SQLite

Check-in [844d40b837]
Login

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

Overview
Comment:More locking fixes. Now makes it all the way through quick.test. There are errors but no assertion faults. Progress. (CVS 4319)
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 844d40b8379d3374130e2d94f6e32c2cda34e0ca
User & Date: drh 2007-08-29 00:33:07.000
Context
2007-08-29
04:00
Better asserts(). But now some of the tests are busted again. (CVS 4320) (check-in: e8060f85e7 user: drh tags: trunk)
00:33
More locking fixes. Now makes it all the way through quick.test. There are errors but no assertion faults. Progress. (CVS 4319) (check-in: 844d40b837 user: drh tags: trunk)
2007-08-28
23:28
The shared_err test runs with no errors. But a potential deadlock has been discovered and is still unfixed. (CVS 4318) (check-in: f093a0d7b2 user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/btmutex.c.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
/*
** 2007 August 27
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** $Id: btmutex.c,v 1.3 2007/08/28 23:28:08 drh Exp $
**
** This file contains code used to implement mutexes on Btree objects.
** This code really belongs in btree.c.  But btree.c is getting too
** big and we want to break it down some.  This packaged seemed like
** a good breakout.
*/
#include "btreeInt.h"












|







1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
/*
** 2007 August 27
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** $Id: btmutex.c,v 1.4 2007/08/29 00:33:07 drh Exp $
**
** This file contains code used to implement mutexes on Btree objects.
** This code really belongs in btree.c.  But btree.c is getting too
** big and we want to break it down some.  This packaged seemed like
** a good breakout.
*/
#include "btreeInt.h"
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
    if( p->wantToLock==0 ){
      assert( p->locked );
      sqlite3_mutex_leave(p->pBt->mutex);
      p->locked = 0;
    }
  }
}
























































/*
** Potentially dd a new Btree pointer to a BtreeMutexArray.
** Really only add the Btree if it can possibly be shared with
** another database connection.
**
** The Btrees are kept in sorted order by pBtree->pBt.  That
** way when we go to enter all the mutexes, we can enter them
** in order without every having to backup and retry and without
** worrying about deadlock.
**
** The number of shared btrees will always be small (usually 0 or 1)
** so an insertion sort is an adequate algorithm here.
*/
void sqlite3BtreeMutexArrayInsert(BtreeMutexArray *pSet, Btree *pBtree){
  int i, j;
  BtShared *pBt;
  if( !pBtree->sharable ) return;
#ifndef NDEBUG
  {
    for(i=0; i<pSet->nMutex; i++){
      assert( pSet->aBtree[i]!=pBtree );
    }
  }
#endif
  assert( pSet->nMutex>=0 );
  assert( pSet->nMutex<sizeof(pSet->aBtree)/sizeof(pSet->aBtree[0])-1 );
  pBt = pBtree->pBt;
  for(i=0; i<pSet->nMutex; i++){
    assert( pSet->aBtree[i]!=pBtree );
    if( pSet->aBtree[i]->pBt>pBt ){
      for(j=pSet->nMutex; j>i; j--){
        pSet->aBtree[j] = pSet->aBtree[j-1];
      }
      pSet->aBtree[i] = pBtree;

      return;
    }
  }
  pSet->aBtree[pSet->nMutex++] = pBtree;
}

/*
** Enter the mutex of every btree in the array.  This routine is
** called at the beginning of sqlite3VdbeExec().  The mutexes are
** exited at the end of the same function.
*/
void sqlite3BtreeMutexArrayEnter(BtreeMutexArray *pSet){
  int i;
  for(i=0; i<pSet->nMutex; i++){
    Btree *p = pSet->aBtree[i];
    /* Some basic sanity checking */
    assert( i==0 || pSet->aBtree[i-1]->pBt<p->pBt );
    assert( !p->locked || p->wantToLock>0 );
    assert( p->sharable );

    /* We should already hold a lock on the database connection */
    assert( sqlite3BtreeMutexHeld(p->pSqlite->mutex) );

    p->wantToLock++;
    if( !p->locked ){
      sqlite3_mutex_enter(p->pBt->mutex);
      p->locked = 1;
    }
  }
}

/*
** Leave the mutex of every btree in the group.
*/
void sqlite3BtreeMutexArrayLeave(BtreeMutexArray *pSet){
  int i;
  for(i=0; i<pSet->nMutex; i++){
    Btree *p = pSet->aBtree[i];
    /* Some basic sanity checking */
    assert( i==0 || pSet->aBtree[i-1]->pBt<p->pBt );
    assert( p->locked );
    assert( p->sharable );
    assert( p->wantToLock>0 );

