public void ReaderWriterLockBasicAsync()
{
int maxRead = 0;
int maxWrite = 0;
object @lock = new object();
SlimReadWriteLock rwl = new SlimReadWriteLock();
Action readSub = () =>
{
Verify.False(rwl.EnteredWriters > 0, "Read and write locks held concurrently");
lock (@lock)
{
int readers = rwl.EnteredReaders;
if (readers > maxRead)
{
maxRead = readers;
}
int writers = rwl.EnteredWriters;
if (writers > maxWrite)
{
maxWrite = writers;
}
}
// simulate long running read operation
Thread.Sleep(TimeSpan.FromMilliseconds(1));
Verify.False(rwl.IsReadLockEntered && rwl.IsWriteLockEntered, "Read and write locks held concurrently");
};
Func<Task> reader = async () =>
{
using (rwl.EnterReadLock())
{
await Task.Run(readSub);
}
};
Action writeSub = () =>
{
Verify.False(rwl.EnteredReaders > 0, "Read and write locks held concurrently");
lock (@lock)
{
int readers = rwl.EnteredReaders;
if (readers > maxRead)
{
maxRead = readers;
}
int writers = rwl.EnteredWriters;
if (writers > maxWrite)
{
maxWrite = writers;
}
}
// simulate long running write operation
Thread.Sleep(TimeSpan.FromMilliseconds(10));
Verify.False(rwl.IsReadLockEntered && rwl.IsWriteLockEntered, "Read and write locks held concurrently");
Verify.True(rwl.WaitingReaders > 0, "Zero waiting readers when greater than zero expected");
};
Func<Task> writer = async () =>
{
using (rwl.EnterWriteLock())
{
await Task.Run(writeSub);
}
};
var tasks = new Task[Parallelism];
for (int i = 0; i < tasks.Length; i++)
{
tasks[i] = Task.Run(i == Parallelism / 2 ? writer : reader);
Thread.Sleep(1);
}
Task.WaitAll(tasks);
Verify.Equal(1, maxWrite);
Verify.True(maxRead > 1, "Parallel reads were not encoutnered");
Verify.Equal(0, rwl.EnteredReaders);
Verify.Equal(0, rwl.EnteredWriters);
}
public void ReaderWriterLockExcptionalSync()
{
SlimReadWriteLock rwl = new SlimReadWriteLock();
Action reader = () =>
{
try
{
using (rwl.EnterReadLock())
{
Verify.False(rwl.IsReadLockEntered && rwl.IsWriteLockEntered);
throw new Exception();
}
}
catch
{
}
};
Action writer = () =>
{
try
{
using (rwl.EnterWriteLock())
{
Verify.False(rwl.IsReadLockEntered && rwl.IsWriteLockEntered);
throw new Exception();
}
}
catch
{
}
};
var tasks = new Task[Parallelism];
for (int i = 0; i < tasks.Length; i++)
{
tasks[i] = Task.Run(i == Parallelism / 2 ? writer : reader);
Thread.Sleep(1);
}
Task.WaitAll(tasks);
Verify.Equal(0, rwl.EnteredReaders);
Verify.Equal(0, rwl.EnteredWriters); ;
}
public void ReaderWriterLockExcptionalAsync()
{
SlimReadWriteLock rwl = new SlimReadWriteLock();
Action readerSub = () =>
{
Verify.False(rwl.IsReadLockEntered && rwl.IsWriteLockEntered);
// simulate long running read operation
Thread.Sleep(TimeSpan.FromMilliseconds(1));
throw new Exception();
};
Func<Task> reader = async () =>
{
try
{
using (rwl.EnterReadLock())
{
await Task.Run(readerSub);
}
}
catch
{
}
};
Action writerSub = () =>
{
Verify.False(rwl.IsReadLockEntered && rwl.IsWriteLockEntered);
// simulate long runngin write operation
Thread.Sleep(TimeSpan.FromMilliseconds(10));
throw new Exception();
};
Func<Task> writer = async () =>
{
try
{
using (rwl.EnterWriteLock())
{
await Task.Run(writerSub);
}
}
catch
{
}
};
var tasks = new Task[Parallelism];
for (int i = 0; i < tasks.Length; i++)
{
tasks[i] = Task.Run(i == Parallelism / 2 ? writer : reader);
Thread.Sleep(1);
}
Task.WaitAll(tasks);
Verify.Equal(0, rwl.EnteredReaders);
Verify.Equal(0, rwl.EnteredWriters);
}