SQLite

/*
** Configure five tasks in different ways, then run tests.
*/
--if vfsname() GLOB 'unix'
PRAGMA page_size=8192;
--task 1
  PRAGMA journal_mode=PERSIST;
  PRAGMA mmap_size=0;
--end
--task 2
  PRAGMA journal_mode=TRUNCATE;
  PRAGMA mmap_size=28672;
--end
--task 3
  PRAGMA journal_mode=MEMORY;
--end
--task 4
  PRAGMA journal_mode=OFF;
--end
--task 4
  PRAGMA mmap_size(268435456);
--end
--source multiwrite01.test
--wait all
PRAGMA page_size=16384;
VACUUM;
CREATE TABLE pgsz(taskid, sz INTEGER);
--task 1
  INSERT INTO pgsz VALUES(1, eval('PRAGMA page_size'));

/*
** Configure five tasks in different ways, then run tests.
*/
PRAGMA page_size=512;
--task 1
  PRAGMA mmap_size=0;
--end
--task 2
  PRAGMA mmap_size=28672;
--end
--task 3
  PRAGMA mmap_size=8192;
--end
--task 4
  PRAGMA mmap_size=65536;
--end
--task 5
  PRAGMA mmap_size=268435456;
--end
--source multiwrite01.test
--source crash02.subtest
PRAGMA page_size=1024;
VACUUM;
CREATE TABLE pgsz(taskid, sz INTEGER);
--task 1

    if( pBt==0 ){
      rc = SQLITE_NOMEM;
      goto btree_open_out;
    }
    rc = sqlite3PagerOpen(pVfs, &pBt->pPager, zFilename,
                          EXTRA_SIZE, flags, vfsFlags, pageReinit);
    if( rc==SQLITE_OK ){
      sqlite3PagerSetMmapLimit(pBt->pPager, db->szMmap);
      rc = sqlite3PagerReadFileheader(pBt->pPager,sizeof(zDbHeader),zDbHeader);
    }
    if( rc!=SQLITE_OK ){
      goto btree_open_out;
    }
    pBt->openFlags = (u8)flags;
    pBt->db = db;

  return SQLITE_OK;
}

/*
** Change the limit on the amount of the database file that may be
** memory mapped.
*/
int sqlite3BtreeSetMmapLimit(Btree *p, sqlite3_int64 szMmap){
  BtShared *pBt = p->pBt;
  assert( sqlite3_mutex_held(p->db->mutex) );
  sqlite3BtreeEnter(p);
  sqlite3PagerSetMmapLimit(pBt->pPager, szMmap);
  sqlite3BtreeLeave(p);
  return SQLITE_OK;
}

/*
** Change the way data is synced to disk in order to increase or decrease
** how well the database resists damage due to OS crashes and power

#endif
#ifdef SQLITE_DEBUG
  "DEBUG",
#endif
#ifdef SQLITE_DEFAULT_LOCKING_MODE
  "DEFAULT_LOCKING_MODE=" CTIMEOPT_VAL(SQLITE_DEFAULT_LOCKING_MODE),
#endif
#ifdef SQLITE_DEFAULT_MMAP_SIZE
  "DEFAULT_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_DEFAULT_MMAP_SIZE),
#endif
#ifdef SQLITE_DISABLE_DIRSYNC
  "DISABLE_DIRSYNC",
#endif
#ifdef SQLITE_DISABLE_LFS
  "DISABLE_LFS",
#endif



#ifdef SQLITE_ENABLE_ATOMIC_WRITE
  "ENABLE_ATOMIC_WRITE",
#endif
#ifdef SQLITE_ENABLE_CEROD
  "ENABLE_CEROD",
#endif
#ifdef SQLITE_ENABLE_COLUMN_METADATA

#endif
#ifdef SQLITE_INT64_TYPE
  "INT64_TYPE",
#endif
#ifdef SQLITE_LOCK_TRACE
  "LOCK_TRACE",
#endif
#ifdef SQLITE_MAX_MMAP_SIZE
  "MAX_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_MAX_MMAP_SIZE),
#endif
#ifdef SQLITE_MAX_SCHEMA_RETRY
  "MAX_SCHEMA_RETRY=" CTIMEOPT_VAL(SQLITE_MAX_SCHEMA_RETRY),
#endif
#ifdef SQLITE_MEMDEBUG
  "MEMDEBUG",
#endif
#ifdef SQLITE_MIXED_ENDIAN_64BIT_FLOAT

   500,                       /* nLookaside */
   {0,0,0,0,0,0,0,0},         /* m */
   {0,0,0,0,0,0,0,0,0},       /* mutex */
   {0,0,0,0,0,0,0,0,0,0,0,0,0},/* pcache2 */
   (void*)0,                  /* pHeap */
   0,                         /* nHeap */
   0, 0,                      /* mnHeap, mxHeap */
   SQLITE_DEFAULT_MMAP_SIZE,  /* szMmap */
   SQLITE_MAX_MMAP_SIZE,      /* mxMmap */
   (void*)0,                  /* pScratch */
   0,                         /* szScratch */
   0,                         /* nScratch */
   (void*)0,                  /* pPage */
   0,                         /* szPage */
   0,                         /* nPage */
   0,                         /* mxParserStack */

      typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
      sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
      sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
      break;
    }
#endif

    case SQLITE_CONFIG_MMAP_SIZE: {
      sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
      sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
      if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
        mxMmap = SQLITE_MAX_MMAP_SIZE;
      }
      sqlite3GlobalConfig.mxMmap = mxMmap;
      if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
      if( szMmap>mxMmap) szMmap = mxMmap;
      sqlite3GlobalConfig.szMmap = szMmap;
      break;
    }

    default: {
      rc = SQLITE_ERROR;
      break;
    }

  db->magic = SQLITE_MAGIC_BUSY;
  db->aDb = db->aDbStatic;

  assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
  memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
  db->autoCommit = 1;
  db->nextAutovac = -1;
  db->szMmap = sqlite3GlobalConfig.szMmap;
  db->nextPagesize = 0;
  db->flags |= SQLITE_ShortColNames | SQLITE_AutoIndex | SQLITE_EnableTrigger
#if SQLITE_DEFAULT_FILE_FORMAT<4
                 | SQLITE_LegacyFileFmt
#endif
#ifdef SQLITE_ENABLE_LOAD_EXTENSION
                 | SQLITE_LoadExtension

  int bExtend,                    /* True to extend file if necessary */
  void volatile **pp              /* OUT: Pointer to mapping */
){
  DO_OS_MALLOC_TEST(id);
  return id->pMethods->xShmMap(id, iPage, pgsz, bExtend, pp);
}

