[PATCH v2 1/2] msvcrt: Avoid expensive timezone queries from plain time() calls.

[Benjamin Fischer]

From: Benjamin Fischer <[e-mail]>

The implementations of _time32 & _time64 internally used _ftime64, which also needs to query timezone information via GetTimeZoneInformation() which can be fairly expensive i.e. somewhere down the line is a localtime() call that practically always triggers at least a stat syscall, which is a lot of overhead for merely querying the time.
---
 dlls/msvcrt/time.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/dlls/msvcrt/time.c b/dlls/msvcrt/time.c
index 9b0cbb4969f..1bca5ec6495 100644
--- a/dlls/msvcrt/time.c
+++ b/dlls/msvcrt/time.c
@@ -780,11 +780,16 @@ int CDECL _ftime32_s(struct __timeb32 *buf)
 __time64_t CDECL _time64(__time64_t *buf)
 {
     __time64_t curtime;
-    struct __timeb64 tb;
+    FILETIME ft;
+    ULONGLONG time;
+
+    _tzset_init();
+
+    GetSystemTimeAsFileTime(&ft);
 
-    _ftime64(&tb);
+    time = ((ULONGLONG)ft.dwHighDateTime << 32) | ft.dwLowDateTime;
 
-    curtime = tb.time;
+    curtime = time / TICKSPERSEC - SECS_1601_TO_1970;
     return buf ? *buf = curtime : curtime;
 }
 
@@ -794,11 +799,11 @@ __time64_t CDECL _time64(__time64_t *buf)
 __time32_t CDECL _time32(__time32_t *buf)
 {
     __time32_t curtime;
-    struct __timeb64 tb;
+    __time64_t time;
 
-    _ftime64(&tb);
+    time = _time64(NULL);
 
-    curtime = (tb.time == (__time32_t)tb.time) ? tb.time : -1;
+    curtime = (time == (__time32_t)time) ? time : -1;
     return buf ? *buf = curtime : curtime;
 }
 
-- 
GitLab


https://gitlab.winehq.org/wine/wine/-/merge_requests/10893