timer: init only once

This avoids trouble if another mpv instance is initialized in the same
process.

Since timeBeginPeriod/timeEndPeriod are hereby not easily matched
anymore, use an atexit() handler to call timeEndPeriod, so that we
can be sure these calls are matched, even if we allow multiple
initializations later when introducing the client API.

1 files changed, 10 insertions, 2 deletions

diff --git a/osdep/timer-win2.c b/osdep/timer-win2.c
index 136bb0becc..ed09ed18db 100644
--- a/osdep/timer-win2.c
+++ b/osdep/timer-win2.c
@@ -21,6 +21,7 @@
 #include <windows.h>
 #include <sys/time.h>
 #include <mmsystem.h>
+#include <stdlib.h>
 #include "timer.h"
 
 void mp_sleep_us(int64_t us)
@@ -42,8 +43,15 @@ uint64_t mp_raw_time_us(void)
     return tv.tv_sec * 1000000LL + tv.tv_usec;
 }
 
+static void restore_timer(void)
+{
+    // The MSDN documents that begin/end "must" be matched. This satisfies
+    // this requirement.
+    timeEndPeriod(1);
+}
+
 void mp_raw_time_init(void)
 {
-    // request 1ms timer resolution
-    timeBeginPeriod(1);
+    timeBeginPeriod(1); // request 1ms timer resolution
+    atexit(restore_timer);
 }