[PATCH 2/2] libs/fluidsynth: Fix data race in g_get_monotonic_time().

[Jinoh Kang]

From: Jinoh Kang

Fixes: f768d6b31bebc35fbaf751d0cd57c8bd302a8d60
---
 libs/fluidsynth/glib.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/libs/fluidsynth/glib.c b/libs/fluidsynth/glib.c
index cd938a4fb6b..a399850c915 100644
--- a/libs/fluidsynth/glib.c
+++ b/libs/fluidsynth/glib.c
@@ -40,10 +40,14 @@ int g_snprintf( char *buffer, size_t size, const char *format, ... )

double g_get_monotonic_time(void)
 {
-    static LARGE_INTEGER frequency = {0};
-    LARGE_INTEGER counter;
+    static volatile LONG64 freq_cache;
+    LARGE_INTEGER counter, frequency;

-    if (!frequency.QuadPart) QueryPerformanceFrequency( &frequency );
+    if (!(frequency.QuadPart = ReadNoFence64( &freq_cache )))
+    {
+        QueryPerformanceFrequency( &frequency );
+        WriteNoFence64( &freq_cache, frequency.QuadPart );
+    }
     QueryPerformanceCounter( &counter );

return counter.QuadPart * 1000000.0 / frequency.QuadPart; /* time in micros */