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| author | Shaohua Li <shli@kernel.org> | 2013-11-14 15:16:16 +1100 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2013-11-14 15:16:16 +1100 |
| commit | 82e06c811163c4d853ed335d56c3378088bc89cc (patch) | |
| tree | 83ca8da3fcda9ebb1ec6ce5bb275533d8d4bd952 /include | |
| parent | ba8805b97320416e7c5bb8f55d2bd06d5c319e7d (diff) | |
| download | linux-0-day-82e06c811163c4d853ed335d56c3378088bc89cc.tar.gz linux-0-day-82e06c811163c4d853ed335d56c3378088bc89cc.tar.xz | |
wait: add wait_event_cmd()
Add a new API wait_event_cmd(). It's a variant of wait_even() with two
commands executed. One is executed before sleep, another after sleep.
Modified to match use wait.h approach based on suggestion by
Peter Zijlstra <peterz@infradead.org> - neilb
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/wait.h | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/wait.h b/include/linux/wait.h index 61939ba30aa0a..eaa00b10abaaa 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -278,6 +278,31 @@ do { \ __ret; \ }) +#define __wait_event_cmd(wq, condition, cmd1, cmd2) \ + (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ + cmd1; schedule(); cmd2) + +/** + * wait_event_cmd - sleep until a condition gets true + * @wq: the waitqueue to wait on + * @condition: a C expression for the event to wait for + * cmd1: the command will be executed before sleep + * cmd2: the command will be executed after sleep + * + * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the + * @condition evaluates to true. The @condition is checked each time + * the waitqueue @wq is woken up. + * + * wake_up() has to be called after changing any variable that could + * change the result of the wait condition. + */ +#define wait_event_cmd(wq, condition, cmd1, cmd2) \ +do { \ + if (condition) \ + break; \ + __wait_event_cmd(wq, condition, cmd1, cmd2); \ +} while (0) + #define __wait_event_interruptible(wq, condition) \ ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ schedule()) |