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Overview
Comment:Finally bring OS/2 to the 3.5 level. This at least is a first draft version that survives very basic tests. It still contains a lot of debugging stuff... (CVS 4500)
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 46b2d1034b3d25ded71085c901301ad64b5aaba2
User & Date: pweilbacher 2007-10-21 22:47:03
Context
2007-10-21
22:59
We need an extra define to activate OS/2 semaphores for compiling/linking. (CVS 4501) check-in: 0604dace user: pweilbacher tags: trunk
22:47
Finally bring OS/2 to the 3.5 level. This at least is a first draft version that survives very basic tests. It still contains a lot of debugging stuff... (CVS 4500) check-in: 46b2d103 user: pweilbacher tags: trunk
2007-10-20
20:58
Use the 2-argument version of substr() in the SQL contained in the VACUUM and ALTER TABLE commands. Ticket #2737. (CVS 4499) check-in: 82b08a3d user: drh tags: trunk
Changes
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** This file contains code that is specific to OS/2.
*/

#include "sqliteInt.h"

#if OS_OS2

/*


























** Macros used to determine whether or not to use threads.
*/
#if defined(THREADSAFE) && THREADSAFE

# define SQLITE_OS2_THREADS 1
#endif

/*
** Include code that is common to all os_*.c files
*/
#include "os_common.h"

/*
** The os2File structure is subclass of OsFile specific for the OS/2
** protability layer.
*/
typedef struct os2File os2File;
struct os2File {
  IoMethod const *pMethod;  /* Always the first entry */
  HFILE h;                  /* Handle for accessing the file */
  int delOnClose;           /* True if file is to be deleted on close */
  char* pathToDel;          /* Name of file to delete on close */
  unsigned char locktype;   /* Type of lock currently held on this file */
};

/*
** Do not include any of the File I/O interface procedures if the
** SQLITE_OMIT_DISKIO macro is defined (indicating that there database
** will be in-memory only)
*/
#ifndef SQLITE_OMIT_DISKIO

/*
** Delete the named file
*/
int sqlite3Os2Delete( const char *zFilename ){
  APIRET rc = NO_ERROR;

  rc = DosDelete( (PSZ)zFilename );
  OSTRACE2( "DELETE \"%s\"\n", zFilename );
  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
}

/*
** Return TRUE if the named file exists.
*/
int sqlite3Os2FileExists( const char *zFilename ){
  FILESTATUS3 fsts3ConfigInfo;
  memset(&fsts3ConfigInfo, 0, sizeof(fsts3ConfigInfo));
  return DosQueryPathInfo( (PSZ)zFilename, FIL_STANDARD,
        &fsts3ConfigInfo, sizeof(FILESTATUS3) ) == NO_ERROR;
}

/* Forward declaration */
int allocateOs2File( os2File *pInit, OsFile **pld );

/*
** Attempt to open a file for both reading and writing.  If that
** fails, try opening it read-only.  If the file does not exist,
** try to create it.
**
** On success, a handle for the open file is written to *id
** and *pReadonly is set to 0 if the file was opened for reading and
** writing or 1 if the file was opened read-only.  The function returns
** SQLITE_OK.
**
** On failure, the function returns SQLITE_CANTOPEN and leaves
** *id and *pReadonly unchanged.
*/
int sqlite3Os2OpenReadWrite(
  const char *zFilename,
  OsFile **pld,
  int *pReadonly
){
  os2File  f;
  HFILE    hf;
  ULONG    ulAction;
  APIRET   rc = NO_ERROR;

  assert( *pld == 0 );
  rc = DosOpen( (PSZ)zFilename, &hf, &ulAction, 0L,
            FILE_ARCHIVED | FILE_NORMAL,
                OPEN_ACTION_CREATE_IF_NEW | OPEN_ACTION_OPEN_IF_EXISTS,
                OPEN_FLAGS_FAIL_ON_ERROR | OPEN_FLAGS_RANDOM |
                    OPEN_SHARE_DENYNONE | OPEN_ACCESS_READWRITE, (PEAOP2)NULL );
  if( rc != NO_ERROR ){
    rc = DosOpen( (PSZ)zFilename, &hf, &ulAction, 0L,
            FILE_ARCHIVED | FILE_NORMAL,
                OPEN_ACTION_CREATE_IF_NEW | OPEN_ACTION_OPEN_IF_EXISTS,
                OPEN_FLAGS_FAIL_ON_ERROR | OPEN_FLAGS_RANDOM |
                        OPEN_SHARE_DENYWRITE | OPEN_ACCESS_READONLY, (PEAOP2)NULL );
    if( rc != NO_ERROR ){
        return SQLITE_CANTOPEN;
    }
    *pReadonly = 1;
  }
  else{
    *pReadonly = 0;
  }
  f.h = hf;
  f.locktype = NO_LOCK;
  f.delOnClose = 0;
  f.pathToDel = NULL;
  OpenCounter(+1);
  OSTRACE3( "OPEN R/W %d \"%s\"\n", hf, zFilename );
  return allocateOs2File( &f, pld );
}


/*
** Attempt to open a new file for exclusive access by this process.
** The file will be opened for both reading and writing.  To avoid
** a potential security problem, we do not allow the file to have
** previously existed.  Nor do we allow the file to be a symbolic
** link.
**
** If delFlag is true, then make arrangements to automatically delete
** the file when it is closed.
**
** On success, write the file handle into *id and return SQLITE_OK.
**
** On failure, return SQLITE_CANTOPEN.
*/
int sqlite3Os2OpenExclusive( const char *zFilename, OsFile **pld, int delFlag ){
  os2File  f;
  HFILE    hf;
  ULONG    ulAction;
  APIRET   rc = NO_ERROR;

  assert( *pld == 0 );
  rc = DosOpen( (PSZ)zFilename, &hf, &ulAction, 0L, FILE_NORMAL,
            OPEN_ACTION_CREATE_IF_NEW | OPEN_ACTION_REPLACE_IF_EXISTS,
            OPEN_FLAGS_FAIL_ON_ERROR | OPEN_FLAGS_RANDOM |
                OPEN_SHARE_DENYREADWRITE | OPEN_ACCESS_READWRITE, (PEAOP2)NULL );
  if( rc != NO_ERROR ){
    return SQLITE_CANTOPEN;
  }

  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.
**
** On success, write the file handle into *id and return SQLITE_OK.
**
** On failure, return SQLITE_CANTOPEN.
*/
int sqlite3Os2OpenReadOnly( const char *zFilename, OsFile **pld ){
  os2File  f;
  HFILE    hf;
  ULONG    ulAction;
  APIRET   rc = NO_ERROR;

  assert( *pld == 0 );
  rc = DosOpen( (PSZ)zFilename, &hf, &ulAction, 0L,
            FILE_NORMAL, OPEN_ACTION_OPEN_IF_EXISTS,
            OPEN_FLAGS_FAIL_ON_ERROR | OPEN_FLAGS_RANDOM |
                OPEN_SHARE_DENYWRITE | OPEN_ACCESS_READONLY, (PEAOP2)NULL );
  if( rc != NO_ERROR ){
    return SQLITE_CANTOPEN;
  }
  f.h = hf;
  f.locktype = NO_LOCK;
  f.delOnClose = 0;
  f.pathToDel = NULL;
  OpenCounter( +1 );
  OSTRACE3( "OPEN RO %d \"%s\"\n", hf, zFilename );
  return allocateOs2File( &f, pld );
}

/*
** Attempt to open a file descriptor for the directory that contains a
** file.  This file descriptor can be used to fsync() the directory
** in order to make sure the creation of a new file is actually written
** to disk.
**
** This routine is only meaningful for Unix.  It is a no-op under
** OS/2 since OS/2 does not support hard links.
**
** On success, a handle for a previously open file is at *id is
** updated with the new directory file descriptor and SQLITE_OK is
** returned.
**
** On failure, the function returns SQLITE_CANTOPEN and leaves
** *id unchanged.
*/
int os2OpenDirectory(
  OsFile *id,
  const char *zDirname
){
  return SQLITE_OK;
}

