SQLite

Check-in [5153ad19da]
Login

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

Overview
Comment:Additional changes to pcache1 to prevent the page buffer memory from being configured if pcache1 is not enabled. Ticket #3872. (CVS 6669)
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 5153ad19daf0f3b0334b2a06655142899203abbf
User & Date: drh 2009-05-22 11:10:24.000
Context
2009-05-22
11:12
Add an assert() to pcache1.c to double-check that page cache buffer memory is never allocated if pcache1 is not enabled. Ticket #3872 (CVS 6670) (check-in: 93369d91ab user: drh tags: trunk)
11:10
Additional changes to pcache1 to prevent the page buffer memory from being configured if pcache1 is not enabled. Ticket #3872. (CVS 6669) (check-in: 5153ad19da user: drh tags: trunk)
10:53
Make sure sqlite3_shutdown() completely disables the default pager cache mechanism in pcache1.c. Ticket #3872. Also fix some comments associated with configuring the page cache. (CVS 6668) (check-in: 6240992cef user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/pcache1.c.
︙︙
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

**
** This file implements the default page cache implementation (the
** sqlite3_pcache interface). It also contains part of the implementation
** of the SQLITE_CONFIG_PAGECACHE and sqlite3_release_memory() features.
** If the default page cache implementation is overriden, then neither of
** these two features are available.
**
** @(#) $Id: pcache1.c,v 1.13 2009/05/22 10:53:29 drh Exp $
*/

#include "sqliteInt.h"

typedef struct PCache1 PCache1;
typedef struct PgHdr1 PgHdr1;
typedef struct PgFreeslot PgFreeslot;








|








12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

**
** This file implements the default page cache implementation (the
** sqlite3_pcache interface). It also contains part of the implementation
** of the SQLITE_CONFIG_PAGECACHE and sqlite3_release_memory() features.
** If the default page cache implementation is overriden, then neither of
** these two features are available.
**
** @(#) $Id: pcache1.c,v 1.14 2009/05/22 11:10:24 drh Exp $
*/

#include "sqliteInt.h"

typedef struct PCache1 PCache1;
typedef struct PgHdr1 PgHdr1;
typedef struct PgFreeslot PgFreeslot;
︙︙
84
85
86
87
88
89
90

91
92
93
94
95
96
97

  int nCurrentPage;                   /* Number of purgeable pages allocated */
  PgHdr1 *pLruHead, *pLruTail;        /* LRU list of unpinned pages */

  /* Variables related to SQLITE_CONFIG_PAGECACHE settings. */
  int szSlot;                         /* Size of each free slot */
  void *pStart, *pEnd;                /* Bounds of pagecache malloc range */
  PgFreeslot *pFree;                  /* Free page blocks */

} pcache1_g;

/*
** All code in this file should access the global structure above via the
** alias "pcache1". This ensures that the WSD emulation is used when
** compiling for systems that do not support real WSD.
*/








>








84
85
86
87
88
89
90
91
92
93
94
95
96
97
98

  int nCurrentPage;                   /* Number of purgeable pages allocated */
  PgHdr1 *pLruHead, *pLruTail;        /* LRU list of unpinned pages */

  /* Variables related to SQLITE_CONFIG_PAGECACHE settings. */
  int szSlot;                         /* Size of each free slot */
  void *pStart, *pEnd;                /* Bounds of pagecache malloc range */
  PgFreeslot *pFree;                  /* Free page blocks */
  int isInit;                         /* True if initialized */
} pcache1_g;

/*
** All code in this file should access the global structure above via the
** alias "pcache1". This ensures that the WSD emulation is used when
** compiling for systems that do not support real WSD.
*/
︙︙
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

/*
** This function is called during initialization if a static buffer is 
** supplied to use for the page-cache by passing the SQLITE_CONFIG_PAGECACHE
** verb to sqlite3_config(). Parameter pBuf points to an allocation large
** enough to contain 'n' buffers of 'sz' bytes each.
*/
void sqlite3PCacheBufferSetup(void *pBuf, int sz, int n){

  PgFreeslot *p;
  sz = ROUNDDOWN8(sz);
  pcache1.szSlot = sz;
  pcache1.pStart = pBuf;
  pcache1.pFree = 0;
  while( n-- ){
    p = (PgFreeslot*)pBuf;
    p->pNext = pcache1.pFree;
    pcache1.pFree = p;
    pBuf = (void*)&((char*)pBuf)[sz];
  }
  pcache1.pEnd = pBuf;

}

/*
** Malloc function used within this file to allocate space from the buffer
** configured using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no 
** such buffer exists or there is no space left in it, this function falls 
** back to sqlite3Malloc().








>
|
|
|
|
|
|
|
|
|
|
|
|
>








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

/*
** This function is called during initialization if a static buffer is 
** supplied to use for the page-cache by passing the SQLITE_CONFIG_PAGECACHE
** verb to sqlite3_config(). Parameter pBuf points to an allocation large
** enough to contain 'n' buffers of 'sz' bytes each.
*/
void sqlite3PCacheBufferSetup(void *pBuf, int sz, int n){
  if( pcache1.isInit ){
    PgFreeslot *p;
    sz = ROUNDDOWN8(sz);
    pcache1.szSlot = sz;
    pcache1.pStart = pBuf;
    pcache1.pFree = 0;
    while( n-- ){
      p = (PgFreeslot*)pBuf;
      p->pNext = pcache1.pFree;
      pcache1.pFree = p;
      pBuf = (void*)&((char*)pBuf)[sz];
    }
    pcache1.pEnd = pBuf;
  }
}

/*
** Malloc function used within this file to allocate space from the buffer
** configured using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no 
** such buffer exists or there is no space left in it, this function falls 
** back to sqlite3Malloc().
︙︙
385
386
387
388
389
390
391

392
393
394
395

396
397
398
399
400
401
402
403

404
405
406
407
408
409
410

/******** sqlite3_pcache Methods **********************************************/

/*
** Implementation of the sqlite3_pcache.xInit method.
*/
static int pcache1Init(void *NotUsed){
  UNUSED_PARAMETER(NotUsed);

  memset(&pcache1, 0, sizeof(pcache1));
  if( sqlite3GlobalConfig.bCoreMutex ){
    pcache1.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_LRU);
  }

  return SQLITE_OK;
}

/*
** Implementation of the sqlite3_pcache.xShutdown method.
*/
static void pcache1Shutdown(void *NotUsed){
  UNUSED_PARAMETER(NotUsed);

  memset(&pcache1, 0, sizeof(pcache1));
}

/*
** Implementation of the sqlite3_pcache.xCreate method.
**
** Allocate a new cache.








>




>








>








388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416

/******** sqlite3_pcache Methods **********************************************/

/*
** Implementation of the sqlite3_pcache.xInit method.
*/
static int pcache1Init(void *NotUsed){
  UNUSED_PARAMETER(NotUsed);
  assert( pcache1.isInit==0 );
  memset(&pcache1, 0, sizeof(pcache1));
  if( sqlite3GlobalConfig.bCoreMutex ){
    pcache1.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_LRU);
  }
  pcache1.isInit = 1;
  return SQLITE_OK;
}

/*
** Implementation of the sqlite3_pcache.xShutdown method.
*/
static void pcache1Shutdown(void *NotUsed){
  UNUSED_PARAMETER(NotUsed);
  assert( pcache1.isInit!=0 );
  memset(&pcache1, 0, sizeof(pcache1));
}

/*
** Implementation of the sqlite3_pcache.xCreate method.
**
** Allocate a new cache.
︙︙