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/** BEGIN COPYRIGHT BLOCK
* 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.
*
* In addition, as a special exception, Red Hat, Inc. gives You the additional
* right to link the code of this Program with code not covered under the GNU
* General Public License ("Non-GPL Code") and to distribute linked combinations
* including the two, subject to the limitations in this paragraph. Non-GPL Code
* permitted under this exception must only link to the code of this Program
* through those well defined interfaces identified in the file named EXCEPTION
* found in the source code files (the "Approved Interfaces"). The files of
* Non-GPL Code may instantiate templates or use macros or inline functions from
* the Approved Interfaces without causing the resulting work to be covered by
* the GNU General Public License. Only Red Hat, Inc. may make changes or
* additions to the list of Approved Interfaces. You must obey the GNU General
* Public License in all respects for all of the Program code and other code used
* in conjunction with the Program except the Non-GPL Code covered by this
* exception. If you modify this file, you may extend this exception to your
* version of the file, but you are not obligated to do so. If you do not wish to
* provide this exception without modification, you must delete this exception
* statement from your version and license this file solely under the GPL without
* exception.
*
*
* Copyright (C) 2001 Sun Microsystems, Inc. Used by permission.
* Copyright (C) 2005 Red Hat, Inc.
* All rights reserved.
* END COPYRIGHT BLOCK **/
/*
* fsmutex: Mutexes that are filesystem-based so they're available from more
* than one process and address space
*
* Rob McCool
*/
#ifndef FSMUTEX_H
#define FSMUTEX_H
#include "netsite.h"
typedef void * FSMUTEX;
/* ------------------------------ Prototypes ------------------------------ */
NSPR_BEGIN_EXTERN_C
/*
Flags to fsmutex_init.
FSMUTEX_VISIBLE makes a filesystem mutex which can be opened by other
programs or processes.
FSMUTEX_NEEDCRIT specifies that the fsmutex_lock and fsmutex_unlock
functions should also use a critical section to ensure that more than
one thread does not acquire the mutex at a time. If this flag is not
specified, it is up to the caller to ensure that only thread within a
process tries to acquire the lock at any given time.
*/
#define FSMUTEX_VISIBLE 0x01
#define FSMUTEX_NEEDCRIT 0x02
/*
fsmutex_init creates a new filesystem-based mutex. The resulting mutex
is part of the filesystem. The name and number parameters are used to
create a name for the mutex. If the FSMUTEX_VISIBLE flag is specified,
the mutex will be left in the filesystem for other programs and processes
to access. If a mutex with the given name/number combination already
exists, the calling process is allowed access to it. If the mutex does
not already exist, the mutex is created.
Returns NULL on failure, a void pointer to a fsmutex structure otherwise.
This fsmutex structure is local to the current process.
*/
NSAPI_PUBLIC FSMUTEX fsmutex_init(char *name, int number, int flags);
/*
Sets the ownership of the underlying filesystem object to the given
uid and gid. Only effective if the server is running as root.
*/
#ifdef XP_UNIX
#include <unistd.h>
#ifdef __sony
#include <sys/types.h>
#endif
NSAPI_PUBLIC void fsmutex_setowner(FSMUTEX fsm, uid_t uid, gid_t gid);
#endif
/*
fsmutex_terminate deletes a filesystem-based mutex. A mutex will only
be deleted when every process which has an open pointer to the mutex
calls this function.
*/
NSAPI_PUBLIC void fsmutex_terminate(FSMUTEX id);
/*
fsmutex_lock attempts to acquire the given filesystem-based mutex. If
another process is holding the mutex, or if the FSMUTEX_NEEDCRIT flag
was passed to fsmutex_init and another thread in the current process is
holding the mutex, then the calling thread will block until the mutex
is available.
*/
NSAPI_PUBLIC void fsmutex_lock(FSMUTEX id);
/*
fsmutex_unlock releases a filesystem-based mutex previously acquired
by fsmutex_lock.
*/
NSAPI_PUBLIC void fsmutex_unlock(FSMUTEX id);
NSPR_END_EXTERN_C
#endif
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