~drizzle-trunk/drizzle/development

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/*****************************************************************************

Copyright (c) 1995, 2009, Innobase Oy. All Rights Reserved.

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; version 2 of the License.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA 02111-1307 USA

*****************************************************************************/

/******************************************************
The interface to the operating system synchronization primitives.

Created 9/6/1995 Heikki Tuuri
*******************************************************/

#ifdef __WIN__
#include <winbase.h>
#endif

/**************************************************************
Acquires ownership of a fast mutex. Currently in Windows this is the same
as os_fast_mutex_lock! */
UNIV_INLINE
ulint
os_fast_mutex_trylock(
/*==================*/
						/* out: 0 if success, != 0 if
						was reserved by another
						thread */
	os_fast_mutex_t*	fast_mutex)	/* in: mutex to acquire */
{
#ifdef __WIN__
	EnterCriticalSection(fast_mutex);

	return(0);
#else
#if defined(UNIV_HOTBACKUP) && defined(UNIV_HPUX10)
	/* Since the hot backup version is standalone, MySQL does not redefine
	pthread_mutex_trylock for HP-UX-10.20, and consequently we must invert
	the return value here */

	return((ulint) (1 - pthread_mutex_trylock(fast_mutex)));
#else
	/* NOTE that the MySQL my_pthread.h redefines pthread_mutex_trylock
	so that it returns 0 on success. In the operating system
	libraries, HP-UX-10.20 follows the old Posix 1003.4a Draft 4 and
	returns 1 on success (but MySQL remaps that to 0), while Linux,
	FreeBSD, Solaris, AIX, Tru64 Unix, HP-UX-11.0 return 0 on success. */

	return((ulint) pthread_mutex_trylock(fast_mutex));
#endif
#endif
}