}

  f.h = hf;
  f.locktype = NO_LOCK;
  f.delOnClose = delFlag ? 1 : 0;
  f.pathToDel = delFlag ? sqlite3OsFullPathname( zFilename ) : NULL;
  OpenCounter( +1 );
  if( delFlag ) DosForceDelete( sqlite3OsFullPathname( zFilename ) );
  OSTRACE3( "OPEN EX %d \"%s\"\n", hf, sqlite3OsFullPathname ( zFilename ) );
  return allocateOs2File( &f, pld );
}

/*
** Attempt to open a new file for read-only access.
**
................................................................................
int sqlite3Os2TempFileName( char *zBuf ){
  static const unsigned char zChars[] =
    "abcdefghijklmnopqrstuvwxyz"
    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    "0123456789";
  int i, j;
  PSZ zTempPath = 0;
  if( DosScanEnv( "TEMP", &zTempPath ) ){
    if( DosScanEnv( "TMP", &zTempPath ) ){
      if( DosScanEnv( "TMPDIR", &zTempPath ) ){
           ULONG ulDriveNum = 0, ulDriveMap = 0;
           DosQueryCurrentDisk( &ulDriveNum, &ulDriveMap );
           sprintf( zTempPath, "%c:", (char)( 'A' + ulDriveNum - 1 ) );
      }
    }
  }
  for(;;){
      sprintf( zBuf, "%s\\"TEMP_FILE_PREFIX, zTempPath );
      j = strlen( zBuf );
      sqlite3Randomness( 15, &zBuf[j] );
................................................................................
  os2File *pFile;
  APIRET rc = NO_ERROR;
  if( pld && (pFile = (os2File*)*pld) != 0 ){
    OSTRACE2( "CLOSE %d\n", pFile->h );
    rc = DosClose( pFile->h );
    pFile->locktype = NO_LOCK;
    if( pFile->delOnClose != 0 ){
        rc = DosForceDelete( pFile->pathToDel );
    }
    *pld = 0;
    OpenCounter( -1 );
  }

  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
}
................................................................................
  ULONG got;
  assert( id!=0 );
  SimulateIOError( return SQLITE_IOERR );
  OSTRACE3( "READ %d lock=%d\n", ((os2File*)id)->h, ((os2File*)id)->locktype );
  DosRead( ((os2File*)id)->h, pBuf, amt, &got );
  if (got == (ULONG)amt)
    return SQLITE_OK;
  else if (got < 0)
    return SQLITE_IOERR_READ;
  else {
    memset(&((char*)pBuf)[got], 0, amt-got);
    return SQLITE_IOERR_SHORT_READ;
  }
}

................................................................................
    ULONG cbzBufLen = SQLITE_TEMPNAME_SIZE;
    char zDrive[2];
    char *zBuff;

    zBuff = sqliteMalloc( cbzBufLen );
    if( zBuff != 0 ){
      DosQueryCurrentDisk( &ulDriveNum, &ulDriveMap );
      if( DosQueryCurrentDir( ulDriveNum, zBuff, &cbzBufLen ) == NO_ERROR ){
        sprintf( zDrive, "%c", (char)('A' + ulDriveNum - 1) );
        sqlite3SetString( &zFull, zDrive, ":\\", zBuff,
                          "\\", zRelative, (char*)0 );
      }
      sqliteFree( zBuff );
    }
  }
................................................................................
** Interfaces for opening a shared library, finding entry points
** within the shared library, and closing the shared library.
*/
void *sqlite3Os2Dlopen(const char *zFilename){
  UCHAR loadErr[256];
  HMODULE hmod;
  APIRET rc;
  rc = DosLoadModule(loadErr, sizeof(loadErr), zFilename, &hmod);
  if (rc != NO_ERROR) return 0;
  return (void*)hmod;
}
void *sqlite3Os2Dlsym(void *pHandle, const char *zSymbol){
  PFN pfn;
  APIRET rc;
  rc = DosQueryProcAddr((HMODULE)pHandle, 0L, zSymbol, &pfn);
................................................................................
     * symbol with an extra underscore, that might be needed depending
     * on the calling convention */
    char _zSymbol[256] = "_";
    strncat(_zSymbol, zSymbol, 255);
    rc = DosQueryProcAddr((HMODULE)pHandle, 0L, _zSymbol, &pfn);
  }
  if (rc != NO_ERROR) return 0;
  return pfn;
}
int sqlite3Os2Dlclose(void *pHandle){
  return DosFreeModule((HMODULE)pHandle);
}
#endif /* SQLITE_OMIT_LOAD_EXTENSION */


................................................................................
** multi-threaded processes.  Only a single thread is allowed to
** executed code that is surrounded by EnterMutex() and LeaveMutex().
**
** SQLite uses only a single Mutex.  There is not much critical
** code and what little there is executes quickly and without blocking.
*/
void sqlite3Os2EnterMutex(){
  PTIB ptib;
#ifdef SQLITE_OS2_THREADS

  DosEnterCritSec();
  DosGetInfoBlocks( &ptib, NULL );
  mutexOwner = ptib->tib_ptib2->tib2_ultid;
#endif
  assert( !inMutex );
  inMutex = 1;
}
void sqlite3Os2LeaveMutex(){

  PTIB ptib;

  assert( inMutex );
  inMutex = 0;
#ifdef SQLITE_OS2_THREADS
  DosGetInfoBlocks( &ptib, NULL );
  assert( mutexOwner == ptib->tib_ptib2->tib2_ultid );
  DosExitCritSec();
#endif

