From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: [PATCH 1/2] eal: add API that sleeps while waiting
 for threads
Date: Thu, 11 Oct 2018 13:32:13 -0700
Message-ID: <20181011133213.2c37a464@xeon-e3>
References: <20181011195753.4778-1-ferruh.yigit@intel.com>
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Cc: dev@dpdk.org
To: Ferruh Yigit <ferruh.yigit@intel.com>
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On Thu, 11 Oct 2018 20:57:52 +0100
Ferruh Yigit <ferruh.yigit@intel.com> wrote:

> +/*
> + * Wait until a lcore finished its job by sleeping.
> + * Sleep time will be times of 'usec'
> + */
> +int
> +rte_eal_wait_lcore_sleep(unsigned slave_id, size_t usec)
> +{
> +	if (lcore_config[slave_id].state == WAIT)
> +		return 0;
> +
> +	while (lcore_config[slave_id].state != WAIT &&
> +	       lcore_config[slave_id].state != FINISHED)
> +			usleep(usec);
> +
> +	rte_rmb();
> +
> +	/* we are in finished state, go to wait state */
> +	lcore_config[slave_id].state = WAIT;
> +	return lcore_config[slave_id].ret;
> +}
> +

Since lcore threads are really pthreads you could avoid doing polling by
using a pthread condition (ie. pthread_cond_wait and/or pthread_cond_timedwait)