Commit e036215f authored by Ben Walker's avatar Ben Walker Committed by Darek Stojaczyk
Browse files

thread: Add a mechanism to exit a lightweight thread 



Lightweight threads may now be exited by calling
spdk_thread_exit() within the thread. The framework
polling the thread can release the resources associated
with that lightweight thread by calling
spdk_thread_destroy().

Change-Id: I6586b9d22556b3874fb113ce5402c6b1f371786e
Signed-off-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/455319


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarSeth Howell <seth.howell5141@gmail.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-by: default avatarDarek Stojaczyk <dariusz.stojaczyk@intel.com>
parent f658a867

examples/bdev/fio_plugin/fio_plugin.c

+1 −0
Original line number Diff line number Diff line
@@ -147,6 +147,7 @@ spdk_fio_cleanup_thread(struct spdk_fio_thread *fio_thread) 
	spdk_set_thread(fio_thread->thread);



	spdk_thread_exit(fio_thread->thread);

	spdk_thread_destroy(fio_thread->thread);

	free(fio_thread->iocq);

	free(fio_thread);

}

include/spdk/thread.h

+13 −3
Original line number Diff line number Diff line
@@ -206,8 +206,9 @@ void spdk_thread_lib_fini(void); 
struct spdk_thread *spdk_thread_create(const char *name, struct spdk_cpuset *cpumask);



/**

 * Release any resources related to the given thread and destroy it. Execution

 * continues on the current system thread after returning.

 * Mark the thread as exited, failing all future spdk_thread_poll() calls. May

 * only be called within an spdk poller or message.

 *

 *

 * \param thread The thread to destroy.

 *
@@ -216,6 +217,15 @@ struct spdk_thread *spdk_thread_create(const char *name, struct spdk_cpuset *cpu 
 */

void spdk_thread_exit(struct spdk_thread *thread);



/**

 * Destroy a thread, releasing all of its resources. May only be called

 * on a thread previously marked as exited.

 *

 * \param thread The thread to destroy.

 *

 */

void spdk_thread_destroy(struct spdk_thread *thread);



/**

 * Return a pointer to this thread's context.

 *
@@ -255,7 +265,7 @@ struct spdk_thread *spdk_thread_get_from_ctx(void *ctx); 
 * \param now The current time, in ticks. Optional. If 0 is passed, this

 *            function may call spdk_get_ticks() to get the current time.

 *

 * \return 1 if work was done. 0 if no work was done. -1 if unknown.

 * \return 1 if work was done. 0 if no work was done. -1 if thread has exited.

 */

int spdk_thread_poll(struct spdk_thread *thread, uint32_t max_msgs, uint64_t now);

lib/event/reactor.c

+8 −1
Original line number Diff line number Diff line
@@ -258,6 +258,7 @@ _spdk_reactor_run(void *arg) 


	while (1) {

		uint64_t now;

		int rc;



		/* For each loop through the reactor, capture the time. This time

		 * is used for all threads. */
@@ -268,7 +269,11 @@ _spdk_reactor_run(void *arg) 
		TAILQ_FOREACH_SAFE(lw_thread, &reactor->threads, link, tmp) {

			thread = spdk_thread_get_from_ctx(lw_thread);



			spdk_thread_poll(thread, 0, now);

			rc = spdk_thread_poll(thread, 0, now);

			if (rc < 0) {

				TAILQ_REMOVE(&reactor->threads, lw_thread, link);

				spdk_thread_destroy(thread);

			}

		}



		if (g_reactor_state != SPDK_REACTOR_STATE_RUNNING) {
@@ -286,7 +291,9 @@ _spdk_reactor_run(void *arg) 
	TAILQ_FOREACH_SAFE(lw_thread, &reactor->threads, link, tmp) {

		thread = spdk_thread_get_from_ctx(lw_thread);

		TAILQ_REMOVE(&reactor->threads, lw_thread, link);

		spdk_set_thread(thread);

		spdk_thread_exit(thread);

		spdk_thread_destroy(thread);

	}



	return 0;

lib/thread/thread.c

+27 −1
Original line number Diff line number Diff line
@@ -105,6 +105,8 @@ struct spdk_thread { 
	TAILQ_ENTRY(spdk_thread)	tailq;

	char				*name;



	bool				exit;



	struct spdk_cpuset		*cpumask;



	uint64_t			tsc_last;
@@ -330,7 +332,19 @@ spdk_set_thread(struct spdk_thread *thread) 
void

spdk_thread_exit(struct spdk_thread *thread)

{

	SPDK_DEBUGLOG(SPDK_LOG_THREAD, "Freeing thread %s\n", thread->name);

	SPDK_DEBUGLOG(SPDK_LOG_THREAD, "Exit thread %s\n", thread->name);



	assert(tls_thread == thread);



	thread->exit = true;

}



void

spdk_thread_destroy(struct spdk_thread *thread)

{

	SPDK_DEBUGLOG(SPDK_LOG_THREAD, "Destroy thread %s\n", thread->name);



	assert(thread->exit == true);



	if (tls_thread == thread) {

		tls_thread = NULL;
@@ -400,6 +414,10 @@ _spdk_msg_queue_run_batch(struct spdk_thread *thread, uint32_t max_msgs) 
		assert(msg != NULL);

		msg->fn(msg->arg);



		if (thread->exit) {

			break;

		}



		if (thread->msg_cache_count < SPDK_MSG_MEMPOOL_CACHE_SIZE) {

			/* Insert the messages at the head. We want to re-use the hot

			 * ones. */
@@ -459,6 +477,10 @@ spdk_thread_poll(struct spdk_thread *thread, uint32_t max_msgs, uint64_t now) 
				   active_pollers_head, tailq, tmp) {

		int poller_rc;



		if (thread->exit) {

			break;

		}



		if (poller->state == SPDK_POLLER_STATE_UNREGISTERED) {

			TAILQ_REMOVE(&thread->active_pollers, poller, tailq);

			free(poller);
@@ -491,6 +513,10 @@ spdk_thread_poll(struct spdk_thread *thread, uint32_t max_msgs, uint64_t now) 
	TAILQ_FOREACH_SAFE(poller, &thread->timer_pollers, tailq, tmp) {

		int timer_rc = 0;



		if (thread->exit) {

			break;

		}



		if (poller->state == SPDK_POLLER_STATE_UNREGISTERED) {

			TAILQ_REMOVE(&thread->timer_pollers, poller, tailq);

			free(poller);

test/common/lib/ut_multithread.c

+1 −0
Original line number Diff line number Diff line
@@ -106,6 +106,7 @@ free_threads(void) 
	for (i = 0; i < g_ut_num_threads; i++) {

		set_thread(i);

		spdk_thread_exit(g_ut_threads[i].thread);

		spdk_thread_destroy(g_ut_threads[i].thread);

		g_ut_threads[i].thread = NULL;

	}