  }

  f.h = hf;
  f.locktype = NO_LOCK;
  f.delOnClose = delFlag ? 1 : 0;
  f.pathToDel = delFlag ? sqlite3OsFullPathname( zFilename ) : NULL;
  OpenCounter( +1 );
  if( delFlag ) DosForceDelete( (PSZ)sqlite3OsFullPathname( zFilename ) );
  OSTRACE3( "OPEN EX %d \"%s\"\n", hf, sqlite3OsFullPathname ( zFilename ) );
  return allocateOs2File( &f, pld );
}

/*
** Attempt to open a new file for read-only access.
**
................................................................................
int sqlite3Os2TempFileName( char *zBuf ){
  static const unsigned char zChars[] =
    "abcdefghijklmnopqrstuvwxyz"
    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    "0123456789";
  int i, j;
  PSZ zTempPath = 0;
  if( DosScanEnv( (PSZ)"TEMP", &zTempPath ) ){
    if( DosScanEnv( (PSZ)"TMP", &zTempPath ) ){
      if( DosScanEnv( (PSZ)"TMPDIR", &zTempPath ) ){
           ULONG ulDriveNum = 0, ulDriveMap = 0;
           DosQueryCurrentDisk( &ulDriveNum, &ulDriveMap );
           sprintf( (char*)zTempPath, "%c:", (char)( 'A' + ulDriveNum - 1 ) );
      }
    }
  }
  for(;;){
      sprintf( zBuf, "%s\\"TEMP_FILE_PREFIX, zTempPath );
      j = strlen( zBuf );
      sqlite3Randomness( 15, &zBuf[j] );
................................................................................
  os2File *pFile;
  APIRET rc = NO_ERROR;
  if( pld && (pFile = (os2File*)*pld) != 0 ){
    OSTRACE2( "CLOSE %d\n", pFile->h );
    rc = DosClose( pFile->h );
    pFile->locktype = NO_LOCK;
    if( pFile->delOnClose != 0 ){
        rc = DosForceDelete( (PSZ)pFile->pathToDel );
    }
    *pld = 0;
    OpenCounter( -1 );
  }

  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
}
................................................................................
  ULONG got;
  assert( id!=0 );
  SimulateIOError( return SQLITE_IOERR );
  OSTRACE3( "READ %d lock=%d\n", ((os2File*)id)->h, ((os2File*)id)->locktype );
  DosRead( ((os2File*)id)->h, pBuf, amt, &got );
  if (got == (ULONG)amt)
    return SQLITE_OK;
  else if (got == 0)
    return SQLITE_IOERR_READ;
  else {
    memset(&((char*)pBuf)[got], 0, amt-got);
    return SQLITE_IOERR_SHORT_READ;
  }
}

................................................................................
    ULONG cbzBufLen = SQLITE_TEMPNAME_SIZE;
    char zDrive[2];
    char *zBuff;

    zBuff = sqliteMalloc( cbzBufLen );
    if( zBuff != 0 ){
      DosQueryCurrentDisk( &ulDriveNum, &ulDriveMap );
      if( DosQueryCurrentDir( ulDriveNum, (PBYTE)zBuff, &cbzBufLen ) == NO_ERROR ){
        sprintf( zDrive, "%c", (char)('A' + ulDriveNum - 1) );
        sqlite3SetString( &zFull, zDrive, ":\\", zBuff,
                          "\\", zRelative, (char*)0 );
      }
      sqliteFree( zBuff );
    }
  }
................................................................................
** Interfaces for opening a shared library, finding entry points
** within the shared library, and closing the shared library.
*/
void *sqlite3Os2Dlopen(const char *zFilename){
  UCHAR loadErr[256];
  HMODULE hmod;
  APIRET rc;
  rc = DosLoadModule((PSZ)loadErr, sizeof(loadErr), zFilename, &hmod);
  if (rc != NO_ERROR) return 0;
  return (void*)hmod;
}
void *sqlite3Os2Dlsym(void *pHandle, const char *zSymbol){
  PFN pfn;
  APIRET rc;
  rc = DosQueryProcAddr((HMODULE)pHandle, 0L, zSymbol, &pfn);
................................................................................
     * symbol with an extra underscore, that might be needed depending
     * on the calling convention */
    char _zSymbol[256] = "_";
    strncat(_zSymbol, zSymbol, 255);
    rc = DosQueryProcAddr((HMODULE)pHandle, 0L, _zSymbol, &pfn);
  }
  if (rc != NO_ERROR) return 0;
  return (void *)pfn;
}
int sqlite3Os2Dlclose(void *pHandle){
  return DosFreeModule((HMODULE)pHandle);
}
#endif /* SQLITE_OMIT_LOAD_EXTENSION */


................................................................................
** multi-threaded processes.  Only a single thread is allowed to
** executed code that is surrounded by EnterMutex() and LeaveMutex().
**
** SQLite uses only a single Mutex.  There is not much critical
** code and what little there is executes quickly and without blocking.
*/
void sqlite3Os2EnterMutex(){

#ifdef SQLITE_OS2_THREADS
  PTIB ptib;
  DosEnterCritSec();
  DosGetInfoBlocks( &ptib, NULL );
  mutexOwner = ptib->tib_ptib2->tib2_ultid;
#endif
  assert( !inMutex );
  inMutex = 1;
}
void sqlite3Os2LeaveMutex(){
#ifdef SQLITE_OS2_THREADS
  PTIB ptib;
#endif
  assert( inMutex );
  inMutex = 0;
#ifdef SQLITE_OS2_THREADS
  DosGetInfoBlocks( &ptib, NULL );
  assert( mutexOwner == ptib->tib_ptib2->tib2_ultid );
  DosExitCritSec();
#endif