michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: #ifndef __SSLMUTEX_H_
michael@0: #define __SSLMUTEX_H_ 1
michael@0: 
michael@0: /* What SSL really wants is portable process-shared unnamed mutexes in 
michael@0:  * shared memory, that have the property that if the process that holds
michael@0:  * them dies, they are released automatically, and that (unlike fcntl 
michael@0:  * record locking) lock to the thread, not to the process.  
michael@0:  * NSPR doesn't provide that.  
michael@0:  * Windows has mutexes that meet that description, but they're not portable.  
michael@0:  * POSIX mutexes are not automatically released when the holder dies, 
michael@0:  * and other processes/threads cannot release the mutex on behalf of the 
michael@0:  * dead holder.  
michael@0:  * POSIX semaphores can be used to accomplish this on systems that implement 
michael@0:  * process-shared unnamed POSIX semaphores, because a watchdog thread can 
michael@0:  * discover and release semaphores that were held by a dead process.  
michael@0:  * On systems that do not support process-shared POSIX unnamed semaphores, 
michael@0:  * they can be emulated using pipes.  
michael@0:  * The performance cost of doing that is not yet measured.
michael@0:  *
michael@0:  * So, this API looks a lot like POSIX pthread mutexes.
michael@0:  */
michael@0: 
michael@0: #include "prtypes.h"
michael@0: #include "prlock.h"
michael@0: 
michael@0: #if defined(NETBSD)
michael@0: #include <sys/param.h> /* for __NetBSD_Version__ */
michael@0: #endif
michael@0: 
michael@0: #if defined(WIN32)
michael@0: 
michael@0: #include <wtypes.h>
michael@0: 
michael@0: typedef struct 
michael@0: {
michael@0:     PRBool isMultiProcess;
michael@0: #ifdef WINNT
michael@0:     /* on WINNT we need both the PRLock and the Win32 mutex for fibers */
michael@0:     struct {
michael@0: #else
michael@0:     union {
michael@0: #endif
michael@0:         PRLock* sslLock;
michael@0:         HANDLE sslMutx;
michael@0:     } u;
michael@0: } sslMutex;
michael@0: 
michael@0: typedef int    sslPID;
michael@0: 
michael@0: #elif defined(LINUX) || defined(AIX) || defined(BEOS) || defined(BSDI) || (defined(NETBSD) && __NetBSD_Version__ < 500000000) || defined(OPENBSD)
michael@0: 
michael@0: #include <sys/types.h>
michael@0: #include "prtypes.h"
michael@0: 
michael@0: typedef struct { 
michael@0:     PRBool isMultiProcess;
michael@0:     union {
michael@0:         PRLock* sslLock;
michael@0:         struct {
michael@0:             int      mPipes[3]; 
michael@0:             PRInt32  nWaiters;
michael@0:         } pipeStr;
michael@0:     } u;
michael@0: } sslMutex;
michael@0: typedef pid_t sslPID;
michael@0: 
michael@0: #elif defined(XP_UNIX) /* other types of Unix */
michael@0: 
michael@0: #include <sys/types.h>	/* for pid_t */
michael@0: #include <semaphore.h>  /* for sem_t, and sem_* functions */
michael@0: 
michael@0: typedef struct
michael@0: {
michael@0:     PRBool isMultiProcess;
michael@0:     union {
michael@0:         PRLock* sslLock;
michael@0:         sem_t  sem;
michael@0:     } u;
michael@0: } sslMutex;
michael@0: 
michael@0: typedef pid_t sslPID;
michael@0: 
michael@0: #else
michael@0: 
michael@0: /* what platform is this ?? */
michael@0: 
michael@0: typedef struct { 
michael@0:     PRBool isMultiProcess;
michael@0:     union {
michael@0:         PRLock* sslLock;
michael@0:         /* include cross-process locking mechanism here */
michael@0:     } u;
michael@0: } sslMutex;
michael@0: 
michael@0: typedef int sslPID;
michael@0: 
michael@0: #endif
michael@0: 
michael@0: #include "seccomon.h"
michael@0: 
michael@0: SEC_BEGIN_PROTOS
michael@0: 
michael@0: extern SECStatus sslMutex_Init(sslMutex *sem, int shared);
michael@0: 
michael@0: /* If processLocal is set to true, then just free resources which are *only* associated
michael@0:  * with the current process. Leave any shared resources (including the state of 
michael@0:  * shared memory) intact. */
michael@0: extern SECStatus sslMutex_Destroy(sslMutex *sem, PRBool processLocal);
michael@0: 
michael@0: extern SECStatus sslMutex_Unlock(sslMutex *sem);
michael@0: 
michael@0: extern SECStatus sslMutex_Lock(sslMutex *sem);
michael@0: 
michael@0: #ifdef WINNT
michael@0: 
michael@0: extern SECStatus sslMutex_2LevelInit(sslMutex *sem);
michael@0: 
michael@0: #endif
michael@0: 
michael@0: SEC_END_PROTOS
michael@0: 
michael@0: #endif