/*
** Create a temporary file name in zBuf.  zBuf must be big enough to
** hold at least SQLITE_TEMPNAME_SIZE characters.
*/
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 ) );
      }
    }
  }
  /* strip off a trailing slashes or backslashes, otherwise we would get *
   * multiple (back)slashes which causes DosOpen() to fail               */
  j = strlen(zTempPath);
  while( j > 0 && zTempPath[j-1] == '\\' || zTempPath[j-1] == '/' ){
      j--;
  }
  zTempPath[j] = '\0';
  for(;;){
      sprintf( zBuf, "%s\\"TEMP_FILE_PREFIX, zTempPath );
      j = strlen( zBuf );
      sqlite3Randomness( 15, &zBuf[j] );
      for( i = 0; i < 15; i++, j++ ){
        zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
      }
      zBuf[j] = 0;
      if( !sqlite3OsFileExists( zBuf ) ) break;
  }
  OSTRACE2( "TEMP FILENAME: %s\n", zBuf );
  return SQLITE_OK;
}

/*
** Close a file.
*/
int os2Close( OsFile **pld ){
  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;
}

/*
** Read data from a file into a buffer.  Return SQLITE_OK if all
** bytes were read successfully and SQLITE_IOERR if anything goes
** wrong.
*/
int os2Read( OsFile *id, void *pBuf, int amt ){






  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;
  }
}

/*
** Write data from a buffer into a file.  Return SQLITE_OK on success
** or some other error code on failure.
*/
int os2Write( OsFile *id, const void *pBuf, int amt ){






  APIRET rc = NO_ERROR;
  ULONG wrote;

  assert( id!=0 );
  SimulateIOError( return SQLITE_IOERR );
  SimulateDiskfullError( return SQLITE_FULL );
  OSTRACE3( "WRITE %d lock=%d\n", ((os2File*)id)->h, ((os2File*)id)->locktype );




  while( amt > 0 &&
      (rc = DosWrite( ((os2File*)id)->h, (PVOID)pBuf, amt, &wrote )) && wrote > 0 ){


      amt -= wrote;
      pBuf = &((char*)pBuf)[wrote];
  }

  return ( rc != NO_ERROR || amt > (int)wrote ) ? SQLITE_FULL : SQLITE_OK;
}

/*
** Move the read/write pointer in a file.
*/
int os2Seek( OsFile *id, i64 offset ){
  APIRET rc = NO_ERROR;
  ULONG filePointer = 0L;
  assert( id!=0 );
  rc = DosSetFilePtr( ((os2File*)id)->h, offset, FILE_BEGIN, &filePointer );
  OSTRACE3( "SEEK %d %lld\n", ((os2File*)id)->h, offset );
  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
}

/*
** Make sure all writes to a particular file are committed to disk.
*/
int os2Sync( OsFile *id, int dataOnly ){
  assert( id!=0 );
  OSTRACE3( "SYNC %d lock=%d\n", ((os2File*)id)->h, ((os2File*)id)->locktype );
  return DosResetBuffer( ((os2File*)id)->h ) == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
}

/*
** Sync the directory zDirname. This is a no-op on operating systems other
** than UNIX.
*/
int sqlite3Os2SyncDirectory( const char *zDirname ){
  SimulateIOError( return SQLITE_IOERR );
  return SQLITE_OK;
}

/*
** Truncate an open file to a specified size
*/
int os2Truncate( OsFile *id, i64 nByte ){
  APIRET rc = NO_ERROR;
  ULONG upperBits = nByte>>32;
  assert( id!=0 );
  OSTRACE3( "TRUNCATE %d %lld\n", ((os2File*)id)->h, nByte );
  SimulateIOError( return SQLITE_IOERR );
  rc = DosSetFilePtr( ((os2File*)id)->h, nByte, FILE_BEGIN, &upperBits );
  if( rc != NO_ERROR ){
    return SQLITE_IOERR;
  }
  rc = DosSetFilePtr( ((os2File*)id)->h, 0L, FILE_END, &upperBits );
  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
}

/*
** Determine the current size of a file in bytes
*/
int os2FileSize( OsFile *id, i64 *pSize ){
  APIRET rc = NO_ERROR;
  FILESTATUS3 fsts3FileInfo;
  memset(&fsts3FileInfo, 0, sizeof(fsts3FileInfo));
  assert( id!=0 );
  SimulateIOError( return SQLITE_IOERR );
  rc = DosQueryFileInfo( ((os2File*)id)->h, FIL_STANDARD, &fsts3FileInfo, sizeof(FILESTATUS3) );
  if( rc == NO_ERROR ){
    *pSize = fsts3FileInfo.cbFile;
    return SQLITE_OK;
  }
  else{
    return SQLITE_IOERR;
  }
}

/*
** Acquire a reader lock.
*/
static int getReadLock( os2File *id ){
  FILELOCK  LockArea,
            UnlockArea;

  memset(&LockArea, 0, sizeof(LockArea));
  memset(&UnlockArea, 0, sizeof(UnlockArea));
  LockArea.lOffset = SHARED_FIRST;
  LockArea.lRange = SHARED_SIZE;
  UnlockArea.lOffset = 0L;
  UnlockArea.lRange = 0L;
  return DosSetFileLocks( id->h, &UnlockArea, &LockArea, 2000L, 1L );


}

/*
** Undo a readlock
*/
static int unlockReadLock( os2File *id ){
  FILELOCK  LockArea,
            UnlockArea;

  memset(&LockArea, 0, sizeof(LockArea));
  memset(&UnlockArea, 0, sizeof(UnlockArea));
  LockArea.lOffset = 0L;
  LockArea.lRange = 0L;
  UnlockArea.lOffset = SHARED_FIRST;
  UnlockArea.lRange = SHARED_SIZE;
  return DosSetFileLocks( id->h, &UnlockArea, &LockArea, 2000L, 1L );
}

#ifndef SQLITE_OMIT_PAGER_PRAGMAS
/*
** Check that a given pathname is a directory and is writable
**
*/
int sqlite3Os2IsDirWritable( char *zDirname ){
  FILESTATUS3 fsts3ConfigInfo;
  APIRET rc = NO_ERROR;
  memset(&fsts3ConfigInfo, 0, sizeof(fsts3ConfigInfo));
  if( zDirname==0 ) return 0;
  if( strlen(zDirname)>CCHMAXPATH ) return 0;
  rc = DosQueryPathInfo( (PSZ)zDirname, FIL_STANDARD, &fsts3ConfigInfo, sizeof(FILESTATUS3) );
  if( rc != NO_ERROR ) return 0;
  if( (fsts3ConfigInfo.attrFile & FILE_DIRECTORY) != FILE_DIRECTORY ) return 0;


  return 1;
}
#endif /* SQLITE_OMIT_PAGER_PRAGMAS */

/*
** Lock the file with the lock specified by parameter locktype - one
** of the following:
**
**     (1) SHARED_LOCK
**     (2) RESERVED_LOCK
**     (3) PENDING_LOCK
................................................................................
**    PENDING -> EXCLUSIVE
**
** This routine will only increase a lock.  The os2Unlock() routine
** erases all locks at once and returns us immediately to locking level 0.
** It is not possible to lower the locking level one step at a time.  You
** must go straight to locking level 0.
*/
int os2Lock( OsFile *id, int locktype ){
  APIRET rc = SQLITE_OK;    /* Return code from subroutines */
  APIRET res = NO_ERROR;    /* Result of an OS/2 lock call */
  int newLocktype;       /* Set id->locktype to this value before exiting */
  int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */
  FILELOCK  LockArea,
            UnlockArea;
  os2File *pFile = (os2File*)id;
  memset(&LockArea, 0, sizeof(LockArea));
  memset(&UnlockArea, 0, sizeof(UnlockArea));
  assert( pFile!=0 );
  OSTRACE4( "LOCK %d %d was %d\n", pFile->h, locktype, pFile->locktype );

  /* If there is already a lock of this type or more restrictive on the
  ** OsFile, do nothing. Don't use the end_lock: exit path, as
  ** sqlite3OsEnterMutex() hasn't been called yet.
  */
  if( pFile->locktype>=locktype ){

    return SQLITE_OK;
  }

  /* Make sure the locking sequence is correct
  */
  assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
  assert( locktype!=PENDING_LOCK );
................................................................................

