nl_tokens: compass task works at multi threads .
pl_tokens: function ( options , cb ) { // if no sassDir or files are not identify, error. if ( ! options . sassDir ) { grunt . log . error ( 'compass-multiple needs sassDir for searching scss files.' ) ; cb ( false ) ; } // search scss files.(Additional Implementation) if ( options . sassFiles ) { var pathes = options . sassFiles ; var pathesCount = pathes . length ; var currentCount = 0 ; var files = [ ] ; for ( var i = 0 ; i < pathes . length ; i ++ ) { glob ( pathes [ i ] , function ( error , tmpFiles ) { if ( error ) { console . log ( 'error: ' , error ) ; cb ( false ) ; } files = files . concat ( tmpFiles ) ; currentCount ++ ; if ( pathesCount === currentCount ) { // compass compile. grunt . log . writeln ( 'pathes: ' , files ) ; compileFiles ( options , files , cb ) ; } } ) ; } } else { // use sassDir var searchPath = options . sassDir + '/**/*.scss' ; glob ( searchPath , function ( error , files ) { if ( error ) { console . log ( 'error: ' , error ) ; cb ( false ) ; } // compass compile. compileFiles ( options , <mask> , cb ) ; } ) ; } }