SQLite

static int unixSync(sqlite3_file *id, int flags){
  int rc;
  unixFile *pFile = (unixFile*)id;

  int isDataOnly = (flags&SQLITE_SYNC_DATAONLY);
  int isFullsync = (flags&0x0F)==SQLITE_SYNC_FULL;

  /* Check that one of SQLITE_SYNC_NORMAL, FULL or BARRIER was passed */
  assert((flags&0x0F)==SQLITE_SYNC_NORMAL
      || (flags&0x0F)==SQLITE_SYNC_FULL
      || (flags&0x0F)==SQLITE_SYNC_BARRIER
  );

  assert( pFile );
  OSTRACE2("SYNC    %-3d\n", pFile->h);
  rc = full_fsync(pFile->h, isFullsync, isDataOnly);
  SimulateIOError( rc=1 );
  if( rc ){

** on how SQLite interfaces are suppose to operate.
**
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
**
** @(#) $Id: sqlite.h.in,v 1.248 2007/08/30 14:10:30 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.

**
** When SQLite invokes the xSync() method of an [sqlite3_io_methods]
** object it uses a combination of the following integer values as
** the second argument.
**
** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
** sync operation only needs to flush data to mass storage.  Inode
** information need not be flushed.  The SQLITE_SYNC_BARRIER flag
** means that the nothing actually needs to be synched to mass storage,
** but all write operations that occur before the barrier must complete
** before any write operations that occur after the barrier begin.
** The SQLITE_SYNC_NORMAL means to use normal fsync() semantics.
** The SQLITE_SYNC_FULL flag means to use Mac OS-X style fullsync
** instead of fsync().
*/
#define SQLITE_SYNC_BARRIER       0x00001
#define SQLITE_SYNC_NORMAL        0x00002
#define SQLITE_SYNC_FULL          0x00003
#define SQLITE_SYNC_DATAONLY      0x00010


/*
** CAPI3REF: OS Interface Open File Handle

/*
** CAPI3REF: OS Interface File Virtual Methods Object
**
** Every open file in the [sqlite3_vfs] xOpen method contains a pointer to
** an instance of the following object.  This object defines the
** methods used to perform various operations against the open file.
**
** The flags argument to xSync may be one of SQLITE_SYNC_BARRIER,
** SQLITE_SYNC_NORMAL, SQLITE_SYNC_FULL.  The first choice means that
** data is not necessarily synced to disk completely, only that
** all writes that occur before the sync complete before any
** writes that occur after the sync.  The second flag is the
** normal fsync().  The third flag is a OS-X style fullsync.
** The SQLITE_SYNC_DATA flag may be ORed in to indicate that only
** the data of the file and not its inode needs to be synced.

** 
** The integer values to xLock() and xUnlock() are one of
** SQLITE_LOCK_NONE, SQLITE_LOCK_READ, SQLITE_LOCK_RESERVED,
** SQLITE_LOCK_PENDING, or SQLITE_LOCK_EXCLUSIVE.  xLock()
** increases the lock. xUnlock() decreases the lock.  
** The xCheckReservedLock() method looks
** to see if any database connection, either in this