#if SQLITE_MAX_MMAP_SIZE>0
/* The real implementation of xFetch and xUnfetch */
int sqlite3OsFetch(sqlite3_file *id, i64 iOff, int iAmt, void **pp){
  DO_OS_MALLOC_TEST(id);
  return id->pMethods->xFetch(id, iOff, iAmt, pp);
}
int sqlite3OsUnfetch(sqlite3_file *id, i64 iOff, void *p){
  return id->pMethods->xUnfetch(id, iOff, p);

  void *lockingContext;               /* Locking style specific state */
  UnixUnusedFd *pUnused;              /* Pre-allocated UnixUnusedFd */
  const char *zPath;                  /* Name of the file */
  unixShm *pShm;                      /* Shared memory segment information */
  int szChunk;                        /* Configured by FCNTL_CHUNK_SIZE */
  int nFetchOut;                      /* Number of outstanding xFetch refs */
  sqlite3_int64 mmapSize;             /* Usable size of mapping at pMapRegion */
  sqlite3_int64 mmapSizeActual;       /* Actual size of mapping at pMapRegion */
  sqlite3_int64 mmapSizeMax;          /* Configured FCNTL_MMAP_SIZE value */
  void *pMapRegion;                   /* Memory mapped region */
#ifdef __QNXNTO__
  int sectorSize;                     /* Device sector size */
  int deviceCharacteristics;          /* Precomputed device characteristics */
#endif
#if SQLITE_ENABLE_LOCKING_STYLE
  int openFlags;                      /* The flags specified at open() */

#if 0
  assert( pFile->pUnused==0
       || offset>=PENDING_BYTE+512
       || offset+amt<=PENDING_BYTE 
  );
#endif

#if SQLITE_MAX_MMAP_SIZE>0
  /* Deal with as much of this read request as possible by transfering
  ** data from the memory mapping using memcpy().  */
  if( offset<pFile->mmapSize ){
    if( offset+amt <= pFile->mmapSize ){
      memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], amt);
      return SQLITE_OK;
    }else{

      if( rc!=4 || memcmp(oldCntr, &((char*)pBuf)[24-offset], 4)!=0 ){
        pFile->transCntrChng = 1;  /* The transaction counter has changed */
      }
    }
  }
#endif

#if SQLITE_MAX_MMAP_SIZE>0
  /* Deal with as much of this write request as possible by transfering
  ** data from the memory mapping using memcpy().  */
  if( offset<pFile->mmapSize ){
    if( offset+amt <= pFile->mmapSize ){
      memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, amt);
      return SQLITE_OK;
    }else{

        if( nWrite!=1 ) return SQLITE_IOERR_WRITE;
        iWrite += nBlk;
      }
#endif
    }
  }

  if( pFile->mmapSizeMax>0 && nByte>pFile->mmapSize ){
    int rc;
    if( pFile->szChunk<=0 ){
      if( robust_ftruncate(pFile->h, nByte) ){
        pFile->lastErrno = errno;
        return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);
      }
    }

      char *zTFile = sqlite3_malloc( pFile->pVfs->mxPathname );
      if( zTFile ){
        unixGetTempname(pFile->pVfs->mxPathname, zTFile);
        *(char**)pArg = zTFile;
      }
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_MMAP_SIZE: {
      i64 newLimit = *(i64*)pArg;
      if( newLimit>sqlite3GlobalConfig.mxMmap ){
        newLimit = sqlite3GlobalConfig.mxMmap;
      }
      *(i64*)pArg = pFile->mmapSizeMax;
      if( newLimit>=0 ){
        pFile->mmapSizeMax = newLimit;
        if( newLimit<pFile->mmapSize ) pFile->mmapSize = newLimit;
      }
      return SQLITE_OK;
    }
#ifdef SQLITE_DEBUG
    /* The pager calls this method to signal that it has done
    ** a rollback and that the database is therefore unchanged and

#endif /* #ifndef SQLITE_OMIT_WAL */

/*
** If it is currently memory mapped, unmap file pFd.
*/
static void unixUnmapfile(unixFile *pFd){
  assert( pFd->nFetchOut==0 );
#if SQLITE_MAX_MMAP_SIZE>0
  if( pFd->pMapRegion ){
    osMunmap(pFd->pMapRegion, pFd->mmapSizeActual);
    pFd->pMapRegion = 0;
    pFd->mmapSize = 0;
    pFd->mmapSizeActual = 0;
  }
#endif
}

#if SQLITE_MAX_MMAP_SIZE>0
/*
** Return the system page size.
*/
static int unixGetPagesize(void){
#if HAVE_MREMAP
  return 512;
#elif defined(_BSD_SOURCE)
  return getpagesize();
#else
  return (int)sysconf(_SC_PAGESIZE);
#endif
}
#endif /* SQLITE_MAX_MMAP_SIZE>0 */

#if SQLITE_MAX_MMAP_SIZE>0
/*
** Attempt to set the size of the memory mapping maintained by file 
** descriptor pFd to nNew bytes. Any existing mapping is discarded.
**
** If successful, this function sets the following variables:
**
**       unixFile.pMapRegion
**       unixFile.mmapSize
**       unixFile.mmapSizeActual
**
** If unsuccessful, an error message is logged via sqlite3_log() and
** the three variables above are zeroed. In this case SQLite should
** continue accessing the database using the xRead() and xWrite()
** methods.
*/
static void unixRemapfile(
  unixFile *pFd,                  /* File descriptor object */
  i64 nNew                        /* Required mapping size */
){
  const char *zErr = "mmap";
  int h = pFd->h;                      /* File descriptor open on db file */
  u8 *pOrig = (u8 *)pFd->pMapRegion;   /* Pointer to current file mapping */
  i64 nOrig = pFd->mmapSizeActual;     /* Size of pOrig region in bytes */
  u8 *pNew = 0;                        /* Location of new mapping */
  int flags = PROT_READ;               /* Flags to pass to mmap() */

  assert( pFd->nFetchOut==0 );
  assert( nNew>pFd->mmapSize );
  assert( nNew<=pFd->mmapSizeMax );
  assert( nNew>0 );
  assert( pFd->mmapSizeActual>=pFd->mmapSize );
  assert( MAP_FAILED!=0 );

  if( (pFd->ctrlFlags & UNIXFILE_RDONLY)==0 ) flags |= PROT_WRITE;

  if( pOrig ){
    const int szSyspage = unixGetPagesize();
    i64 nReuse = (pFd->mmapSize & ~(szSyspage-1));

    pNew = 0;
    nNew = 0;
    unixLogError(SQLITE_OK, zErr, pFd->zPath);