  /* Lock the PENDING_LOCK byte if we need to acquire a PENDING lock or
  ** a SHARED lock.  If we are acquiring a SHARED lock, the acquisition of
  ** the PENDING_LOCK byte is temporary.
  */
  newLocktype = pFile->locktype;
  if( pFile->locktype==NO_LOCK
   || (locktype==EXCLUSIVE_LOCK && pFile->locktype==RESERVED_LOCK)
  ){
    int cnt = 3;

    LockArea.lOffset = PENDING_BYTE;
    LockArea.lRange = 1L;
    UnlockArea.lOffset = 0L;
    UnlockArea.lRange = 0L;

    while( cnt-->0 && (res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L) )!=NO_ERROR ){


      /* Try 3 times to get the pending lock.  The pending lock might be
      ** held by another reader process who will release it momentarily.
      */
      OSTRACE2( "could not get a PENDING lock. cnt=%d\n", cnt );
      DosSleep(1);
    }

    gotPendingLock = res;


  }

  /* Acquire a shared lock
  */
  if( locktype==SHARED_LOCK && res ){
    assert( pFile->locktype==NO_LOCK );
    res = getReadLock(pFile);
    if( res == NO_ERROR ){
      newLocktype = SHARED_LOCK;
    }

  }

  /* Acquire a RESERVED lock
  */
  if( locktype==RESERVED_LOCK && res ){
    assert( pFile->locktype==SHARED_LOCK );
    LockArea.lOffset = RESERVED_BYTE;
    LockArea.lRange = 1L;
    UnlockArea.lOffset = 0L;
    UnlockArea.lRange = 0L;
    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    if( res == NO_ERROR ){
      newLocktype = RESERVED_LOCK;
    }

  }

  /* Acquire a PENDING lock
  */
  if( locktype==EXCLUSIVE_LOCK && res ){
    newLocktype = PENDING_LOCK;
    gotPendingLock = 0;

  }

  /* Acquire an EXCLUSIVE lock
  */
  if( locktype==EXCLUSIVE_LOCK && res ){
    assert( pFile->locktype>=SHARED_LOCK );
    res = unlockReadLock(pFile);
    OSTRACE2( "unreadlock = %d\n", res );
    LockArea.lOffset = SHARED_FIRST;
    LockArea.lRange = SHARED_SIZE;
    UnlockArea.lOffset = 0L;
    UnlockArea.lRange = 0L;
    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    if( res == NO_ERROR ){
      newLocktype = EXCLUSIVE_LOCK;
    }else{
      OSTRACE2( "error-code = %d\n", res );

    }

  }

  /* If we are holding a PENDING lock that ought to be released, then
  ** release it now.
  */
  if( gotPendingLock && locktype==SHARED_LOCK ){

    LockArea.lOffset = 0L;
    LockArea.lRange = 0L;
    UnlockArea.lOffset = PENDING_BYTE;
    UnlockArea.lRange = 1L;
    DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );

  }

  /* Update the state of the lock has held in the file descriptor then
  ** return the appropriate result code.
  */
  if( res == NO_ERROR ){
    rc = SQLITE_OK;
  }else{
    OSTRACE4( "LOCK FAILED %d trying for %d but got %d\n", pFile->h,
           locktype, newLocktype );
    rc = SQLITE_BUSY;
  }
  pFile->locktype = newLocktype;

  return rc;
}

/*
** This routine checks if there is a RESERVED lock held on the specified
** file by this or any other process. If such a lock is held, return
** non-zero, otherwise zero.
*/
int os2CheckReservedLock( OsFile *id ){
  APIRET rc = NO_ERROR;
  os2File *pFile = (os2File*)id;
  assert( pFile!=0 );
  if( pFile->locktype>=RESERVED_LOCK ){
    rc = 1;
    OSTRACE3( "TEST WR-LOCK %d %d (local)\n", pFile->h, rc );
  }else{
................................................................................
    memset(&LockArea, 0, sizeof(LockArea));
    memset(&UnlockArea, 0, sizeof(UnlockArea));
    LockArea.lOffset = RESERVED_BYTE;
    LockArea.lRange = 1L;
    UnlockArea.lOffset = 0L;
    UnlockArea.lRange = 0L;
    rc = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );

    if( rc == NO_ERROR ){

      LockArea.lOffset = 0L;
      LockArea.lRange = 0L;
      UnlockArea.lOffset = RESERVED_BYTE;
      UnlockArea.lRange = 1L;
      rc = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );

    }
    OSTRACE3( "TEST WR-LOCK %d %d (remote)\n", pFile->h, rc );
  }
  return rc;
}

/*
................................................................................
** If the locking level of the file descriptor is already at or below
** the requested locking level, this routine is a no-op.
**
** It is not possible for this routine to fail if the second argument
** is NO_LOCK.  If the second argument is SHARED_LOCK then this routine
** might return SQLITE_IOERR;
*/
int os2Unlock( OsFile *id, int locktype ){
  int type;
  APIRET rc = SQLITE_OK;
  os2File *pFile = (os2File*)id;


  FILELOCK  LockArea,
            UnlockArea;
  memset(&LockArea, 0, sizeof(LockArea));
  memset(&UnlockArea, 0, sizeof(UnlockArea));
  assert( pFile!=0 );
  assert( locktype<=SHARED_LOCK );
  OSTRACE4( "UNLOCK %d to %d was %d\n", pFile->h, locktype, pFile->locktype );
  type = pFile->locktype;
  if( type>=EXCLUSIVE_LOCK ){
    LockArea.lOffset = 0L;
    LockArea.lRange = 0L;
    UnlockArea.lOffset = SHARED_FIRST;
    UnlockArea.lRange = SHARED_SIZE;
    DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );

    if( locktype==SHARED_LOCK && getReadLock(pFile) != NO_ERROR ){
      /* This should never happen.  We should always be able to
      ** reacquire the read lock */

      rc = SQLITE_IOERR;
    }
  }
  if( type>=RESERVED_LOCK ){
    LockArea.lOffset = 0L;
    LockArea.lRange = 0L;
    UnlockArea.lOffset = RESERVED_BYTE;
    UnlockArea.lRange = 1L;
    DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );

  }
  if( locktype==NO_LOCK && type>=SHARED_LOCK ){
    unlockReadLock(pFile);

  }
  if( type>=PENDING_LOCK ){
    LockArea.lOffset = 0L;
    LockArea.lRange = 0L;
    UnlockArea.lOffset = PENDING_BYTE;
    UnlockArea.lRange = 1L;
    DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );

  }
  pFile->locktype = locktype;

  return rc;
}

/*
** Turn a relative pathname into a full pathname.  Return a pointer
** to the full pathname stored in space obtained from sqliteMalloc().
** The calling function is responsible for freeing this space once it
** is no longer needed.
*/



char *sqlite3Os2FullPathname( const char *zRelative ){
  char *zFull = 0;
  if( strchr(zRelative, ':') ){
    sqlite3SetString( &zFull, zRelative, (char*)0 );
  }else{
    ULONG ulDriveNum = 0;
    ULONG ulDriveMap = 0;
    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 );
    }
  }
  return zFull;
}

/*
** The fullSync option is meaningless on os2, or correct me if I'm wrong.  This is a no-op.
** From os_unix.c: Change the value of the fullsync flag in the given file descriptor.
** From os_unix.c: ((unixFile*)id)->fullSync = v;
*/
static void os2SetFullSync( OsFile *id, int v ){
  return;
}

/*
** Return the underlying file handle for an OsFile
*/
static int os2FileHandle( OsFile *id ){
  return (int)((os2File*)id)->h;
}

/*
** Return an integer that indices the type of lock currently held
** by this handle.  (Used for testing and analysis only.)
*/
static int os2LockState( OsFile *id ){
  return ((os2File*)id)->locktype;
}

/*
** Return the sector size in bytes of the underlying block device for
** the specified file. This is almost always 512 bytes, but may be
** larger for some devices.
**
** SQLite code assumes this function cannot fail. It also assumes that
** if two files are created in the same file-system directory (i.e.
** a database and it's journal file) that the sector size will be the
** same for both.
*/
static int os2SectorSize(OsFile *id){
  return SQLITE_DEFAULT_SECTOR_SIZE;
}

/*







** This vector defines all the methods that can operate on an OsFile
** for os2.
*/
static const IoMethod sqlite3Os2IoMethod = {


  os2Close,
  os2OpenDirectory,
  os2Read,
  os2Write,
  os2Seek,
  os2Truncate,
  os2Sync,
  os2SetFullSync,
  os2FileHandle,
  os2FileSize,
  os2Lock,
  os2Unlock,
  os2LockState,
  os2CheckReservedLock,

  os2SectorSize,

};







/*
** Allocate memory for an OsFile.  Initialize the new OsFile
** to the value given in pInit and return a pointer to the new
** OsFile.  If we run out of memory, close the file and return NULL.