    /* We should already hold a lock on the database connection */
    assert( sqlite3BtreeMutexHeld(p->pSqlite->mutex) );








>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>














|





|
|



|
|

|
|
|
|
|

|
>



|







|

|
|

|

















|

|
|

|







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
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
    if( p->wantToLock==0 ){
      assert( p->locked );
      sqlite3_mutex_leave(p->pBt->mutex);
      p->locked = 0;
    }
  }
}

/*
** Enter the mutex on every Btree associated with a database
** connection.  This is needed (for example) prior to parsing
** a statement since we will be comparing table and column names
** against all schemas and we do not want those schemas being
** reset out from under us.
**
** There is a corresponding leave-all procedures.
**
** Enter the mutexes in accending order by BtShared pointer address
** to avoid the possibility of deadlock when two threads with
** two or more btrees in common both try to lock all their btrees
** at the same instant.
*/
void sqlite3BtreeEnterAll(sqlite3 *db){
  int i;
  Btree *p;
  assert( sqlite3_mutex_held(db->mutex) );
  for(i=0; i<db->nDb && ((p = db->aDb[i].pBt)==0 || p->sharable==0); i++){}
  if( i<db->nDb ){
    while( p->pNext ) p = p->pNext;
    while( 1 ){
      if( p->locked ){
        sqlite3_mutex_leave(p->pBt->mutex);
        p->locked = 0;
      }
      if( p->pPrev==0 ) break;
      p = p->pPrev;
    }
    while( p ){
      p->wantToLock++;
      sqlite3_mutex_enter(p->pBt->mutex);
      p->locked = 1;
      p = p->pNext;
    }
  }
}
void sqlite3BtreeLeaveAll(sqlite3 *db){
  int i;
  Btree *p;
  assert( sqlite3_mutex_held(db->mutex) );
  for(i=0; i<db->nDb && ((p = db->aDb[i].pBt)==0 || p->sharable==0); i++){}
  if( i<db->nDb ){
    while( p->pPrev ) p = p->pPrev;
    while( p ){
      p->wantToLock--;
      if( p->wantToLock==0 ){
        sqlite3_mutex_leave(p->pBt->mutex);
        p->locked = 0;
      }
      p = p->pNext;
    }
  }
}

/*
** Potentially dd a new Btree pointer to a BtreeMutexArray.
** Really only add the Btree if it can possibly be shared with
** another database connection.
**
** The Btrees are kept in sorted order by pBtree->pBt.  That
** way when we go to enter all the mutexes, we can enter them
** in order without every having to backup and retry and without
** worrying about deadlock.
**
** The number of shared btrees will always be small (usually 0 or 1)
** so an insertion sort is an adequate algorithm here.
*/
void sqlite3BtreeMutexArrayInsert(BtreeMutexArray *pArray, Btree *pBtree){
  int i, j;
  BtShared *pBt;
  if( !pBtree->sharable ) return;
#ifndef NDEBUG
  {
    for(i=0; i<pArray->nMutex; i++){
      assert( pArray->aBtree[i]!=pBtree );
    }
  }
#endif
  assert( pArray->nMutex>=0 );
  assert( pArray->nMutex<sizeof(pArray->aBtree)/sizeof(pArray->aBtree[0])-1 );
  pBt = pBtree->pBt;
  for(i=0; i<pArray->nMutex; i++){
    assert( pArray->aBtree[i]!=pBtree );
    if( pArray->aBtree[i]->pBt>pBt ){
      for(j=pArray->nMutex; j>i; j--){
        pArray->aBtree[j] = pArray->aBtree[j-1];
      }
      pArray->aBtree[i] = pBtree;
      pArray->nMutex++;
      return;
    }
  }
  pArray->aBtree[pArray->nMutex++] = pBtree;
}

/*
** Enter the mutex of every btree in the array.  This routine is
** called at the beginning of sqlite3VdbeExec().  The mutexes are
** exited at the end of the same function.
*/
void sqlite3BtreeMutexArrayEnter(BtreeMutexArray *pArray){
  int i;
  for(i=0; i<pArray->nMutex; i++){
    Btree *p = pArray->aBtree[i];
    /* Some basic sanity checking */
    assert( i==0 || pArray->aBtree[i-1]->pBt<p->pBt );
    assert( !p->locked || p->wantToLock>0 );
    assert( p->sharable );

    /* We should already hold a lock on the database connection */
    assert( sqlite3BtreeMutexHeld(p->pSqlite->mutex) );

    p->wantToLock++;
    if( !p->locked ){
      sqlite3_mutex_enter(p->pBt->mutex);
      p->locked = 1;
    }
  }
}

