Move bundled copy of sqlite one level deeper to better separate it...

third_party/sqlite/src/test6.c

Index: third_party/sqlite/src/test6.c
===================================================================
--- third_party/sqlite/src/test6.c	(revision 56608)
+++ third_party/sqlite/src/test6.c	(working copy)
@@ -1,974 +0,0 @@
-/*
-** 2004 May 22
-**
-** 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.
-**
-******************************************************************************
-**
-** This file contains code that modified the OS layer in order to simulate
-** the effect on the database file of an OS crash or power failure.  This
-** is used to test the ability of SQLite to recover from those situations.
-**
-** $Id: test6.c,v 1.43 2009/02/11 14:27:04 danielk1977 Exp $
-*/
-#if SQLITE_TEST          /* This file is used for testing only */
-#include "sqliteInt.h"
-#include "tcl.h"
-
-#ifndef SQLITE_OMIT_DISKIO  /* This file is a no-op if disk I/O is disabled */
-
-/* #define TRACE_CRASHTEST */
-
-typedef struct CrashFile CrashFile;
-typedef struct CrashGlobal CrashGlobal;
-typedef struct WriteBuffer WriteBuffer;
-
-/*
-** Method:
-**
-**   This layer is implemented as a wrapper around the "real" 
-**   sqlite3_file object for the host system. Each time data is 
-**   written to the file object, instead of being written to the
-**   underlying file, the write operation is stored in an in-memory 
-**   structure (type WriteBuffer). This structure is placed at the
-**   end of a global ordered list (the write-list).
-**
-**   When data is read from a file object, the requested region is
-**   first retrieved from the real file. The write-list is then 
-**   traversed and data copied from any overlapping WriteBuffer 
-**   structures to the output buffer. i.e. a read() operation following
-**   one or more write() operations works as expected, even if no
-**   data has actually been written out to the real file.
-**
-**   When a fsync() operation is performed, an operating system crash 
-**   may be simulated, in which case exit(-1) is called (the call to 
-**   xSync() never returns). Whether or not a crash is simulated,
-**   the data associated with a subset of the WriteBuffer structures 
-**   stored in the write-list is written to the real underlying files 
-**   and the entries removed from the write-list. If a crash is simulated,
-**   a subset of the buffers may be corrupted before the data is written.
-**
-**   The exact subset of the write-list written and/or corrupted is
-**   determined by the simulated device characteristics and sector-size.
-**
-** "Normal" mode:
-**
-**   Normal mode is used when the simulated device has none of the
-**   SQLITE_IOCAP_XXX flags set.
-**
-**   In normal mode, if the fsync() is not a simulated crash, the 
-**   write-list is traversed from beginning to end. Each WriteBuffer
-**   structure associated with the file handle used to call xSync()
-**   is written to the real file and removed from the write-list.
-**
-**   If a crash is simulated, one of the following takes place for 
-**   each WriteBuffer in the write-list, regardless of which 
-**   file-handle it is associated with:
-**
-**     1. The buffer is correctly written to the file, just as if
-**        a crash were not being simulated.
-**
-**     2. Nothing is done.
-**
-**     3. Garbage data is written to all sectors of the file that 
-**        overlap the region specified by the WriteBuffer. Or garbage
-**        data is written to some contiguous section within the 
-**        overlapped sectors.
-**
-** Device Characteristic flag handling:
-**
-**   If the IOCAP_ATOMIC flag is set, then option (3) above is 
-**   never selected.
-**
-**   If the IOCAP_ATOMIC512 flag is set, and the WriteBuffer represents
-**   an aligned write() of an integer number of 512 byte regions, then
-**   option (3) above is never selected. Instead, each 512 byte region
-**   is either correctly written or left completely untouched. Similar
-**   logic governs the behaviour if any of the other ATOMICXXX flags
-**   is set.
-**
-**   If either the IOCAP_SAFEAPPEND or IOCAP_SEQUENTIAL flags are set
-**   and a crash is being simulated, then an entry of the write-list is
-**   selected at random. Everything in the list after the selected entry 
-**   is discarded before processing begins.
-**
-**   If IOCAP_SEQUENTIAL is set and a crash is being simulated, option 
-**   (1) is selected for all write-list entries except the last. If a 
-**   crash is not being simulated, then all entries in the write-list
-**   that occur before at least one write() on the file-handle specified
-**   as part of the xSync() are written to their associated real files.
-**
-**   If IOCAP_SAFEAPPEND is set and the first byte written by the write()
-**   operation is one byte past the current end of the file, then option
-**   (1) is always selected.
-*/
-
-/*
-** Each write operation in the write-list is represented by an instance
-** of the following structure.
