[core] sys-time.h - localtime_r,gmtime_r macros

sys-time.h - localtime_r,gmtime_r macros if needed

provide rudimentary localtime_r() and gmtime_r() if not present
(wraps localtime() and gmtime() funtions, but are not thread-safe since
 they do not take a lock around access to localtime() and gmtime())

(import from one of my development branches from 2015)

src/Makefile.am

@@ -466,7 +466,7 @@ hdr = base64.h buffer.h burl.h network.h log.h http_kv.h keyvalue.h \
 	configparser.h mod_ssi_exprparser.h \
 	rand.h \
 	sys-crypto.h sys-crypto-md.h \
-	sys-endian.h sys-mmap.h sys-socket.h sys-strings.h \
+	sys-endian.h sys-mmap.h sys-socket.h sys-strings.h sys-time.h \
 	mod_cml.h mod_cml_funcs.h \
 	safe_memclear.h sock_addr.h status_counter.h \
 	mod_magnet_cache.h \

src/sys-time.h

@@ -0,0 +1,33 @@
+/*
+ * sys-time.h - time.h wrapper for localtime_r() and gmtime_r()
+ *
+ * Copyright(c) 2015 Glenn Strauss gstrauss()gluelogic.com  All rights reserved
+ * License: BSD 3-clause (same as lighttpd)
+ */
+#ifndef INCLUDED_SYS_TIME_H
+#define INCLUDED_SYS_TIME_H
+/* _XOPEN_SOURCE for strptime() */
+#ifndef _XOPEN_SOURCE
+#define _XOPEN_SOURCE 700
+#endif
+#include "first.h"
+
+#include <sys/time.h>/* gettimeofday() */
+#include <time.h>    /* time() localtime_r() gmtime_r() strftime() strptime() */
+
+/*(provide rudimentary localtime_r() and gmtime_r() for platforms lacking)
+ *(Note that 'result' preprocessor arg is repeated, so callers should avoid
+ * side-effects.  Also note that there is still a race condition before the
+ * result of localtime()/gmtime() is copied.  In any case, this exists here
+ * so that the rest of the code can use localtime_r() and gmtime_r() syntax.
+ * Platforms requiring thread-safety and lacking localtime_r() or gmtime_r()
+ * could turn these into subroutines which take a local mutex to protect the
+ * calls to localtime() or gmtime()) */
+#ifndef HAVE_LOCALTIME_R
+#define localtime_r(timep,result) ((*(result) = *(localtime(timep))), (result))
+#endif
+#ifndef HAVE_GMTIME_R
+#define gmtime_r(timep,result)    ((*(result) = *(gmtime(timep))),    (result))
+#endif
+
+#endif