/*
** Leave the mutex of every btree in the group.
*/
void sqlite3BtreeMutexArrayLeave(BtreeMutexArray *pArray){
  int i;
  for(i=0; i<pArray->nMutex; i++){
    Btree *p = pArray->aBtree[i];
    /* Some basic sanity checking */
    assert( i==0 || pArray->aBtree[i-1]->pBt<p->pBt );
    assert( p->locked );
    assert( p->sharable );
    assert( p->wantToLock>0 );

    /* We should already hold a lock on the database connection */
    assert( sqlite3BtreeMutexHeld(p->pSqlite->mutex) );

Changes to src/btree.h.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.88 2007/08/28 23:28:08 drh Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
*/







|







9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.89 2007/08/29 00:33:07 drh Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
*/
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
int sqlite3BtreeIsInTrans(Btree*);
int sqlite3BtreeIsInStmt(Btree*);
int sqlite3BtreeIsInReadTrans(Btree*);
void *sqlite3BtreeSchema(Btree *, int, void(*)(void *));
int sqlite3BtreeSchemaLocked(Btree *);
int sqlite3BtreeLockTable(Btree *, int, u8);

/*
** If we are not using shared cache, then there is no need to
** use mutexes to access the BtShared structures.  So make the
** Enter and Leave procedures no-ops.
*/
#if SQLITE_THREADSAFE && !defined(SQLITE_OMIT_SHARED_CACHE)
  void sqlite3BtreeEnter(Btree*);
  void sqlite3BtreeLeave(Btree*);
# define sqlite3BtreeMutexHeld(X) sqlite3_mutex_held(X)
#else
# define sqlite3BtreeEnter(X)
# define sqlite3BtreeLeave(X)
# define sqlite3BtreeMutexHeld(X) 1
#endif

const char *sqlite3BtreeGetFilename(Btree *);
const char *sqlite3BtreeGetDirname(Btree *);
const char *sqlite3BtreeGetJournalname(Btree *);
int sqlite3BtreeCopyFile(Btree *, Btree *);

int sqlite3BtreeIncrVacuum(Btree *);








<
<
<
<
<
<
<
<
<
<
<
<
<
<
<







103
104
105
106
107
108
109















110
111
112
113
114
115
116
int sqlite3BtreeIsInTrans(Btree*);
int sqlite3BtreeIsInStmt(Btree*);
int sqlite3BtreeIsInReadTrans(Btree*);
void *sqlite3BtreeSchema(Btree *, int, void(*)(void *));
int sqlite3BtreeSchemaLocked(Btree *);
int sqlite3BtreeLockTable(Btree *, int, u8);
















const char *sqlite3BtreeGetFilename(Btree *);
const char *sqlite3BtreeGetDirname(Btree *);
const char *sqlite3BtreeGetJournalname(Btree *);
int sqlite3BtreeCopyFile(Btree *, Btree *);

int sqlite3BtreeIncrVacuum(Btree *);

178
179
180
181
182
183
184





185





186
187
188
189





190
191
192
193
194
195
196
197

#ifdef SQLITE_TEST
int sqlite3BtreeCursorInfo(BtCursor*, int*, int);
void sqlite3BtreeCursorList(Btree*);
int sqlite3BtreePageDump(Btree*, int, int recursive);
#endif






#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE





  void sqlite3BtreeMutexArrayEnter(BtreeMutexArray*);
  void sqlite3BtreeMutexArrayLeave(BtreeMutexArray*);
  void sqlite3BtreeMutexArrayInsert(BtreeMutexArray*, Btree*);
#else





# define sqlite3BtreeMutexArrayEnter(X)
# define sqlite3BtreeMutexArrayLeave(X)
# define sqlite3BtreeMutexArrayInsert(X,Y)
#endif



#endif /* _BTREE_H_ */







>
>
>
>
>

>
>
>
>
>




>
>
>
>
>








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

#ifdef SQLITE_TEST
int sqlite3BtreeCursorInfo(BtCursor*, int*, int);
void sqlite3BtreeCursorList(Btree*);
int sqlite3BtreePageDump(Btree*, int, int recursive);
#endif

