SQLite

Check-in [12a23c0a66]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Use a symbolic constant instead of a literal (-1) to identify a warn-on-contention mutex.
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | multithreaded-checks
Files: files | file ages | folders
SHA3-256: 12a23c0a66fac5c9674120b390f6abaeaba3f7ff04693b281af1eefb93d6f47c
User & Date: dan 2017-11-28 07:47:57.520
Context
2017-11-28
07:52
Add experimental feature to detect threading bugs in apps that use SQLITE_CONFIG_MULTITHREADED. Enabled at compile time using SQLITE_ENABLE_MULTITHREADED_CHECKS. (check-in: 40b598c839 user: dan tags: trunk)
07:47
Use a symbolic constant instead of a literal (-1) to identify a warn-on-contention mutex. (Closed-Leaf check-in: 12a23c0a66 user: dan tags: multithreaded-checks)
2017-11-25
21:09
Fix builds with both SQLITE_ENABLE_MULTITHREADED_CHECKS and SQLITE_THREADSAFE=0 defined. (check-in: 7d0b12fcb5 user: dan tags: multithreaded-checks)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/mutex.c.
︙︙
40
41
42
43
44
45
46
47





48
49
50
51
52
53


54
55
56
57
58
59
60

**
** This type of mutex is used as the database handle mutex when testing
** apps that usually use SQLITE_CONFIG_MULTITHREAD mode.
*/

/* 
** Type for all mutexes used when SQLITE_ENABLE_MULTITHREADED_CHECKS
** is defined.





*/
typedef struct CheckMutex CheckMutex;
struct CheckMutex {
  int iType;
  sqlite3_mutex *mutex;
};



/* 
** Pointer to real mutex methods object used by the CheckMutex
** implementation. Set by checkMutexInit(). 
*/
static SQLITE_WSD const sqlite3_mutex_methods *pGlobalMutexMethods;









|
>
>
>
>
>






>
>








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

**
** This type of mutex is used as the database handle mutex when testing
** apps that usually use SQLITE_CONFIG_MULTITHREAD mode.
*/

/* 
** Type for all mutexes used when SQLITE_ENABLE_MULTITHREADED_CHECKS
** is defined. Variable CheckMutex.mutex is a pointer to the real mutex
** allocated by the system mutex implementation. Variable iType is usually set
** to the type of mutex requested - SQLITE_MUTEX_RECURSIVE, SQLITE_MUTEX_FAST
** or one of the static mutex identifiers. Or, if this is a recursive mutex
** that has been configured using sqlite3MutexWarnOnContention(), it is
** set to SQLITE_MUTEX_WARNONCONTENTION.
*/
typedef struct CheckMutex CheckMutex;
struct CheckMutex {
  int iType;
  sqlite3_mutex *mutex;
};

#define SQLITE_MUTEX_WARNONCONTENTION  (-1)

/* 
** Pointer to real mutex methods object used by the CheckMutex
** implementation. Set by checkMutexInit(). 
*/
static SQLITE_WSD const sqlite3_mutex_methods *pGlobalMutexMethods;
︙︙
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

  return (sqlite3_mutex*)p;
}

/*
** Free a mutex.
*/
static void checkMutexFree(sqlite3_mutex *p){




#if SQLITE_ENABLE_API_ARMOR
  if( p->iType<2 ){
#endif
  {
    CheckMutex *pCheck = (CheckMutex*)p;
    pGlobalMutexMethods->xMutexFree(pCheck->mutex);
    sqlite3_free(pCheck);
  }
#ifdef SQLITE_ENABLE_API_ARMOR
  else{
    (void)SQLITE_MISUSE_BKPT;
  }
#endif
}

/*
** Enter the mutex.
*/
static void checkMutexEnter(sqlite3_mutex *p){
  CheckMutex *pCheck = (CheckMutex*)p;
  if( pCheck->iType<0 ){
    if( SQLITE_OK==pGlobalMutexMethods->xMutexTry(pCheck->mutex) ){
      return;
    }
    sqlite3_log(SQLITE_MISUSE, 
        "illegal multi-threaded access to database connection"
    );
  }








>
>
>
>




















|








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

  return (sqlite3_mutex*)p;
}

/*
** Free a mutex.
*/
static void checkMutexFree(sqlite3_mutex *p){
  assert( SQLITE_MUTEX_RECURSIVE<2 );
  assert( SQLITE_MUTEX_FAST<2 );
  assert( SQLITE_MUTEX_WARNONCONTENTION<2 );

#if SQLITE_ENABLE_API_ARMOR
  if( p->iType<2 ){
#endif
  {
    CheckMutex *pCheck = (CheckMutex*)p;
    pGlobalMutexMethods->xMutexFree(pCheck->mutex);
    sqlite3_free(pCheck);
  }
#ifdef SQLITE_ENABLE_API_ARMOR
  else{
    (void)SQLITE_MISUSE_BKPT;
  }
#endif
}

/*
** Enter the mutex.
*/
static void checkMutexEnter(sqlite3_mutex *p){
  CheckMutex *pCheck = (CheckMutex*)p;
  if( pCheck->iType==SQLITE_MUTEX_WARNONCONTENTION ){
    if( SQLITE_OK==pGlobalMutexMethods->xMutexTry(pCheck->mutex) ){
      return;
    }
    sqlite3_log(SQLITE_MISUSE, 
        "illegal multi-threaded access to database connection"
    );
  }
︙︙
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207

** Mark the SQLITE_MUTEX_RECURSIVE mutex passed as the only argument as
** one on which there should be no contention.
*/
void sqlite3MutexWarnOnContention(sqlite3_mutex *p){
  if( sqlite3GlobalConfig.mutex.xMutexAlloc==checkMutexAlloc ){
    CheckMutex *pCheck = (CheckMutex*)p;
    assert( pCheck->iType==SQLITE_MUTEX_RECURSIVE );
    pCheck->iType = -1;
  }
}
#endif   /* ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS */

/*
** Initialize the mutex system.
*/








|








204
205
206
207
208
209
210
211
212
213
214
215
216
217
218

** Mark the SQLITE_MUTEX_RECURSIVE mutex passed as the only argument as
** one on which there should be no contention.
*/
void sqlite3MutexWarnOnContention(sqlite3_mutex *p){
  if( sqlite3GlobalConfig.mutex.xMutexAlloc==checkMutexAlloc ){
    CheckMutex *pCheck = (CheckMutex*)p;
    assert( pCheck->iType==SQLITE_MUTEX_RECURSIVE );
    pCheck->iType = SQLITE_MUTEX_WARNONCONTENTION;
  }
}
#endif   /* ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS */

/*
** Initialize the mutex system.
*/
︙︙