OpenSSL多线程互斥锁

最新推荐文章于 2022-02-21 20:11:04 发布

原创最新推荐文章于 2022-02-21 20:11:04 发布 · 2k 阅读

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CC 4.0 BY-SA版权

本文介绍了一个使用OpenSSL库中的多线程锁机制的具体实现。通过定义静态的pthread_mutex_t数组作为锁，并初始化这些锁，实现了对OpenSSL内部资源的安全并发访问。此外，还提供了设置回调函数的方法，用于获取当前线程ID以及锁定和解锁相应的锁。

static pthread_mutex_t *crypto_lock = NULL;

static pthread_t pthread_id_cb()
{
    return pthread_self();
}

static void pthread_locking_cb(int mode, int n, const char *file, int line)
{
    if(mode & CRYPTO_LOCK)
        pthread_mutex_lock(&crypto_lock[n]);
    else
        pthread_mutex_unlock(&crypto_lock[n]);
}

int pthread_setup()
{
    int loop = 0;
    crypto_lock = (pthread_mutex_t*)OPENSSL_malloc(CRYPTO_num_locks()*sizeof(pthread_mutex_t));
    if(!crypto_lock)
        return 0;
    for(loop = 0; loop < CRYPTO_num_locks(); loop ++)
        pthread_mutex_init(&crypto_lock[loop], NULL);
    CRYPTO_set_id_callback(pthread_id_cb);
    CRYPTO_set_locking_callback(pthread_locking_cb);
    return 1;
}

int pthread_cleanup()
{
    int loop = 0;
    if(!crypto_lock)
        return 0;
    CRYPTO_set_id_callback(NULL);
    CRYPTO_set_locking_callback(NULL);
    for(loop = 0; loop < CRYPTO_num_locks(); loop ++)
        pthread_mutex_destroy(&crypto_lock[loop]);
    OPENSSL_free(crypto_lock);
    crypto_lock = NULL;
    return 1;
}