Commit Graph

4 Commits

Author SHA1 Message Date
Peter Fang 3fe4c3f2a8 dm: provide timer callback handlers the number of expirations
It is possible for multiple timeouts to occur in one mevent epoll
iteration. Providing the number of timer expirations to the timer
callback handlers can be useful. E.g., this could improve emulation of
timing-sensitive hardware components.

Tracked-On: #2319
Signed-off-by: Peter Fang <peter.fang@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>
2019-01-23 10:33:28 +08:00
Peter Fang 0f7535fdbe dm: add absolute timer mode
Allow specifying the initial expiration in absolute time.

Tracked-On: #2319
Signed-off-by: Peter Fang <peter.fang@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>
2019-01-23 10:33:28 +08:00
Yin Fengwei 64d9c59aa1 dm: enhence the mevent API
There is one race issue between mevent callback (which is called
in mevent_dispatch thread) and mevent_delete (which could be called
in dev thread). And the callback is called after mevent_delete.

libevent have the exactly same issue. The issue is decripted here:
https://github.com/libevent/libevent/blob/master/whatsnew-2.1.txt

The fixing is:
We introduce a teardown callback to mevent and make sure there is
no race issue between callback and teardown call.

This patch updates the mevent API and the caller as well.

Tracked-On: #1877
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>
2018-12-07 20:21:33 +08:00
Victor Sun 6ffa1aa367 DM: add acrn_timer api for timer emulation
We will use timerfd and epoll mechanism to emulate kinds of timers like
PIT/RTC/WDT/PMTIMER/... in device model under Linux. The api is unified
in this patch.

Compare with sigevent mechanism, timerfd has a advantage that it could
avoid race condition on resource accessing in the async sigev thread.

change log:
	v1 -> v2: add NULL pointer check for function parameter;
	v2 -> v3: rename file name of vtimer.* to timer.*;
		  rename structure name of vtimer to acrn_timer;
		  add read() in timer handler to consume I/O event;
	v3 -> v4: replace bool clock_realtime with int clockid;
		  close acrn_timer->fd properly;

Tracked-On: #1489
Signed-off-by: Victor Sun <victor.sun@intel.com>
Reviewed-by: Jian Jun Chen <jian.jun.chen@intel.com>
Acked-by: Yin Fengwei <fengwei.yin@intel.com>
2018-10-17 14:31:09 +08:00