    /* If the mmap() above failed, assume that all subsequent mmap() calls
    ** will probably fail too. Fall back to using xRead/xWrite exclusively
    ** in this case.  */
    pFd->mmapSizeMax = 0;
  }
  pFd->pMapRegion = (void *)pNew;
  pFd->mmapSize = pFd->mmapSizeActual = nNew;
}
#endif

/*
** Memory map or remap the file opened by file-descriptor pFd (if the file
** is already mapped, the existing mapping is replaced by the new). Or, if 
** there already exists a mapping for this file, and there are still 
** outstanding xFetch() references to it, this function is a no-op.
**
** If parameter nByte is non-negative, then it is the requested size of 
** the mapping to create. Otherwise, if nByte is less than zero, then the 
** requested size is the size of the file on disk. The actual size of the
** created mapping is either the requested size or the value configured 
** using SQLITE_FCNTL_MMAP_LIMIT, whichever is smaller.
**
** SQLITE_OK is returned if no error occurs (even if the mapping is not
** recreated as a result of outstanding references) or an SQLite error
** code otherwise.
*/
static int unixMapfile(unixFile *pFd, i64 nByte){
#if SQLITE_MAX_MMAP_SIZE>0
  i64 nMap = nByte;
  int rc;

  assert( nMap>=0 || pFd->nFetchOut==0 );
  if( pFd->nFetchOut>0 ) return SQLITE_OK;

  if( nMap<0 ){
    struct stat statbuf;          /* Low-level file information */
    rc = osFstat(pFd->h, &statbuf);
    if( rc!=SQLITE_OK ){
      return SQLITE_IOERR_FSTAT;
    }
    nMap = statbuf.st_size;
  }
  if( nMap>pFd->mmapSizeMax ){
    nMap = pFd->mmapSizeMax;
  }

  if( nMap!=pFd->mmapSize ){
    if( nMap>0 ){
      unixRemapfile(pFd, nMap);
    }else{
      unixUnmapfile(pFd);

** Finally, if an error does occur, return an SQLite error code. The final
** value of *pp is undefined in this case.
**
** If this function does return a pointer, the caller must eventually 
** release the reference by calling unixUnfetch().
*/
static int unixFetch(sqlite3_file *fd, i64 iOff, int nAmt, void **pp){
#if SQLITE_MAX_MMAP_SIZE>0
  unixFile *pFd = (unixFile *)fd;   /* The underlying database file */
#endif
  *pp = 0;

#if SQLITE_MAX_MMAP_SIZE>0
  if( pFd->mmapSizeMax>0 ){
    if( pFd->pMapRegion==0 ){
      int rc = unixMapfile(pFd, -1);
      if( rc!=SQLITE_OK ) return rc;
    }
    if( pFd->mmapSize >= iOff+nAmt ){
      *pp = &((u8 *)pFd->pMapRegion)[iOff];
      pFd->nFetchOut++;

  assert( zFilename!=0 || (ctrlFlags & UNIXFILE_NOLOCK)!=0 );

  OSTRACE(("OPEN    %-3d %s\n", h, zFilename));
  pNew->h = h;
  pNew->pVfs = pVfs;
  pNew->zPath = zFilename;
  pNew->ctrlFlags = (u8)ctrlFlags;
  pNew->mmapSizeMax = sqlite3GlobalConfig.mxMmap;
  if( sqlite3_uri_boolean(((ctrlFlags & UNIXFILE_URI) ? zFilename : 0),
                           "psow", SQLITE_POWERSAFE_OVERWRITE) ){
    pNew->ctrlFlags |= UNIXFILE_PSOW;
  }
  if( strcmp(pVfs->zName,"unix-excl")==0 ){
    pNew->ctrlFlags |= UNIXFILE_EXCL;
  }

#if SQLITE_OS_WINCE
  LPWSTR zDeleteOnClose;  /* Name of file to delete when closing */
  HANDLE hMutex;          /* Mutex used to control access to shared lock */  
  HANDLE hShared;         /* Shared memory segment used for locking */
  winceLock local;        /* Locks obtained by this instance of winFile */
  winceLock *shared;      /* Global shared lock memory for the file  */
#endif
  int nFetchOut;                /* Number of outstanding xFetch references */
  HANDLE hMap;                  /* Handle for accessing memory mapping */
  void *pMapRegion;             /* Area memory mapped */
  sqlite3_int64 mmapSize;       /* Usable size of mapped region */
  sqlite3_int64 mmapSizeActual; /* Actual size of mapped region */
  sqlite3_int64 mmapSizeMax;    /* Configured FCNTL_MMAP_SIZE value */
};

/*
** Allowed values for winFile.ctrlFlags
*/
#define WINFILE_RDONLY          0x02   /* Connection is read only */
#define WINFILE_PERSIST_WAL     0x04   /* Persistent WAL mode */

  int nRetry = 0;                 /* Number of retrys */

  assert( id!=0 );
  assert( amt>0 );
  SimulateIOError(return SQLITE_IOERR_READ);
  OSTRACE(("READ %d lock=%d\n", pFile->h, pFile->locktype));

#if SQLITE_MAX_MMAP_SIZE>0
  /* Deal with as much of this read request as possible by transfering
  ** data from the memory mapping using memcpy().  */
  if( offset<pFile->mmapSize ){
    if( offset+amt <= pFile->mmapSize ){
      memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], amt);
      return SQLITE_OK;
    }else{

  assert( amt>0 );
  assert( pFile );
  SimulateIOError(return SQLITE_IOERR_WRITE);
  SimulateDiskfullError(return SQLITE_FULL);

  OSTRACE(("WRITE %d lock=%d\n", pFile->h, pFile->locktype));

#if SQLITE_MAX_MMAP_SIZE>0
  /* Deal with as much of this write request as possible by transfering
  ** data from the memory mapping using memcpy().  */
  if( offset<pFile->mmapSize ){
    if( offset+amt <= pFile->mmapSize ){
      memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, amt);
      return SQLITE_OK;
    }else{

