From 3eac0000f02cd2cb160464ae01b04fe3415e4b60 Mon Sep 17 00:00:00 2001 From: zml Date: Fri, 30 Apr 2010 16:29:05 +0000 Subject: Handle taskqueue_drain(9) correctly on a threaded taskqueue: taskqueue_drain(9) will not correctly detect whether a task is currently running. The check is against a field in the taskqueue struct, but for a threaded queue with more than one thread, multiple threads can simultaneously be running a task, thus stomping over the tq_running field. Submitted by: Matthew Fleming Reviewed by: jhb Approved by: dfr (mentor) --- sys/kern/subr_taskqueue.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'sys/kern/subr_taskqueue.c') diff --git a/sys/kern/subr_taskqueue.c b/sys/kern/subr_taskqueue.c index 8405b3d..3b18269 100644 --- a/sys/kern/subr_taskqueue.c +++ b/sys/kern/subr_taskqueue.c @@ -51,7 +51,6 @@ struct taskqueue { const char *tq_name; taskqueue_enqueue_fn tq_enqueue; void *tq_context; - struct task *tq_running; struct mtx tq_mutex; struct thread **tq_threads; int tq_tcount; @@ -233,13 +232,13 @@ taskqueue_run(struct taskqueue *queue) STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link); pending = task->ta_pending; task->ta_pending = 0; - queue->tq_running = task; + task->ta_flags |= TA_FLAGS_RUNNING; TQ_UNLOCK(queue); task->ta_func(task->ta_context, pending); TQ_LOCK(queue); - queue->tq_running = NULL; + task->ta_flags &= ~TA_FLAGS_RUNNING; wakeup(task); } @@ -256,14 +255,16 @@ taskqueue_drain(struct taskqueue *queue, struct task *task) { if (queue->tq_spin) { /* XXX */ mtx_lock_spin(&queue->tq_mutex); - while (task->ta_pending != 0 || task == queue->tq_running) + while (task->ta_pending != 0 || + (task->ta_flags & TA_FLAGS_RUNNING) != 0) msleep_spin(task, &queue->tq_mutex, "-", 0); mtx_unlock_spin(&queue->tq_mutex); } else { WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__); mtx_lock(&queue->tq_mutex); - while (task->ta_pending != 0 || task == queue->tq_running) + while (task->ta_pending != 0 || + (task->ta_flags & TA_FLAGS_RUNNING) != 0) msleep(task, &queue->tq_mutex, PWAIT, "-", 0); mtx_unlock(&queue->tq_mutex); } -- cgit v1.1