Cygwin: timerfd: implement TFD_IOC_SET_TICKS ioctl

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygwin/fhandler_timerfd.cc

@@ -176,15 +176,29 @@ int
 fhandler_timerfd::ioctl (unsigned int cmd, void *p)
 {
   int ret = -1;
+  uint64_t ov_cnt;
 
   switch (cmd)
     {
     case TFD_IOC_SET_TICKS:
-      /* TODO */
+      __try
+	{
+	  timer_tracker *tt = (timer_tracker *) timerid;
+
+	  ov_cnt = *(uint64_t *) p;
+	  if (!ov_cnt)
+	    {
+	      set_errno (EINVAL);
+	      break;
+	    }
+	  tt->set_event (ov_cnt);
+	}
+      __except (EFAULT) {}
+      __endtry
       ret = 0;
       break;
     default:
-      set_errno (EINVAL);
+      ret = fhandler_base::ioctl (cmd, p);
       break;
     }
   syscall_printf ("%d = ioctl_timerfd(%x, %p)", ret, cmd, p);

winsup/cygwin/timer.cc

@@ -132,6 +132,22 @@ timer_tracker::arm_event ()
   return ret;
 }
 
+void
+timer_tracker::set_event (uint64_t ov_cnt)
+{
+  LONG ret;
+
+  while ((ret = InterlockedCompareExchange (&event_running, EVENT_LOCK,
+					    EVENT_DISARMED)) == EVENT_LOCK)
+    yield ();
+  InterlockedExchange64 (&overrun_count, ov_cnt);
+  if (ret == EVENT_DISARMED)
+    {
+      SetEvent (get_timerfd_handle ());
+      InterlockedExchange (&event_running, EVENT_ARMED);
+    }
+}
+
 LONG64
 timer_tracker::_disarm_event ()
 {

winsup/cygwin/timer.h

@@ -55,7 +55,9 @@ class timer_tracker
 
   void gettime (itimerspec *);
   int settime (int, const itimerspec *, itimerspec *);
+
   LONG arm_event ();
+  void set_event (uint64_t ov_cnt);
   unsigned int disarm_event ();
 
   DWORD thread_func ();