-**
-** If zBuf is 0, then this structure represents a call to xTruncate(), 
-** not xWrite(). In that case, iOffset is the size that the file is
-** truncated to.
-*/
-struct WriteBuffer {
-  i64 iOffset;                 /* Byte offset of the start of this write() */
-  int nBuf;                    /* Number of bytes written */
-  u8 *zBuf;                    /* Pointer to copy of written data */
-  CrashFile *pFile;            /* File this write() applies to */
-
-  WriteBuffer *pNext;          /* Next in CrashGlobal.pWriteList */
-};
-
-struct CrashFile {
-  const sqlite3_io_methods *pMethod;   /* Must be first */
-  sqlite3_file *pRealFile;             /* Underlying "real" file handle */
-  char *zName;
-  int flags;                           /* Flags the file was opened with */
-
-  /* Cache of the entire file. This is used to speed up OsRead() and 
-  ** OsFileSize() calls. Although both could be done by traversing the
-  ** write-list, in practice this is impractically slow.
-  */
-  int iSize;                           /* Size of file in bytes */
-  int nData;                           /* Size of buffer allocated at zData */
-  u8 *zData;                           /* Buffer containing file contents */
-};
-
-struct CrashGlobal {
-  WriteBuffer *pWriteList;     /* Head of write-list */
-  WriteBuffer *pWriteListEnd;  /* End of write-list */
-
-  int iSectorSize;             /* Value of simulated sector size */
-  int iDeviceCharacteristics;  /* Value of simulated device characteristics */
-
-  int iCrash;                  /* Crash on the iCrash'th call to xSync() */
-  char zCrashFile[500];        /* Crash during an xSync() on this file */ 
-};
-
-static CrashGlobal g = {0, 0, SQLITE_DEFAULT_SECTOR_SIZE, 0, 0};
-
-/*
-** Set this global variable to 1 to enable crash testing.
-*/
-static int sqlite3CrashTestEnable = 0;
-
-static void *crash_malloc(int nByte){
-  return (void *)Tcl_Alloc((size_t)nByte);
-}
-static void crash_free(void *p){
-  Tcl_Free(p);
-}
-static void *crash_realloc(void *p, int n){
-  return (void *)Tcl_Realloc(p, (size_t)n);
-}
-
-/*
-** Wrapper around the sqlite3OsWrite() function that avoids writing to the
-** 512 byte block begining at offset PENDING_BYTE.
-*/
-static int writeDbFile(CrashFile *p, u8 *z, i64 iAmt, i64 iOff){
-  int rc;
-  int iSkip = 0;
-  if( iOff==PENDING_BYTE && (p->flags&SQLITE_OPEN_MAIN_DB) ){
-    iSkip = 512;
-  }
-  if( (iAmt-iSkip)>0 ){
-    rc = sqlite3OsWrite(p->pRealFile, &z[iSkip], iAmt-iSkip, iOff+iSkip);
-  }
-  return rc;
-}
-
-/*
-** Flush the write-list as if xSync() had been called on file handle
-** pFile. If isCrash is true, simulate a crash.
-*/
-static int writeListSync(CrashFile *pFile, int isCrash){
-  int rc = SQLITE_OK;
-  int iDc = g.iDeviceCharacteristics;
-
-  WriteBuffer *pWrite;
-  WriteBuffer **ppPtr;
-
-  /* If this is not a crash simulation, set pFinal to point to the 
-  ** last element of the write-list that is associated with file handle
-  ** pFile.
-  **
-  ** If this is a crash simulation, set pFinal to an arbitrarily selected
-  ** element of the write-list.
-  */
-  WriteBuffer *pFinal = 0;
-  if( !isCrash ){
-    for(pWrite=g.pWriteList; pWrite; pWrite=pWrite->pNext){
-      if( pWrite->pFile==pFile ){
-        pFinal = pWrite;
-      }
-    }
-  }else if( iDc&(SQLITE_IOCAP_SEQUENTIAL|SQLITE_IOCAP_SAFE_APPEND) ){
-    int nWrite = 0;
-    int iFinal;
-    for(pWrite=g.pWriteList; pWrite; pWrite=pWrite->pNext) nWrite++;
-    sqlite3_randomness(sizeof(int), &iFinal);
-    iFinal = ((iFinal<0)?-1*iFinal:iFinal)%nWrite;
-    for(pWrite=g.pWriteList; iFinal>0; pWrite=pWrite->pNext) iFinal--;
-    pFinal = pWrite;
-  }
-
-#ifdef TRACE_CRASHTEST
-  printf("Sync %s (is %s crash)\n", pFile->zName, (isCrash?"a":"not a"));
-#endif
-
-  ppPtr = &g.pWriteList;
-  for(pWrite=*ppPtr; rc==SQLITE_OK && pWrite; pWrite=*ppPtr){
-    sqlite3_file *pRealFile = pWrite->pFile->pRealFile;
-
-    /* (eAction==1)      -> write block out normally,
-    ** (eAction==2)      -> do nothing,
-    ** (eAction==3)      -> trash sectors.
