To implement gettimeofday(), a broken-down UTC time was requested from the
system using GetSystemTime(), then tm_to_time_t() was used to convert it
to a time_t because it does not look at the current timezone, which
mktime() would do.
Use GetSystemTimeAsFileTime() and a different conversion path to avoid this
back-reference from the compatibility layer to the generic code.
Signed-off-by: Johannes Sixt <j6t@xxxxxxxx>
---
This is new. It was triggered by Junio's "mark function static" series.
The patch that I sent out in response there was too simple to be correct.
compat/mingw.c | 36 +++++++++++++++++++-----------------
1 files changed, 19 insertions(+), 17 deletions(-)
diff --git a/compat/mingw.c b/compat/mingw.c
index 74ffc18..ab65f77 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -140,12 +140,20 @@ int mingw_open (const char *filename, int oflags, ...)
return fd;
}
-static inline time_t filetime_to_time_t(const FILETIME *ft)
+/*
+ * The unit of FILETIME is 100-nanoseconds since January 1, 1601, UTC.
+ * Returns the 100-nanoseconds ("hekto nanoseconds") since the epoch.
+ */
+static inline long long filetime_to_hnsec(const FILETIME *ft)
{
long long winTime = ((long long)ft->dwHighDateTime << 32) + ft->dwLowDateTime;
- winTime -= 116444736000000000LL; /* Windows to Unix Epoch conversion */
- winTime /= 10000000; /* Nano to seconds resolution */
- return (time_t)winTime;
+ /* Windows to Unix Epoch conversion */
+ return winTime - 116444736000000000LL;
+}
+
+static inline time_t filetime_to_time_t(const FILETIME *ft)
+{
+ return (time_t)(filetime_to_hnsec(ft) / 10000000);
}
/* We keep the do_lstat code in a separate function to avoid recursion.
@@ -281,19 +289,13 @@ int mkstemp(char *template)
int gettimeofday(struct timeval *tv, void *tz)
{
- SYSTEMTIME st;
- struct tm tm;
- GetSystemTime(&st);
- tm.tm_year = st.wYear-1900;
- tm.tm_mon = st.wMonth-1;
- tm.tm_mday = st.wDay;
- tm.tm_hour = st.wHour;
- tm.tm_min = st.wMinute;
- tm.tm_sec = st.wSecond;
- tv->tv_sec = tm_to_time_t(&tm);
- if (tv->tv_sec < 0)
- return -1;
- tv->tv_usec = st.wMilliseconds*1000;
+ FILETIME ft;
+ long long hnsec;
+
+ GetSystemTimeAsFileTime(&ft);
+ hnsec = filetime_to_hnsec(&ft);
+ tv->tv_sec = hnsec / 10000000;
+ tv->tv_usec = (hnsec % 10000000) / 10;
return 0;
}
--
1.6.6.218.g3e6eb
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html