diff options
| -rw-r--r-- | share/man/man9/Makefile | 1 | ||||
| -rw-r--r-- | share/man/man9/taskqueue.9 | 27 | ||||
| -rw-r--r-- | sys/kern/subr_taskqueue.c | 18 | ||||
| -rw-r--r-- | sys/sys/taskqueue.h | 2 |
4 files changed, 48 insertions, 0 deletions
diff --git a/share/man/man9/Makefile b/share/man/man9/Makefile index e6a490a..ecb1dff 100644 --- a/share/man/man9/Makefile +++ b/share/man/man9/Makefile @@ -1212,6 +1212,7 @@ MLINKS+=sysctl_ctx_init.9 sysctl_ctx_entry_add.9 \ sysctl_ctx_init.9 sysctl_ctx_entry_find.9 \ sysctl_ctx_init.9 sysctl_ctx_free.9 MLINKS+=taskqueue.9 TASK_INIT.9 \ + taskqueue.9 taskqueue_cancel.9 \ taskqueue.9 taskqueue_create.9 \ taskqueue.9 taskqueue_create_fast.9 \ taskqueue.9 TASKQUEUE_DECLARE.9 \ diff --git a/share/man/man9/taskqueue.9 b/share/man/man9/taskqueue.9 index d5e096a..168ca70 100644 --- a/share/man/man9/taskqueue.9 +++ b/share/man/man9/taskqueue.9 @@ -63,6 +63,8 @@ struct task { .Fn taskqueue_enqueue "struct taskqueue *queue" "struct task *task" .Ft int .Fn taskqueue_enqueue_fast "struct taskqueue *queue" "struct task *task" +.Ft int +.Fn taskqueue_cancel "struct taskqueue *queue" "struct task *task" "u_int *pendp" .Ft void .Fn taskqueue_drain "struct taskqueue *queue" "struct task *task" .Ft int @@ -162,6 +164,31 @@ is called on the task pointer passed to .Fn taskqueue_enqueue . .Pp The +.Fn taskqueue_cancel +function is used to cancel a task. +The +.Va ta_pending +count is cleared, and the old value returned in the reference +parameter +.Fa pendp , +if it is non- Dv NULL . +If the task is currently running, +.Dv EBUSY +is returned, otherwise 0. +To implement a blocking +.Fn taskqueue_cancel +that waits for a running task to finish, it could look like: +.Bd -literal -offset indent +while (taskqueue_cancel(tq, task, NULL) != 0) + taskqueue_drain(tq, task); +.Ed +.Pp +Note that, as with +.Fn taskqueue_drain , +the caller is responsible for ensuring that the task is not re-enqueued +after being canceled. +.Pp +The .Fn taskqueue_drain function is used to wait for the task to finish. There is no guarantee that the task will not be diff --git a/sys/kern/subr_taskqueue.c b/sys/kern/subr_taskqueue.c index fd6dd4f..d31d668 100644 --- a/sys/kern/subr_taskqueue.c +++ b/sys/kern/subr_taskqueue.c @@ -275,6 +275,24 @@ task_is_running(struct taskqueue *queue, struct task *task) return (0); } +int +taskqueue_cancel(struct taskqueue *queue, struct task *task, u_int *pendp) +{ + u_int pending; + int error; + + TQ_LOCK(queue); + if ((pending = task->ta_pending) > 0) + STAILQ_REMOVE(&queue->tq_queue, task, task, ta_link); + task->ta_pending = 0; + error = task_is_running(queue, task) ? EBUSY : 0; + TQ_UNLOCK(queue); + + if (pendp != NULL) + *pendp = pending; + return (error); +} + void taskqueue_drain(struct taskqueue *queue, struct task *task) { diff --git a/sys/sys/taskqueue.h b/sys/sys/taskqueue.h index bf2e4ee..c7a7b16 100644 --- a/sys/sys/taskqueue.h +++ b/sys/sys/taskqueue.h @@ -54,6 +54,8 @@ struct taskqueue *taskqueue_create(const char *name, int mflags, int taskqueue_start_threads(struct taskqueue **tqp, int count, int pri, const char *name, ...) __printflike(4, 5); int taskqueue_enqueue(struct taskqueue *queue, struct task *task); +int taskqueue_cancel(struct taskqueue *queue, struct task *task, + u_int *pendp); void taskqueue_drain(struct taskqueue *queue, struct task *task); void taskqueue_free(struct taskqueue *queue); void taskqueue_run(struct taskqueue *queue); |
