private static AsyncLock GetExclusiveLock <T>(this T obj)
where T : class
{
AsyncLock @lock;
switch (obj)
{
case null:
throw new ArgumentNullException(nameof(obj));
case AsyncExclusiveLock exclusive:
@lock = AsyncLock.Exclusive(exclusive);
break;
case SemaphoreSlim semaphore:
@lock = AsyncLock.Semaphore(semaphore);
break;
case AsyncReaderWriterLock rwl:
@lock = AsyncLock.WriteLock(rwl);
break;
case ReaderWriterLockSlim _:
case WaitHandle _:
case ReaderWriterLock _:
throw new ArgumentException(ExceptionMessages.UnsupportedLockAcquisition, nameof(obj));
default:
@lock = AsyncLock.Exclusive(obj.GetUserData()
.GetOrSet(ExclusiveLock, () => new AsyncExclusiveLock()));
break;
}
return(@lock);
}
public static async Task SemaphoreLock()
{
using var sem = new SemaphoreSlim(3);
using var @lock = AsyncLock.Semaphore(sem);
var holder = await @lock.TryAcquireAsync(DefaultTimeout, CancellationToken.None);
if (holder)
{
}
else
{
throw new Exception();
}
Equal(2, sem.CurrentCount);
holder.Dispose();
Equal(3, sem.CurrentCount);
}
private static AsyncLock GetExclusiveLock <T>(this T obj)
where T : class
{
AsyncLock @lock;
switch (obj)
{
case null:
throw new ArgumentNullException(nameof(obj));
case AsyncSharedLock shared:
@lock = AsyncLock.Exclusive(shared);
break;
case AsyncExclusiveLock exclusive:
@lock = AsyncLock.Exclusive(exclusive);
break;
case SemaphoreSlim semaphore:
@lock = AsyncLock.Semaphore(semaphore);
break;
case AsyncReaderWriterLock rwl:
@lock = AsyncLock.WriteLock(rwl);
break;
case ReaderWriterLockSlim _:
case WaitHandle _:
case ReaderWriterLock _:
case string str when !(string.IsInterned(str) is null):
throw new InvalidOperationException(ExceptionMessages.UnsupportedLockAcquisition);
default:
@lock = AsyncLock.Exclusive(obj.GetUserData().GetOrSet(ExclusiveLock));
break;
}
return(@lock);
}
