Function _sftx_create

components/lwp/lwp_futex.c:300–335

* @brief Create a Shared FuTeX (sftx) * * @param[in] key Pointer to shared futex key structure * @param[in] lwp Pointer to lightweight process structure * * @return Pointer to created futex on success, NULL on failure * * @note This function: * - Allocates memory for new futex * - Creates custom object with _sftx_destroy as destructor * - Adds futex to global table *

 *       - Initializes futex members (mutex, waiting_thread list)
 */
static rt_futex_t _sftx_create(struct shared_futex_key *key, struct rt_lwp *lwp)
{
    rt_futex_t futex = RT_NULL;
    struct rt_object *obj = RT_NULL;

    if (lwp)
    {
        futex = (rt_futex_t)rt_calloc(1, sizeof(struct rt_futex));
        if (futex)
        {
            /* create a Shared FuTeX (sftx) */
            obj = rt_custom_object_create("sftx", (void *)futex, _sftx_destroy);
            if (!obj)
            {
                rt_free(futex);
                futex = RT_NULL;
            }
            else
            {
                if (futex_global_table_add(key, futex))
                {
                    rt_object_delete(obj);
                    rt_free(futex);
                    futex = RT_NULL;
                }
                else
                {
                    futex->mutex = RT_NULL;
                    rt_list_init(&(futex->waiting_thread));
                    futex->custom_obj = obj;
                }
            }
        }
    }
    return futex;
}

/**
 * @brief Get or create a Shared FuTeX (sftx) for given user address