  }else if( 0==osSetEndOfFile(pFile->h) &&
            ((lastErrno = osGetLastError())!=ERROR_USER_MAPPED_FILE) ){
    pFile->lastErrno = lastErrno;
    rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
                     "winTruncate2", pFile->zPath);
  }

#if SQLITE_MAX_MMAP_SIZE>0
  /* If the file was truncated to a size smaller than the currently
  ** mapped region, reduce the effective mapping size as well. SQLite will
  ** use read() and write() to access data beyond this point from now on.
  */
  if( pFile->pMapRegion && nByte<pFile->mmapSize ){
    pFile->mmapSize = nByte;
  }

      char *zTFile = sqlite3MallocZero( pFile->pVfs->mxPathname );
      if( zTFile ){
        getTempname(pFile->pVfs->mxPathname, zTFile);
        *(char**)pArg = zTFile;
      }
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_MMAP_SIZE: {
      i64 newLimit = *(i64*)pArg;
      if( newLimit>sqlite3GlobalConfig.mxMmap ){
        newLimit = sqlite3GlobalConfig.mxMmap;
      }
      *(i64*)pArg = pFile->mmapSizeMax;
      if( newLimit>=0 ) pFile->mmapSizeMax = newLimit;
      return SQLITE_OK;
    }
  }
  return SQLITE_NOTFOUND;
}

/*

#endif /* #ifndef SQLITE_OMIT_WAL */

/*
** Cleans up the mapped region of the specified file, if any.
*/
static int winUnmapfile(winFile *pFile){
  assert( pFile!=0 );
#if SQLITE_MAX_MMAP_SIZE>0
  if( pFile->pMapRegion ){
    if( !osUnmapViewOfFile(pFile->pMapRegion) ){
      pFile->lastErrno = osGetLastError();
      return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
                         "winUnmap1", pFile->zPath);
    }
    pFile->pMapRegion = 0;
    pFile->mmapSize = 0;
    pFile->mmapSizeActual = 0;
  }
  if( pFile->hMap!=NULL ){
    if( !osCloseHandle(pFile->hMap) ){
      pFile->lastErrno = osGetLastError();
      return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
                         "winUnmap2", pFile->zPath);
    }
    pFile->hMap = NULL;
  }
#endif
  return SQLITE_OK;
}

#if SQLITE_MAX_MMAP_SIZE>0
/*
** Memory map or remap the file opened by file-descriptor pFd (if the file
** is already mapped, the existing mapping is replaced by the new). Or, if 
** there already exists a mapping for this file, and there are still 
** outstanding xFetch() references to it, this function is a no-op.
**
** If parameter nByte is non-negative, then it is the requested size of 
** the mapping to create. Otherwise, if nByte is less than zero, then the 
** requested size is the size of the file on disk. The actual size of the
** created mapping is either the requested size or the value configured 
** using SQLITE_FCNTL_MMAP_SIZE, whichever is smaller.
**
** SQLITE_OK is returned if no error occurs (even if the mapping is not
** recreated as a result of outstanding references) or an SQLite error
** code otherwise.
*/
static int winMapfile(winFile *pFd, sqlite3_int64 nByte){
  sqlite3_int64 nMap = nByte;
  int rc;

  assert( nMap>=0 || pFd->nFetchOut==0 );
  if( pFd->nFetchOut>0 ) return SQLITE_OK;

  if( nMap<0 ){
    rc = winFileSize((sqlite3_file*)pFd, &nMap);
    if( rc ){
      return SQLITE_IOERR_FSTAT;
    }
  }
  if( nMap>pFd->mmapSizeMax ){
    nMap = pFd->mmapSizeMax;
  }
  nMap &= ~(sqlite3_int64)(winSysInfo.dwPageSize - 1);
 
  if( nMap==0 && pFd->mmapSize>0 ){
    winUnmapfile(pFd);
  }
  if( nMap!=pFd->mmapSize ){

      pFd->lastErrno = osGetLastError();
      winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,
                  "winMapfile", pFd->zPath);
      return SQLITE_OK;
    }
    pFd->pMapRegion = pNew;
    pFd->mmapSize = nMap;
    pFd->mmapSizeActual = nMap;
  }

  return SQLITE_OK;
}
#endif /* SQLITE_MAX_MMAP_SIZE>0 */

/*
** If possible, return a pointer to a mapping of file fd starting at offset
** iOff. The mapping must be valid for at least nAmt bytes.
**
** If such a pointer can be obtained, store it in *pp and return SQLITE_OK.
** Or, if one cannot but no error occurs, set *pp to 0 and return SQLITE_OK.
** Finally, if an error does occur, return an SQLite error code. The final
** value of *pp is undefined in this case.
**
** If this function does return a pointer, the caller must eventually 
** release the reference by calling unixUnfetch().
*/
static int winFetch(sqlite3_file *fd, i64 iOff, int nAmt, void **pp){
  winFile *pFd = (winFile*)fd;   /* The underlying database file */
  *pp = 0;

#if SQLITE_MAX_MMAP_SIZE>0
  if( pFd->mmapSizeMax>0 ){
    if( pFd->pMapRegion==0 ){
      int rc = winMapfile(pFd, -1);
      if( rc!=SQLITE_OK ) return rc;
    }
    if( pFd->mmapSize >= iOff+nAmt ){
      *pp = &((u8 *)pFd->pMapRegion)[iOff];
      pFd->nFetchOut++;

    pFile->ctrlFlags |= WINFILE_PSOW;
  }
  pFile->lastErrno = NO_ERROR;
  pFile->zPath = zName;
  pFile->hMap = NULL;
  pFile->pMapRegion = 0;
  pFile->mmapSize = 0;
  pFile->mmapSizeActual = 0;
  pFile->mmapSizeMax = sqlite3GlobalConfig.mxMmap;

  OpenCounter(+1);
  return rc;
}

/*
** Delete the named file.

  sqlite3_backup *pBackup;    /* Pointer to list of ongoing backup processes */
  PagerSavepoint *aSavepoint; /* Array of active savepoints */
  int nSavepoint;             /* Number of elements in aSavepoint[] */
  char dbFileVers[16];        /* Changes whenever database file changes */

  u8 bUseFetch;               /* True to use xFetch() */
  int nMmapOut;               /* Number of mmap pages currently outstanding */
  sqlite3_int64 szMmap;       /* Desired maximum mmap size */
  PgHdr *pMmapFreelist;       /* List of free mmap page headers (pDirty) */
  /*
  ** End of the routinely-changing class members
  ***************************************************************************/

  u16 nExtra;                 /* Add this many bytes to each in-memory page */
  i16 nReserve;               /* Number of unused bytes at end of each page */

