Date: Wed, 21 Nov 2018 17:18:27 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r340730 - in head: share/man/man9 sys/kern sys/sys Message-ID: <201811211718.wALHIRE4055336@repo.freebsd.org>
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Author: markj Date: Wed Nov 21 17:18:27 2018 New Revision: 340730 URL: https://svnweb.freebsd.org/changeset/base/340730 Log: Add a taskqueue_quiesce(9) KPI. This is similar to taskqueue_drain_all(9) but will wait for the queue to become idle before returning instead of only waiting for already-enqueued tasks to finish. This will be used in the opensolaris compat layer. PR: 227784 Reviewed by: cem MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17975 Modified: head/share/man/man9/Makefile head/share/man/man9/taskqueue.9 head/sys/kern/subr_taskqueue.c head/sys/sys/taskqueue.h Modified: head/share/man/man9/Makefile ============================================================================== --- head/share/man/man9/Makefile Wed Nov 21 17:14:57 2018 (r340729) +++ head/share/man/man9/Makefile Wed Nov 21 17:18:27 2018 (r340730) @@ -2056,6 +2056,7 @@ MLINKS+=taskqueue.9 TASK_INIT.9 \ taskqueue.9 TASKQUEUE_FAST_DEFINE_THREAD.9 \ taskqueue.9 taskqueue_free.9 \ taskqueue.9 taskqueue_member.9 \ + taskqueue.9 taskqueue_quiesce.9 \ taskqueue.9 taskqueue_run.9 \ taskqueue.9 taskqueue_set_callback.9 \ taskqueue.9 taskqueue_start_threads.9 \ Modified: head/share/man/man9/taskqueue.9 ============================================================================== --- head/share/man/man9/taskqueue.9 Wed Nov 21 17:14:57 2018 (r340729) +++ head/share/man/man9/taskqueue.9 Wed Nov 21 17:18:27 2018 (r340730) @@ -28,7 +28,7 @@ .\" .\" $FreeBSD$ .\" -.Dd July 30, 2017 +.Dd November 21, 2018 .Dt TASKQUEUE 9 .Os .Sh NAME @@ -94,6 +94,8 @@ struct timeout_task; .Ft void .Fn taskqueue_drain_all "struct taskqueue *queue" .Ft void +.Fn taskqueue_quiesce "struct taskqueue *queue" +.Ft void .Fn taskqueue_block "struct taskqueue *queue" .Ft void .Fn taskqueue_unblock "struct taskqueue *queue" @@ -298,6 +300,12 @@ do not extend the wait time of and may complete after .Fn taskqueue_drain_all returns. +The +.Fn taskqueue_quiesce +function is used to wait for the queue to become empty and for all +running tasks to finish. +To avoid blocking indefinitely, the caller must ensure by some mechanism +that tasks will eventually stop being posted to the queue. .Pp The .Fn taskqueue_block Modified: head/sys/kern/subr_taskqueue.c ============================================================================== --- head/sys/kern/subr_taskqueue.c Wed Nov 21 17:14:57 2018 (r340729) +++ head/sys/kern/subr_taskqueue.c Wed Nov 21 17:18:27 2018 (r340730) @@ -346,13 +346,13 @@ taskqueue_task_nop_fn(void *context, int pending) * have begun execution. Tasks queued during execution of * this function are ignored. */ -static void +static int taskqueue_drain_tq_queue(struct taskqueue *queue) { struct task t_barrier; if (STAILQ_EMPTY(&queue->tq_queue)) - return; + return (0); /* * Enqueue our barrier after all current tasks, but with @@ -372,6 +372,7 @@ taskqueue_drain_tq_queue(struct taskqueue *queue) */ while (t_barrier.ta_pending != 0) TQ_SLEEP(queue, &t_barrier, &queue->tq_mutex, PWAIT, "-", 0); + return (1); } /* @@ -379,13 +380,13 @@ taskqueue_drain_tq_queue(struct taskqueue *queue) * complete. Tasks that begin execution during the execution * of this function are ignored. */ -static void +static int taskqueue_drain_tq_active(struct taskqueue *queue) { struct taskqueue_busy tb_marker, *tb_first; if (TAILQ_EMPTY(&queue->tq_active)) - return; + return (0); /* Block taskq_terminate().*/ queue->tq_callouts++; @@ -412,6 +413,7 @@ taskqueue_drain_tq_active(struct taskqueue *queue) queue->tq_callouts--; if ((queue->tq_flags & TQ_FLAGS_ACTIVE) == 0) wakeup_one(queue->tq_threads); + return (1); } void @@ -582,8 +584,8 @@ taskqueue_drain_all(struct taskqueue *queue) WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__); TQ_LOCK(queue); - taskqueue_drain_tq_queue(queue); - taskqueue_drain_tq_active(queue); + (void)taskqueue_drain_tq_queue(queue); + (void)taskqueue_drain_tq_active(queue); TQ_UNLOCK(queue); } @@ -609,6 +611,20 @@ taskqueue_drain_timeout(struct taskqueue *queue, */ TQ_LOCK(queue); timeout_task->f &= ~DT_DRAIN_IN_PROGRESS; + TQ_UNLOCK(queue); +} + +void +taskqueue_quiesce(struct taskqueue *queue) +{ + int ret; + + TQ_LOCK(queue); + do { + ret = taskqueue_drain_tq_queue(queue); + if (ret == 0) + ret = taskqueue_drain_tq_active(queue); + } while (ret != 0); TQ_UNLOCK(queue); } Modified: head/sys/sys/taskqueue.h ============================================================================== --- head/sys/sys/taskqueue.h Wed Nov 21 17:14:57 2018 (r340729) +++ head/sys/sys/taskqueue.h Wed Nov 21 17:18:27 2018 (r340730) @@ -93,6 +93,7 @@ void taskqueue_drain(struct taskqueue *queue, struct t void taskqueue_drain_timeout(struct taskqueue *queue, struct timeout_task *timeout_task); void taskqueue_drain_all(struct taskqueue *queue); +void taskqueue_quiesce(struct taskqueue *queue); void taskqueue_free(struct taskqueue *queue); void taskqueue_run(struct taskqueue *queue); void taskqueue_block(struct taskqueue *queue);
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