*/
int allocateOs2File( os2File *pInit, OsFile **pld ){











  os2File *pNew;
  pNew = sqliteMalloc( sizeof(*pNew) );
  if( pNew==0 ){
    DosClose( pInit->h );
    *pld = 0;
    return SQLITE_NOMEM;











  }else{
    *pNew = *pInit;









































































    pNew->pMethod = &sqlite3Os2IoMethod;
    pNew->locktype = NO_LOCK;
    *pld = (OsFile*)pNew;

    OpenCounter(+1);

    return SQLITE_OK;
  }
}





















































































#endif /* SQLITE_OMIT_DISKIO */
/***************************************************************************
** Everything above deals with file I/O.  Everything that follows deals
** with other miscellanous aspects of the operating system interface
****************************************************************************/




































#ifndef SQLITE_OMIT_LOAD_EXTENSION
/*
** 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);
  if (rc != NO_ERROR) {
    /* if the symbol itself was not found, search again for the same
     * 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 */







/*
** Get information to seed the random number generator.  The seed
** is written into the buffer zBuf[256].  The calling function must
** supply a sufficiently large buffer.
*/


int sqlite3Os2RandomSeed( char *zBuf ){
  /* We have to initialize zBuf to prevent valgrind from reporting
  ** errors.  The reports issued by valgrind are incorrect - we would
  ** prefer that the randomness be increased by making use of the
  ** uninitialized space in zBuf - but valgrind errors tend to worry
  ** some users.  Rather than argue, it seems easier just to initialize
  ** the whole array and silence valgrind, even if that means less randomness
  ** in the random seed.
  **
  ** When testing, initializing zBuf[] to zero is all we do.  That means
  ** that we always use the same random number sequence. This makes the
  ** tests repeatable.
  */
  memset( zBuf, 0, 256 );
  DosGetDateTime( (PDATETIME)zBuf );
  return SQLITE_OK;


}

/*
** Sleep for a little while.  Return the amount of time slept.
*/
int sqlite3Os2Sleep( int ms ){
  DosSleep( ms );
  return ms;





}

/*
** Static variables used for thread synchronization
*/
static int inMutex = 0;
#ifdef SQLITE_OS2_THREADS
static ULONG mutexOwner;
#endif

/*
** The following pair of routines implement mutual exclusion for
** 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
}






























/*
** Return TRUE if the mutex is currently held.
**
** If the thisThreadOnly parameter is true, return true if and only if the
** calling thread holds the mutex.  If the parameter is false, return
** true if any thread holds the mutex.






*/
int sqlite3Os2InMutex( int thisThreadOnly ){
#ifdef SQLITE_OS2_THREADS
  PTIB ptib;
  DosGetInfoBlocks( &ptib, NULL );
  return inMutex>0 && (thisThreadOnly==0 || mutexOwner==ptib->tib_ptib2->tib2_ultid);
#else


  return inMutex>0;
#endif
}

/*
** The following variable, if set to a non-zero value, becomes the result
** returned from sqlite3OsCurrentTime().  This is used for testing.
*/
#ifdef SQLITE_TEST
................................................................................
#endif

/*
** Find the current time (in Universal Coordinated Time).  Write the
** current time and date as a Julian Day number into *prNow and
** return 0.  Return 1 if the time and date cannot be found.
*/
int sqlite3Os2CurrentTime( double *prNow ){
  double now;
  USHORT second, minute, hour,
         day, month, year;
  DATETIME dt;
  DosGetDateTime( &dt );
  second = (USHORT)dt.seconds;
  minute = (USHORT)dt.minutes + dt.timezone;
................................................................................
    *prNow = sqlite3_current_time/86400.0 + 2440587.5;
  }
#endif
  return 0;
}

/*
** Remember the number of thread-specific-data blocks allocated.
** Use this to verify that we are not leaking thread-specific-data.
** Ticket #1601

*/
#ifdef SQLITE_TEST
int sqlite3_tsd_count = 0;
# define TSD_COUNTER_INCR InterlockedIncrement( &sqlite3_tsd_count )
# define TSD_COUNTER_DECR InterlockedDecrement( &sqlite3_tsd_count )
#else
# define TSD_COUNTER_INCR  /* no-op */
# define TSD_COUNTER_DECR  /* no-op */
#endif


/*
** If called with allocateFlag>1, then return a pointer to thread
** specific data for the current thread.  Allocate and zero the
** thread-specific data if it does not already exist necessary.
**
** If called with allocateFlag==0, then check the current thread
** specific data.  Return it if it exists.  If it does not exist,
** then return NULL.
**
** If called with allocateFlag<0, check to see if the thread specific
** data is allocated and is all zero.  If it is then deallocate it.
** Return a pointer to the thread specific data or NULL if it is
** unallocated or gets deallocated.
*/
ThreadData *sqlite3Os2ThreadSpecificData( int allocateFlag ){
  static ThreadData **s_ppTsd = NULL;
  static const ThreadData zeroData = {0, 0, 0};
  ThreadData *pTsd;

  if( !s_ppTsd ){
    sqlite3OsEnterMutex();
    if( !s_ppTsd ){
      PULONG pul;
      APIRET rc = DosAllocThreadLocalMemory(1, &pul);
      if( rc != NO_ERROR ){
        sqlite3OsLeaveMutex();
        return 0;
      }
      s_ppTsd = (ThreadData **)pul;
    }
    sqlite3OsLeaveMutex();

  }
  pTsd = *s_ppTsd;
  if( allocateFlag>0 ){
    if( !pTsd ){
      pTsd = sqlite3OsMalloc( sizeof(zeroData) );
      if( pTsd ){
        *pTsd = zeroData;
        *s_ppTsd = pTsd;
        TSD_COUNTER_INCR;
      }
    }
  }else if( pTsd!=0 && allocateFlag<0
              && memcmp( pTsd, &zeroData, sizeof(ThreadData) )==0 ){
    sqlite3OsFree(pTsd);
    *s_ppTsd = NULL;
    TSD_COUNTER_DECR;
    pTsd = 0;
  }
  return pTsd;
}
#endif /* OS_OS2 */








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1011
** This file contains code that is specific to OS/2.
*/

#include "sqliteInt.h"

#if OS_OS2

/*
** A Note About Memory Allocation:
**
** This driver uses malloc()/free() directly rather than going through
** the SQLite-wrappers sqlite3_malloc()/sqlite3_free().  Those wrappers
** are designed for use on embedded systems where memory is scarce and
** malloc failures happen frequently.  OS/2 does not typically run on
** embedded systems, and when it does the developers normally have bigger
** problems to worry about than running out of memory.  So there is not
** a compelling need to use the wrappers.
**
** But there is a good reason to not use the wrappers.  If we use the
** wrappers then we will get simulated malloc() failures within this
** driver.  And that causes all kinds of problems for our tests.  We
** could enhance SQLite to deal with simulated malloc failures within
** the OS driver, but the code to deal with those failure would not
** be exercised on Linux (which does not need to malloc() in the driver)
** and so we would have difficulty writing coverage tests for that
** code.  Better to leave the code out, we think.
**
** The point of this discussion is as follows:  When creating a new
** OS layer for an embedded system, if you use this file as an example,
** avoid the use of malloc()/free().  Those routines work ok on OS/2
** desktops but not so well in embedded systems.
*/

/*
** Macros used to determine whether or not to use threads.
*/

#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE
# define SQLITE_OS2_THREADS 1
#endif

/*
** Include code that is common to all os_*.c files
*/
#include "os_common.h"

/*
** The os2File structure is subclass of sqlite3_file specific for the OS/2
** protability layer.
*/
typedef struct os2File os2File;
struct os2File {
  const sqlite3_io_methods *pMethod;  /* Always the first entry */
  HFILE h;                  /* Handle for accessing the file */
  int delOnClose;           /* True if file is to be deleted on close */
  char* pathToDel;          /* Name of file to delete on close */
  unsigned char locktype;   /* Type of lock currently held on this file */
};

/*****************************************************************************
** The next group of routines implement the I/O methods specified
** by the sqlite3_io_methods object.
******************************************************************************/



/*


















































































































































































































** Close a file.
*/
int os2Close( sqlite3_file *id ){

  APIRET rc = NO_ERROR;
  os2File *pFile;
  if( id && (pFile = (os2File*)id) != 0 ){
    OSTRACE2( "CLOSE %d\n", pFile->h );
    rc = DosClose( pFile->h );
    pFile->locktype = NO_LOCK;
    if( pFile->delOnClose != 0 ){
      rc = DosForceDelete( (PSZ)pFile->pathToDel );
    }
    if( pFile->pathToDel ){
      free( pFile->pathToDel );
    }
    id = 0;
    OpenCounter( -1 );
  }

