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
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
/********************************************************************************
* *
* R e a d - W r i t e L o c k C l a s s *
* *
*********************************************************************************
* Copyright (C) 2004,2022 by Jeroen van der Zijp. All Rights Reserved. *
*********************************************************************************
* This library is free software; you can redistribute it and/or modify *
* it under the terms of the GNU Lesser General Public License as published by *
* the Free Software Foundation; either version 3 of the License, or *
* (at your option) any later version. *
* *
* This library 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 Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/> *
********************************************************************************/
#include "xincs.h"
#include "fxver.h"
#include "fxdefs.h"
#include "FXReadWriteLock.h"
/*
Notes:
- Read/write lock variable.
*/
using namespace FX;
/*******************************************************************************/
namespace FX {
#if defined(WIN32)
struct RWLOCK {
CRITICAL_SECTION mutex[1];
CRITICAL_SECTION access[1];
DWORD readers;
};
#endif
// Initialize read/write lock
FXReadWriteLock::FXReadWriteLock(){
#if defined(WIN32) && (_WIN32_WINNT >= 0x0600) // Vista or newer
// If this fails on your machine, determine what value
// of sizeof(RWLOCK) is supposed to be on your
// machine and mail it to: jeroen@fox-toolkit.net!!
//FXTRACE((150,"sizeof(SRWLOCK)=%d\n",sizeof(SRWLOCK)));
FXASSERT_STATIC(sizeof(data)>=sizeof(SRWLOCK));
InitializeSRWLock((SRWLOCK*)data);
#elif defined(WIN32)
// If this fails on your machine, determine what value
// of sizeof(RWLOCK) is supposed to be on your
// machine and mail it to: jeroen@fox-toolkit.net!!
//FXTRACE((150,"sizeof(RWLOCK)=%d\n",sizeof(RWLOCK)));
FXASSERT_STATIC(sizeof(data)>=sizeof(RWLOCK));
InitializeCriticalSection(((RWLOCK*)data)->mutex);
InitializeCriticalSection(((RWLOCK*)data)->access);
((RWLOCK*)data)->readers=0;
#elif (_XOPEN_SOURCE >= 500) || (_POSIX_C_SOURCE >= 200809L)
// If this fails on your machine, determine what value
// of sizeof(pthread_rwlock_t) is supposed to be on your
// machine and mail it to: jeroen@fox-toolkit.net!!
//FXTRACE((150,"sizeof(pthread_rwlock_t)=%d\n",sizeof(pthread_rwlock_t)));
FXASSERT_STATIC(sizeof(data)>=sizeof(pthread_rwlock_t));
pthread_rwlockattr_t rwlockatt;
pthread_rwlockattr_init(&rwlockatt);
pthread_rwlockattr_setkind_np(&rwlockatt,PTHREAD_RWLOCK_PREFER_WRITER_NP);
pthread_rwlock_init((pthread_rwlock_t*)data,&rwlockatt);
pthread_rwlockattr_destroy(&rwlockatt);
#else
// If this fails on your machine, determine what value
// of sizeof(pthread_rwlock_t) is supposed to be on your
// machine and mail it to: jeroen@fox-toolkit.net!!
