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>