1 /* This Source Code Form is subject to the terms of the Mozilla Public 2 * License, v. 2.0. If a copy of the MPL was not distributed with this 3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 4 #ifndef __SSLMUTEX_H_ 5 #define __SSLMUTEX_H_ 1 6 7 /* What SSL really wants is portable process-shared unnamed mutexes in 8 * shared memory, that have the property that if the process that holds 9 * them dies, they are released automatically, and that (unlike fcntl 10 * record locking) lock to the thread, not to the process. 11 * NSPR doesn't provide that. 12 * Windows has mutexes that meet that description, but they're not portable. 13 * POSIX mutexes are not automatically released when the holder dies, 14 * and other processes/threads cannot release the mutex on behalf of the 15 * dead holder. 16 * POSIX semaphores can be used to accomplish this on systems that implement 17 * process-shared unnamed POSIX semaphores, because a watchdog thread can 18 * discover and release semaphores that were held by a dead process. 19 * On systems that do not support process-shared POSIX unnamed semaphores, 20 * they can be emulated using pipes. 21 * The performance cost of doing that is not yet measured. 22 * 23 * So, this API looks a lot like POSIX pthread mutexes. 24 */ 25 26 #include "prtypes.h" 27 #include "prlock.h" 28 29 #if defined(NETBSD) 30 #include <sys/param.h> /* for __NetBSD_Version__ */ 31 #endif 32 33 #if defined(WIN32) 34 35 #include <wtypes.h> 36 37 typedef struct 38 { 39 PRBool isMultiProcess; 40 #ifdef WINNT 41 /* on WINNT we need both the PRLock and the Win32 mutex for fibers */ 42 struct { 43 #else 44 union { 45 #endif 46 PRLock* sslLock; 47 HANDLE sslMutx; 48 } u; 49 } sslMutex; 50 51 typedef int sslPID; 52 53 #elif defined(LINUX) || defined(AIX) || defined(BEOS) || defined(BSDI) || (defined(NETBSD) && __NetBSD_Version__ < 500000000) || defined(OPENBSD) 54 55 #include <sys/types.h> 56 #include "prtypes.h" 57 58 typedef struct { 59 PRBool isMultiProcess; 60 union { 61 PRLock* sslLock; 62 struct { 63 int mPipes[3]; 64 PRInt32 nWaiters; 65 } pipeStr; 66 } u; 67 } sslMutex; 68 typedef pid_t sslPID; 69 70 #elif defined(XP_UNIX) /* other types of Unix */ 71 72 #include <sys/types.h> /* for pid_t */ 73 #include <semaphore.h> /* for sem_t, and sem_* functions */ 74 75 typedef struct 76 { 77 PRBool isMultiProcess; 78 union { 79 PRLock* sslLock; 80 sem_t sem; 81 } u; 82 } sslMutex; 83 84 typedef pid_t sslPID; 85 86 #else 87 88 /* what platform is this ?? */ 89 90 typedef struct { 91 PRBool isMultiProcess; 92 union { 93 PRLock* sslLock; 94 /* include cross-process locking mechanism here */ 95 } u; 96 } sslMutex; 97 98 typedef int sslPID; 99 100 #endif 101 102 #include "seccomon.h" 103 104 SEC_BEGIN_PROTOS 105 106 extern SECStatus sslMutex_Init(sslMutex *sem, int shared); 107 108 /* If processLocal is set to true, then just free resources which are *only* associated 109 * with the current process. Leave any shared resources (including the state of 110 * shared memory) intact. */ 111 extern SECStatus sslMutex_Destroy(sslMutex *sem, PRBool processLocal); 112 113 extern SECStatus sslMutex_Unlock(sslMutex *sem); 114 115 extern SECStatus sslMutex_Lock(sslMutex *sem); 116 117 #ifdef WINNT 118 119 extern SECStatus sslMutex_2LevelInit(sslMutex *sem); 120 121 #endif 122 123 SEC_END_PROTOS 124 125 #endif 126