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 async Task WriterToUpgradeableReaderChain()
{
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.TryEnterUpgradeableReadLockAsync(TimeSpan.FromMilliseconds(10)));
True(ThreadPool.QueueUserWorkItem(ev => ev.Set(), are, false));
await rwLock.EnterUpgradeableReadLockAsync(DefaultTimeout);
rwLock.ExitUpgradeableReadLock();
task.SetResult(true);
});
are.WaitOne(DefaultTimeout);
rwLock.ExitWriteLock();
await task.Task;
}
public static void GracefulShutdown4()
{
using var @lock = new AsyncReaderWriterLock();
True(@lock.TryEnterWriteLock());
var acquisition1 = @lock.EnterUpgradeableReadLockAsync(CancellationToken.None);
False(acquisition1.IsCompleted);
var task = @lock.DisposeAsync();
False(task.IsCompleted);
var acquisition2 = @lock.EnterReadLockAsync(CancellationToken.None);
False(task.IsCompleted);
@lock.ExitWriteLock();
True(acquisition1.IsCompletedSuccessfully);
False(acquisition2.IsCompleted);
False(task.IsCompleted);
@lock.ExitUpgradeableReadLock();
True(acquisition2.IsFaulted);
True(task.IsCompletedSuccessfully);
Throws <ObjectDisposedException>(acquisition2.GetAwaiter().GetResult);
}