//FXTRACE((150,"sizeof(pthread_rwlock_t)=%d\n",sizeof(pthread_rwlock_t)));
FXASSERT_STATIC(sizeof(data)>=sizeof(pthread_rwlock_t));
pthread_rwlock_init((pthread_rwlock_t*)data,nullptr);
#endif
}
// Acquire read lock for read/write lock
void FXReadWriteLock::readLock(){
#if defined(WIN32) && (_WIN32_WINNT >= 0x0600) // Vista or newer
AcquireSRWLockShared((SRWLOCK*)data);
#elif defined(WIN32)
EnterCriticalSection(((RWLOCK*)data)->mutex);
if(++((RWLOCK*)data)->readers==1){
EnterCriticalSection(((RWLOCK*)data)->access);
}
LeaveCriticalSection(((RWLOCK*)data)->mutex);
#else
pthread_rwlock_rdlock((pthread_rwlock_t*)data);
#endif
}
// Try to acquire read lock for read/write lock
FXbool FXReadWriteLock::tryReadLock(){
#if defined(WIN32) && (_WIN32_WINNT >= 0x0600) // Vista or newer
return TryAcquireSRWLockShared((SRWLOCK*)data)!=0;
#elif defined(WIN32)
if(TryEnterCriticalSection(((RWLOCK*)data)->mutex)){
if(++((RWLOCK*)data)->readers==1 && !TryEnterCriticalSection(((RWLOCK*)data)->access)){
--((RWLOCK*)data)->readers;
LeaveCriticalSection(((RWLOCK*)data)->mutex);
return false;
}
LeaveCriticalSection(((RWLOCK*)data)->mutex);
return true;
}
return false;
#else
return pthread_rwlock_tryrdlock((pthread_rwlock_t*)data)==0;
#endif
}
// Unlock read lock
void FXReadWriteLock::readUnlock(){
#if defined(WIN32) && (_WIN32_WINNT >= 0x0600) // Vista or newer
ReleaseSRWLockShared((SRWLOCK*)data);
#elif defined(WIN32)
EnterCriticalSection(((RWLOCK*)data)->mutex);
if(--((RWLOCK*)data)->readers==0){
LeaveCriticalSection(((RWLOCK*)data)->access);
}
LeaveCriticalSection(((RWLOCK*)data)->mutex);
#else
pthread_rwlock_unlock((pthread_rwlock_t*)data);
#endif
}
// Test if read locked
FXbool FXReadWriteLock::readLocked(){
if(tryReadLock()){
readUnlock();
return false;
}
return true;
}
// Acquire write lock for read/write lock
void FXReadWriteLock::writeLock(){
#if defined(WIN32) && (_WIN32_WINNT >= 0x0600) // Vista or newer
AcquireSRWLockExclusive((SRWLOCK*)data);
#elif defined(WIN32)
EnterCriticalSection(((RWLOCK*)data)->access);
#else
pthread_rwlock_wrlock((pthread_rwlock_t*)data);
#endif
}
// Try to acquire write lock for read/write lock
FXbool FXReadWriteLock::tryWriteLock(){
#if defined(WIN32) && (_WIN32_WINNT >= 0x0600) // Vista or newer
return TryAcquireSRWLockExclusive((SRWLOCK*)data)!=0;
#elif defined(WIN32) && (_WIN32_WINNT >= 0x0400)
return TryEnterCriticalSection(((RWLOCK*)data)->access)!=0;
#elif defined(WIN32)
return false;
#else
return pthread_rwlock_trywrlock((pthread_rwlock_t*)data)==0;
#endif
}
// Unlock write lock
void FXReadWriteLock::writeUnlock(){
#if defined(WIN32) && (_WIN32_WINNT >= 0x0600) // Vista or newer
ReleaseSRWLockExclusive((SRWLOCK*)data);
#elif defined(WIN32)
LeaveCriticalSection(((RWLOCK*)data)->access);
#else
pthread_rwlock_unlock((pthread_rwlock_t*)data);
#endif
}
// Test if write locked
FXbool FXReadWriteLock::writeLocked(){
if(tryWriteLock()){
writeUnlock();
return false;
}
return true;
}
// Delete read/write lock
FXReadWriteLock::~FXReadWriteLock(){
#if defined(WIN32) && (_WIN32_WINNT >= 0x0600) // Vista or newer
// NOP //
#elif defined(WIN32)
DeleteCriticalSection(((RWLOCK*)data)->mutex);
DeleteCriticalSection(((RWLOCK*)data)->access);
#else
pthread_rwlock_destroy((pthread_rwlock_t*)data);
#endif
}
}
|
