From 3979afceecb98780549fda60c7f75c8015bb33d8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A1szl=C3=B3=20N=C3=A9meth?=
 <laszlo.nemeth@collabora.com>
Date: Fri, 1 Apr 2016 23:16:27 +0200
Subject: [PATCH] osl_getSystemTime: use high precision timer of W32, if
 available

Change-Id: I7029f37639ead7a8b597ff39d1abcd295fab0551
---
 sal/osl/w32/time.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/sal/osl/w32/time.c b/sal/osl/w32/time.c
index 90d659a8cca0..325c57e9831a 100644
--- a/sal/osl/w32/time.c
+++ b/sal/osl/w32/time.c
@@ -35,10 +35,28 @@ sal_Bool SAL_CALL osl_getSystemTime(TimeValue* pTimeVal)
     FILETIME   CurTime, OffTime;
     __int64    Value;
 
+    typedef BOOL (WINAPI *CheckTokenMembership_PROC)( HANDLE, PSID, PBOOL );
+
+    static HMODULE  hModule = NULL;
+    static CheckTokenMembership_PROC    pCheckTokenMembership = NULL;
+
     OSL_ASSERT(pTimeVal != 0);
 
-    GetSystemTime(&SystemTime);
-    SystemTimeToFileTime(&SystemTime, &CurTime);
+    if ( !hModule )
+    {
+        hModule = GetModuleHandleA( "Kernel32.dll" );
+        if ( hModule )
+            pCheckTokenMembership = (CheckTokenMembership_PROC)GetProcAddress( hModule, "GetSystemTimePreciseAsFileTime" );
+    }
+
+    // use ~1 microsecond resolution if available
+    if ( pCheckTokenMembership )
+        GetSystemTimePreciseAsFileTime(&CurTime);
+    else
+    {
+        GetSystemTime(&SystemTime);
+        SystemTimeToFileTime(&SystemTime, &CurTime);
+    }
 
     SystemTime.wYear         = 1970;
     SystemTime.wMonth        = 1;