-    */
-    int eAction = 0;
-    if( !isCrash ){
-      eAction = 2;
-      if( (pWrite->pFile==pFile || iDc&SQLITE_IOCAP_SEQUENTIAL) ){
-        eAction = 1;
-      }
-    }else{
-      char random;
-      sqlite3_randomness(1, &random);
-
-      /* Do not select option 3 (sector trashing) if the IOCAP_ATOMIC flag 
-      ** is set or this is an OsTruncate(), not an Oswrite().
-      */
-      if( (iDc&SQLITE_IOCAP_ATOMIC) || (pWrite->zBuf==0) ){
-        random &= 0x01;
-      }
-
-      /* If IOCAP_SEQUENTIAL is set and this is not the final entry
-      ** in the truncated write-list, always select option 1 (write
-      ** out correctly).
-      */
-      if( (iDc&SQLITE_IOCAP_SEQUENTIAL && pWrite!=pFinal) ){
-        random = 0;
-      }
-
-      /* If IOCAP_SAFE_APPEND is set and this OsWrite() operation is
-      ** an append (first byte of the written region is 1 byte past the
-      ** current EOF), always select option 1 (write out correctly).
-      */
-      if( iDc&SQLITE_IOCAP_SAFE_APPEND && pWrite->zBuf ){
-        i64 iSize;
-        sqlite3OsFileSize(pRealFile, &iSize);
-        if( iSize==pWrite->iOffset ){
-          random = 0;
-        }
-      }
-
-      if( (random&0x06)==0x06 ){
-        eAction = 3;
-      }else{
-        eAction = ((random&0x01)?2:1);
-      }
-    }
-
-    switch( eAction ){
-      case 1: {               /* Write out correctly */
-        if( pWrite->zBuf ){
-          rc = writeDbFile(
-              pWrite->pFile, pWrite->zBuf, pWrite->nBuf, pWrite->iOffset
-          );
-        }else{
-          rc = sqlite3OsTruncate(pRealFile, pWrite->iOffset);
-        }
-        *ppPtr = pWrite->pNext;
-#ifdef TRACE_CRASHTEST
-        if( isCrash ){
-          printf("Writing %d bytes @ %d (%s)\n", 
-            pWrite->nBuf, (int)pWrite->iOffset, pWrite->pFile->zName
-          );
-        }
-#endif
-        crash_free(pWrite);
-        break;
-      }
-      case 2: {               /* Do nothing */
-        ppPtr = &pWrite->pNext;
-#ifdef TRACE_CRASHTEST
-        if( isCrash ){
-          printf("Omiting %d bytes @ %d (%s)\n", 
-            pWrite->nBuf, (int)pWrite->iOffset, pWrite->pFile->zName
-          );
-        }
-#endif
-        break;
-      }
-      case 3: {               /* Trash sectors */
-        u8 *zGarbage;
-        int iFirst = (pWrite->iOffset/g.iSectorSize);
-        int iLast = (pWrite->iOffset+pWrite->nBuf-1)/g.iSectorSize;
-
-        assert(pWrite->zBuf);
-
-#ifdef TRACE_CRASHTEST
-        printf("Trashing %d sectors @ sector %d (%s)\n", 
-            1+iLast-iFirst, iFirst, pWrite->pFile->zName
-        );
-#endif
-
-        zGarbage = crash_malloc(g.iSectorSize);
-        if( zGarbage ){
-          sqlite3_int64 i;
-          for(i=iFirst; rc==SQLITE_OK && i<=iLast; i++){
-            sqlite3_randomness(g.iSectorSize, zGarbage); 
-            rc = writeDbFile(
-              pWrite->pFile, zGarbage, g.iSectorSize, i*g.iSectorSize
-            );
-          }
-          crash_free(zGarbage);
-        }else{
-          rc = SQLITE_NOMEM;
-        }
-
-        ppPtr = &pWrite->pNext;
-        break;
-      }
-
-      default:
-        assert(!"Cannot happen");
-    }
-
-    if( pWrite==pFinal ) break;
-  }
-
-  if( rc==SQLITE_OK && isCrash ){
-    exit(-1);
-  }
-
-  for(pWrite=g.pWriteList; pWrite && pWrite->pNext; pWrite=pWrite->pNext);
-  g.pWriteListEnd = pWrite;
-
-  return rc;
-}
-
-/*
-** Add an entry to the end of the write-list.
