/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#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(NETBSD)

#include <sys/param.h> /* for __NetBSD_Version__ */

#endif

#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(BEOS) || defined(BSDI) || (defined(NETBSD) && __NetBSD_Version__ < 500000000) || defined(OPENBSD)

#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);

/* If processLocal is set to true, then just free resources which are *only* associated

 * with the current process. Leave any shared resources (including the state of 

 * shared memory) intact. */

extern SECStatus sslMutex_Destroy(sslMutex *sem, PRBool processLocal);

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