1 : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2 : * vim: sw=2 ts=8 et :
3 : */
4 : /* ***** BEGIN LICENSE BLOCK *****
5 : * Version: MPL 1.1/GPL 2.0/LGPL 2.1
6 : *
7 : * The contents of this file are subject to the Mozilla Public License Version
8 : * 1.1 (the "License"); you may not use this file except in compliance with
9 : * the License. You may obtain a copy of the License at
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12 : * Software distributed under the License is distributed on an "AS IS" basis,
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15 : * License.
16 : *
17 : * The Original Code is Mozilla IPC.
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21 : * Portions created by the Initial Developer are Copyright (C) 2010
22 : * the Initial Developer. All Rights Reserved.
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25 : *
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38 : * ***** END LICENSE BLOCK ***** */
39 :
40 : #ifndef mozilla_ipc_SharedMemorySysV_h
41 : #define mozilla_ipc_SharedMemorySysV_h
42 :
43 : #if defined(OS_LINUX) && !defined(ANDROID)
44 :
45 : // SysV shared memory isn't available on Windows, but we define the
46 : // following macro so that #ifdefs are clearer (compared to #ifdef
47 : // OS_LINUX).
48 : #define MOZ_HAVE_SHAREDMEMORYSYSV
49 :
50 : #include "SharedMemory.h"
51 :
52 : #include "nsDebug.h"
53 :
54 : #include <errno.h>
55 : #include <fcntl.h>
56 : #include <stdio.h>
57 : #include <string.h>
58 : #include <sys/ipc.h>
59 : #include <sys/shm.h>
60 :
61 : //
62 : // This is a low-level wrapper around platform shared memory. Don't
63 : // use it directly; use Shmem allocated through IPDL interfaces.
64 : //
65 :
66 : namespace mozilla {
67 : namespace ipc {
68 :
69 :
70 : class SharedMemorySysV : public SharedMemory
71 : {
72 : public:
73 : typedef int Handle;
74 :
75 0 : SharedMemorySysV() :
76 : mHandle(-1),
77 0 : mData(nsnull)
78 : {
79 0 : }
80 :
81 0 : SharedMemorySysV(Handle aHandle) :
82 : mHandle(aHandle),
83 0 : mData(nsnull)
84 : {
85 0 : }
86 :
87 0 : virtual ~SharedMemorySysV()
88 0 : {
89 0 : shmdt(mData);
90 0 : mHandle = -1;
91 0 : mData = nsnull;
92 0 : }
93 :
94 : NS_OVERRIDE
95 0 : virtual bool Create(size_t aNbytes)
96 : {
97 0 : int id = shmget(IPC_PRIVATE, aNbytes, IPC_CREAT | 0600);
98 0 : if (id == -1)
99 0 : return false;
100 :
101 0 : mHandle = id;
102 0 : mAllocSize = aNbytes;
103 0 : Created(aNbytes);
104 :
105 0 : return Map(aNbytes);
106 : }
107 :
108 : NS_OVERRIDE
109 0 : virtual bool Map(size_t nBytes)
110 : {
111 : // already mapped
112 0 : if (mData)
113 0 : return true;
114 :
115 0 : if (!IsHandleValid(mHandle))
116 0 : return false;
117 :
118 0 : void* mem = shmat(mHandle, nsnull, 0);
119 0 : if (mem == (void*) -1) {
120 : char warning[256];
121 : snprintf(warning, sizeof(warning)-1,
122 0 : "shmat(): %s (%d)\n", strerror(errno), errno);
123 :
124 0 : NS_WARNING(warning);
125 :
126 0 : return false;
127 : }
128 :
129 : // Mark the handle as deleted so that, should this process go away, the
130 : // segment is cleaned up.
131 0 : shmctl(mHandle, IPC_RMID, 0);
132 :
133 0 : mData = mem;
134 :
135 : #ifdef NS_DEBUG
136 : struct shmid_ds info;
137 0 : if (shmctl(mHandle, IPC_STAT, &info) < 0)
138 0 : return false;
139 :
140 0 : NS_ABORT_IF_FALSE(nBytes <= info.shm_segsz,
141 : "Segment doesn't have enough space!");
142 : #endif
143 :
144 0 : Mapped(nBytes);
145 0 : return true;
146 : }
147 :
148 : NS_OVERRIDE
149 0 : virtual void* memory() const
150 : {
151 0 : return mData;
152 : }
153 :
154 : NS_OVERRIDE
155 0 : virtual SharedMemoryType Type() const
156 : {
157 0 : return TYPE_SYSV;
158 : }
159 :
160 0 : Handle GetHandle() const
161 : {
162 0 : NS_ABORT_IF_FALSE(IsHandleValid(mHandle), "invalid handle");
163 0 : return mHandle;
164 : }
165 :
166 0 : static Handle NULLHandle()
167 : {
168 0 : return -1;
169 : }
170 :
171 0 : static bool IsHandleValid(Handle aHandle)
172 : {
173 0 : return aHandle != -1;
174 : }
175 :
176 : private:
177 : Handle mHandle;
178 : void* mData;
179 : };
180 :
181 : } // namespace ipc
182 : } // namespace mozilla
183 :
184 : #endif // OS_LINUX
185 :
186 : #endif // ifndef mozilla_ipc_SharedMemorySysV_h
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