AutoResetEvent.hpp

//
//  Copyright PHOENIX CONTACT Electronics GmbH
//
#pragma once
#include "Arp/System/Core/Arp.h"
 
#include <boost/thread/locks.hpp>
#include <boost/interprocess/sync/interprocess_mutex.hpp>
#include <boost/interprocess/sync/interprocess_condition.hpp>
 
#include <mutex>
#include <thread>
#include <memory>
 
 
namespace Arp { namespace System { namespace Commons { namespace Ipc
{
 
class AutoResetEvent
{
public: // typedefs
    typedef std::shared_ptr<AutoResetEvent> Ptr;
 
public:
    explicit AutoResetEvent(bool initial = false);
 
    void Set(void);
 
    void Reset(void);
 
    bool WaitOne(unsigned long timeoutMs = 0);
 
private: // methods.
    bool WaitOneInfinite(void);
    bool TimedWaitOne(unsigned long timeoutMs);
 
private: // deleted methods
    AutoResetEvent(const AutoResetEvent&) = delete;
    AutoResetEvent& operator=(const AutoResetEvent&) = delete;
 
private: // fields.
    bool flag;
    boost::interprocess::interprocess_mutex syncRoot;
    boost::interprocess::interprocess_condition signal;
};
 
// inline methods of class AutoResetEvent
inline AutoResetEvent::AutoResetEvent(bool initial)
    : flag(initial)
{
}
 
inline void AutoResetEvent::Set()
{
    boost::lock_guard<boost::interprocess::interprocess_mutex> lock(this->syncRoot);
    this->flag = true;
    this->signal.notify_one();
}
 
inline void AutoResetEvent::Reset()
{
    boost::lock_guard<boost::interprocess::interprocess_mutex> lock(this->syncRoot);
    this->flag = false;
}
 
inline bool AutoResetEvent::WaitOne(unsigned long timeoutMs)
{
    return (timeoutMs == 0) ? WaitOneInfinite() : TimedWaitOne(timeoutMs);
}
 
inline bool AutoResetEvent::WaitOneInfinite()
{
    boost::unique_lock<boost::interprocess::interprocess_mutex> lock(this->syncRoot);
    while (!this->flag) // prevent spurious wakeups from doing harm (OR: is really necessary, see https://en.wikipedia.org/wiki/Spurious_wakeup)
    {
        this->signal.wait(lock);
    }
    this->flag = false; // WaitOne auto-resets this flag
    return true;
}
 
}}}} // end of namespace Arp::System::Commons::Threading