# define MEMDB pPager->memDb
#endif

/*
** The macro USEFETCH is true if we are allowed to use the xFetch and xUnfetch
** interfaces to access the database using memory-mapped I/O.
*/
#if SQLITE_MAX_MMAP_SIZE>0
# define USEFETCH(x) ((x)->bUseFetch)
#else
# define USEFETCH(x) 0
#endif

/*
** The maximum legal page number is (2^31 - 1).
*/
#define PAGER_MAX_PGNO 2147483647

** Change the maximum number of in-memory pages that are allowed.
*/
void sqlite3PagerSetCachesize(Pager *pPager, int mxPage){
  sqlite3PcacheSetCachesize(pPager->pPCache, mxPage);
}

/*
** Invoke SQLITE_FCNTL_MMAP_SIZE based on the current value of szMmap.
*/
static void pagerFixMaplimit(Pager *pPager){
#if SQLITE_MAX_MMAP_SIZE>0
  sqlite3_file *fd = pPager->fd;
  if( isOpen(fd) ){
    sqlite3_int64 sz;
    pPager->bUseFetch = (fd->pMethods->iVersion>=3) && pPager->szMmap>0;
    sz = pPager->szMmap;
    sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_MMAP_SIZE, &sz);
  }
#endif
}

/*
** Change the maximum size of any memory mapping made of the database file.
*/
void sqlite3PagerSetMmapLimit(Pager *pPager, sqlite3_int64 szMmap){
  pPager->szMmap = szMmap;
  pagerFixMaplimit(pPager);
}

/*
** Free as much memory as possible from the pager.
*/
void sqlite3PagerShrink(Pager *pPager){

  }else if( memDb ){
    pPager->journalMode = PAGER_JOURNALMODE_MEMORY;
  }
  /* pPager->xBusyHandler = 0; */
  /* pPager->pBusyHandlerArg = 0; */
  pPager->xReiniter = xReinit;
  /* memset(pPager->aHash, 0, sizeof(pPager->aHash)); */
  /* pPager->szMmap = SQLITE_DEFAULT_MMAP_SIZE // will be set by btree.c */

  *ppPager = pPager;
  return SQLITE_OK;
}

      int size = sqlite3Atoi(zRight);
      pDb->pSchema->cache_size = size;
      sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
    }
  }else

  /*
  **  PRAGMA [database.]mmap_size(N)
  **
  ** Used to set mapping size limit. The mapping size limit is
  ** used to limit the aggregate size of all memory mapped regions of the
  ** database file. If this parameter is set to zero, then memory mapping
  ** is not used at all.  If N is negative, then the default memory map
  ** limit determined by sqlite3_config(SQLITE_CONFIG_MMAP_SIZE) is set.
  ** The parameter N is measured in bytes.
  **
  ** This value is advisory.  The underlying VFS is free to memory map
  ** as little or as much as it wants.  Except, if N is set to 0 then the
  ** upper layers will never invoke the xFetch interfaces to the VFS.
  */
  if( sqlite3StrICmp(zLeft,"mmap_size")==0 ){
    sqlite3_int64 sz;
    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
    if( zRight ){
      int ii;
      sqlite3Atoi64(zRight, &sz, 1000, SQLITE_UTF8);
      if( sz<0 ) sz = sqlite3GlobalConfig.szMmap;
      if( pId2->n==0 ) db->szMmap = sz;
      for(ii=db->nDb-1; ii>=0; ii--){
        if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){
          sqlite3BtreeSetMmapLimit(db->aDb[ii].pBt, sz);
        }
      }
    }
    sz = -1;
    if( sqlite3_file_control(db,zDb,SQLITE_FCNTL_MMAP_SIZE,&sz)==SQLITE_OK ){
#if SQLITE_MAX_MMAP_SIZE==0
      sz = 0;
#endif
      returnSingleInt(pParse, "mmap_size", sz);
    }
  }else

  /*
  **   PRAGMA temp_store
  **   PRAGMA temp_store = "default"|"memory"|"file"
  **

#endif
#ifdef SQLITE_ENABLE_MULTIPLEX
    }else if( strcmp(z,"-multiplex")==0 ){
      extern int sqlite3_multiple_initialize(const char*,int);
      sqlite3_multiplex_initialize(0, 1);
#endif
    }else if( strcmp(z,"-mmap")==0 ){
      sqlite3_int64 sz = integerValue(cmdline_option_value(argc,argv,++i));
      sqlite3_config(SQLITE_CONFIG_MMAP_SIZE, sz, sz);
    }else if( strcmp(z,"-vfs")==0 ){
      sqlite3_vfs *pVfs = sqlite3_vfs_find(cmdline_option_value(argc,argv,++i));
      if( pVfs ){
        sqlite3_vfs_register(pVfs, 1);
      }else{
        fprintf(stderr, "no such VFS: \"%s\"\n", argv[i]);
        exit(1);

** to have SQLite generate a
** temporary filename using the same algorithm that is followed to generate
** temporary filenames for TEMP tables and other internal uses.  The
** argument should be a char** which will be filled with the filename
** written into memory obtained from [sqlite3_malloc()].  The caller should
** invoke [sqlite3_free()] on the result to avoid a memory leak.
**
** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
** maximum number of bytes that will be used for memory-mapped I/O.
** The argument is a pointer to a value of type sqlite3_int64 that
** is an advisory maximum number of bytes in the file to memory map.  The
** pointer is overwritten with the old value.  The limit is not changed if
** the value originally pointed to is negative, and so the current limit 
** can be queried by passing in a pointer to a negative number.  This
** file-control is used internally to implement [PRAGMA mmap_size].
**
** </ul>
*/
#define SQLITE_FCNTL_LOCKSTATE               1
#define SQLITE_GET_LOCKPROXYFILE             2
#define SQLITE_SET_LOCKPROXYFILE             3
#define SQLITE_LAST_ERRNO                    4
#define SQLITE_FCNTL_SIZE_HINT               5
#define SQLITE_FCNTL_CHUNK_SIZE              6
#define SQLITE_FCNTL_FILE_POINTER            7
#define SQLITE_FCNTL_SYNC_OMITTED            8
#define SQLITE_FCNTL_WIN32_AV_RETRY          9
#define SQLITE_FCNTL_PERSIST_WAL            10
#define SQLITE_FCNTL_OVERWRITE              11
#define SQLITE_FCNTL_VFSNAME                12
#define SQLITE_FCNTL_POWERSAFE_OVERWRITE    13
#define SQLITE_FCNTL_PRAGMA                 14
#define SQLITE_FCNTL_BUSYHANDLER            15
#define SQLITE_FCNTL_TEMPFILENAME           16
#define SQLITE_FCNTL_MMAP_SIZE              18

