SQLite

  sqlite3_int64 tElapse,           /* Elapse time of system call */
  const char *zOp,                 /* Type of system call */
  sqlite3_int64 iArg1,             /* First argument */
  sqlite3_int64 iArg2,             /* Second argument */
  const char *zArg3,               /* Third argument */
  int iRes                         /* Result */
){
  char z1[40], z2[40], z3[2000];
  if( pLog==0 ) return;
  if( iArg1>=0 ){
    sqlite3_snprintf(sizeof(z1), z1, "%lld", iArg1);
  }else{
    z1[0] = 0;
  }
  if( iArg2>=0 ){
    sqlite3_snprintf(sizeof(z2), z2, "%lld", iArg2);
  }else{
    z2[0] = 0;
  }
  if( zArg3 ){
    sqlite3_snprintf(sizeof(z3), z3, "\"%.*w\"", sizeof(z3)-4, zArg3);
  }else{
    z3[0] = 0;
  }
  fprintf(pLog->out,"%lld,%lld,%s,%d,%s,%s,%s,%d\n",
      tStart, tElapse, zOp, pLog->zFilename==0, z1, z2, z3, iRes);
}

}

/*
** Unlock an vlog-file.
*/
static int vlogUnlock(sqlite3_file *pFile, int eLock){
  int rc;
  sqlite3_uint64 tStart;
  VLogFile *p = (VLogFile *)pFile;
  tStart = vlog_time();
  vlogLogPrint(p->pLog, tStart, 0, "UNLOCK", eLock, -1, 0, 0);
  rc = p->pReal->pMethods->xUnlock(p->pReal, eLock);


  return rc;
}

/*
** Check if another file-handle holds a RESERVED lock on an vlog-file.
*/
static int vlogCheckReservedLock(sqlite3_file *pFile, int *pResOut){

  int rc;
  tStart = vlog_time();
  rc = p->pReal->pMethods->xFileControl(p->pReal, op, pArg);
  if( op==SQLITE_FCNTL_VFSNAME && rc==SQLITE_OK ){
    *(char**)pArg = sqlite3_mprintf("vlog/%z", *(char**)pArg);
  }
  tElapse = vlog_time() - tStart;
  if( op==SQLITE_FCNTL_TRACE ){
    vlogLogPrint(p->pLog, tStart, tElapse, "TRACE", op, -1, pArg, rc);
  }else if( op==SQLITE_FCNTL_PRAGMA ){
    const char **azArg = (const char **)pArg;
    vlogLogPrint(p->pLog, tStart, tElapse, "FILECONTROL", op, -1, azArg[1], rc);
  }else if( op==SQLITE_FCNTL_SIZE_HINT ){
    sqlite3_int64 sz = *(sqlite3_int64*)pArg;
    vlogLogPrint(p->pLog, tStart, tElapse, "FILECONTROL", op, sz, 0, rc);
  }else{
    vlogLogPrint(p->pLog, tStart, tElapse, "FILECONTROL", op, -1, 0, rc);

** The argument is a pointer to a value of type sqlite3_int64 that
** is an advisory maximum number of bytes in the file to memory map.  The
** pointer is overwritten with the old value.  The limit is not changed if
** the value originally pointed to is negative, and so the current limit 
** can be queried by passing in a pointer to a negative number.  This
** file-control is used internally to implement [PRAGMA mmap_size].
**
** <li>[[SQLITE_FCNTL_TRACE]]
** The [SQLITE_FCNTL_TRACE] file control provides advisory information
** to the VFS about what the higher layers of the SQLite stack are doing.
** This file control is used by some VFS activity tracing [shims].
** The argument is a zero-terminated string.  Higher layers in the
** SQLite stack may generate instances of this file control if
** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
**
** </ul>
*/
#define SQLITE_FCNTL_LOCKSTATE               1
#define SQLITE_GET_LOCKPROXYFILE             2
#define SQLITE_SET_LOCKPROXYFILE             3
#define SQLITE_LAST_ERRNO                    4
#define SQLITE_FCNTL_SIZE_HINT               5
#define SQLITE_FCNTL_CHUNK_SIZE              6
#define SQLITE_FCNTL_FILE_POINTER            7
#define SQLITE_FCNTL_SYNC_OMITTED            8
#define SQLITE_FCNTL_WIN32_AV_RETRY          9
#define SQLITE_FCNTL_PERSIST_WAL            10
#define SQLITE_FCNTL_OVERWRITE              11
#define SQLITE_FCNTL_VFSNAME                12
#define SQLITE_FCNTL_POWERSAFE_OVERWRITE    13
#define SQLITE_FCNTL_PRAGMA                 14
#define SQLITE_FCNTL_BUSYHANDLER            15
#define SQLITE_FCNTL_TEMPFILENAME           16
#define SQLITE_FCNTL_MMAP_SIZE              18
#define SQLITE_FCNTL_TRACE                  19

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

   && !p->doingRerun
   && (zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0
  ){
    z = sqlite3VdbeExpandSql(p, zTrace);
    db->xTrace(db->pTraceArg, z);
    sqlite3DbFree(db, z);
  }
#ifdef SQLITE_USE_FCNTL_TRACE
  zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql);
  if( zTrace ){
    int i;
    for(i=0; i<db->nDb; i++){
      if( ((1<<i) & p->btreeMask)==0 ) continue;
      sqlite3_file_control(db, db->aDb[i].zName, SQLITE_FCNTL_TRACE, zTrace);
    }
  }
#endif /* SQLITE_USE_FCNTL_TRACE */
#ifdef SQLITE_DEBUG
  if( (db->flags & SQLITE_SqlTrace)!=0
   && (zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0
  ){
    sqlite3DebugPrintf("SQL-trace: %s\n", zTrace);
  }
#endif /* SQLITE_DEBUG */