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author | Tejun Heo <tj@kernel.org> | 2010-09-16 08:48:29 (GMT) |
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committer | Tejun Heo <tj@kernel.org> | 2010-09-19 15:51:05 (GMT) |
commit | 09383498c5d35262e643bfdbae84826177a3c624 (patch) | |
tree | ec75ee767bff28cabbd1d1b82cfc3457147dda33 /kernel/workqueue.c | |
parent | baf59022c37d43f202e62d5130e4bac5e825b426 (diff) | |
download | linux-09383498c5d35262e643bfdbae84826177a3c624.tar.xz |
workqueue: implement flush[_delayed]_work_sync()
Implement flush[_delayed]_work_sync(). These are flush functions
which also make sure no CPU is still executing the target work from
earlier queueing instances. These are similar to
cancel[_delayed]_work_sync() except that the target work item is
flushed instead of cancelled.
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/workqueue.c')
-rw-r--r-- | kernel/workqueue.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 33d31d7..19e4bc1 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2435,6 +2435,41 @@ static bool wait_on_work(struct work_struct *work) return ret; } +/** + * flush_work_sync - wait until a work has finished execution + * @work: the work to flush + * + * Wait until @work has finished execution. On return, it's + * guaranteed that all queueing instances of @work which happened + * before this function is called are finished. In other words, if + * @work hasn't been requeued since this function was called, @work is + * guaranteed to be idle on return. + * + * RETURNS: + * %true if flush_work_sync() waited for the work to finish execution, + * %false if it was already idle. + */ +bool flush_work_sync(struct work_struct *work) +{ + struct wq_barrier barr; + bool pending, waited; + + /* we'll wait for executions separately, queue barr only if pending */ + pending = start_flush_work(work, &barr, false); + + /* wait for executions to finish */ + waited = wait_on_work(work); + + /* wait for the pending one */ + if (pending) { + wait_for_completion(&barr.done); + destroy_work_on_stack(&barr.work); + } + + return pending || waited; +} +EXPORT_SYMBOL_GPL(flush_work_sync); + /* * Upon a successful return (>= 0), the caller "owns" WORK_STRUCT_PENDING bit, * so this work can't be re-armed in any way. @@ -2539,6 +2574,27 @@ bool flush_delayed_work(struct delayed_work *dwork) EXPORT_SYMBOL(flush_delayed_work); /** + * flush_delayed_work_sync - wait for a dwork to finish + * @dwork: the delayed work to flush + * + * Delayed timer is cancelled and the pending work is queued for + * execution immediately. Other than timer handling, its behavior + * is identical to flush_work_sync(). + * + * RETURNS: + * %true if flush_work_sync() waited for the work to finish execution, + * %false if it was already idle. + */ +bool flush_delayed_work_sync(struct delayed_work *dwork) +{ + if (del_timer_sync(&dwork->timer)) + __queue_work(raw_smp_processor_id(), + get_work_cwq(&dwork->work)->wq, &dwork->work); + return flush_work_sync(&dwork->work); +} +EXPORT_SYMBOL(flush_delayed_work_sync); + +/** * cancel_delayed_work_sync - cancel a delayed work and wait for it to finish * @dwork: the delayed work cancel * |