sema.cpp

/***********************************************************************
  * Copyright (c) 2012, Baidu Inc. All rights reserved.
  * 
  * Licensed under the BSD License
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  * 
  *      license.txt
  *********************************************************************/

#include "sema.h"
#include "time_util.h"
#include "bgcc_error.h"

namespace bgcc {

    Semaphore::Semaphore(int ninit) {
        if (ninit < 0) {
            ninit = 0;
        }
#ifdef _WIN32
        _sem = CreateSemaphore(NULL, ninit, LONG_MAX, NULL);
#else
        sem_init(&_sem, 0, ninit);
#endif
    }

    Semaphore::~Semaphore() {
#ifdef _WIN32
        if (NULL != _sem) {
            BOOL ret = CloseHandle(_sem);
            if (0 != ret) {
                _sem = NULL;
            }
        }
#else
        sem_destroy(&_sem);
#endif
    }

    int32_t Semaphore::wait(uint32_t millisecond) {
#ifdef _WIN32
        if (NULL == _sem) {
            return E_BGCC_NULL_POINTER;
        }

        DWORD ret = WaitForSingleObject(_sem, millisecond);
        if (WAIT_OBJECT_0 == ret || WAIT_ABANDONED == ret) {
            return 0;
        }
        else if (WAIT_TIMEOUT == ret) {
            return E_BGCC_TIMEOUT;
        }
        else {
            return E_BGCC_SYSERROR;
        }
#else
        int32_t ret = 0;

        if (BGCC_SEMA_WAIT_INFINITE == millisecond) {
            ret = sem_wait(&_sem);
        }
        else {
            struct timespec ts = {0, 0};
            TimeUtil::get_abs_timespec(&ts, millisecond);
            ret = sem_timedwait(&_sem, &ts);
        }

        if (-1 == ret) {
            int32_t e = BgccGetLastError();
            if (ETIMEDOUT == e) {
                return E_BGCC_TIMEOUT;
            }
            else {
                return E_BGCC_SYSERROR;
            }
        }

        return 0;
#endif
    }

    int32_t Semaphore::signal() {
#ifdef _WIN32
        BOOL ret = FALSE;

        if (NULL != _sem) {
            ret = ReleaseSemaphore(_sem, 1, NULL);
        }
        return (0 != ret ? 0 : E_BGCC_SYSERROR);
#else
        int32_t ret = sem_post(&_sem);
        if (-1 == ret) {
            return E_BGCC_SYSERROR;
        }
        else {
            return 0;
        }
#endif
    }
}