Function timer_set_running_state

dpdk/lib/timer/rte_timer.c:271–304

* if timer is pending, mark timer as running */

 * if timer is pending, mark timer as running
 */
static int
timer_set_running_state(struct rte_timer *tim)
{
	union rte_timer_status prev_status, status;
	unsigned lcore_id = rte_lcore_id();
	int success = 0;

	/* wait that the timer is in correct status before update,
	 * and mark it as running */
	prev_status.u32 = rte_atomic_load_explicit(&tim->status.u32, rte_memory_order_relaxed);

	while (success == 0) {
		/* timer is not pending anymore */
		if (prev_status.state != RTE_TIMER_PENDING)
			return -1;

		/* we know that the timer will be pending at this point
		 * mark it atomically as being running
		 */
		status.state = RTE_TIMER_RUNNING;
		status.owner = (int16_t)lcore_id;
		/* RUNNING states are acting as locked states. If the
		 * timer is in RUNNING state, the state cannot be changed
		 * by other threads. So, we should use ACQUIRE here.
		 */
		success = rte_atomic_compare_exchange_strong_explicit(&tim->status.u32,
					      (uint32_t *)(uintptr_t)&prev_status.u32,
					      status.u32,
					      rte_memory_order_acquire,
					      rte_memory_order_relaxed);
	}

	return 0;
}

/*
 * Return a skiplist level for a new entry.