/// <summary>
/// Releases a reference to a doorman. If the ref-count hits zero, then the doorman is
/// returned to the pool (or is simply left for the garbage collector to cleanup if the
/// pool is already full).
/// </summary>
/// <param name="doorman">The <see cref="Doorman"/>.</param>
private static void ReleaseDoorman(Doorman doorman)
{
bool lockTaken = false;
try
{
spinLock.Enter(ref lockTaken);
if (--doorman.RefCount == 0)
{
Keys.Remove(doorman.Key);
if (Pool.Count < MaxPoolSize)
{
doorman.Key = null;
Pool.Push(doorman);
}
}
}
finally
{
if (lockTaken)
{
spinLock.Exit();
}
}
}
/// <inheritdoc />
public void Dispose()
{
lock (Keys)
{
Doorman doorman = Keys[this.key];
--doorman.RefCount;
if (doorman.RefCount == 0)
{
Keys.Remove(this.key);
doorman.Reset();
DoormanPool.Return(doorman);
}
doorman.Semaphore.Release();
}
}
/// <summary>
/// Locks the current thread in write mode asynchronously.
/// </summary>
/// <param name="key">The key identifying the specific object to lock against.</param>
/// <returns>
/// The <see cref="Task{IDisposable}"/> that will release the lock.
/// </returns>
public async Task <IDisposable> WriterLockAsync(string key)
{
Doorman doorman = GetDoorman(key);
return(await doorman.WriterLockAsync().ConfigureAwait(false));
}
/// <summary>
/// Locks the current thread in read mode asynchronously.
/// </summary>
/// <param name="key">The key identifying the specific object to lock against.</param>
/// <returns>
/// The <see cref="Task{IDisposable}"/> that will release the lock.
/// </returns>
public async Task <IDisposable> ReaderLockAsync(string key)
{
Doorman doorman = GetDoorman(key);
return(await doorman.ReaderLockAsync());
}
internal Releaser(Doorman toRelease, bool writer)
{
this.toRelease = toRelease;
this.writer = writer;
}
/// <summary>
/// Returns an doorman to the pool that was previously obtained using the <see cref="Rent"></see>
/// method on the same <see cref="DoormanPool"></see> instance.
/// </summary>
/// <param name="doorman">The doorman to return</param>
public static void Return(Doorman doorman)
{
Guard.NotNull(doorman, nameof(doorman));
Pool.Add(doorman);
}
/// <summary>
/// Locks the current thread in read mode asynchronously.
/// </summary>
/// <param name="key">The key identifying the specific object to lock against.</param>
/// <returns>
/// The <see cref="Task{IDisposable}"/> that will release the lock.
/// </returns>
public async Task <IDisposable> ReaderLockAsync(string key)
{
Doorman doorman = Keys.GetOrAdd(key, GetDoorman);
return(await doorman.ReaderLockAsync().ConfigureAwait(false));
}