/*
** If we are not using shared cache, then there is no need to
** use mutexes to access the BtShared structures.  So make the
** Enter and Leave procedures no-ops.
*/
#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE
  void sqlite3BtreeEnter(Btree*);
  void sqlite3BtreeLeave(Btree*);
# define sqlite3BtreeMutexHeld(X) sqlite3_mutex_held(X)
  void sqlite3BtreeEnterAll(sqlite3*);
  void sqlite3BtreeLeaveAll(sqlite3*);
  void sqlite3BtreeMutexArrayEnter(BtreeMutexArray*);
  void sqlite3BtreeMutexArrayLeave(BtreeMutexArray*);
  void sqlite3BtreeMutexArrayInsert(BtreeMutexArray*, Btree*);
#else
# define sqlite3BtreeEnter(X)
# define sqlite3BtreeLeave(X)
# define sqlite3BtreeMutexHeld(X) 1
# define sqlite3BtreeEnterAll(X)
# define sqlite3BtreeLeaveAll(X)
# define sqlite3BtreeMutexArrayEnter(X)
# define sqlite3BtreeMutexArrayLeave(X)
# define sqlite3BtreeMutexArrayInsert(X,Y)
#endif



#endif /* _BTREE_H_ */
Changes to src/btreeInt.h.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
/*
** 2004 April 6
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btreeInt.h,v 1.11 2007/08/28 22:24:35 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.











|







1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
/*
** 2004 April 6
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btreeInt.h,v 1.12 2007/08/29 00:33:07 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
struct Btree {
  sqlite3 *pSqlite;  /* The database connection holding this btree */
  BtShared *pBt;     /* Sharable content of this btree */
  u8 inTrans;        /* TRANS_NONE, TRANS_READ or TRANS_WRITE */
  u8 sharable;       /* True if we can share pBt with other pSqlite */
  u8 locked;         /* True if pSqlite currently has pBt locked */
  int wantToLock;    /* Number of nested calls to sqlite3BtreeEnter() */
  Btree *pNext;      /* List of Btrees with the same pSqlite value */
  Btree *pPrev;      /* Back pointer of the same list */
};

/*
** Btree.inTrans may take one of the following values.
**
** If the shared-data extension is enabled, there may be multiple users







|







327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
struct Btree {
  sqlite3 *pSqlite;  /* The database connection holding this btree */
  BtShared *pBt;     /* Sharable content of this btree */
  u8 inTrans;        /* TRANS_NONE, TRANS_READ or TRANS_WRITE */
  u8 sharable;       /* True if we can share pBt with other pSqlite */
  u8 locked;         /* True if pSqlite currently has pBt locked */
  int wantToLock;    /* Number of nested calls to sqlite3BtreeEnter() */
  Btree *pNext;      /* List of other sharable Btrees from the same pSqlite */
  Btree *pPrev;      /* Back pointer of the same list */
};

/*
** Btree.inTrans may take one of the following values.
**
** If the shared-data extension is enabled, there may be multiple users
354
355
356
357
358
359
360
361



362
363
364
365
366
367
368
** sharing the same database file, each connection has it own
** private Btree object for the file and each of those Btrees points
** to this one BtShared object.  BtShared.nRef is the number of
** connections currently sharing this database file.
**
** Fields in this structure are accessed under the BtShared.mutex
** mutex, except for nRef and pNext which are accessed under the
** global SQLITE_MUTEX_STATIC_MASTER mutex.



*/
struct BtShared {
  Pager *pPager;        /* The page cache */
  BtCursor *pCursor;    /* A list of all open cursors */
  MemPage *pPage1;      /* First page of the database */
  u8 inStmt;            /* True if we are in a statement subtransaction */
  u8 readOnly;          /* True if the underlying file is readonly */







|
>
>
>







354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
** sharing the same database file, each connection has it own
** private Btree object for the file and each of those Btrees points
** to this one BtShared object.  BtShared.nRef is the number of
** connections currently sharing this database file.
**
** Fields in this structure are accessed under the BtShared.mutex
** mutex, except for nRef and pNext which are accessed under the
** global SQLITE_MUTEX_STATIC_MASTER mutex.  The pPager field
** may not be modified once it is initially set as long as nRef>0.
** The pSchema field may be set once under BtShared.mutex and
** thereafter is unchanged as long as nRef>0.
*/
struct BtShared {
  Pager *pPager;        /* The page cache */
  BtCursor *pCursor;    /* A list of all open cursors */
  MemPage *pPage1;      /* First page of the database */
  u8 inStmt;            /* True if we are in a statement subtransaction */
  u8 readOnly;          /* True if the underlying file is readonly */
Changes to src/prepare.c.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_prepare()
** interface, and routines that contribute to loading the database schema
** from disk.
**
** $Id: prepare.c,v 1.58 2007/08/22 02:56:44 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.







|







9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_prepare()
** interface, and routines that contribute to loading the database schema
** from disk.
**
** $Id: prepare.c,v 1.59 2007/08/29 00:33:07 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
43
44
45
46
47
48
49

