public static async Task TrivialLock()
{
using (var rwLock = new AsyncReaderWriterLock())
{
//read lock
True(await rwLock.TryEnterReadLock(TimeSpan.FromMilliseconds(10)));
True(await rwLock.TryEnterReadLock(TimeSpan.FromMilliseconds(10)));
False(await rwLock.TryEnterWriteLock(TimeSpan.FromMilliseconds(20)));
rwLock.ExitReadLock();
False(await rwLock.TryEnterWriteLock(TimeSpan.FromMilliseconds(20)));
rwLock.ExitReadLock();
//write lock
True(await rwLock.TryEnterWriteLock(TimeSpan.FromMilliseconds(20)));
False(await rwLock.TryEnterReadLock(TimeSpan.FromMilliseconds(20)));
rwLock.ExitWriteLock();
//upgradeable read lock
True(await rwLock.TryEnterReadLock(TimeSpan.FromMilliseconds(10)));
True(await rwLock.TryEnterReadLock(TimeSpan.FromMilliseconds(10)));
True(await rwLock.TryEnterUpgradeableReadLock(TimeSpan.FromMilliseconds(20)));
False(await rwLock.TryEnterWriteLock(TimeSpan.FromMilliseconds(20)));
False(await rwLock.TryEnterUpgradeableReadLock(TimeSpan.FromMilliseconds(20)));
rwLock.ExitUpgradeableReadLock();
False(await rwLock.TryEnterWriteLock(TimeSpan.FromMilliseconds(20)));
True(await rwLock.TryEnterUpgradeableReadLock(TimeSpan.FromMilliseconds(20)));
rwLock.ExitReadLock();
False(await rwLock.TryEnterUpgradeableReadLock(TimeSpan.FromMilliseconds(20)));
rwLock.ExitReadLock();
rwLock.ExitUpgradeableReadLock();
}
}
public static async Task InvalidExits()
{
using (var rwLock = new AsyncReaderWriterLock())
{
Throws <SynchronizationLockException>(rwLock.ExitReadLock);
Throws <SynchronizationLockException>(rwLock.ExitUpgradeableReadLock);
Throws <SynchronizationLockException>(rwLock.ExitWriteLock);
await rwLock.EnterReadLock(TimeSpan.FromMilliseconds(10));
Throws <SynchronizationLockException>(rwLock.ExitUpgradeableReadLock);
Throws <SynchronizationLockException>(rwLock.ExitWriteLock);
rwLock.ExitReadLock();
await rwLock.EnterUpgradeableReadLock(TimeSpan.FromMilliseconds(10));
Throws <SynchronizationLockException>(rwLock.ExitReadLock);
Throws <SynchronizationLockException>(rwLock.ExitWriteLock);
rwLock.ExitUpgradeableReadLock();
await rwLock.EnterWriteLock(TimeSpan.FromMilliseconds(10));
Throws <SynchronizationLockException>(rwLock.ExitReadLock);
Throws <SynchronizationLockException>(rwLock.ExitUpgradeableReadLock);
rwLock.ExitWriteLock();
}
}
public static void GracefulShutdown2()
{
using var @lock = new AsyncReaderWriterLock();
True(@lock.TryEnterReadLock());
var task = @lock.DisposeAsync();
False(task.IsCompleted);
var acquisition = @lock.EnterWriteLockAsync(CancellationToken.None);
False(acquisition.IsCompleted);
@lock.ExitReadLock();
True(task.IsCompletedSuccessfully);
True(acquisition.IsFaulted);
Throws <ObjectDisposedException>(acquisition.GetAwaiter().GetResult);
}
public static void OptimisticRead()
{
using var rwLock = new AsyncReaderWriterLock();
var stamp = rwLock.TryOptimisticRead();
True(stamp.IsValid);
True(rwLock.TryEnterReadLock());
Equal(1, rwLock.CurrentReadCount);
True(stamp.IsValid);
rwLock.ExitReadLock();
Equal(stamp, rwLock.TryOptimisticRead());
True(rwLock.TryEnterWriteLock());
False(rwLock.IsReadLockHeld);
True(rwLock.IsWriteLockHeld);
False(stamp.IsValid);
}
public static async Task WriterToReaderChain()
{
using var are = new AutoResetEvent(false);
using var rwLock = new AsyncReaderWriterLock();
await rwLock.EnterWriteLockAsync(DefaultTimeout);
var task = new TaskCompletionSource <bool>();
ThreadPool.QueueUserWorkItem(async state =>
{
False(await rwLock.TryEnterReadLockAsync(TimeSpan.FromMilliseconds(10)));
True(ThreadPool.QueueUserWorkItem(static ev => ev.Set(), are, false));
await rwLock.EnterReadLockAsync(DefaultTimeout);
rwLock.ExitReadLock();
task.SetResult(true);
});