  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
}

/*
** Read data from a file into a buffer.  Return SQLITE_OK if all
** bytes were read successfully and SQLITE_IOERR if anything goes
** wrong.
*/
int os2Read(
  sqlite3_file *id,               /* File to read from */
  void *pBuf,                     /* Write content into this buffer */
  int amt,                        /* Number of bytes to read */
  sqlite3_int64 offset            /* Begin reading at this offset */
){
  ULONG fileLocation = 0L;
  ULONG got;
  os2File *pFile = (os2File*)id;
  assert( id!=0 );
  SimulateIOError( return SQLITE_IOERR_READ );
  OSTRACE3( "READ %d lock=%d\n", pFile->h, pFile->locktype );
  if( DosSetFilePtr(pFile->h, offset, FILE_BEGIN, &fileLocation) != NO_ERROR ){
    return SQLITE_IOERR;
  }
  if( DosRead( pFile->h, pBuf, amt, &got ) != NO_ERROR ){
    return SQLITE_IOERR_READ;
  }
  if( got == (ULONG)amt )
    return SQLITE_OK;


  else {
    memset(&((char*)pBuf)[got], 0, amt-got);
    return SQLITE_IOERR_SHORT_READ;
  }
}

/*
** Write data from a buffer into a file.  Return SQLITE_OK on success
** or some other error code on failure.
*/
int os2Write(
  sqlite3_file *id,               /* File to write into */
  const void *pBuf,               /* The bytes to be written */
  int amt,                        /* Number of bytes to write */
  sqlite3_int64 offset            /* Offset into the file to begin writing at */
){
  ULONG fileLocation = 0L;
  APIRET rc = NO_ERROR;
  ULONG wrote;
  os2File *pFile = (os2File*)id;
  assert( id!=0 );
  SimulateIOError( return SQLITE_IOERR_WRITE );
  SimulateDiskfullError( return SQLITE_FULL );
  OSTRACE3( "WRITE %d lock=%d\n", pFile->h, pFile->locktype );
  if( DosSetFilePtr(pFile->h, offset, FILE_BEGIN, &fileLocation) != NO_ERROR ){
    return SQLITE_IOERR;
  }
  assert( amt>0 );
  while( amt > 0 &&
         (rc = DosWrite( pFile->h, (PVOID)pBuf, amt, &wrote )) &&
         wrote > 0
  ){
    amt -= wrote;
    pBuf = &((char*)pBuf)[wrote];
  }

  return ( rc != NO_ERROR || amt > (int)wrote ) ? SQLITE_FULL : SQLITE_OK;
}

/*
** Truncate an open file to a specified size
*/
int os2Truncate( sqlite3_file *id, i64 nByte ){
  APIRET rc = NO_ERROR;
  ULONG filePosition = 0L;
  os2File *pFile = (os2File*)id;
  OSTRACE3( "TRUNCATE %d %lld\n", pFile->h, nByte );
  SimulateIOError( return SQLITE_IOERR_TRUNCATE );
  rc = DosSetFilePtr( pFile->h, nByte, FILE_BEGIN, &filePosition );
  if( rc != NO_ERROR ){
    return SQLITE_IOERR;
  }
  rc = DosSetFilePtr( pFile->h, 0L, FILE_END, &filePosition );
  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
}

#ifdef SQLITE_TEST
/*
** Count the number of fullsyncs and normal syncs.  This is used to test
** that syncs and fullsyncs are occuring at the right times.
*/
int sqlite3_sync_count = 0;
int sqlite3_fullsync_count = 0;
#endif

/*
** Make sure all writes to a particular file are committed to disk.
*/
int os2Sync( sqlite3_file *id, int flags ){
  os2File *pFile = (os2File*)id;
  OSTRACE3( "SYNC %d lock=%d\n", pFile->h, pFile->locktype );
#ifdef SQLITE_TEST
  if( flags & SQLITE_SYNC_FULL){
    sqlite3_fullsync_count++;
  }
  sqlite3_sync_count++;
#endif
  return DosResetBuffer( pFile->h ) == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;






}

/*
** Determine the current size of a file in bytes
*/
int os2FileSize( sqlite3_file *id, sqlite3_int64 *pSize ){
  APIRET rc = NO_ERROR;
  FILESTATUS3 fsts3FileInfo;
  memset(&fsts3FileInfo, 0, sizeof(fsts3FileInfo));
  assert( id!=0 );
  SimulateIOError( return SQLITE_IOERR );
  rc = DosQueryFileInfo( ((os2File*)id)->h, FIL_STANDARD, &fsts3FileInfo, sizeof(FILESTATUS3) );
  if( rc == NO_ERROR ){
    *pSize = fsts3FileInfo.cbFile;
    return SQLITE_OK;

  }else{
    return SQLITE_IOERR;
  }
}

/*
** Acquire a reader lock.
*/
static int getReadLock( os2File *pFile ){
  FILELOCK  LockArea,
            UnlockArea;
  APIRET res;
  memset(&LockArea, 0, sizeof(LockArea));
  memset(&UnlockArea, 0, sizeof(UnlockArea));
  LockArea.lOffset = SHARED_FIRST;
  LockArea.lRange = SHARED_SIZE;
  UnlockArea.lOffset = 0L;
  UnlockArea.lRange = 0L;
  res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
  OSTRACE3( "GETREADLOCK %d res=%d\n", pFile->h, res );
  return res;
}

/*
** Undo a readlock
*/
static int unlockReadLock( os2File *id ){
  FILELOCK  LockArea,
            UnlockArea;
  APIRET res;
  memset(&LockArea, 0, sizeof(LockArea));
  memset(&UnlockArea, 0, sizeof(UnlockArea));
  LockArea.lOffset = 0L;
  LockArea.lRange = 0L;
  UnlockArea.lOffset = SHARED_FIRST;
  UnlockArea.lRange = SHARED_SIZE;
  res = DosSetFileLocks( id->h, &UnlockArea, &LockArea, 2000L, 1L );

















  OSTRACE3( "UNLOCK-READLOCK file handle=%d res=%d?\n", id->h, res );
  return res;
}


/*
** Lock the file with the lock specified by parameter locktype - one
** of the following:
**
**     (1) SHARED_LOCK
**     (2) RESERVED_LOCK
**     (3) PENDING_LOCK
................................................................................
**    PENDING -> EXCLUSIVE
**
** This routine will only increase a lock.  The os2Unlock() routine
** erases all locks at once and returns us immediately to locking level 0.
** It is not possible to lower the locking level one step at a time.  You
** must go straight to locking level 0.
*/
int os2Lock( sqlite3_file *id, int locktype ){
  int rc = SQLITE_OK;       /* Return code from subroutines */
  APIRET res = NO_ERROR;    /* Result of an OS/2 lock call */
  int newLocktype;       /* Set pFile->locktype to this value before exiting */
  int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */
  FILELOCK  LockArea,
            UnlockArea;
  os2File *pFile = (os2File*)id;
  memset(&LockArea, 0, sizeof(LockArea));
  memset(&UnlockArea, 0, sizeof(UnlockArea));
  assert( pFile!=0 );
  OSTRACE4( "LOCK %d %d was %d\n", pFile->h, locktype, pFile->locktype );

  /* If there is already a lock of this type or more restrictive on the
  ** os2File, do nothing. Don't use the end_lock: exit path, as
  ** sqlite3OsEnterMutex() hasn't been called yet.
  */
  if( pFile->locktype>=locktype ){
    OSTRACE3( "LOCK %d %d ok (already held)\n", pFile->h, locktype );
    return SQLITE_OK;
  }

  /* Make sure the locking sequence is correct
  */
  assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
  assert( locktype!=PENDING_LOCK );
................................................................................