50
51
52
53
54
55
56
**
*/
int sqlite3InitCallback(void *pInit, int argc, char **argv, char **azColName){
  InitData *pData = (InitData*)pInit;
  sqlite3 *db = pData->db;
  int iDb = pData->iDb;


  pData->rc = SQLITE_OK;
  DbClearProperty(db, iDb, DB_Empty);
  if( db->mallocFailed ){
    corruptSchema(pData, 0);
    return SQLITE_NOMEM;
  }








>







43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
**
*/
int sqlite3InitCallback(void *pInit, int argc, char **argv, char **azColName){
  InitData *pData = (InitData*)pInit;
  sqlite3 *db = pData->db;
  int iDb = pData->iDb;

  assert( sqlite3_mutex_held(db->mutex) );
  pData->rc = SQLITE_OK;
  DbClearProperty(db, iDb, DB_Empty);
  if( db->mallocFailed ){
    corruptSchema(pData, 0);
    return SQLITE_NOMEM;
  }

152
153
154
155
156
157
158

159
160
161
162
163
164
165
  ;
#else
  #define temp_master_schema 0
#endif

  assert( iDb>=0 && iDb<db->nDb );
  assert( db->aDb[iDb].pSchema );


  /* zMasterSchema and zInitScript are set to point at the master schema
  ** and initialisation script appropriate for the database being
  ** initialised. zMasterName is the name of the master table.
  */
  if( !OMIT_TEMPDB && iDb==1 ){
    zMasterSchema = temp_master_schema;







>







153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
  ;
#else
  #define temp_master_schema 0
#endif

  assert( iDb>=0 && iDb<db->nDb );
  assert( db->aDb[iDb].pSchema );
  assert( sqlite3_mutex_held(db->mutex) );

  /* zMasterSchema and zInitScript are set to point at the master schema
  ** and initialisation script appropriate for the database being
  ** initialised. zMasterName is the name of the master table.
  */
  if( !OMIT_TEMPDB && iDb==1 ){
    zMasterSchema = temp_master_schema;
193
194
195
196
197
198
199

200
201
202

203
204
205
206
207
208
209
  pDb = &db->aDb[iDb];
  if( pDb->pBt==0 ){
    if( !OMIT_TEMPDB && iDb==1 ){
      DbSetProperty(db, 1, DB_SchemaLoaded);
    }
    return SQLITE_OK;
  }

  rc = sqlite3BtreeCursor(pDb->pBt, MASTER_ROOT, 0, 0, 0, &curMain);
  if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){
    sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);

    return rc;
  }

  /* Get the database meta information.
  **
  ** Meta values are as follows:
  **    meta[0]   Schema cookie.  Changes with each schema change.







>



>







195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
  pDb = &db->aDb[iDb];
  if( pDb->pBt==0 ){
    if( !OMIT_TEMPDB && iDb==1 ){
      DbSetProperty(db, 1, DB_SchemaLoaded);
    }
    return SQLITE_OK;
  }
  sqlite3BtreeEnter(pDb->pBt);
  rc = sqlite3BtreeCursor(pDb->pBt, MASTER_ROOT, 0, 0, 0, &curMain);
  if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){
    sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
    sqlite3BtreeLeave(pDb->pBt);
    return rc;
  }

  /* Get the database meta information.
  **
  ** Meta values are as follows:
  **    meta[0]   Schema cookie.  Changes with each schema change.
224
225
226
227
228
229
230

231
232
233
234
235
236
237
    int i;
    for(i=0; rc==SQLITE_OK && i<sizeof(meta)/sizeof(meta[0]); i++){
      rc = sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]);
    }
    if( rc ){
      sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
      sqlite3BtreeCloseCursor(curMain);

      return rc;
    }
  }else{
    memset(meta, 0, sizeof(meta));
  }
  pDb->pSchema->schema_cookie = meta[0];








>







228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
    int i;
    for(i=0; rc==SQLITE_OK && i<sizeof(meta)/sizeof(meta[0]); i++){
      rc = sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]);
    }
    if( rc ){
      sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
      sqlite3BtreeCloseCursor(curMain);
      sqlite3BtreeLeave(pDb->pBt);
      return rc;
    }
  }else{
    memset(meta, 0, sizeof(meta));
  }
  pDb->pSchema->schema_cookie = meta[0];

