Function sys_sem_create

components/lwp/lwp_syscall.c:1681–1714

* @brief Creates a semaphore. * * This system call creates a new semaphore with the specified `name` and initializes * its value. The semaphore is used for synchronizing access to shared resources in * concurrent programming. The semaphore's behavior is defined by the value (`value`) * and any flags (`flag`) that specify additional properties or settings. * * @param name The name of the sem

 * @see sem_wait(), sem_post(), sem_destroy()
 */
rt_sem_t sys_sem_create(const char *name, rt_uint32_t value, rt_uint8_t flag)
{
    int len = 0;
    char *kname = RT_NULL;

    len = lwp_user_strlen(name);
    if (len <= 0)
    {
        return RT_NULL;
    }

    kname = (char *)kmem_get(len + 1);
    if (!kname)
    {
        return RT_NULL;
    }

    if (lwp_get_from_user(kname, (void *)name, len + 1) != (len + 1))
    {
        kmem_put(kname);
        return RT_NULL;
    }

    rt_sem_t sem = rt_sem_create(kname, value, flag);
    if (lwp_user_object_add(lwp_self(), (rt_object_t)sem) != 0)
    {
        rt_sem_delete(sem);
        sem = NULL;
    }

    kmem_put(kname);

    return sem;
}

/**
 * @brief Deletes a semaphore and releases associated resources.