  /* Lock the PENDING_LOCK byte if we need to acquire a PENDING lock or
  ** a SHARED lock.  If we are acquiring a SHARED lock, the acquisition of
  ** the PENDING_LOCK byte is temporary.
  */
  newLocktype = pFile->locktype;
  if( pFile->locktype==NO_LOCK
      || (locktype==EXCLUSIVE_LOCK && pFile->locktype==RESERVED_LOCK)
  ){
    int cnt = 3;

    LockArea.lOffset = PENDING_BYTE;
    LockArea.lRange = 1L;
    UnlockArea.lOffset = 0L;
    UnlockArea.lRange = 0L;

    while( cnt-->0 && ( res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L) )
                      != NO_ERROR
    ){
      /* Try 3 times to get the pending lock.  The pending lock might be
      ** held by another reader process who will release it momentarily.
      */
      OSTRACE2( "LOCK could not get a PENDING lock. cnt=%d\n", cnt );
      DosSleep(1);
    }
    if( res == NO_ERROR){
      gotPendingLock = 1;
      OSTRACE3( "LOCK %d pending lock boolean set.  res=%d\n", pFile->h, res );
    }
  }

  /* Acquire a shared lock
  */
  if( locktype==SHARED_LOCK && res == NO_ERROR ){
    assert( pFile->locktype==NO_LOCK );
    res = getReadLock(pFile);
    if( res == NO_ERROR ){
      newLocktype = SHARED_LOCK;
    }
    OSTRACE3( "LOCK %d acquire shared lock. res=%d\n", pFile->h, res );
  }

  /* Acquire a RESERVED lock
  */
  if( locktype==RESERVED_LOCK && res == NO_ERROR ){
    assert( pFile->locktype==SHARED_LOCK );
    LockArea.lOffset = RESERVED_BYTE;
    LockArea.lRange = 1L;
    UnlockArea.lOffset = 0L;
    UnlockArea.lRange = 0L;
    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    if( res == NO_ERROR ){
      newLocktype = RESERVED_LOCK;
    }
    OSTRACE3( "LOCK %d acquire reserved lock. res=%d\n", pFile->h, res );
  }

  /* Acquire a PENDING lock
  */
  if( locktype==EXCLUSIVE_LOCK && res == NO_ERROR ){
    newLocktype = PENDING_LOCK;
    gotPendingLock = 0;
    OSTRACE2( "LOCK %d acquire pending lock. pending lock boolean unset.\n", pFile->h );
  }

  /* Acquire an EXCLUSIVE lock
  */
  if( locktype==EXCLUSIVE_LOCK && res == NO_ERROR ){
    assert( pFile->locktype>=SHARED_LOCK );
    res = unlockReadLock(pFile);
    OSTRACE2( "unreadlock = %d\n", res );
    LockArea.lOffset = SHARED_FIRST;
    LockArea.lRange = SHARED_SIZE;
    UnlockArea.lOffset = 0L;
    UnlockArea.lRange = 0L;
    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    if( res == NO_ERROR ){
      newLocktype = EXCLUSIVE_LOCK;
    }else{
      OSTRACE2( "OS/2 error-code = %d\n", res );
      getReadLock(pFile);
    }
    OSTRACE3( "LOCK %d acquire exclusive lock.  res=%d\n", pFile->h, res );
  }

  /* If we are holding a PENDING lock that ought to be released, then
  ** release it now.
  */
  if( gotPendingLock && locktype==SHARED_LOCK ){
    int r;
    LockArea.lOffset = 0L;
    LockArea.lRange = 0L;
    UnlockArea.lOffset = PENDING_BYTE;
    UnlockArea.lRange = 1L;
    r = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    OSTRACE3( "LOCK %d unlocking pending/is shared. r=%d\n", pFile->h, r );
  }

  /* Update the state of the lock has held in the file descriptor then
  ** return the appropriate result code.
  */
  if( res == NO_ERROR ){
    rc = SQLITE_OK;
  }else{
    OSTRACE4( "LOCK FAILED %d trying for %d but got %d\n", pFile->h,
              locktype, newLocktype );
    rc = SQLITE_BUSY;
  }
  pFile->locktype = newLocktype;
  OSTRACE3( "LOCK %d now %d\n", pFile->h, pFile->locktype );
  return rc;
}

/*
** This routine checks if there is a RESERVED lock held on the specified
** file by this or any other process. If such a lock is held, return
** non-zero, otherwise zero.
*/
int os2CheckReservedLock( sqlite3_file *id ){
  APIRET rc = NO_ERROR;
  os2File *pFile = (os2File*)id;
  assert( pFile!=0 );
  if( pFile->locktype>=RESERVED_LOCK ){
    rc = 1;
    OSTRACE3( "TEST WR-LOCK %d %d (local)\n", pFile->h, rc );
  }else{
................................................................................
    memset(&LockArea, 0, sizeof(LockArea));
    memset(&UnlockArea, 0, sizeof(UnlockArea));
    LockArea.lOffset = RESERVED_BYTE;
    LockArea.lRange = 1L;
    UnlockArea.lOffset = 0L;
    UnlockArea.lRange = 0L;
    rc = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    OSTRACE3( "TEST WR-LOCK %d lock reserved byte rc=%d\n", pFile->h, rc );
    if( rc == NO_ERROR ){
      int r;
      LockArea.lOffset = 0L;
      LockArea.lRange = 0L;
      UnlockArea.lOffset = RESERVED_BYTE;
      UnlockArea.lRange = 1L;
      r = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
      OSTRACE3( "TEST WR-LOCK %d unlock reserved byte r=%d\n", pFile->h, r );
    }
    OSTRACE3( "TEST WR-LOCK %d %d (remote)\n", pFile->h, rc );
  }
  return rc;
}

/*
................................................................................
** If the locking level of the file descriptor is already at or below
** the requested locking level, this routine is a no-op.
**
** It is not possible for this routine to fail if the second argument
** is NO_LOCK.  If the second argument is SHARED_LOCK then this routine
** might return SQLITE_IOERR;
*/
int os2Unlock( sqlite3_file *id, int locktype ){
  int type;

  os2File *pFile = (os2File*)id;
  APIRET rc = SQLITE_OK;
  APIRET res = NO_ERROR;
  FILELOCK  LockArea,
            UnlockArea;
  memset(&LockArea, 0, sizeof(LockArea));
  memset(&UnlockArea, 0, sizeof(UnlockArea));
  assert( pFile!=0 );
  assert( locktype<=SHARED_LOCK );
  OSTRACE4( "UNLOCK %d to %d was %d\n", pFile->h, locktype, pFile->locktype );
  type = pFile->locktype;
  if( type>=EXCLUSIVE_LOCK ){
    LockArea.lOffset = 0L;
    LockArea.lRange = 0L;
    UnlockArea.lOffset = SHARED_FIRST;
    UnlockArea.lRange = SHARED_SIZE;
    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    OSTRACE3( "UNLOCK %d exclusive lock res=%d\n", pFile->h, res );
    if( locktype==SHARED_LOCK && getReadLock(pFile) != NO_ERROR ){
      /* This should never happen.  We should always be able to
      ** reacquire the read lock */
      OSTRACE3( "UNLOCK %d to %d getReadLock() failed\n", pFile->h, locktype );
      rc = SQLITE_IOERR_UNLOCK;
    }
  }
  if( type>=RESERVED_LOCK ){
    LockArea.lOffset = 0L;
    LockArea.lRange = 0L;
    UnlockArea.lOffset = RESERVED_BYTE;
    UnlockArea.lRange = 1L;
    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    OSTRACE3( "UNLOCK %d reserved res=%d\n", pFile->h, res );
  }
  if( locktype==NO_LOCK && type>=SHARED_LOCK ){
    res = unlockReadLock(pFile);
    OSTRACE5( "UNLOCK %d is %d want %d res=%d\n", pFile->h, type, locktype, res );
  }
  if( type>=PENDING_LOCK ){
    LockArea.lOffset = 0L;
    LockArea.lRange = 0L;
    UnlockArea.lOffset = PENDING_BYTE;
    UnlockArea.lRange = 1L;
    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 2000L, 1L );
    OSTRACE3( "UNLOCK %d pending res=%d\n", pFile->h, res );
  }
  pFile->locktype = locktype;
  OSTRACE3( "UNLOCK %d now %d\n", pFile->h, pFile->locktype );
  return rc;
}

/*
** Control and query of the open file handle.