-*/
-static int writeListAppend(
-  sqlite3_file *pFile,
-  sqlite3_int64 iOffset,
-  const u8 *zBuf,
-  int nBuf
-){
-  WriteBuffer *pNew;
-
-  assert((zBuf && nBuf) || (!nBuf && !zBuf));
-
-  pNew = (WriteBuffer *)crash_malloc(sizeof(WriteBuffer) + nBuf);
-  if( pNew==0 ){
-    fprintf(stderr, "out of memory in the crash simulator\n");
-  }
-  memset(pNew, 0, sizeof(WriteBuffer)+nBuf);
-  pNew->iOffset = iOffset;
-  pNew->nBuf = nBuf;
-  pNew->pFile = (CrashFile *)pFile;
-  if( zBuf ){
-    pNew->zBuf = (u8 *)&pNew[1];
-    memcpy(pNew->zBuf, zBuf, nBuf);
-  }
-
-  if( g.pWriteList ){
-    assert(g.pWriteListEnd);
-    g.pWriteListEnd->pNext = pNew;
-  }else{
-    g.pWriteList = pNew;
-  }
-  g.pWriteListEnd = pNew;
-  
-  return SQLITE_OK;
-}
-
-/*
-** Close a crash-file.
-*/
-static int cfClose(sqlite3_file *pFile){
-  CrashFile *pCrash = (CrashFile *)pFile;
-  writeListSync(pCrash, 0);
-  sqlite3OsClose(pCrash->pRealFile);
-  return SQLITE_OK;
-}
-
-/*
-** Read data from a crash-file.
-*/
-static int cfRead(
-  sqlite3_file *pFile, 
-  void *zBuf, 
-  int iAmt, 
-  sqlite_int64 iOfst
-){
-  CrashFile *pCrash = (CrashFile *)pFile;
-
-  /* Check the file-size to see if this is a short-read */
-  if( pCrash->iSize<(iOfst+iAmt) ){
-    return SQLITE_IOERR_SHORT_READ;
-  }
-
-  memcpy(zBuf, &pCrash->zData[iOfst], iAmt);
-  return SQLITE_OK;
-}
-
-/*
-** Write data to a crash-file.
-*/
-static int cfWrite(
-  sqlite3_file *pFile, 
-  const void *zBuf, 
-  int iAmt, 
-  sqlite_int64 iOfst
-){
-  CrashFile *pCrash = (CrashFile *)pFile;
-  if( iAmt+iOfst>pCrash->iSize ){
-    pCrash->iSize = iAmt+iOfst;
-  }
-  while( pCrash->iSize>pCrash->nData ){
-    u8 *zNew;
-    int nNew = (pCrash->nData*2) + 4096;
-    zNew = crash_realloc(pCrash->zData, nNew);
-    if( !zNew ){
-      return SQLITE_NOMEM;
-    }
-    memset(&zNew[pCrash->nData], 0, nNew-pCrash->nData);
-    pCrash->nData = nNew;
-    pCrash->zData = zNew;
-  }
-  memcpy(&pCrash->zData[iOfst], zBuf, iAmt);
-  return writeListAppend(pFile, iOfst, zBuf, iAmt);
-}
-
-/*
-** Truncate a crash-file.
-*/
-static int cfTruncate(sqlite3_file *pFile, sqlite_int64 size){
-  CrashFile *pCrash = (CrashFile *)pFile;
-  assert(size>=0);
-  if( pCrash->iSize>size ){
-    pCrash->iSize = size;
-  }
-  return writeListAppend(pFile, size, 0, 0);
-}
-
-/*
-** Sync a crash-file.
-*/
-static int cfSync(sqlite3_file *pFile, int flags){
-  CrashFile *pCrash = (CrashFile *)pFile;
-  int isCrash = 0;
-
-  const char *zName = pCrash->zName;
-  const char *zCrashFile = g.zCrashFile;
-  int nName = strlen(zName);
-  int nCrashFile = strlen(zCrashFile);
-
-  if( nCrashFile>0 && zCrashFile[nCrashFile-1]=='*' ){
-    nCrashFile--;
-    if( nName>nCrashFile ) nName = nCrashFile;
-  }
-
-  if( nName==nCrashFile && 0==memcmp(zName, zCrashFile, nName) ){
-    if( (--g.iCrash)==0 ) isCrash = 1;
-  }
-
-  return writeListSync(pCrash, isCrash);
-}
-
-/*
-** Return the current file-size of the crash-file.