/*
** CAPI3REF: Mutex Handle
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks
** at the internal representation of an [sqlite3_mutex].  It only

** passed as the second argument has just been opened. The third argument
** points to a buffer containing the name of the main database file. If the
** fourth parameter is 1, then the SQL statement that the third parameter
** points to has just been executed. Or, if the fourth parameter is 2, then
** the connection being passed as the second parameter is being closed. The
** third parameter is passed NULL In this case.
**
** [[SQLITE_CONFIG_MMAP_SIZE]]
** <dt>SQLITE_CONFIG_MMAP_SIZE
** <dd>SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
** that are the default mmap size limit (the default setting for
** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
** The default setting can be overridden by each database connection using
** either the [PRAGMA mmap_size] command, or by using the
** [SQLITE_FCNTL_MMAP_SIZE] file control.  The maximum allowed mmap size
** cannot be changed at run-time.  Nor may the maximum allowed mmap size
** exceed the compile-time maximum mmap size set by the
** [SQLITE_MAX_MMAP_SIZE] compile-time option.  
** If either argument to this option is negative, then that argument is
** changed to its compile-time default.
** </dl>
*/
#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
#define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */

#define SQLITE_CONFIG_GETPCACHE    15  /* no-op */
#define SQLITE_CONFIG_LOG          16  /* xFunc, void* */
#define SQLITE_CONFIG_URI          17  /* int */
#define SQLITE_CONFIG_PCACHE2      18  /* sqlite3_pcache_methods2* */
#define SQLITE_CONFIG_GETPCACHE2   19  /* sqlite3_pcache_methods2* */
#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */
#define SQLITE_CONFIG_SQLLOG       21  /* xSqllog, void* */
#define SQLITE_CONFIG_MMAP_SIZE    22  /* sqlite3_int64, sqlite3_int64 */

/*
** CAPI3REF: Database Connection Configuration Options
**
** These constants are the available integer configuration options that
** can be passed as the second argument to the [sqlite3_db_config()] interface.
**

#ifdef SQLITE_4_BYTE_ALIGNED_MALLOC
# define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&3)==0)
#else
# define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
#endif

/*
** Disable MMAP on platforms where it is known to not work
*/
#if defined(__OpenBSD__) || defined(__QNXNTO__)
# undef SQLITE_MAX_MMAP_SIZE
# define SQLITE_MAX_MMAP_SIZE 0
#endif

/*
** Default maximum size of memory used by memory-mapped I/O in the VFS
*/
#ifdef __APPLE__
# include <TargetConditionals.h>
# if TARGET_OS_IPHONE
#   undef SQLITE_MAX_MMAP_SIZE
#   define SQLITE_MAX_MMAP_SIZE 0
# endif
#endif
#ifndef SQLITE_MAX_MMAP_SIZE
# if defined(__linux__) \
  || defined(_WIN32) \
  || (defined(__APPLE__) && defined(__MACH__)) \
  || defined(__sun)
#   define SQLITE_MAX_MMAP_SIZE 2147483648
# else
#   define SQLITE_MAX_MMAP_SIZE 0
# endif
#endif

/*
** The default MMAP_SIZE is zero on all platforms.  Or, even if a larger
** default MMAP_SIZE is specified at compile-time, make sure that it does
** not exceed the maximum mmap size.
*/
#ifndef SQLITE_DEFAULT_MMAP_SIZE
# define SQLITE_DEFAULT_MMAP_SIZE 0
#endif
#if SQLITE_DEFAULT_MMAP_SIZE>SQLITE_MAX_MMAP_SIZE
# undef SQLITE_DEFAULT_MMAP_SIZE
# define SQLITE_DEFAULT_MMAP_SIZE SQLITE_MAX_MMAP_SIZE
#endif

/*
** An instance of the following structure is used to store the busy-handler
** callback for a given sqlite handle. 
**
** The sqlite.busyHandler member of the sqlite struct contains the busy
** callback for the database handle. Each pager opened via the sqlite

  struct Vdbe *pVdbe;           /* List of active virtual machines */
  CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
  sqlite3_mutex *mutex;         /* Connection mutex */
  Db *aDb;                      /* All backends */
  int nDb;                      /* Number of backends currently in use */
  int flags;                    /* Miscellaneous flags. See below */
  i64 lastRowid;                /* ROWID of most recent insert (see above) */
  i64 szMmap;                   /* Default mmap_size setting */
  unsigned int openFlags;       /* Flags passed to sqlite3_vfs.xOpen() */
  int errCode;                  /* Most recent error code (SQLITE_*) */
  int errMask;                  /* & result codes with this before returning */
  u16 dbOptFlags;               /* Flags to enable/disable optimizations */
  u8 autoCommit;                /* The auto-commit flag. */
  u8 temp_store;                /* 1: file 2: memory 0: default */
  u8 mallocFailed;              /* True if we have seen a malloc failure */

  int nLookaside;                   /* Default lookaside buffer count */
  sqlite3_mem_methods m;            /* Low-level memory allocation interface */
  sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
  sqlite3_pcache_methods2 pcache2;  /* Low-level page-cache interface */
  void *pHeap;                      /* Heap storage space */
  int nHeap;                        /* Size of pHeap[] */
  int mnReq, mxReq;                 /* Min and max heap requests sizes */
  sqlite3_int64 szMmap;             /* mmap() space per open file */
  sqlite3_int64 mxMmap;             /* Maximum value for szMmap */
  void *pScratch;                   /* Scratch memory */
  int szScratch;                    /* Size of each scratch buffer */
  int nScratch;                     /* Number of scratch buffers */
  void *pPage;                      /* Page cache memory */
  int szPage;                       /* Size of each page in pPage[] */
  int nPage;                        /* Number of pages in pPage[] */
  int mxParserStack;                /* maximum depth of the parser stack */

** A value of 1 means that a trigger program will not be able to itself
** fire any triggers. A value of 0 means that no trigger programs at all 
** may be executed.
*/
#ifndef SQLITE_MAX_TRIGGER_DEPTH
# define SQLITE_MAX_TRIGGER_DEPTH 1000
#endif