*/
static int os2FileControl(sqlite3_file *id, int op, void *pArg){
  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE: {
      *(int*)pArg = ((os2File*)id)->locktype;
      OSTRACE3( "FCNTL_LOCKSTATE %d lock=%d\n", ((os2File*)id)->h, ((os2File*)id)->locktype );




















      return SQLITE_OK;
    }
  }






  return SQLITE_ERROR;















}

/*
** Return the sector size in bytes of the underlying block device for
** the specified file. This is almost always 512 bytes, but may be
** larger for some devices.
**
** SQLite code assumes this function cannot fail. It also assumes that
** if two files are created in the same file-system directory (i.e.
** a database and it's journal file) that the sector size will be the
** same for both.
*/
static int os2SectorSize(sqlite3_file *id){
  return SQLITE_DEFAULT_SECTOR_SIZE;
}

/*
** Return a vector of device characteristics.
*/
static int os2DeviceCharacteristics(sqlite3_file *id){
  return 0;
}

/*
** This vector defines all the methods that can operate on an
** sqlite3_file for os2.
*/

static const sqlite3_io_methods os2IoMethod = {
  1,                        /* iVersion */
  os2Close,

  os2Read,
  os2Write,

  os2Truncate,
  os2Sync,


  os2FileSize,
  os2Lock,
  os2Unlock,

  os2CheckReservedLock,
  os2FileControl,
  os2SectorSize,
  os2DeviceCharacteristics
};

/***************************************************************************
** Here ends the I/O methods that form the sqlite3_io_methods object.
**
** The next block of code implements the VFS methods.
****************************************************************************/

/*



** Open a file.
*/

static int os2Open(
  sqlite3_vfs *pVfs,            /* Not used */
  const char *zName,            /* Name of the file */
  sqlite3_file *id,             /* Write the SQLite file handle here */
  int flags,                    /* Open mode flags */
  int *pOutFlags                /* Status return flags */
){
  HFILE h;
  ULONG ulFileAttribute = 0;
  ULONG ulOpenFlags = 0;
  ULONG ulOpenMode = 0;
  os2File *pFile = (os2File*)id;





  APIRET rc = NO_ERROR;
  ULONG ulAction;

  memset(pFile, 0, sizeof(*pFile));

  OSTRACE2( "OPEN want %d\n", flags );

  //ulOpenMode = flags & SQLITE_OPEN_READWRITE ? OPEN_ACCESS_READWRITE : OPEN_ACCESS_READONLY;
  if( flags & SQLITE_OPEN_READWRITE ){
    ulOpenMode |= OPEN_ACCESS_READWRITE;
    OSTRACE1( "OPEN read/write\n" );
  }else{

    ulOpenMode |= OPEN_ACCESS_READONLY;
    OSTRACE1( "OPEN read only\n" );
  }

  //ulOpenFlags = flags & SQLITE_OPEN_CREATE ? OPEN_ACTION_CREATE_IF_NEW : OPEN_ACTION_FAIL_IF_NEW;
  if( flags & SQLITE_OPEN_CREATE ){
    ulOpenFlags |= OPEN_ACTION_OPEN_IF_EXISTS | OPEN_ACTION_CREATE_IF_NEW;
    OSTRACE1( "OPEN open new/create\n" );
  }else{
    ulOpenFlags |= OPEN_ACTION_OPEN_IF_EXISTS | OPEN_ACTION_FAIL_IF_NEW;
    OSTRACE1( "OPEN open existing\n" );
  }

  //ulOpenMode |= flags & SQLITE_OPEN_MAIN_DB ? OPEN_SHARE_DENYNONE : OPEN_SHARE_DENYWRITE;
  if( flags & SQLITE_OPEN_MAIN_DB ){
    ulOpenMode |= OPEN_SHARE_DENYNONE;
    OSTRACE1( "OPEN share read/write\n" );
  }else{
    ulOpenMode |= OPEN_SHARE_DENYWRITE;
    OSTRACE1( "OPEN share read only\n" );
  }

  if( flags & (SQLITE_OPEN_TEMP_DB | SQLITE_OPEN_TEMP_JOURNAL
               | SQLITE_OPEN_SUBJOURNAL) ){
    //ulFileAttribute = FILE_HIDDEN;  //for debugging, we want to make sure it is deleted
    ulFileAttribute = FILE_NORMAL;
    pFile->delOnClose = 1;
    pFile->pathToDel = (char*)malloc(sizeof(char) * pVfs->mxPathname);
    sqlite3OsFullPathname(pVfs, zName, pVfs->mxPathname, pFile->pathToDel);
    OSTRACE1( "OPEN hidden/delete on close file attributes\n" );
  }else{
    ulFileAttribute = FILE_ARCHIVED | FILE_NORMAL;
    pFile->delOnClose = 0;
    pFile->pathToDel = NULL;
    OSTRACE1( "OPEN normal file attribute\n" );
  }

  //ulOpenMode |= flags & (SQLITE_OPEN_MAIN_DB | SQLITE_OPEN_TEMP_DB) ?
  //                  OPEN_FLAGS_RANDOM : OPEN_FLAGS_SEQUENTIAL;
  if( flags & (SQLITE_OPEN_MAIN_DB | SQLITE_OPEN_TEMP_DB) ){
    ulOpenMode |= OPEN_FLAGS_RANDOM;
    OSTRACE1( "OPEN random access\n" );
  }else{
    ulOpenMode |= OPEN_FLAGS_SEQUENTIAL;
    OSTRACE1( "OPEN sequential access\n" );
  }
  ulOpenMode |= OPEN_FLAGS_FAIL_ON_ERROR;

  rc = DosOpen( (PSZ)zName,
                &h,
                &ulAction,
                0L,
                ulFileAttribute,
                ulOpenFlags,
                ulOpenMode,
                (PEAOP2)NULL );
  if( rc != NO_ERROR ){
    OSTRACE7( "OPEN Invalid handle rc=%d: zName=%s, ulAction=%#lx, ulAttr=%#lx, ulFlags=%#lx, ulMode=%#lx\n",
              rc, zName, ulAction, ulFileAttribute, ulOpenFlags, ulOpenMode );
    if( flags & SQLITE_OPEN_READWRITE ){
      OSTRACE2( "OPEN %d Invalid handle\n", ((flags | SQLITE_OPEN_READONLY) & ~SQLITE_OPEN_READWRITE) );
      return os2Open( 0, zName, id,
                      ((flags | SQLITE_OPEN_READONLY) & ~SQLITE_OPEN_READWRITE),
                      pOutFlags );
    }else{
      return SQLITE_CANTOPEN;
    }
  }

  if( pOutFlags ){
    *pOutFlags = flags & SQLITE_OPEN_READWRITE ? SQLITE_OPEN_READWRITE : SQLITE_OPEN_READONLY;
  }

  pFile->pMethod = &os2IoMethod;


  pFile->h = h;
  OpenCounter(+1);
  OSTRACE3( "OPEN %d pOutFlags=%d\n", pFile->h, pOutFlags );
  return SQLITE_OK;
}

/*
** Delete the named file.
*/
int os2Delete(
  sqlite3_vfs *pVfs,                     /* Not used on os2 */
  const char *zFilename,                 /* Name of file to delete */
  int syncDir                            /* Not used on os2 */
){
  APIRET rc = NO_ERROR;
  SimulateIOError(return SQLITE_IOERR_DELETE);
  rc = DosDelete( (PSZ)zFilename );
  OSTRACE2( "DELETE \"%s\"\n", zFilename );
  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
}

/*
** Check the existance and status of a file.
*/
static int os2Access(
  sqlite3_vfs *pVfs,        /* Not used on os2 */
  const char *zFilename,    /* Name of file to check */
  int flags                 /* Type of test to make on this file */
){
  FILESTATUS3 fsts3ConfigInfo;
  APIRET rc = NO_ERROR;

  memset(&fsts3ConfigInfo, 0, sizeof(fsts3ConfigInfo));
  rc = DosQueryPathInfo( (PSZ)zFilename, FIL_STANDARD,
                         &fsts3ConfigInfo, sizeof(FILESTATUS3) );
  OSTRACE4( "ACCESS fsts3ConfigInfo.attrFile=%d flags=%d rc=%d\n",
            fsts3ConfigInfo.attrFile, flags, rc );
  switch( flags ){
    case SQLITE_ACCESS_READ:
    case SQLITE_ACCESS_EXISTS:
      rc = (rc == NO_ERROR);
      OSTRACE3( "ACCESS %s access of read and exists  rc=%d\n", zFilename, rc );
      break;
    case SQLITE_ACCESS_READWRITE:
      rc = (fsts3ConfigInfo.attrFile & FILE_READONLY) == 0;
      OSTRACE3( "ACCESS %s access of read/write  rc=%d\n", zFilename, rc );
      break;
    default:
      assert( !"Invalid flags argument" );
  }
  return rc;
}