-*/
-static int cfFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
-  CrashFile *pCrash = (CrashFile *)pFile;
-  *pSize = (i64)pCrash->iSize;
-  return SQLITE_OK;
-}
-
-/*
-** Calls related to file-locks are passed on to the real file handle.
-*/
-static int cfLock(sqlite3_file *pFile, int eLock){
-  return sqlite3OsLock(((CrashFile *)pFile)->pRealFile, eLock);
-}
-static int cfUnlock(sqlite3_file *pFile, int eLock){
-  return sqlite3OsUnlock(((CrashFile *)pFile)->pRealFile, eLock);
-}
-static int cfCheckReservedLock(sqlite3_file *pFile, int *pResOut){
-  return sqlite3OsCheckReservedLock(((CrashFile *)pFile)->pRealFile, pResOut);
-}
-static int cfFileControl(sqlite3_file *pFile, int op, void *pArg){
-  return sqlite3OsFileControl(((CrashFile *)pFile)->pRealFile, op, pArg);
-}
-
-/*
-** The xSectorSize() and xDeviceCharacteristics() functions return
-** the global values configured by the [sqlite_crashparams] tcl
-*  interface.
-*/
-static int cfSectorSize(sqlite3_file *pFile){
-  return g.iSectorSize;
-}
-static int cfDeviceCharacteristics(sqlite3_file *pFile){
-  return g.iDeviceCharacteristics;
-}
-
-static const sqlite3_io_methods CrashFileVtab = {
-  1,                            /* iVersion */
-  cfClose,                      /* xClose */
-  cfRead,                       /* xRead */
-  cfWrite,                      /* xWrite */
-  cfTruncate,                   /* xTruncate */
-  cfSync,                       /* xSync */
-  cfFileSize,                   /* xFileSize */
-  cfLock,                       /* xLock */
-  cfUnlock,                     /* xUnlock */
-  cfCheckReservedLock,          /* xCheckReservedLock */
-  cfFileControl,                /* xFileControl */
-  cfSectorSize,                 /* xSectorSize */
-  cfDeviceCharacteristics       /* xDeviceCharacteristics */
-};
-
-/*
-** Application data for the crash VFS
-*/
-struct crashAppData {
-  sqlite3_vfs *pOrig;                   /* Wrapped vfs structure */
-};
-
-/*
-** Open a crash-file file handle.
-**
-** The caller will have allocated pVfs->szOsFile bytes of space
-** at pFile. This file uses this space for the CrashFile structure
-** and allocates space for the "real" file structure using 
-** sqlite3_malloc(). The assumption here is (pVfs->szOsFile) is
-** equal or greater than sizeof(CrashFile).
-*/
-static int cfOpen(
-  sqlite3_vfs *pCfVfs,
-  const char *zName,
-  sqlite3_file *pFile,
-  int flags,
-  int *pOutFlags
-){
-  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
-  int rc;
-  CrashFile *pWrapper = (CrashFile *)pFile;
-  sqlite3_file *pReal = (sqlite3_file*)&pWrapper[1];
-
-  memset(pWrapper, 0, sizeof(CrashFile));
-  rc = sqlite3OsOpen(pVfs, zName, pReal, flags, pOutFlags);
-
-  if( rc==SQLITE_OK ){
-    i64 iSize;
-    pWrapper->pMethod = &CrashFileVtab;
-    pWrapper->zName = (char *)zName;
-    pWrapper->pRealFile = pReal;
-    rc = sqlite3OsFileSize(pReal, &iSize);
-    pWrapper->iSize = (int)iSize;
-    pWrapper->flags = flags;
-  }
-  if( rc==SQLITE_OK ){
-    pWrapper->nData = (4096 + pWrapper->iSize);
-    pWrapper->zData = crash_malloc(pWrapper->nData);
-    if( pWrapper->zData ){
-      /* os_unix.c contains an assert() that fails if the caller attempts
-      ** to read data from the 512-byte locking region of a file opened
-      ** with the SQLITE_OPEN_MAIN_DB flag. This region of a database file
-      ** never contains valid data anyhow. So avoid doing such a read here.