#ifdef SQLITE_DISABLE_LFS
  Tcl_SetVar2(interp, "sqlite_options", "lfs", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "lfs", "1", TCL_GLOBAL_ONLY);
#endif

#if SQLITE_MAX_MMAP_SIZE>0
  Tcl_SetVar2(interp, "sqlite_options", "mmap", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "mmap", "0", TCL_GLOBAL_ONLY);
#endif

#if 1 /* def SQLITE_MEMDEBUG */
  Tcl_SetVar2(interp, "sqlite_options", "memdebug", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "memdebug", "0", TCL_GLOBAL_ONLY);
#endif

proc db_write {db {reset 0}} {
  sqlite3_db_status $db CACHE_WRITE $reset
}

do_test 1.1 {
  db close
  sqlite3 db test.db
  execsql { PRAGMA mmap_size = 0 }
  expr {[file size test.db] / 1024}
} 6

do_test 1.2 {
  execsql { SELECT b FROM t1 WHERE a=2 }
  db_hit_miss db
} {{0 2 0} {0 4 0}}

  finish_test
  return
}

# Tests in this file verify that locking_mode=exclusive causes SQLite to
# use cached pages even if the database is changed on disk. This doesn't
# work with mmap.
if {[permutation]=="mmap"} {
  finish_test
  return
}

# This module does not work right if the cache spills at unexpected
# moments.  So disable the soft-heap-limit.
#

} {1}
do_test func-29.3 {
  db close
  sqlite3 db test.db
  sqlite3_db_status db CACHE_MISS 1
  db eval {SELECT typeof(+x) FROM t29 ORDER BY id}
} {integer null real blob text}
if {[permutation] != "mmap"} {
  do_test func-29.4 {
    set x [lindex [sqlite3_db_status db CACHE_MISS 1] 1]
    if {$x>100} {set x many}
    set x
  } {many}
}
do_test func-29.5 {

    }
  }

  db close
  forcedelete test.db test.db-journal

  sqlite3 db test.db
  execsql "PRAGMA mmap_size = 0"
  execsql "PRAGMA auto_vacuum = $AutoVacuumMode"

  do_test incrblob-2.$AutoVacuumMode.1 {
    set ::str [string repeat abcdefghij 2900]
    execsql {
      BEGIN;
      CREATE TABLE blobs(k PRIMARY KEY, v BLOB, i INTEGER);

    } $AutoVacuumMode
  }

  do_test incrblob-2.$AutoVacuumMode.3 {
    # Open and close the db to make sure the page cache is empty.
    db close
    sqlite3 db test.db
    execsql "PRAGMA mmap_size = 0"
  
    # Read the last 20 bytes of the blob via a blob handle.
    set ::blob [db incrblob blobs v 1]
    seek $::blob -20 end
    set ::fragment [read $::blob]
    close $::blob
  

    string range [db one {SELECT v FROM blobs}] end-19 end
  } $::fragment

  do_test incrblob-2.$AutoVacuumMode.5 {
    # Open and close the db to make sure the page cache is empty.
    db close
    sqlite3 db test.db
    execsql "PRAGMA mmap_size = 0"
  
    # Write the second-to-last 20 bytes of the blob via a blob handle.
    #
    set ::blob [db incrblob blobs v 1]
    seek $::blob -40 end
    puts -nonewline $::blob "1234567890abcdefghij"
    flush $::blob

    string range [db one {SELECT v FROM blobs}] end-39 end-20
  } "1234567890abcdefghij"

  do_test incrblob-2.$AutoVacuumMode.8 {
    # Open and close the db to make sure the page cache is empty.
    db close
    sqlite3 db test.db
    execsql { PRAGMA mmap_size = 0 }

    execsql { SELECT i FROM blobs } 
  } {45}

  do_test incrblob-2.$AutoVacuumMode.9 {
    nRead db
  } [expr $AutoVacuumMode ? 4 : 30]

      set str [format %.8x [expr [set ::rcnt] ^ 0xbdf20da3]] 
      string range [string repeat [set str] [expr [set n]/4]] 1 [set n]
    }
    $dbname func rblob rblob
  }]
}

foreach {t mmap_size nRead c2init} {
  1.1 { PRAGMA mmap_size = 67108864 }   4 {PRAGMA mmap_size = 0}
  1.2 { PRAGMA mmap_size =    53248 } 150 {PRAGMA mmap_size = 0}
  1.3 { PRAGMA mmap_size =        0 } 344 {PRAGMA mmap_size = 0}
  1.4 { PRAGMA mmap_size = 67108864 }   4 {PRAGMA mmap_size = 67108864 }
  1.5 { PRAGMA mmap_size =    53248 } 150 {PRAGMA mmap_size = 67108864 }
  1.6 { PRAGMA mmap_size =        0 } 344 {PRAGMA mmap_size = 67108864 }
} {
  do_multiclient_test tn {
    sql1 {PRAGMA page_size=1024}
    sql1 $mmap_size
    sql2 $c2init

    code2 [register_rblob_code db2 0]

    sql2 {
      PRAGMA page_size=1024;
      PRAGMA auto_vacuum = 1;

    # Have connection 2 grow the file again. Check connection 1 is still ok.
    sql2 { INSERT INTO t1 SELECT rblob(500), rblob(500) FROM t1 }
    do_test $t.$tn.4 {
      sql1 "SELECT count(*) FROM t1; PRAGMA integrity_check ; PRAGMA page_count"
    } {64 ok 149}

    # Check that the number of pages read by connection 1 indicates that the
    # "PRAGMA mmap_size" command worked.
    do_test $t.$tn.5 { nRead db } $nRead
  }
}

set ::rcnt 0
proc rblob {n} {
  set ::rcnt [expr (($::rcnt << 3) + $::rcnt + 456) & 0xFFFFFFFF]
  set str [format %.8x [expr $::rcnt ^ 0xbdf20da3]] 
  string range [string repeat $str [expr $n/4]] 1 $n
}

reset_db
db func rblob rblob

do_execsql_test 2.1 {
  PRAGMA auto_vacuum = 1;
  PRAGMA mmap_size = 67108864;
  PRAGMA journal_mode = wal;
  CREATE TABLE t1(a, b, UNIQUE(a, b));
  INSERT INTO t1 VALUES(rblob(500), rblob(500));
  INSERT INTO t1 SELECT rblob(500), rblob(500) FROM t1; --    2
  INSERT INTO t1 SELECT rblob(500), rblob(500) FROM t1; --    4
  INSERT INTO t1 SELECT rblob(500), rblob(500) FROM t1; --    8
  INSERT INTO t1 SELECT rblob(500), rblob(500) FROM t1; --   16

