On GNU/Linux, use timerfd for asynchronous timers.

* configure.ac (toplevel): Check whether GNU/Linux-specific
timerfd functions and macros are available.
* m4/clock_time.m4 (gl_CLOCK_TIME): Check for clock_getres as well.
* src/atimer.c (toplevel) [HAVE_TIMERFD]: Include sys/timerfd.h.
(toplevel): Rename alarm_timer_ok to special_timer_available.
[HAVE_TIMERFD]: Declare timerfd.
[HAVE_CLOCK_GETRES]: Declare resolution.
(start_atimer) [HAVE_CLOCK_GETRES]: Round up timestamp to
system timer resolution.
(set_alarm) [HAVE_TIMERFD]: Use timerfd_settime.
(timerfd_callback) [HAVE_TIMERFD]: New function.
(atimer_result, debug_timer_callback, Fdebug_timer_check)
[ENABLE_CHECKING]: New function for the sake of automated tests.
(init_atimer) [HAVE_TIMERFD]: Setup timerfd.
[HAVE_CLOCK_GETRES]: Likewise for system timer resolution.
[ENABLE_CHECKING]: Defsubr test function.
* src/atimer.h (timerfd_callback) [HAVE_TIMERFD]: Add prototype.
* src/lisp.h (add_timer_wait_descriptor) [HAVE_TIMERFD]: Likewise.
* src/process.c (add_timer_wait_descriptor) [HAVE_TIMERFD]: New function.
* test/automated/timer-tests.el (timer-tests-debug-timer-check): New test.

2 files changed, 9 insertions, 1 deletions

diff --git a/test/ChangeLog b/test/ChangeLog
index 6afa9ea8959..140b5d04efd 100644
--- a/test/ChangeLog
+++ b/test/ChangeLog
@@ -1,3 +1,7 @@
+2014-07-28  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        * automated/timer-tests.el (timer-tests-debug-timer-check): New test.
+
 2014-07-26  Ulf Jasper  <ulf.jasper@web.de>
 
         * automated/icalendar-tests.el (icalendar-tests--do-test-import):
diff --git a/test/automated/timer-tests.el b/test/automated/timer-tests.el
index bc95df5e773..f8e8414f8d7 100644
--- a/test/automated/timer-tests.el
+++ b/test/automated/timer-tests.el
@@ -34,5 +34,9 @@
     (sit-for 0 t)
     (should timer-ran)))
 
-;;; timer-tests.el ends here
+(ert-deftest timer-tests-debug-timer-check ()
+  ;; This function exists only if --enable-checking.
+  (if (fboundp 'debug-timer-check)
+      (should (debug-timer-check)) t))
 
+;;; timer-tests.el ends here