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[PATCH v2 1/3] date.c: switch to reentrant {gm,local}time_r

From
Doan Tran Cong Danh <congdanhqx@gmail.com>
Date
Nov 28, 2019, 12:25 UTC
Message-ID
<71de738864d273c925ed8a9a93fe1a85fa8b81b6.1574943677.git.congdanhqx@gmail.com>
In-Reply-To
<cover.1574943677.git.congdanhqx@gmail.com>

Originally, git was intended to be single-thread executable. `gmtime(3)' and `localtime(3)' can be used in such codebase for cleaner code.

Overtime, we're employing multithread in our code base.

Let's phase out `gmtime(3)' and `localtime(3)' in favour of `gmtime_r(3)' and `localtime_r(3)'.

Signed-off-by: Doan Tran Cong Danh <congdanhqx@gmail.com>
---
 date.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/date.c b/date.c
index 041db7db4e..b0d9a8421d 100644
--- a/date.c
+++ b/date.c
@@ -64,16 +64,16 @@ static time_t gm_time_t(timestamp_t time, int tz)
  * thing, which means that tz -0100 is passed in as the integer -100,
  * even though it means "sixty minutes off"
  */
-static struct tm *time_to_tm(timestamp_t time, int tz)
+static struct tm *time_to_tm(timestamp_t time, int tz, struct tm *tm)
 {
 	time_t t = gm_time_t(time, tz);
-	return gmtime(&t);
+	return gmtime_r(&t, tm);
 }
 
-static struct tm *time_to_tm_local(timestamp_t time)
+static struct tm *time_to_tm_local(timestamp_t time, struct tm *tm)
 {
 	time_t t = time;
-	return localtime(&t);
+	return localtime_r(&t, tm);
 }
 
 /*
@@ -283,6 +283,7 @@ static void show_date_normal(struct strbuf *buf, timestamp_t time, struct tm *tm
 const char *show_date(timestamp_t time, int tz, const struct date_mode *mode)
 {
 	struct tm *tm;
+	struct tm tmbuf = { 0 };
 	struct tm human_tm = { 0 };
 	int human_tz = -1;
 	static struct strbuf timebuf = STRBUF_INIT;
@@ -318,11 +319,11 @@ const char *show_date(timestamp_t time, int tz, const struct date_mode *mode)
 	}
 
 	if (mode->local)
-		tm = time_to_tm_local(time);
+		tm = time_to_tm_local(time, &tmbuf);
 	else
-		tm = time_to_tm(time, tz);
+		tm = time_to_tm(time, tz, &tmbuf);
 	if (!tm) {
-		tm = time_to_tm(0, 0);
+		tm = time_to_tm(0, 0, &tmbuf);
 		tz = 0;
 	}
 
@@ -959,10 +960,11 @@ void datestamp(struct strbuf *out)
 {
 	time_t now;
 	int offset;
+	struct tm tm = { 0 };
 
 	time(&now);
 
-	offset = tm_to_time_t(localtime(&now)) - now;
+	offset = tm_to_time_t(localtime_r(&now, &tm)) - now;
 	offset /= 60;
 
 	date_string(now, offset, out);
-- 
2.24.0.615.g37f5bfbdea
Previous: Doan Tran Cong DanhNext: Doan Tran Cong Danh
Message 13 of 15 in “drop non-reentrant time usage”
  1. 0/5 drop non-reentrant time usageDoan Tran Cong Danh, Nov 27, 2019
  2. 1/5 date.c::datestamp: switch to reentrant localtime_rDoan Tran Cong Danh, Nov 27, 2019
  3. 2/5 date.c::time_to_tm_local: use reentrant localtime_r(3)Doan Tran Cong Danh, Nov 27, 2019
  4. 3/5 date.c::time_to_tm: use reentrant gmtime_r(3)Doan Tran Cong Danh, Nov 27, 2019
  5. 4/5 archive-zip: use reentrant localtime_r(3)Doan Tran Cong Danh, Nov 27, 2019
  6. 5/5 mingw: use {gm,local}time_s as backend for {gm,local}time_rDoan Tran Cong Danh, Nov 27, 2019
  7. Johannes SchindelinNov 27, 2019
  8. Johannes SchindelinNov 27, 2019
  9. Danh DoanNov 28, 2019
  10. Jeff KingNov 27, 2019
  11. Danh DoanNov 28, 2019
  12. 0/3 Phase out non-reentrant time functionsDoan Tran Cong Danh, Nov 28, 2019
  13. 1/3 date.c: switch to reentrant {gm,local}time_rDoan Tran Cong Danh, Nov 28, 2019
  14. 2/3 archive-zip.c: switch to reentrant localtime_rDoan Tran Cong Danh, Nov 28, 2019
  15. 3/3 mingw: use {gm,local}time_s as backend for {gm,local}time_rDoan Tran Cong Danh, Nov 28, 2019

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