Linux C mutex mutex usage record

One, mutex mutex mainly contains a few functions:

1, int pthread_mutex_init (pthread_mutex_t *mutex, const pthread_mutexattr_t *attr);

Initializes a mutex, and if attr is NULL, the default value is initialized, and a mutex can be initialized as follows when the mutex is defined:

pthread_mutex_t mutex = Pthread_mutex_initializer;

A lock semaphore that can be restored directly to the initial state without generating an error.

2, int Pthread_mutex_destroy (pthread_mutex_t *mutex);

Destroys a mutex that can be destroyed only if it is idle (without being unlock by lock or lock), destroying a lock's semaphore and generating (16,device or resource busy) error;

The amount of the destroyed semaphore can be re-initialized.

3, int pthread_mutex_lock (pthread_mutex_t *mutex) and int pthread_mutex_trylock (pthread_mutex_t *mutex) and int pthread_ Mutex_timedlock (pthread_mutex_t *mutex,const struct timespec *abstime);

These three functions are similar in that they all lock (get) a mutex mutex, except that pthread_mutex_trylock non-blocking mode functions return immediately, Pthread_mutex_lock and Pthread_mutex_ Timedlock is a blocking mode;

Pthread_mutex_timedlock Timeout wait time abstime is absolute time and can be set as follows:

void set_abswaittime (structint  ms) {

Long sec;
Long usec;
struct Timeval tnow;
Gettimeofday (&tnow, NULL);
USEC = tnow.tv_usec + ms*1000;
SEC = tnow.tv_sec+usec/1000000;
Outtime->tv_nsec= (usec%1000000) *1000;
outtime->tv_sec=sec;

}

4, int pthread_mutex_unlock (pthread_mutex_t *mutex);

Frees a mutex mutex, and if the thread attempts to unlock an unlocked mutex, Pthread_mutex_unlock will follow the table below.

Reference: http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_lock.html#tag_16_439

Linux C mutex mutex usage record