Function sem_init

components/libc/posix/ipc/semaphore.c:275–306

* @brief Initializes a POSIX semaphore. * @param sem Pointer to the semaphore structure to be initialized. * @param pshared Flag indicating whether the semaphore is to be shared between processes. * @param value Initial value of the semaphore. * @return Upon successful completion, returns 0; otherwise, returns -1 and sets errno to indicate the error. * * @note This function initi

 *          After successful initialization, the semaphore structure is inserted into the linked list of POSIX semaphores.
 */
int sem_init(sem_t *sem, int pshared, unsigned int value)
{
    char name[RT_NAME_MAX];
    static rt_uint16_t psem_number = 0;

    if (sem == RT_NULL)
    {
        rt_set_errno(EINVAL);

        return -1;
    }

    rt_snprintf(name, sizeof(name), "psem%02d", psem_number++);
    sem->sem = rt_sem_create(name, value, RT_IPC_FLAG_FIFO);
    if (sem->sem == RT_NULL)
    {
        rt_set_errno(ENOMEM);

        return -1;
    }

    /* initialize posix semaphore */
    sem->refcount = 1;
    sem->unlinked = 0;
    sem->unamed = 1;
    /* lock posix semaphore list */
    rt_sem_take(&posix_sem_lock, RT_WAITING_FOREVER);
    posix_sem_insert(sem);
    rt_sem_release(&posix_sem_lock);

    return 0;
}
RTM_EXPORT(sem_init);

/**