent, ref this.numWriteWaiters, millisecondsTimeout))
{
return(false);
}
}
this.owners = -1;
this.write_thread = Thread.CurrentThread;
goto IL_178;
}
