AutoResetEvent.h

// AutoResetEvent.h
//
// Author David Barrett-Lennard
// (C)opyright Cedanet Pty Ltd 2013

#pragma once
#ifndef Ceda_cxMessage_AutoResetEvent_H
#define Ceda_cxMessage_AutoResetEvent_H

#include "cxMessage.h"
#include "Ceda/cxUtils/CedaAssert.h"
#include <mutex>
#include <condition_variable>

namespace ceda
{
class AutoResetEvent
{
    cxNotCloneable(AutoResetEvent)

public:
    explicit AutoResetEvent(bool signaled = false) : signaled_(signaled) {}

    void Signal()
    {
        std::lock_guard<std::mutex> lock(mutex_);
        signaled_ = true;
        cv_.notify_one();
    }

    void Reset()
    {
        std::lock_guard<std::mutex> lock(mutex_);
        signaled_ = false;
    }

    void Wait()
    {
        std::unique_lock<std::mutex> lock(mutex_);
        cv_.wait(lock,[this]{return signaled_;});
        signaled_ = false; // auto reset
    }

    // Wait with a timeout.  
    // Returns true if the wait was completed successfully because the event had been signalled
    bool Wait(uint32 msec)
    {
        std::unique_lock<std::mutex> lock(mutex_);
        if (cv_.wait_for(lock,std::chrono::milliseconds(msec),[this]{return signaled_;}))
        {
            cxAssert(signaled_);
            signaled_ = false; // auto reset
            return true;
        }
        else
        {
            cxAssert(!signaled_);
            return false;
        }
    }

private:
    bool signaled_;
    std::mutex mutex_;
    std::condition_variable cv_;
};
} // namespace ceda
#endif // include guard