diff options
Diffstat (limited to 'sys/kern')
| -rw-r--r-- | sys/kern/subr_taskqueue.c | 75 |
1 files changed, 45 insertions, 30 deletions
diff --git a/sys/kern/subr_taskqueue.c b/sys/kern/subr_taskqueue.c index 8bd3868..fd6dd4f 100644 --- a/sys/kern/subr_taskqueue.c +++ b/sys/kern/subr_taskqueue.c @@ -46,12 +46,17 @@ static MALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues"); static void *taskqueue_giant_ih; static void *taskqueue_ih; +struct taskqueue_busy { + struct task *tb_running; + TAILQ_ENTRY(taskqueue_busy) tb_link; +}; + struct taskqueue { STAILQ_HEAD(, task) tq_queue; const char *tq_name; taskqueue_enqueue_fn tq_enqueue; void *tq_context; - struct task *tq_running; + TAILQ_HEAD(, taskqueue_busy) tq_active; struct mtx tq_mutex; struct thread **tq_threads; int tq_tcount; @@ -102,6 +107,7 @@ _taskqueue_create(const char *name, int mflags, return NULL; STAILQ_INIT(&queue->tq_queue); + TAILQ_INIT(&queue->tq_active); queue->tq_name = name; queue->tq_enqueue = enqueue; queue->tq_context = context; @@ -140,6 +146,7 @@ taskqueue_free(struct taskqueue *queue) TQ_LOCK(queue); queue->tq_flags &= ~TQ_FLAGS_ACTIVE; taskqueue_terminate(queue->tq_threads, queue); + KASSERT(TAILQ_EMPTY(&queue->tq_active), ("Tasks still running?")); mtx_destroy(&queue->tq_mutex); free(queue->tq_threads, M_TASKQUEUE); free(queue, M_TASKQUEUE); @@ -214,13 +221,17 @@ taskqueue_unblock(struct taskqueue *queue) TQ_UNLOCK(queue); } -void -taskqueue_run(struct taskqueue *queue, struct task **tpp) +static void +taskqueue_run_locked(struct taskqueue *queue) { + struct taskqueue_busy tb; struct task *task; int pending; mtx_assert(&queue->tq_mutex, MA_OWNED); + tb.tb_running = NULL; + TAILQ_INSERT_TAIL(&queue->tq_active, &tb, tb_link); + while (STAILQ_FIRST(&queue->tq_queue)) { /* * Carefully remove the first task from the queue and @@ -230,16 +241,38 @@ taskqueue_run(struct taskqueue *queue, struct task **tpp) STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link); pending = task->ta_pending; task->ta_pending = 0; - task->ta_running = tpp; - *tpp = task; + tb.tb_running = task; TQ_UNLOCK(queue); task->ta_func(task->ta_context, pending); TQ_LOCK(queue); - *tpp = NULL; + tb.tb_running = NULL; wakeup(task); } + TAILQ_REMOVE(&queue->tq_active, &tb, tb_link); +} + +void +taskqueue_run(struct taskqueue *queue) +{ + + TQ_LOCK(queue); + taskqueue_run_locked(queue); + TQ_UNLOCK(queue); +} + +static int +task_is_running(struct taskqueue *queue, struct task *task) +{ + struct taskqueue_busy *tb; + + mtx_assert(&queue->tq_mutex, MA_OWNED); + TAILQ_FOREACH(tb, &queue->tq_active, tb_link) { + if (tb->tb_running == task) + return (1); + } + return (0); } void @@ -250,10 +283,8 @@ taskqueue_drain(struct taskqueue *queue, struct task *task) WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__); TQ_LOCK(queue); - while (task->ta_pending != 0 || - (task->ta_running != NULL && task == *task->ta_running)) { + while (task->ta_pending != 0 || task_is_running(queue, task)) TQ_SLEEP(queue, task, &queue->tq_mutex, PWAIT, "-", 0); - } TQ_UNLOCK(queue); } @@ -266,9 +297,7 @@ taskqueue_swi_enqueue(void *context) static void taskqueue_swi_run(void *dummy) { - TQ_LOCK(taskqueue_swi); - taskqueue_run(taskqueue_swi, &taskqueue_swi->tq_running); - TQ_UNLOCK(taskqueue_swi); + taskqueue_run(taskqueue_swi); } static void @@ -280,9 +309,7 @@ taskqueue_swi_giant_enqueue(void *context) static void taskqueue_swi_giant_run(void *dummy) { - TQ_LOCK(taskqueue_swi_giant); - taskqueue_run(taskqueue_swi_giant, &taskqueue_swi_giant->tq_running); - TQ_UNLOCK(taskqueue_swi_giant); + taskqueue_run(taskqueue_swi_giant); } int @@ -344,22 +371,12 @@ void taskqueue_thread_loop(void *arg) { struct taskqueue **tqp, *tq; - struct task *running; - - /* - * The kernel stack space is globaly addressable, and it would - * be an error to ask whether a task is running after the - * taskqueue has been released. So it is safe to have the - * task point back to an address in the taskqueue's stack to - * determine if the task is running. - */ - running = NULL; tqp = arg; tq = *tqp; TQ_LOCK(tq); while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) { - taskqueue_run(tq, &running); + taskqueue_run_locked(tq); /* * Because taskqueue_run() can drop tq_mutex, we need to * check if the TQ_FLAGS_ACTIVE flag wasn't removed in the @@ -369,7 +386,7 @@ taskqueue_thread_loop(void *arg) break; TQ_SLEEP(tq, tq, &tq->tq_mutex, 0, "-", 0); } - taskqueue_run(tq, &running); + taskqueue_run_locked(tq); /* rendezvous with thread that asked us to terminate */ tq->tq_tcount--; @@ -426,9 +443,7 @@ taskqueue_fast_enqueue(void *context) static void taskqueue_fast_run(void *dummy) { - TQ_LOCK(taskqueue_fast); - taskqueue_run(taskqueue_fast, &taskqueue_fast->tq_running); - TQ_UNLOCK(taskqueue_fast); + taskqueue_run(taskqueue_fast); } TASKQUEUE_FAST_DEFINE(fast, taskqueue_fast_enqueue, NULL, |
