SQLite

      rc = SQLITE_NOMEM;
    }
    sqlite3Error(db, rc);
    goto opendb_out;
  }
  sqlite3BtreeEnter(db->aDb[0].pBt);
  db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
  if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);
  sqlite3BtreeLeave(db->aDb[0].pBt);
  db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);

  /* The default safety_level for the main database is 'full'; for the temp
  ** database it is 'NONE'. This matches the pager layer defaults.  
  */
  db->aDb[0].zName = "main";

  sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
  zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
  if( zFilename8 ){
    rc = openDatabase(zFilename8, ppDb,
                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
    assert( *ppDb || rc==SQLITE_NOMEM );
    if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
      SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
    }
  }else{
    rc = SQLITE_NOMEM;
  }
  sqlite3ValueFree(pVal);

  return sqlite3ApiExit(0, rc);

      */
      if( 
        !(DbHasProperty(db, 0, DB_SchemaLoaded)) || 
        DbHasProperty(db, 0, DB_Empty) 
      ){
        for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
          if( 0==sqlite3StrICmp(zRight, pEnc->zName) ){
            SCHEMA_ENC(db) = ENC(db) =
                pEnc->enc ? pEnc->enc : SQLITE_UTF16NATIVE;
            break;
          }
        }
        if( !pEnc->zName ){
          sqlite3ErrorMsg(pParse, "unsupported encoding: %s", zRight);
        }
      }

** file was of zero-length, then the DB_Empty flag is also set.
*/
int sqlite3Init(sqlite3 *db, char **pzErrMsg){
  int i, rc;
  int commit_internal = !(db->flags&SQLITE_InternChanges);
  
  assert( sqlite3_mutex_held(db->mutex) );
  assert( sqlite3BtreeHoldsMutex(db->aDb[0].pBt) );
  assert( db->init.busy==0 );
  rc = SQLITE_OK;
  db->init.busy = 1;
  ENC(db) = SCHEMA_ENC(db);
  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
    if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue;
    rc = sqlite3InitOne(db, i, pzErrMsg);
    if( rc ){
      sqlite3ResetOneSchema(db, i);
    }
  }

  int flags;                    /* Miscellaneous flags. See below */
  i64 lastRowid;                /* ROWID of most recent insert (see above) */
  i64 szMmap;                   /* Default mmap_size setting */
  unsigned int openFlags;       /* Flags passed to sqlite3_vfs.xOpen() */
  int errCode;                  /* Most recent error code (SQLITE_*) */
  int errMask;                  /* & result codes with this before returning */
  u16 dbOptFlags;               /* Flags to enable/disable optimizations */
  u8 enc;                       /* Text encoding */
  u8 autoCommit;                /* The auto-commit flag. */
  u8 temp_store;                /* 1: file 2: memory 0: default */
  u8 mallocFailed;              /* True if we have seen a malloc failure */
  u8 dfltLockMode;              /* Default locking-mode for attached dbs */
  signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
  u8 suppressErr;               /* Do not issue error messages if true */
  u8 vtabOnConflict;            /* Value to return for s3_vtab_on_conflict() */

  sqlite3_userauth auth;        /* User authentication information */
#endif
};

/*
** A macro to discover the encoding of a database.
*/
#define SCHEMA_ENC(db) ((db)->aDb[0].pSchema->enc)
#define ENC(db)        ((db)->enc)

/*
** Possible values for the sqlite3.flags.
*/
#define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
#define SQLITE_InternChanges  0x00000002  /* Uncommitted Hash table changes */
#define SQLITE_FullFSync      0x00000004  /* Use full fsync on the backend */

    worker_trace(p, "query [%s]", sqlite3_sql(pStmt));
    rc = sqlite3_step(pStmt);
    if( rc!=SQLITE_ROW ){
      worker_error(p, "Failed to step: %s", sqlite3_sql(pStmt));
    }else if( sqlite3_column_int(pStmt, 0)!=400 ){
      worker_error(p, "Wrong result: %d", sqlite3_column_int(pStmt,0));
    }

    sqlite3_finalize(pStmt);
    if( p->nErr ) break;

    if( ((iOuter+p->tid)%3)==0 ){
      sqlite3_db_release_memory(p->db);
      p->nTest++;
    }

    pthread_mutex_lock(p->pWrMutex);
    run_sql(p, "BEGIN;");
    run_sql(p, "UPDATE t1 SET c=NULL WHERE a=55");
    run_sql(p, "UPDATE t2 SET f=NULL WHERE d=42");
    run_sql(p, "UPDATE t3 SET z=NULL WHERE x=31");
    run_sql(p, "ROLLBACK;");
    p->nTest++;
    pthread_mutex_unlock(p->pWrMutex);


    if( iOuter==p->tid ){
      pthread_mutex_lock(p->pWrMutex);
      run_sql(p, "VACUUM");
      pthread_mutex_unlock(p->pWrMutex);
    }

    pStmt = prep_sql(p->db,
       "SELECT t1.rowid, t2.rowid, t3.rowid"
       "  FROM t1, t2, t3"
       " WHERE t1.tid=%d AND t2.tid=%d AND t3.tid=%d"
       "   AND t1.a<>t2.d AND t2.d<>t3.x"
       " ORDER BY 1, 2, 3"
       ,p->tid, p->tid, p->tid);
    worker_trace(p, "query [%s]", sqlite3_sql(pStmt));
    for(i=0; i<p->nWorker; i++){
      rc = sqlite3_step(pStmt);
      if( rc!=SQLITE_ROW ){
        worker_error(p, "Failed to step: %s", sqlite3_sql(pStmt));
        break;
      }
      sched_yield();
    }
    sqlite3_finalize(pStmt);
    if( p->nErr ) break;

    worker_delete_all_content(p, (p->tid+iOuter)%2);
    worker_close_connection(p);
    p->db = 0;
  }
  worker_close_connection(p);
  printf("worker %d finished\n", p->tid); fflush(stdout);