Commit 04b670de authored by Kent Overstreet's avatar Kent Overstreet
Browse files

closures: Add closure_wait_event_timeout() 



Add a closure version of wait_event_timeout(), with the same semantics.

The closure version is useful because unlike wait_event(), it allows
blocking code to run in the conditional expression.

Cc: Coly Li <colyli@suse.de>
Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 9205d24c

include/linux/closure.h

+35 −0
Original line number Diff line number Diff line
@@ -454,4 +454,39 @@ do { \ 
		__closure_wait_event(waitlist, _cond);			\

} while (0)



#define __closure_wait_event_timeout(waitlist, _cond, _until)		\

({									\

	struct closure cl;						\

	long _t;							\

									\

	closure_init_stack(&cl);					\

									\

	while (1) {							\

		closure_wait(waitlist, &cl);				\

		if (_cond) {						\

			_t = max_t(long, 1L, _until - jiffies);		\

			break;						\

		}							\

		_t = max_t(long, 0L, _until - jiffies);			\

		if (!_t)						\

			break;						\

		closure_sync_timeout(&cl, _t);				\

	}								\

	closure_wake_up(waitlist);					\

	closure_sync(&cl);						\

	_t;								\

})



/*

 * Returns 0 if timeout expired, remaining time in jiffies (at least 1) if

 * condition became true

 */

#define closure_wait_event_timeout(waitlist, _cond, _timeout)		\

({									\

	unsigned long _until = jiffies + _timeout;			\

	(_cond)								\

		? max_t(long, 1L, _until - jiffies)			\

		: __closure_wait_event_timeout(waitlist, _cond, _until);\

})



#endif /* _LINUX_CLOSURE_H */