Condition variables in C# [closed]

Answer 1

This version atomically unlocks a Mutex or ReaderWriterLockSlim while waiting for signalling, and relocks it before returning - which is the posix way.

using System.Collections.Concurrent;

namespace System.Threading.More {
    public class ConditionVariable {
        private readonly ConcurrentQueue _waitingThreads = new ConcurrentQueue();

        /// 

        ///     Atomically unlocks and waits for a signal.
        ///     Then relocks the mutex before returning
        /// 
        /// 
        public void Wait(Mutex mutex) {
            if (mutex == null) {
                throw new ArgumentNullException("mutex");
            }
            var waitHandle = new ManualResetEventSlim();
            try {
                _waitingThreads.Enqueue(waitHandle);
                mutex.ReleaseMutex();
                waitHandle.Wait();
            } finally {
                waitHandle.Dispose();
            }
            mutex.WaitOne();
        }

        public void WaitRead(ReaderWriterLockSlim readerWriterLock) {
            if (readerWriterLock == null) {
                throw new ArgumentNullException("readerWriterLock");
            }
            var waitHandle = new ManualResetEventSlim();
            try {
                _waitingThreads.Enqueue(waitHandle);
                readerWriterLock.ExitReadLock();
                waitHandle.Wait();
            } finally {
                waitHandle.Dispose();
            }
            readerWriterLock.EnterReadLock();
        }

        public void Signal() {
            ManualResetEventSlim waitHandle;
            if (_waitingThreads.TryDequeue(out waitHandle)) {
                waitHandle.Set();
            }
        }

        public void Broadcast() {
            ManualResetEventSlim waitHandle;
            while (_waitingThreads.TryDequeue(out waitHandle)) {
                waitHandle.Set();
            }
        }
    }
}