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);
}
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);
}
/// <summary>
/// Acquires reader lock associated with the given object.
/// </summary>
/// <typeparam name="T">The type of the object to be locked.</typeparam>
/// <param name="obj">The object to be locked.</param>
/// <param name="token">The token that can be used to abort acquisition operation.</param>
/// <returns>The acquired lock holder.</returns>
public static Task <AsyncLock.Holder> AcquireWriteLockAsync <T>(this T obj, CancellationToken token)
where T : class => AsyncLock.WriteLock(obj.GetReaderWriterLock()).AcquireAsync(token);
/// <summary>
/// Acquires writer lock associated with the given object.
/// </summary>
/// <typeparam name="T">The type of the object to be locked.</typeparam>
/// <param name="obj">The object to be locked.</param>
/// <param name="timeout">The interval to wait for the lock.</param>
/// <returns>The acquired lock holder.</returns>
/// <exception cref="TimeoutException">The lock cannot be acquired during the specified amount of time.</exception>
public static Task <AsyncLock.Holder> AcquireWriteLockAsync <T>(this T obj, TimeSpan timeout)
where T : class => AsyncLock.WriteLock(obj.GetReaderWriterLock()).AcquireAsync(timeout);
