pjs/security/nss/lib/ssl/sslmutex.h

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C

/*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is the Netscape security libraries.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 2001 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU General Public License Version 2 or later (the
* "GPL"), in which case the provisions of the GPL are applicable
* instead of those above. If you wish to allow use of your
* version of this file only under the terms of the GPL and not to
* allow others to use your version of this file under the MPL,
* indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by
* the GPL. If you do not delete the provisions above, a recipient
* may use your version of this file under either the MPL or the
* GPL.
*
* $Id: sslmutex.h,v 1.6 2002-02-27 21:49:41 bishakhabanerjee%netscape.com Exp $
*/
#ifndef __SSLMUTEX_H_
#define __SSLMUTEX_H_ 1
/* What SSL really wants is portable process-shared unnamed mutexes in
* shared memory, that have the property that if the process that holds
* them dies, they are released automatically, and that (unlike fcntl
* record locking) lock to the thread, not to the process.
* NSPR doesn't provide that.
* Windows has mutexes that meet that description, but they're not portable.
* POSIX mutexes are not automatically released when the holder dies,
* and other processes/threads cannot release the mutex on behalf of the
* dead holder.
* POSIX semaphores can be used to accomplish this on systems that implement
* process-shared unnamed POSIX semaphores, because a watchdog thread can
* discover and release semaphores that were held by a dead process.
* On systems that do not support process-shared POSIX unnamed semaphores,
* they can be emulated using pipes.
* The performance cost of doing that is not yet measured.
*
* So, this API looks a lot like POSIX pthread mutexes.
*/
#include "prtypes.h"
#include "prlock.h"
#if defined(WIN32)
#include <wtypes.h>
typedef struct
{
PRBool isMultiProcess;
#ifdef WINNT
/* on WINNT we need both the PRLock and the Win32 mutex for fibers */
struct {
#else
union {
#endif
PRLock* sslLock;
HANDLE sslMutx;
} u;
} sslMutex;
typedef int sslPID;
#elif defined(LINUX) || defined(AIX) || defined(VMS) || defined(BEOS) || defined(BSDI)
#include <sys/types.h>
#include "prtypes.h"
typedef struct {
PRBool isMultiProcess;
union {
PRLock* sslLock;
struct {
int mPipes[3];
PRInt32 nWaiters;
} pipeStr;
} u;
} sslMutex;
typedef pid_t sslPID;
#elif defined(XP_UNIX) /* other types of Unix */
#include <sys/types.h> /* for pid_t */
#include <semaphore.h> /* for sem_t, and sem_* functions */
typedef struct
{
PRBool isMultiProcess;
union {
PRLock* sslLock;
sem_t sem;
} u;
} sslMutex;
typedef pid_t sslPID;
#else
/* what platform is this ?? */
typedef struct {
PRBool isMultiProcess;
union {
PRLock* sslLock;
/* include cross-process locking mechanism here */
} u;
} sslMutex;
typedef int sslPID;
#endif
#include "seccomon.h"
SEC_BEGIN_PROTOS
extern SECStatus sslMutex_Init(sslMutex *sem, int shared);
extern SECStatus sslMutex_Destroy(sslMutex *sem);
extern SECStatus sslMutex_Unlock(sslMutex *sem);
extern SECStatus sslMutex_Lock(sslMutex *sem);
#ifdef WINNT
extern SECStatus sslMutex_2LevelInit(sslMutex *sem);
#endif
SEC_END_PROTOS
#endif