-      */
-      const int isDb = (flags&SQLITE_OPEN_MAIN_DB);
-      i64 iChunk = pWrapper->iSize;
-      if( iChunk>PENDING_BYTE && isDb ){
-        iChunk = PENDING_BYTE;
-      }
-      memset(pWrapper->zData, 0, pWrapper->nData);
-      rc = sqlite3OsRead(pReal, pWrapper->zData, iChunk, 0); 
-      if( SQLITE_OK==rc && pWrapper->iSize>(PENDING_BYTE+512) && isDb ){
-        i64 iOff = PENDING_BYTE+512;
-        iChunk = pWrapper->iSize - iOff;
-        rc = sqlite3OsRead(pReal, &pWrapper->zData[iOff], iChunk, iOff);
-      }
-    }else{
-      rc = SQLITE_NOMEM;
-    }
-  }
-  if( rc!=SQLITE_OK && pWrapper->pMethod ){
-    sqlite3OsClose(pFile);
-  }
-  return rc;
-}
-
-static int cfDelete(sqlite3_vfs *pCfVfs, const char *zPath, int dirSync){
-  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
-  return pVfs->xDelete(pVfs, zPath, dirSync);
-}
-static int cfAccess(
-  sqlite3_vfs *pCfVfs, 
-  const char *zPath, 
-  int flags, 
-  int *pResOut
-){
-  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
-  return pVfs->xAccess(pVfs, zPath, flags, pResOut);
-}
-static int cfFullPathname(
-  sqlite3_vfs *pCfVfs, 
-  const char *zPath, 
-  int nPathOut,
-  char *zPathOut
-){
-  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
-  return pVfs->xFullPathname(pVfs, zPath, nPathOut, zPathOut);
-}
-static void *cfDlOpen(sqlite3_vfs *pCfVfs, const char *zPath){
-  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
-  return pVfs->xDlOpen(pVfs, zPath);
-}
-static void cfDlError(sqlite3_vfs *pCfVfs, int nByte, char *zErrMsg){
-  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
-  pVfs->xDlError(pVfs, nByte, zErrMsg);
-}
-static void (*cfDlSym(sqlite3_vfs *pCfVfs, void *pH, const char *zSym))(void){
-  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
-  return pVfs->xDlSym(pVfs, pH, zSym);
-}
-static void cfDlClose(sqlite3_vfs *pCfVfs, void *pHandle){
-  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
-  pVfs->xDlClose(pVfs, pHandle);
-}
-static int cfRandomness(sqlite3_vfs *pCfVfs, int nByte, char *zBufOut){
-  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
-  return pVfs->xRandomness(pVfs, nByte, zBufOut);
-}
-static int cfSleep(sqlite3_vfs *pCfVfs, int nMicro){
-  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
-  return pVfs->xSleep(pVfs, nMicro);
-}
-static int cfCurrentTime(sqlite3_vfs *pCfVfs, double *pTimeOut){
-  sqlite3_vfs *pVfs = (sqlite3_vfs *)pCfVfs->pAppData;
-  return pVfs->xCurrentTime(pVfs, pTimeOut);
-}
-
-static int processDevSymArgs(
-  Tcl_Interp *interp,
-  int objc,
-  Tcl_Obj *CONST objv[],
-  int *piDeviceChar,
-  int *piSectorSize
-){
-  struct DeviceFlag {
-    char *zName;
-    int iValue;
-  } aFlag[] = {
-    { "atomic",      SQLITE_IOCAP_ATOMIC      },
-    { "atomic512",   SQLITE_IOCAP_ATOMIC512   },
-    { "atomic1k",    SQLITE_IOCAP_ATOMIC1K    },
-    { "atomic2k",    SQLITE_IOCAP_ATOMIC2K    },
-    { "atomic4k",    SQLITE_IOCAP_ATOMIC4K    },
-    { "atomic8k",    SQLITE_IOCAP_ATOMIC8K    },
-    { "atomic16k",   SQLITE_IOCAP_ATOMIC16K   },
-    { "atomic32k",   SQLITE_IOCAP_ATOMIC32K   },
-    { "atomic64k",   SQLITE_IOCAP_ATOMIC64K   },
-    { "sequential",  SQLITE_IOCAP_SEQUENTIAL  },
-    { "safe_append", SQLITE_IOCAP_SAFE_APPEND },
-    { 0, 0 }
-  };
-
-  int i;
-  int iDc = 0;
-  int iSectorSize = 0;
-  int setSectorsize = 0;
-  int setDeviceChar = 0;
-
-  for(i=0; i<objc; i+=2){
-    int nOpt;
-    char *zOpt = Tcl_GetStringFromObj(objv[i], &nOpt);
-
-    if( (nOpt>11 || nOpt<2 || strncmp("-sectorsize", zOpt, nOpt)) 
-     && (nOpt>16 || nOpt<2 || strncmp("-characteristics", zOpt, nOpt))
-    ){
-      Tcl_AppendResult(interp, 
