#ifdef _TRY_POSIX /// Try posix.

#include "SemaphoreWrapper.h"
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <semaphore.h>
#include <strings.h>
#include <stdio.h>
#include <stdlib.h>
#include "log.h"

class ProcessSemaphore::impl
{
public:
    sem_t* ps;

    int status;
};

ProcessSemaphore::ProcessSemaphore(int key, int action, int default_value) : _p(new impl)
{
    if(_p)
    {
        _p->status=0;
        char buff[64];
        memset(buff,0,64);
        sprintf(buff,"LibSemaphoreWrapper_%d",key);

        if(action==1) /// Must Create New.
        {
            _p->ps=sem_open(buff,O_CREAT|O_EXCL,0777,default_value);
        }
        else /// Must Open
        {
            _p->ps=sem_open(buff,O_RDWR,0777,0);
        }

        if(_p->ps!=SEM_FAILED)
        {
            _p->status=2;
        }
        else
        {
            /// Notice: Most platform reports "Function not implemented" on sem_open.
            dprintf("Failed to sem_open. %s\n",strerror(errno));
        }
    }
}

ProcessSemaphore::~ProcessSemaphore()
{
    if(_p)
    {
        /// Notice that sem_close() is used for named semaphore and sem_destroy() is for unnamed semaphore.
        if(isReady())
        {
            sem_close(_p->ps);
        }

        delete _p;
    }
}

bool ProcessSemaphore::isReady() const
{
    return _p&&_p->status==2;
}

int ProcessSemaphore::p()
{
    return sem_wait(_p->ps);
}

int ProcessSemaphore::v()
{
    return sem_post(_p->ps);
}

int ProcessSemaphore::wait()
{
    return p();
}

int ProcessSemaphore::notify()
{
    return v();
}

#endif /// End of Try Posix