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1 /* ***** BEGIN LICENSE BLOCK *****
2  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
3  *
4  * The contents of this file are subject to the Mozilla Public License Version
5  * 1.1 (the "License"); you may not use this file except in compliance with
6  * the License. You may obtain a copy of the License at
7  * http://www.mozilla.org/MPL/
8  *
9  * Software distributed under the License is distributed on an "AS IS" basis,
10  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
11  * for the specific language governing rights and limitations under the
12  * License.
13  *
14  * The Original Code is the Netscape security libraries.
15  *
16  * The Initial Developer of the Original Code is
17  * Netscape Communications Corporation.
18  * Portions created by the Initial Developer are Copyright (C) 2001
19  * the Initial Developer. All Rights Reserved.
20  *
21  * Contributor(s):
22  *
23  * Alternatively, the contents of this file may be used under the terms of
24  * either the GNU General Public License Version 2 or later (the "GPL"), or
25  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
26  * in which case the provisions of the GPL or the LGPL are applicable instead
27  * of those above. If you wish to allow use of your version of this file only
28  * under the terms of either the GPL or the LGPL, and not to allow others to
29  * use your version of this file under the terms of the MPL, indicate your
30  * decision by deleting the provisions above and replace them with the notice
31  * and other provisions required by the GPL or the LGPL. If you do not delete
32  * the provisions above, a recipient may use your version of this file under
33  * the terms of any one of the MPL, the GPL or the LGPL.
34  *
35  * ***** END LICENSE BLOCK ***** */
36 /* $Id: sslmutex.h,v 1.12 2009/06/05 02:34:15 nelson%bolyard.com Exp $ */
37 #ifndef __SSLMUTEX_H_
38 #define __SSLMUTEX_H_ 1
39 
40 /* What SSL really wants is portable process-shared unnamed mutexes in
41  * shared memory, that have the property that if the process that holds
42  * them dies, they are released automatically, and that (unlike fcntl
43  * record locking) lock to the thread, not to the process.
44  * NSPR doesn't provide that.
45  * Windows has mutexes that meet that description, but they're not portable.
46  * POSIX mutexes are not automatically released when the holder dies,
47  * and other processes/threads cannot release the mutex on behalf of the
48  * dead holder.
49  * POSIX semaphores can be used to accomplish this on systems that implement
50  * process-shared unnamed POSIX semaphores, because a watchdog thread can
51  * discover and release semaphores that were held by a dead process.
52  * On systems that do not support process-shared POSIX unnamed semaphores,
53  * they can be emulated using pipes.
54  * The performance cost of doing that is not yet measured.
55  *
56  * So, this API looks a lot like POSIX pthread mutexes.
57  */
58 
59 #include "prtypes.h"
60 #include "prlock.h"
61 
62 #if defined(NETBSD)
63 #include <sys/param.h> /* for __NetBSD_Version__ */
64 #endif
65 
66 #if defined(WIN32)
67 
68 #include <wtypes.h>
69 
70 typedef struct
71 {
72     PRBool isMultiProcess;
73 #ifdef WINNT
74     /* on WINNT we need both the PRLock and the Win32 mutex for fibers */
75     struct {
76 #else
77     union {
78 #endif
79         PRLock* sslLock;
80         HANDLE sslMutx;
81     } u;
82 } sslMutex;
83 
84 typedef int    sslPID;
85 
86 #elif defined(LINUX) || defined(AIX) || defined(BEOS) || defined(BSDI) || (defined(NETBSD) && __NetBSD_Version__ < 500000000) || defined(OPENBSD)
87 
88 #include <sys/types.h>
89 #include "prtypes.h"
90 
91 typedef struct {
92     PRBool isMultiProcess;
93     union {
94         PRLock* sslLock;
95         struct {
96             int      mPipes[3];
97             PRInt32  nWaiters;
98         } pipeStr;
99     } u;
100 } sslMutex;
101 typedef pid_t sslPID;
102 
103 #elif defined(XP_UNIX) /* other types of Unix */
104 
105 #include <sys/types.h>	/* for pid_t */
106 #include <semaphore.h>  /* for sem_t, and sem_* functions */
107 
108 typedef struct
109 {
110     PRBool isMultiProcess;
111     union {
112         PRLock* sslLock;
113         sem_t  sem;
114     } u;
115 } sslMutex;
116 
117 typedef pid_t sslPID;
118 
119 #else
120 
121 /* what platform is this ?? */
122 
123 typedef struct {
124     PRBool isMultiProcess;
125     union {
126         PRLock* sslLock;
127         /* include cross-process locking mechanism here */
128     } u;
129 } sslMutex;
130 
131 typedef int sslPID;
132 
133 #endif
134 
135 #include "seccomon.h"
136 
137 SEC_BEGIN_PROTOS
138 
139 extern SECStatus sslMutex_Init(sslMutex *sem, int shared);
140 
141 extern SECStatus sslMutex_Destroy(sslMutex *sem);
142 
143 extern SECStatus sslMutex_Unlock(sslMutex *sem);
144 
145 extern SECStatus sslMutex_Lock(sslMutex *sem);
146 
147 #ifdef WINNT
148 
149 extern SECStatus sslMutex_2LevelInit(sslMutex *sem);
150 
151 #endif
152 
153 SEC_END_PROTOS
154 
155 #endif
156