247
248
249
250
251
252
253

254
255
256
257
258
259
260
      db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 6, 0);
    }else{
      /* If opening an attached database, the encoding much match ENC(db) */
      if( meta[4]!=ENC(db) ){
        sqlite3BtreeCloseCursor(curMain);
        sqlite3SetString(pzErrMsg, "attached databases must use the same"
            " text encoding as main database", (char*)0);

        return SQLITE_ERROR;
      }
    }
  }else{
    DbSetProperty(db, iDb, DB_Empty);
  }
  pDb->pSchema->enc = ENC(db);







>







252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
      db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 6, 0);
    }else{
      /* If opening an attached database, the encoding much match ENC(db) */
      if( meta[4]!=ENC(db) ){
        sqlite3BtreeCloseCursor(curMain);
        sqlite3SetString(pzErrMsg, "attached databases must use the same"
            " text encoding as main database", (char*)0);
        sqlite3BtreeLeave(pDb->pBt);
        return SQLITE_ERROR;
      }
    }
  }else{
    DbSetProperty(db, iDb, DB_Empty);
  }
  pDb->pSchema->enc = ENC(db);
273
274
275
276
277
278
279

280
281
282
283
284
285
286
  pDb->pSchema->file_format = meta[1];
  if( pDb->pSchema->file_format==0 ){
    pDb->pSchema->file_format = 1;
  }
  if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){
    sqlite3BtreeCloseCursor(curMain);
    sqlite3SetString(pzErrMsg, "unsupported file format", (char*)0);

    return SQLITE_ERROR;
  }


  /* Read the schema information out of the schema tables
  */
  assert( db->init.busy );







>







279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
  pDb->pSchema->file_format = meta[1];
  if( pDb->pSchema->file_format==0 ){
    pDb->pSchema->file_format = 1;
  }
  if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){
    sqlite3BtreeCloseCursor(curMain);
    sqlite3SetString(pzErrMsg, "unsupported file format", (char*)0);
    sqlite3BtreeLeave(pDb->pBt);
    return SQLITE_ERROR;
  }


  /* Read the schema information out of the schema tables
  */
  assert( db->init.busy );
317
318
319
320
321
322
323

324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340

341
342
343
344
345
346
347
    ** of the schema was loaded before the error occured. The primary
    ** purpose of this is to allow access to the sqlite_master table
    ** even when it's contents have been corrupted.
    */
    DbSetProperty(db, iDb, DB_SchemaLoaded);
    rc = SQLITE_OK;
  }

  return rc;
}

/*
** Initialize all database files - the main database file, the file
** used to store temporary tables, and any additional database files
** created using ATTACH statements.  Return a success code.  If an
** error occurs, write an error message into *pzErrMsg.
**
** After a database is initialized, the DB_SchemaLoaded bit is set
** bit is set in the flags field of the Db structure. If the database
** file was of zero-length, then the DB_Empty flag is also set.
*/
int sqlite3Init(sqlite3 *db, char **pzErrMsg){
  int i, rc;
  int commit_internal = !(db->flags&SQLITE_InternChanges);
  

  if( db->init.busy ) return SQLITE_OK;
  rc = SQLITE_OK;
  db->init.busy = 1;
  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
    if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue;
    rc = sqlite3InitOne(db, i, pzErrMsg);
    if( rc ){







>

















>







324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
    ** of the schema was loaded before the error occured. The primary
    ** purpose of this is to allow access to the sqlite_master table
    ** even when it's contents have been corrupted.
    */
    DbSetProperty(db, iDb, DB_SchemaLoaded);
    rc = SQLITE_OK;
  }
  sqlite3BtreeLeave(pDb->pBt);
  return rc;
}

/*
** Initialize all database files - the main database file, the file
** used to store temporary tables, and any additional database files
** created using ATTACH statements.  Return a success code.  If an
** error occurs, write an error message into *pzErrMsg.
**
** After a database is initialized, the DB_SchemaLoaded bit is set
** bit is set in the flags field of the Db structure. If the database
** file was of zero-length, then the DB_Empty flag is also set.
*/
int sqlite3Init(sqlite3 *db, char **pzErrMsg){
  int i, rc;
  int commit_internal = !(db->flags&SQLITE_InternChanges);
  
  assert( sqlite3_mutex_held(db->mutex) );
  if( db->init.busy ) return SQLITE_OK;
  rc = SQLITE_OK;
  db->init.busy = 1;
  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
    if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue;
    rc = sqlite3InitOne(db, i, pzErrMsg);
    if( rc ){
373
374
375
376
377
378
379