/*
** Create a temporary file name in zBuf.  zBuf must be big enough to
** hold at pVfs->mxPathname characters.
*/
static int os2GetTempname( sqlite3_vfs *pVfs, int nBuf, char *zBuf ){
  static const unsigned char zChars[] =
    "abcdefghijklmnopqrstuvwxyz"
    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    "0123456789";
  int i, j;
  char zTempPath[CCHMAXPATH];
  APIRET rc = NO_ERROR;
  FILESTATUS3 fsts3ConfigInfo;
  if( DosScanEnv( (PSZ)"TEMP", (PSZ*)&zTempPath ) ){
    if( DosScanEnv( (PSZ)"TMP", (PSZ*)&zTempPath ) ){
      if( DosScanEnv( (PSZ)"TMPDIR", (PSZ*)&zTempPath ) ){
           ULONG ulDriveNum = 0, ulDriveMap = 0;
           DosQueryCurrentDisk( &ulDriveNum, &ulDriveMap );
           sprintf( (char*)zTempPath, "%c:", (char)( 'A' + ulDriveNum - 1 ) );
      }
    }
  }
  do{
    assert( nBuf>=pVfs->mxPathname );
    sqlite3_snprintf(pVfs->mxPathname-17, zBuf, "%s\\"SQLITE_TEMP_FILE_PREFIX, zTempPath );
    j = strlen( zBuf );
    sqlite3Randomness( 15, &zBuf[j] );
    for( i = 0; i < 15; i++, j++ ){
      zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
    }
    zBuf[j] = 0;

    memset(&fsts3ConfigInfo, 0, sizeof(fsts3ConfigInfo));
    rc = DosQueryPathInfo( (PSZ)zBuf, FIL_STANDARD,
                           &fsts3ConfigInfo, sizeof(FILESTATUS3) );
  }while( rc != NO_ERROR );
  OSTRACE2( "TEMP FILENAME: %s\n", zBuf );
  return SQLITE_OK;




}


/*
** Turn a relative pathname into a full pathname.  Write the full
** pathname into zFull[].  zFull[] will be at least pVfs->mxPathname
** bytes in size.
*/
static int os2FullPathname(
  sqlite3_vfs *pVfs,          /* Pointer to vfs object */
  const char *zRelative,      /* Possibly relative input path */
  int nFull,                  /* Size of output buffer in bytes */
  char *zFull                 /* Output buffer */
){
  if( strchr(zRelative, ':') ){
    sqlite3SetString( &zFull, zRelative, (char*)0 );
  }else{
    ULONG ulDriveNum = 0;
    ULONG ulDriveMap = 0;
    ULONG cbzBufLen = SQLITE_TEMPNAME_SIZE;
    char zDrive[2];
    char *zBuff = (char*)malloc( cbzBufLen );
    if( zBuff == 0 ){
      return SQLITE_NOMEM;
    }
    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 );
    }
    free( zBuff );
  }
  return SQLITE_OK;
}

#ifndef SQLITE_OMIT_LOAD_EXTENSION
/*
** Interfaces for opening a shared library, finding entry points
** within the shared library, and closing the shared library.
*/

/*
** Interfaces for opening a shared library, finding entry points
** within the shared library, and closing the shared library.
*/
static void *os2DlOpen(sqlite3_vfs *pVfs, const char *zFilename){
  UCHAR loadErr[256];
  HMODULE hmod;
  APIRET rc;
  rc = DosLoadModule((PSZ)loadErr, sizeof(loadErr), zFilename, &hmod);

  return rc != NO_ERROR ? 0 : (void*)hmod;
}
/*
** A no-op since the error code is returned on the DosLoadModule call.
** os2Dlopen returns zero if DosLoadModule is not successful.
*/
static void os2DlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
/* no-op */
}
void *os2DlSym(sqlite3_vfs *pVfs, void *pHandle, const char *zSymbol){
  PFN pfn;
  APIRET rc;
  rc = DosQueryProcAddr((HMODULE)pHandle, 0L, zSymbol, &pfn);
  if( rc != NO_ERROR ){
    /* if the symbol itself was not found, search again for the same
     * 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);
  }
  return rc != NO_ERROR ? 0 : (void*)pfn;

}

void os2DlClose(sqlite3_vfs *pVfs, void *pHandle){
  DosFreeModule((HMODULE)pHandle);
}
#else /* if SQLITE_OMIT_LOAD_EXTENSION is defined: */
  #define os2DlOpen 0
  #define os2DlError 0
  #define os2DlSym 0
  #define os2DlClose 0
#endif


/*
** Write up to nBuf bytes of randomness into zBuf.


*/
static int os2Randomness(sqlite3_vfs *pVfs, int nBuf, char *zBuf ){
  ULONG sizeofULong = sizeof(ULONG);
  int n = 0;
  if( sizeof(DATETIME) <= nBuf - n ){
    DATETIME x;











    DosGetDateTime(&x);

    memcpy(&zBuf[n], &x, sizeof(x));
    n += sizeof(x);
  }







  if( sizeofULong <= nBuf - n ){
    PPIB ppib;
    DosGetInfoBlocks(NULL, &ppib);
    memcpy(&zBuf[n], &ppib->pib_ulpid, sizeofULong);
    n += sizeofULong;
  }



















  if( sizeofULong <= nBuf - n ){
    PTIB ptib;

    DosGetInfoBlocks(&ptib, NULL);
    memcpy(&zBuf[n], &ptib->tib_ptib2->tib2_ultid, sizeofULong);



    n += sizeofULong;
  }












  /* if we still haven't filled the buffer yet the following will */
  /* grab everything once instead of making several calls for a single item */
  if( sizeofULong <= nBuf - n ){
    ULONG ulSysInfo[QSV_MAX];
    DosQuerySysInfo(1L, QSV_MAX, ulSysInfo, sizeofULong * QSV_MAX);

    memcpy(&zBuf[n], &ulSysInfo[QSV_MS_COUNT - 1], sizeofULong);
    n += sizeofULong;

    if( sizeofULong <= nBuf - n ){
      memcpy(&zBuf[n], &ulSysInfo[QSV_TIMER_INTERVAL - 1], sizeofULong);
      n += sizeofULong;
    }
    if( sizeofULong <= nBuf - n ){
      memcpy(&zBuf[n], &ulSysInfo[QSV_TIME_LOW - 1], sizeofULong);
      n += sizeofULong;
    }
    if( sizeofULong <= nBuf - n ){
      memcpy(&zBuf[n], &ulSysInfo[QSV_TIME_HIGH - 1], sizeofULong);
      n += sizeofULong;
    }
    if( sizeofULong <= nBuf - n ){
      memcpy(&zBuf[n], &ulSysInfo[QSV_TOTAVAILMEM - 1], sizeofULong);
      n += sizeofULong;
    }
  }

  return n;
}

/*





** Sleep for a little while.  Return the amount of time slept.
** The argument is the number of microseconds we want to sleep.
** The return value is the number of microseconds of sleep actually
** requested from the underlying operating system, a number which
** might be greater than or equal to the argument, but not less
** than the argument.
*/






static int os2Sleep( sqlite3_vfs *pVfs, int microsec ){
  DosSleep( (microsec/1000) );
  return microsec;

}

/*
** The following variable, if set to a non-zero value, becomes the result
** returned from sqlite3OsCurrentTime().  This is used for testing.
*/
#ifdef SQLITE_TEST
................................................................................
#endif

/*
** Find the current time (in Universal Coordinated Time).  Write the
** current time and date as a Julian Day number into *prNow and
** return 0.  Return 1 if the time and date cannot be found.
*/
int os2CurrentTime( sqlite3_vfs *pVfs, double *prNow ){
  double now;
  USHORT second, minute, hour,
         day, month, year;
  DATETIME dt;
  DosGetDateTime( &dt );
  second = (USHORT)dt.seconds;
  minute = (USHORT)dt.minutes + dt.timezone;
................................................................................
    *prNow = sqlite3_current_time/86400.0 + 2440587.5;
  }
#endif
  return 0;
}

/*
** Return a pointer to the sqlite3DefaultVfs structure.   We use
** a function rather than give the structure global scope because
** some compilers (MSVC) do not allow forward declarations of
** initialized structures.
*/

sqlite3_vfs *sqlite3OsDefaultVfs(void){
  static sqlite3_vfs os2Vfs = {
    1,                 /* iVersion */
    sizeof(os2File),   /* szOsFile */
    CCHMAXPATH,        /* mxPathname */
    0,                 /* pNext */
    "os2",             /* zName */
    0,                 /* pAppData */


    os2Open,           /* xOpen */
    os2Delete,         /* xDelete */
    os2Access,         /* xAccess */
    os2GetTempname,    /* xGetTempname */
    os2FullPathname,   /* xFullPathname */
    os2DlOpen,         /* xDlOpen */
    os2DlError,        /* xDlError */
    os2DlSym,          /* xDlSym */
    os2DlClose,        /* xDlClose */
    os2Randomness,     /* xRandomness */
    os2Sleep,          /* xSleep */
    os2CurrentTime     /* xCurrentTime */














  };



  return &os2Vfs;
}



















#endif /* OS_OS2 */