[babeltrace.git] / include / babeltrace / compat / utc-internal.h

#ifndef _BABELTRACE_UTC_H
#define _BABELTRACE_UTC_H

/*
 * Copyright (C) 2011-2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <time.h>

/* If set, use GNU or BSD timegm(3) */
#if defined(_BSD_SOURCE) || defined(_SVID_SOURCE)

static inline
time_t bt_timegm(struct tm *tm)
{
	return timegm(tm);
}

#elif defined(__MINGW32__)

static inline
time_t bt_timegm(struct tm *tm)
{
	return _mkgmtime(tm);
}

#else

#include <string.h>
#include <stdlib.h>
#include <glib.h>

/*
 * Note: Below implementation of timegm() is not thread safe
 * as it changes the environment
 * variable TZ. It is OK as long as it is kept in self-contained program,
 * but should not be used within thread-safe library code.
 */

static inline
time_t bt_timegm(struct tm *tm)
{
	time_t ret;
	char *tz;

	tz = getenv("TZ");
	/*
	 * Make a temporary copy, as the environment variable will be
	 * modified.
	 */
	if (tz) {
		tz = strdup(tz);
		if (!tz) {
			/*
			 * Memory allocation error.
			 */
			return (time_t) -1;
		}
	}

	/* Temporarily setting TZ to 1 for UTC */
	g_setenv("TZ", "", 1);
	tzset();
	ret = mktime(tm);
	if (tz) {
		g_setenv("TZ", tz, 1);
		free(tz);
	} else {
		unsetenv("TZ");
	}
	tzset();
	return ret;
}

#endif

#endif /* _BABELTRACE_UTC_H */
Commit	Line	Data
a386e246 SKC	1	#ifndef _BABELTRACE_UTC_H
	2	#define _BABELTRACE_UTC_H
	3
	4	/*
	5	* Copyright (C) 2011-2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	6	*
	7	* Permission is hereby granted, free of charge, to any person obtaining a copy
	8	* of this software and associated documentation files (the "Software"), to deal
	9	* in the Software without restriction, including without limitation the rights
	10	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	11	* copies of the Software, and to permit persons to whom the Software is
	12	* furnished to do so, subject to the following conditions:
	13	*
	14	* The above copyright notice and this permission notice shall be included in
	15	* all copies or substantial portions of the Software.
	16	*
	17	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	18	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	19	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	20	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	21	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	22	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	23	* SOFTWARE.
	24	*/
	25
	26	#include <time.h>
	27
	28	/* If set, use GNU or BSD timegm(3) */
	29	#if defined(_BSD_SOURCE) \|\| defined(_SVID_SOURCE)
	30
	31	static inline
03f61dea	32	time_t bt_timegm(struct tm *tm)
a386e246 SKC	33	{
	34	return timegm(tm);
	35	}
	36
3d2f08e7 MJ	37	#elif defined(__MINGW32__)
	38
	39	static inline
	40	time_t bt_timegm(struct tm *tm)
	41	{
	42	return _mkgmtime(tm);
	43	}
	44
a386e246 SKC	45	#else
	46
	47	#include <string.h>
	48	#include <stdlib.h>
fbb2f0da	49	#include <glib.h>
a386e246 SKC	50
	51	/*
	52	* Note: Below implementation of timegm() is not thread safe
	53	* as it changes the environment
	54	* variable TZ. It is OK as long as it is kept in self-contained program,
	55	* but should not be used within thread-safe library code.
	56	*/
	57
	58	static inline
03f61dea	59	time_t bt_timegm(struct tm *tm)
a386e246 SKC	60	{
	61	time_t ret;
	62	char *tz;
	63
	64	tz = getenv("TZ");
	65	/*
	66	* Make a temporary copy, as the environment variable will be
	67	* modified.
	68	*/
	69	if (tz) {
	70	tz = strdup(tz);
	71	if (!tz) {
	72	/*
	73	* Memory allocation error.
	74	*/
	75	return (time_t) -1;
	76	}
	77	}
	78
	79	/* Temporarily setting TZ to 1 for UTC */
fbb2f0da	80	g_setenv("TZ", "", 1);
a386e246 SKC	81	tzset();
	82	ret = mktime(tm);
	83	if (tz) {
fbb2f0da	84	g_setenv("TZ", tz, 1);
a386e246 SKC	85	free(tz);
	86	} else {
	87	unsetenv("TZ");
	88	}
	89	tzset();
	90	return ret;
	91	}
	92
	93	#endif
	94
	95	#endif /* _BABELTRACE_UTC_H */