} $bbb

do_test 5.5 {
  sqlite3_finalize $::STMT
} SQLITE_OK

#-------------------------------------------------------------------------
# Test various mmap_size settings.
#
foreach {tn1 mmap1 mmap2} {
     1 6144       167773
     2 18432      140399
     3 43008      401302
     4 92160      253899
     5 190464          2

      CREATE TABLE t2(x);
      INSERT INTO t2 VALUES('');
    }

    code1 [register_rblob_code db  0]
    code2 [register_rblob_code db2 444]

    sql1 "PRAGMA mmap_size = $mmap1"
    sql2 "PRAGMA mmap_size = $mmap2"

    do_test $tn1.$tn { 
      for {set i 1} {$i <= 100} {incr i} {
        if {$i % 2} {
          set c1 sql1
            set c2 sql2
        } else {

#-------------------------------------------------------------------------
# Test that appending pages to the database file then moving those pages
# to the free-list before the transaction is committed does not cause
# an error.
#
foreach {tn pragma strsize} {
  1 { PRAGMA mmap_size = 0 } 2400
  2 { }                       2400
  3 { PRAGMA mmap_size = 0 } 4400
  4 { }                       4400
} {
  reset_db
  db func a_string a_string
  db eval $pragma
  do_execsql_test 34.$tn.1 {
    CREATE TABLE t1(a, b);

    INSERT INTO t1 SELECT randomblob(200), randomblob(200) FROM t1;
    INSERT INTO t1 SELECT randomblob(200), randomblob(200) FROM t1;
    INSERT INTO t1 SELECT randomblob(200), randomblob(200) FROM t1;
  }
  db close
  sqlite3_test_control_pending_byte 0x0010000
  sqlite3 db test.db
  db eval { PRAGMA mmap_size = 0 }
  catchsql { SELECT sum(length(y)) FROM t1 }
} {1 {database disk image is malformed}}
do_test 42.2 {
  reset_db
  execsql {
    CREATE TABLE t1(x, y);
    INSERT INTO t1 VALUES(randomblob(200), randomblob(200));

    INSERT INTO t2 VALUES(1, 2);
    CREATE TABLE t3(x, y);
    INSERT INTO t3 VALUES(1, 2);
  }
  db close
  sqlite3 db test.db

  db eval { PRAGMA mmap_size = 0 }
  db eval { SELECT * FROM t1 }
  sqlite3_db_status db CACHE_MISS 0
} {0 2 0}

do_test 43.2 {
  db eval { SELECT * FROM t2 }
  sqlite3_db_status db CACHE_MISS 1

  }
  expr {[file size test.db-shm] >= 96*1024}
} {1}
faultsim_save_and_close

do_faultsim_test pagerfault-28a -faults oom* -prep {
  faultsim_restore_and_reopen
  execsql { PRAGMA mmap_size=0 }

  sqlite3 db2 test.db
  db2 eval { SELECT count(*) FROM t2 }

  db func a_string a_string
  execsql { 
    BEGIN;

  }
} [list 0 0 0 $blobcontent]

# But if the other thread modifies the database, then the cache
# must refill.
#
ifcapable mmap {
  set x [expr {[permutation]=="mmap" ? 1 : 6}]
} else {
  set x 6
}
do_test pageropt-1.5 {
  db2 eval {CREATE TABLE t2(y)}
  pagercount_sql {
    SELECT hex(x) FROM t1

  "Very" quick test suite. Runs in less than 5 minutes on a workstation. 
  This test suite is the same as the "quick" tests, except that some files
  that test malloc and IO errors are omitted.
} -files [
  test_set $allquicktests -exclude *malloc* *ioerr* *fault*
]

test_suite "mmap" -prefix "mm-" -description {
  Similar to veryquick. Except with memory mapping disabled.
} -presql {
  pragma mmap_size = 268435456;
} -files [
  test_set $allquicktests -exclude *malloc* *ioerr* *fault* -include malloc.test
]

test_suite "valgrind" -prefix "" -description {
  Run the "veryquick" test suite with a couple of multi-process tests (that
  fail under valgrind) omitted.

}
faultsim_save_and_close

do_faultsim_test 4 -faults vfsfault-* -prep {
  faultsim_restore_and_reopen
  file_control_chunksize_test db main 8192
  execsql { 
    PRAGMA mmap_size = 1000000;
  }
} -body {
  test_syscall errno mmap     EACCES

  execsql {
    SELECT * FROM t1;
  }

} [list 37 [wal_file_size 41 1024]]
do_test wal-11.9 {
  db close
  list [expr [file size test.db]/1024] [log_deleted test.db-wal]
} {37 1}
sqlite3_wal db test.db
set nWal 39
if {[permutation]!="mmap"} {set nWal 37}
ifcapable !mmap {set nWal 37}
do_test wal-11.10 {
  execsql {
    PRAGMA cache_size = 10;
    BEGIN;
      INSERT INTO t1 SELECT blob(900) FROM t1;   -- 32
      SELECT count(*) FROM t1;

    # The checkpoint above only writes page 1 of the db file. The other
    # page (page 2) is locked by the read-transaction opened by the
    # [sql2] commmand above. So normally, the db is 1 page in size here.
    # However, in mmap() mode, the db is pre-allocated to 2 pages at the
    # start of the checkpoint, even though page 2 cannot be written.
    set nDb 2
    if {[permutation]!="mmap"} {set nDb 1}
    ifcapable !mmap {set nDb 1}
    do_test 2.3.$tn.8 { file_page_counts } [list $nDb 4 2 4]
  }

  # Check that checkpoints block on the correct locks. And respond correctly
  # if they cannot obtain those locks. There are three locks that a checkpoint
  # may block on (in the following order):

db close
sqlite3_shutdown
test_sqlite3_log xLog
proc xLog {error_code msg} {
  lappend ::log $msg 
}
sqlite3 db test.db
db eval {PRAGMA mmap_size=0}

do_test win32lock-1.1 {
  db eval {
    PRAGMA cache_size=10;
    CREATE TABLE t1(x,y);
    INSERT INTO t1 VALUES(1,randomblob(100000));
    INSERT INTO t1 VALUES(2,randomblob(50000));