380
381
382
383
384
385
386
/*
** This routine is a no-op if the database schema is already initialised.
** Otherwise, the schema is loaded. An error code is returned.
*/
int sqlite3ReadSchema(Parse *pParse){
  int rc = SQLITE_OK;
  sqlite3 *db = pParse->db;

  if( !db->init.busy ){
    rc = sqlite3Init(db, &pParse->zErrMsg);
  }
  if( rc!=SQLITE_OK ){
    pParse->rc = rc;
    pParse->nErr++;
  }







>







382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
/*
** This routine is a no-op if the database schema is already initialised.
** Otherwise, the schema is loaded. An error code is returned.
*/
int sqlite3ReadSchema(Parse *pParse){
  int rc = SQLITE_OK;
  sqlite3 *db = pParse->db;
  assert( sqlite3_mutex_held(db->mutex) );
  if( !db->init.busy ){
    rc = sqlite3Init(db, &pParse->zErrMsg);
  }
  if( rc!=SQLITE_OK ){
    pParse->rc = rc;
    pParse->nErr++;
  }
395
396
397
398
399
400
401

402
403
404
405
406
407
408
static int schemaIsValid(sqlite3 *db){
  int iDb;
  int rc;
  BtCursor *curTemp;
  int cookie;
  int allOk = 1;


  for(iDb=0; allOk && iDb<db->nDb; iDb++){
    Btree *pBt;
    pBt = db->aDb[iDb].pBt;
    if( pBt==0 ) continue;
    rc = sqlite3BtreeCursor(pBt, MASTER_ROOT, 0, 0, 0, &curTemp);
    if( rc==SQLITE_OK ){
      rc = sqlite3BtreeGetMeta(pBt, 1, (u32 *)&cookie);







>







405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
static int schemaIsValid(sqlite3 *db){
  int iDb;
  int rc;
  BtCursor *curTemp;
  int cookie;
  int allOk = 1;

  assert( sqlite3_mutex_held(db->mutex) );
  for(iDb=0; allOk && iDb<db->nDb; iDb++){
    Btree *pBt;
    pBt = db->aDb[iDb].pBt;
    if( pBt==0 ) continue;
    rc = sqlite3BtreeCursor(pBt, MASTER_ROOT, 0, 0, 0, &curTemp);
    if( rc==SQLITE_OK ){
      rc = sqlite3BtreeGetMeta(pBt, 1, (u32 *)&cookie);
431
432
433
434
435
436
437

438
439
440
441
442
443
444
  ** function should never be used.
  **
  ** We return -1000000 instead of the more usual -1 simply because using
  ** -1000000 as incorrectly using -1000000 index into db->aDb[] is much 
  ** more likely to cause a segfault than -1 (of course there are assert()
  ** statements too, but it never hurts to play the odds).
  */

  if( pSchema ){
    for(i=0; i<db->nDb; i++){
      if( db->aDb[i].pSchema==pSchema ){
        break;
      }
    }
    assert( i>=0 &&i>=0 &&  i<db->nDb );







>







442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
  ** function should never be used.
  **
  ** We return -1000000 instead of the more usual -1 simply because using
  ** -1000000 as incorrectly using -1000000 index into db->aDb[] is much 
  ** more likely to cause a segfault than -1 (of course there are assert()
  ** statements too, but it never hurts to play the odds).
  */
  assert( sqlite3_mutex_held(db->mutex) );
  if( pSchema ){
    for(i=0; i<db->nDb; i++){
      if( db->aDb[i].pSchema==pSchema ){
        break;
      }
    }
    assert( i>=0 &&i>=0 &&  i<db->nDb );
471
472
473
474
475
476
477


478

479
480
481
482

483
484
485
486
487
488
489
  assert( sqlite3_mutex_held(db->mutex) );

  /* If any attached database schemas are locked, do not proceed with
  ** compilation. Instead return SQLITE_LOCKED immediately.
  */
  for(i=0; i<db->nDb; i++) {
    Btree *pBt = db->aDb[i].pBt;


    if( pBt && sqlite3BtreeSchemaLocked(pBt) ){

      const char *zDb = db->aDb[i].zName;
      sqlite3Error(db, SQLITE_LOCKED, "database schema is locked: %s", zDb);
      sqlite3SafetyOff(db);
      return SQLITE_LOCKED;

    }
  }
  
  memset(&sParse, 0, sizeof(sParse));
  sParse.db = db;
  if( nBytes>=0 && zSql[nBytes]!=0 ){
    char *zSqlCopy;







>
>
|
>
|
|
|
|
>







483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
  assert( sqlite3_mutex_held(db->mutex) );