-        "Bad option: \"", zOpt, 
-        "\" - must be \"-characteristics\" or \"-sectorsize\"", 0
-      );
-      return TCL_ERROR;
-    }
-    if( i==objc-1 ){
-      Tcl_AppendResult(interp, "Option requires an argument: \"", zOpt, "\"",0);
-      return TCL_ERROR;
-    }
-
-    if( zOpt[1]=='s' ){
-      if( Tcl_GetIntFromObj(interp, objv[i+1], &iSectorSize) ){
-        return TCL_ERROR;
-      }
-      setSectorsize = 1;
-    }else{
-      int j;
-      Tcl_Obj **apObj;
-      int nObj;
-      if( Tcl_ListObjGetElements(interp, objv[i+1], &nObj, &apObj) ){
-        return TCL_ERROR;
-      }
-      for(j=0; j<nObj; j++){
-        int rc;
-        int iChoice;
-        Tcl_Obj *pFlag = Tcl_DuplicateObj(apObj[j]);
-        Tcl_IncrRefCount(pFlag);
-        Tcl_UtfToLower(Tcl_GetString(pFlag));
- 
-        rc = Tcl_GetIndexFromObjStruct(
-            interp, pFlag, aFlag, sizeof(aFlag[0]), "no such flag", 0, &iChoice
-        );
-        Tcl_DecrRefCount(pFlag);
-        if( rc ){
-          return TCL_ERROR;
-        }
-
-        iDc |= aFlag[iChoice].iValue;
-      }
-      setDeviceChar = 1;
-    }
-  }
-
-  if( setDeviceChar ){
-    *piDeviceChar = iDc;
-  }
-  if( setSectorsize ){
-    *piSectorSize = iSectorSize;
-  }
-
-  return TCL_OK;
-}
-
-/*
-** tclcmd:   sqlite_crash_enable ENABLE
-**
-** Parameter ENABLE must be a boolean value. If true, then the "crash"
-** vfs is added to the system. If false, it is removed.
-*/
-static int crashEnableCmd(
-  void * clientData,
-  Tcl_Interp *interp,
-  int objc,
-  Tcl_Obj *CONST objv[]
-){
-  int isEnable;
-  static sqlite3_vfs crashVfs = {
-    1,                  /* iVersion */
-    0,                  /* szOsFile */
-    0,                  /* mxPathname */
-    0,                  /* pNext */
-    "crash",            /* zName */
-    0,                  /* pAppData */
-  
-    cfOpen,               /* xOpen */
-    cfDelete,             /* xDelete */
-    cfAccess,             /* xAccess */
-    cfFullPathname,       /* xFullPathname */
-    cfDlOpen,             /* xDlOpen */
-    cfDlError,            /* xDlError */
-    cfDlSym,              /* xDlSym */
-    cfDlClose,            /* xDlClose */
-    cfRandomness,         /* xRandomness */
-    cfSleep,              /* xSleep */
-    cfCurrentTime         /* xCurrentTime */
-  };
-
-  if( objc!=2 ){
-    Tcl_WrongNumArgs(interp, 1, objv, "ENABLE");
-    return TCL_ERROR;
-  }
-
-  if( Tcl_GetBooleanFromObj(interp, objv[1], &isEnable) ){
-    return TCL_ERROR;
-  }
-
-  if( (isEnable && crashVfs.pAppData) || (!isEnable && !crashVfs.pAppData) ){
-    return TCL_OK;
-  }
-
-  if( crashVfs.pAppData==0 ){
-    sqlite3_vfs *pOriginalVfs = sqlite3_vfs_find(0);
-    crashVfs.mxPathname = pOriginalVfs->mxPathname;
-    crashVfs.pAppData = (void *)pOriginalVfs;
-    crashVfs.szOsFile = sizeof(CrashFile) + pOriginalVfs->szOsFile;
-    sqlite3_vfs_register(&crashVfs, 0);
-  }else{
-    crashVfs.pAppData = 0;
-    sqlite3_vfs_unregister(&crashVfs);
-  }
-
-  return TCL_OK;
-}
-
-/*
-** tclcmd:   sqlite_crashparams ?OPTIONS? DELAY CRASHFILE
-**
-** This procedure implements a TCL command that enables crash testing
-** in testfixture.  Once enabled, crash testing cannot be disabled.
-**
-** Available options are "-characteristics" and "-sectorsize". Both require
-** an argument. For -sectorsize, this is the simulated sector size in
-** bytes. For -characteristics, the argument must be a list of io-capability
-** flags to simulate. Valid flags are "atomic", "atomic512", "atomic1K",
-** "atomic2K", "atomic4K", "atomic8K", "atomic16K", "atomic32K", 
-** "atomic64K", "sequential" and "safe_append".
