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>
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>
