jsharedmemory.cpp
4.26 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
/***************************************************************************
* Copyright (C) 2005 by Jeff Ferr *
* root@sat *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the *
* Free Software Foundation, Inc., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
***************************************************************************/
#include "Stdafx.h"
#include "jsharedmemory.h"
#include "jmemoryexception.h"
namespace jshared {
#ifdef _WIN32
SharedMemory::SharedMemory(int key_, int memsize_, int perms_):
#else
SharedMemory::SharedMemory(key_t key_, int memsize_, int perms_):
#endif
jcommon::Object()
{
jcommon::Object::SetClassName("SharedMemory");
#ifdef _WIN32
#else
_memsize = memsize_;
_id = shmget(key_, memsize_, IPC_CREAT | IPC_EXCL | perms_);
if (_id < 0) {
/*
if (errno == EINVAL) {
throw MemoryException("Mem size < SHMMIN or > SHMMAXError opening a shared memory");
} else if (errno == EEXIST) {
throw MemoryException("Shared memory key already created");
} else if (errno == ENOMEM) {
throw MemoryException("No memory could be allocated for segment overhead");
} else {
throw MemoryException("Cannot create a new shared memory");
}
*/
_id = shmget(key_, _memsize, perms_);
if (_id < 0) {
if (errno == ENOSPC) {
throw MemoryException("No segment exists for the given key");
} else if (errno == EACCES) {
throw MemoryException("user does not have permission to access the shared memory");
} else {
throw MemoryException("Cannot open a shared memory");
}
}
}
#endif
}
SharedMemory::~SharedMemory()
{
Release();
}
void SharedMemory::Attach()
{
#ifdef _WIN32
#else
_shmp = (char *)shmat(_id, 0, 0);
if (_shmp == (char *)(-1)) {
if (errno == EACCES) {
throw MemoryException("No permission to access the shared memory");
} else if (errno == ENOMEM) {
throw MemoryException("Could not allocate memory");
} else {
throw MemoryException("Attach memory exception");
}
}
memset(_shmp, 0, _memsize);
#endif
}
void SharedMemory::Deatach()
{
#ifdef _WIN32
#else
int r = shmdt(_shmp);
if (r < 0) {
if (errno == EACCES) {
throw MemoryException("No permission to access the shared memory");
} else {
throw MemoryException("Deatach memory exception");
}
}
#endif
}
void SharedMemory::Dealloc()
{
#ifdef _WIN32
#else
int r = shmctl(_id, IPC_RMID, NULL);
if (r < 0) {
if (errno == EACCES) {
throw MemoryException("No permission to access the shared memory");
} else {
throw MemoryException("Exception at dealloc shared memory");
}
}
#endif
}
int SharedMemory::Get(char *data_, int size_)
{
#ifdef _WIN32
return 0;
#else
if ((void *)data_ == NULL) {
throw MemoryException("Null pointer in data parameter");
}
if (size_ <= 0) {
throw MemoryException("Invalid value for size parameter");
}
memcpy(data_, (char *)_shmp, size_);
return size_;
#endif
}
int SharedMemory::Put(const char *data_, int size_)
{
#ifdef _WIN32
return 0;
#else
if ((void *)data_ == NULL) {
throw MemoryException("Null pointer in data parameter");
}
memcpy((char *)_shmp, data_, size_);
return size_;
#endif
}
void SharedMemory::Release()
{
#ifdef _WIN32
#else
Deatach();
Dealloc();
#endif
}
}