-**
-** Example:
-**
-**   sqlite_crashparams -sect 1024 -char {atomic sequential} ./test.db 1
-**
-*/
-static int crashParamsObjCmd(
-  void * clientData,
-  Tcl_Interp *interp,
-  int objc,
-  Tcl_Obj *CONST objv[]
-){
-  int iDelay;
-  const char *zCrashFile;
-  int nCrashFile, iDc, iSectorSize;
-
-  iDc = -1;
-  iSectorSize = -1;
-
-  if( objc<3 ){
-    Tcl_WrongNumArgs(interp, 1, objv, "?OPTIONS? DELAY CRASHFILE");
-    goto error;
-  }
-
-  zCrashFile = Tcl_GetStringFromObj(objv[objc-1], &nCrashFile);
-  if( nCrashFile>=sizeof(g.zCrashFile) ){
-    Tcl_AppendResult(interp, "Filename is too long: \"", zCrashFile, "\"", 0);
-    goto error;
-  }
-  if( Tcl_GetIntFromObj(interp, objv[objc-2], &iDelay) ){
-    goto error;
-  }
-
-  if( processDevSymArgs(interp, objc-3, &objv[1], &iDc, &iSectorSize) ){
-    return TCL_ERROR;
-  }
-
-  if( iDc>=0 ){
-    g.iDeviceCharacteristics = iDc;
-  }
-  if( iSectorSize>=0 ){
-    g.iSectorSize = iSectorSize;
-  }
-
-  g.iCrash = iDelay;
-  memcpy(g.zCrashFile, zCrashFile, nCrashFile+1);
-  sqlite3CrashTestEnable = 1;
-  return TCL_OK;
-
-error:
-  return TCL_ERROR;
-}
-
-static int devSymObjCmd(
-  void * clientData,
-  Tcl_Interp *interp,
-  int objc,
-  Tcl_Obj *CONST objv[]
-){
-  void devsym_register(int iDeviceChar, int iSectorSize);
-
-  int iDc = -1;
-  int iSectorSize = -1;
-
-  if( processDevSymArgs(interp, objc-1, &objv[1], &iDc, &iSectorSize) ){
-    return TCL_ERROR;
-  }
-  devsym_register(iDc, iSectorSize);
-
-  return TCL_OK;
-}
-
-/*
-** tclcmd: register_jt_vfs ?-default? PARENT-VFS
-*/
-static int jtObjCmd(
-  void * clientData,
-  Tcl_Interp *interp,
-  int objc,
-  Tcl_Obj *CONST objv[]
-){
-  int jt_register(char *, int);
-  char *zParent = 0;
-
-  if( objc!=2 && objc!=3 ){
-    Tcl_WrongNumArgs(interp, 1, objv, "?-default? PARENT-VFS");
-    return TCL_ERROR;
-  }
-  zParent = Tcl_GetString(objv[1]);
-  if( objc==3 ){
-    if( strcmp(zParent, "-default") ){
-      Tcl_AppendResult(interp, 
-          "bad option \"", zParent, "\": must be -default", 0
-      );
-      return TCL_ERROR;
-    }
-    zParent = Tcl_GetString(objv[2]);
-  }
-
-  if( !(*zParent) ){
-    zParent = 0;
-  }
-  if( jt_register(zParent, objc==3) ){
-    Tcl_AppendResult(interp, "Error in jt_register", 0);
-    return TCL_ERROR;
-  }
-
-  return TCL_OK;
-}
-
-/*
-** tclcmd: unregister_jt_vfs
-*/
-static int jtUnregisterObjCmd(
-  void * clientData,
-  Tcl_Interp *interp,
-  int objc,
-  Tcl_Obj *CONST objv[]
-){
-  void jt_unregister(void);
-
-  if( objc!=1 ){
-    Tcl_WrongNumArgs(interp, 1, objv, "");
-    return TCL_ERROR;
-  }
-
-  jt_unregister();
-  return TCL_OK;
-}
-
-#endif /* SQLITE_OMIT_DISKIO */
-
-/*
-** This procedure registers the TCL procedures defined in this file.
-*/
-int Sqlitetest6_Init(Tcl_Interp *interp){
-#ifndef SQLITE_OMIT_DISKIO
-  Tcl_CreateObjCommand(interp, "sqlite3_crash_enable", crashEnableCmd, 0, 0);
-  Tcl_CreateObjCommand(interp, "sqlite3_crashparams", crashParamsObjCmd, 0, 0);
-  Tcl_CreateObjCommand(interp, "sqlite3_simulate_device", devSymObjCmd, 0, 0);
-  Tcl_CreateObjCommand(interp, "register_jt_vfs", jtObjCmd, 0, 0);
-  Tcl_CreateObjCommand(interp, "unregister_jt_vfs", jtUnregisterObjCmd, 0, 0);
-#endif
-  return TCL_OK;
-}
-
-#endif /* SQLITE_TEST */