question: @ Override public void free ( long idleStartTime ) { if ( _is == null ) { IllegalStateException exn = new IllegalStateException ( L . l ( "{0} unexpected free of closed stream" , this ) ) ; exn . fillInStackTrace ( ) ; log . log ( Level . FINE , exn . toString ( ) , exn ) ; return ; } long requestStartTime = _requestStartTime ; _requestStartTime = 0 ; if ( requestStartTime > 0 ) _requestTimeProbe . end ( requestStartTime ) ; if ( idleStartTime <= 0 ) { idleStartTime = _is . getReadTime ( ) ; if ( idleStartTime <= 0 ) { idleStartTime = CurrentTime . currentTime ( ) ; } } _idleStartTime = idleStartTime ; _idleProbe . start ( ) ; _isIdle = true ; _pool . free ( this ) ; }
target:  Adds the stream to the free pool. The idleStartTime may be earlier than the current time to deal with TCP buffer delays. Typically it will be recorded as the start time of the request's write.