[Wine-patches] [PATCH 3/4] kernel32: Optimize GetSystemTime.

[Alexander Morozov]

---
 dlls/kernel32/time.c |   21 ++++++++++++++++++---
 1 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/dlls/kernel32/time.c b/dlls/kernel32/time.c
index b30314c..95a6b60 100644
--- a/dlls/kernel32/time.c
+++ b/dlls/kernel32/time.c
@@ -19,6 +19,7 @@
  */
 
 #include "config.h"
+#include "wine/port.h"
 
 #include <string.h>
 #ifdef HAVE_UNISTD_H
@@ -933,13 +934,27 @@ VOID WINAPI GetLocalTime(LPSYSTEMTIME systime)
  */
 VOID WINAPI GetSystemTime(LPSYSTEMTIME systime)
 {
+    static int lock = 0;
+    static SYSTEMTIME old_systime;
+    static LARGE_INTEGER old;
     FILETIME ft;
     LARGE_INTEGER t;
 
+    while (interlocked_cmpxchg(&lock, 1, 0));
     NtQuerySystemTime(&t);
-    ft.dwLowDateTime = t.u.LowPart;
-    ft.dwHighDateTime = t.u.HighPart;
-    FileTimeToSystemTime(&ft, systime);
+    if (t.QuadPart == old.QuadPart)
+    {
+        *systime = old_systime;
+    }
+    else
+    {
+        ft.dwLowDateTime = t.u.LowPart;
+        ft.dwHighDateTime = t.u.HighPart;
+        FileTimeToSystemTime(&ft, systime);
+        old = t;
+        old_systime = *systime;
+    }
+    interlocked_xchg(&lock, 0);
 }
 
 /*********************************************************************
-- 
1.6.1.3.GIT