  /* If any attached database schemas are locked, do not proceed with
  ** compilation. Instead return SQLITE_LOCKED immediately.
  */
  for(i=0; i<db->nDb; i++) {
    Btree *pBt = db->aDb[i].pBt;
    if( pBt ){
      int rc;
      rc = sqlite3BtreeSchemaLocked(pBt);
      if( rc ){
        const char *zDb = db->aDb[i].zName;
        sqlite3Error(db, SQLITE_LOCKED, "database schema is locked: %s", zDb);
        sqlite3SafetyOff(db);
        return SQLITE_LOCKED;
      }
    }
  }
  
  memset(&sParse, 0, sizeof(sParse));
  sParse.db = db;
  if( nBytes>=0 && zSql[nBytes]!=0 ){
    char *zSqlCopy;
571
572
573
574
575
576
577

578

579
580
581
582
583
584
585
586
587
588
589
590
591
592
593

594
595
596
597
598
599
600
601
602
603
604
605
606
607
  const char **pzTail       /* OUT: End of parsed string */
){
  int rc;
  if( sqlite3SafetyCheck(db) ){
    return SQLITE_MISUSE;
  }
  sqlite3_mutex_enter(db->mutex);

  rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, ppStmt, pzTail);

  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Rerun the compilation of a statement after a schema change.
** Return true if the statement was recompiled successfully.
** Return false if there is an error of some kind.
*/
int sqlite3Reprepare(Vdbe *p){
  int rc;
  sqlite3_stmt *pNew;
  const char *zSql;
  sqlite3 *db;


  zSql = sqlite3VdbeGetSql(p);
  if( zSql==0 ){
    return 0;
  }
  db = sqlite3VdbeDb(p);
  assert( sqlite3_mutex_held(db->mutex) );
  rc = sqlite3Prepare(db, zSql, -1, 0, &pNew, 0);
  if( rc ){
    assert( pNew==0 );
    return 0;
  }else{
    assert( pNew!=0 );
  }
  sqlite3VdbeSwap((Vdbe*)pNew, p);







>

>















>






|







587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
  const char **pzTail       /* OUT: End of parsed string */
){
  int rc;
  if( sqlite3SafetyCheck(db) ){
    return SQLITE_MISUSE;
  }
  sqlite3_mutex_enter(db->mutex);
  sqlite3BtreeEnterAll(db);
  rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, ppStmt, pzTail);
  sqlite3BtreeLeaveAll(db);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Rerun the compilation of a statement after a schema change.
** Return true if the statement was recompiled successfully.
** Return false if there is an error of some kind.
*/
int sqlite3Reprepare(Vdbe *p){
  int rc;
  sqlite3_stmt *pNew;
  const char *zSql;
  sqlite3 *db;

  assert( sqlite3_mutex_held(sqlite3VdbeDb(p)->mutex) );
  zSql = sqlite3VdbeGetSql(p);
  if( zSql==0 ){
    return 0;
  }
  db = sqlite3VdbeDb(p);
  assert( sqlite3_mutex_held(db->mutex) );
  rc = sqlite3LockAndPrepare(db, zSql, -1, 0, &pNew, 0);
  if( rc ){
    assert( pNew==0 );
    return 0;
  }else{
    assert( pNew!=0 );
  }
  sqlite3VdbeSwap((Vdbe*)pNew, p);
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676

  if( sqlite3SafetyCheck(db) ){
    return SQLITE_MISUSE;
  }
  sqlite3_mutex_enter(db->mutex);
  zSql8 = sqlite3Utf16to8(db, zSql, nBytes);
  if( zSql8 ){
    rc = sqlite3Prepare(db, zSql8, -1, saveSqlFlag, ppStmt, &zTail8);
  }

  if( zTail8 && pzTail ){
    /* If sqlite3_prepare returns a tail pointer, we calculate the
    ** equivalent pointer into the UTF-16 string by counting the unicode
    ** characters between zSql8 and zTail8, and then returning a pointer
    ** the same number of characters into the UTF-16 string.







|







681
682
683
684
685
686
687
688
689
690
691
692
693
694
695

  if( sqlite3SafetyCheck(db) ){
    return SQLITE_MISUSE;
  }
  sqlite3_mutex_enter(db->mutex);
  zSql8 = sqlite3Utf16to8(db, zSql, nBytes);
  if( zSql8 ){
    rc = sqlite3LockAndPrepare(db, zSql8, -1, saveSqlFlag, ppStmt, &zTail8);
  }

  if( zTail8 && pzTail ){
    /* If sqlite3_prepare returns a tail pointer, we calculate the
    ** equivalent pointer into the UTF-16 string by counting the unicode
    ** characters between zSql8 and zTail8, and then returning a pointer
    ** the same number of characters into the UTF-16 string.