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
170
171
172
173
174
175
176
177
178
179
180
181
182
|
// SharedMemory.cpp
// Gery Vessere - gvessere@illumina.com, gery@vessere.com
// An abstraction over both SysV and POSIX shared memory APIs
#ifndef SHAREDMEMORY_H
#define SHAREDMEMORY_H
#include <string>
#include <semaphore.h>
#include <unistd.h>
#include <exception>
#include <iostream>
enum ErrorState {
ENONE,
ENOTALLOCATED,
ETRYAGAIN,
EALREADYALLOCATED,
EOPENFAILED,
EEXISTS,
EFTRUNCATE,
EMAPFAILED,
ECLOSE,
EUNLINK,
ECOUNTERCREATE,
ECOUNTERREMOVE,
ECOUNTERUSE
};
class SharedMemoryException: public std::exception
{
private:
bool _hasError;
ErrorState _error;
int _errorDetail;
public:
SharedMemoryException()
{
_hasError = false;
_error = ENONE;
_errorDetail = 0;
};
SharedMemoryException(ErrorState error): _error(error)
{};
ErrorState GetErrorCode() const
{
return _error;
};
int GetErrorDetail() const
{
return _errorDetail;
}
bool HasError() const
{
return _hasError;
};
void SetError(ErrorState error, int detail)
{
if (!_hasError)
{
_hasError = true;
_error = error;
_errorDetail = detail;
}
}
void ClearError()
{
_hasError = false;
_error = ENONE;
_errorDetail = 0;
};
};
class SharedMemory
{
public:
void * GetMapped()
{
return (void *) ((char*) _mapped + sizeof(size_t));
};
size_t GetSize()
{
if (!_needsAllocation)
return *_length - sizeof(size_t);
_exception.SetError(ENOTALLOCATED, 0);
return -1;
};
bool NeedsAllocation() const
{
return _needsAllocation;
};
// the owner is the first one that created the named shared memory segment
bool IsAllocator() const
{
return _isAllocator;
};
int GetId() const
{
return _shmID;
};
bool HasError() const
{
return _exception.HasError();
}
void ThrowError(ErrorState error, int detail)
{
if (!_exception.HasError())
{
_exception.SetError(error, detail);
}
throw _exception;
};
void ThrowError(ErrorState error)
{
ThrowError(error, 0);
};
void SetErrorStream(std::ostream * err)
{
_err = err;
};
SharedMemory(key_t key, bool unloadLast);
~SharedMemory();
void Allocate(size_t shmSize);
void Clean();
private:
SharedMemoryException _exception;
int _shmID;
int _sharedCounterID;
void * _counterMem;
void * _mapped;
size_t * _length;
sem_t * _sem;
bool _isAllocator;
bool _needsAllocation;
key_t _key;
key_t _counterKey;
bool _unloadLast;
std::ostream * _err;
int SharedObjectsUseCount();
void OpenIfExists();
void CreateAndInitSharedObject(size_t shmSize);
void MapSharedObjectToMemory();
std::string GetPosixObjectKey();
struct stat GetSharedObjectInfo();
void Close();
void Unlink();
std::string CounterName();
void EnsureCounter();
void RemoveSharedCounter();
void SharedUseIncrement();
void SharedUseDecrement();
};
#endif
|
