Exemplo n.º 1
0
func (clnt *Clnt) recv() {
	var err error
	var buf []byte

	err = nil
	pos := 0
	for {
		// Connect can change the client Msize.
		clntmsize := int(atomic.LoadUint32(&clnt.Msize))
		if len(buf) < clntmsize {
			b := make([]byte, clntmsize*8)
			copy(b, buf[0:pos])
			buf = b
			b = nil
		}

		n, oerr := clnt.conn.Read(buf[pos:])
		if oerr != nil || n == 0 {
			err = &ninep.Error{oerr.Error(), ninep.EIO}
			clnt.Lock()
			clnt.err = err
			clnt.Unlock()
			goto closed
		}

		pos += n
		for pos > 4 {
			sz, _ := ninep.Gint32(buf)
			if pos < int(sz) {
				if len(buf) < int(sz) {
					b := make([]byte, atomic.LoadUint32(&clnt.Msize)*8)
					copy(b, buf[0:pos])
					buf = b
					b = nil
				}

				break
			}

			fc, err, fcsize := ninep.Unpack(buf, clnt.Dotu)
			clnt.Lock()
			if err != nil {
				clnt.err = err
				clnt.conn.Close()
				clnt.Unlock()
				goto closed
			}

			if clnt.Debuglevel > 0 {
				clnt.logFcall(fc)
				if clnt.Debuglevel&DbgPrintPackets != 0 {
					log.Println("}-}", clnt.Id, fmt.Sprint(fc.Pkt))
				}

				if clnt.Debuglevel&DbgPrintFcalls != 0 {
					log.Println("}}}", clnt.Id, fc.String())
				}
			}

			var r *Req = nil
			for r = clnt.reqfirst; r != nil; r = r.next {
				if r.Tc.Tag == fc.Tag {
					break
				}
			}

			if r == nil {
				clnt.err = &ninep.Error{"unexpected response", ninep.EINVAL}
				clnt.conn.Close()
				clnt.Unlock()
				goto closed
			}

			// Good clean fun. There's a race where you can get the response BEFORE the loop
			// in send() thinks it is done with the request. So we have to block on
			// it being sent, because we really can't dequeue any more requests until
			// this one is wrapped up. TODO: consider a goroutine per fid for this,
			// if we need it. The reason I feel this is safe is that if we got a tag back
			// for a request we sent, then r.Sent should be written. If we got a tag
			// back for a request we did not sent, we won't find it here anyway.
			<-r.Sent

			r.Rc = fc
			switch {
			case r.next == nil && r.prev == nil:
				clnt.reqlast = nil
				clnt.reqfirst = nil
			case r.next == nil:
				clnt.reqlast = r.prev
				r.prev.next = nil
				r.prev = nil
			case r.prev == nil:
				clnt.reqfirst = r.next
				r.next.prev = nil
				r.next = nil
			default:
				r.next.prev = r.prev
				r.prev.next = r.next
				r.next = nil
				r.prev = nil
			}
			clnt.Unlock()

			if r.Tc.Type != r.Rc.Type-1 {
				if r.Rc.Type != ninep.Rerror {
					r.Err = &ninep.Error{"invalid response", ninep.EINVAL}
				} else {
					if r.Err == nil {
						r.Err = &ninep.Error{r.Rc.Error, r.Rc.Errornum}
					}
				}
			}

			if r.Done != nil {
				r.Done <- r
			}

			pos -= fcsize
			buf = buf[fcsize:]
		}
	}

closed:
	clnt.Lock()
	// Drain all sent notifications from the send goroutine so
	// that it can accept the done notification below.  This is
	// necessary in cases where the conn.Read returned an error
	// and the normal <-r.Sent is never reached.
	for r := clnt.reqfirst; r != nil; r = r.next {
		<-r.Sent
	}
	clnt.Unlock()

	clnt.done <- true

	/* send error to all pending requests */
	clnt.Lock()
	r := clnt.reqfirst
	clnt.reqfirst = nil
	clnt.reqlast = nil
	if err == nil {
		err = clnt.err
	}
	clnt.Unlock()
	for r != nil {
		next := r.next
		r.Err = err
		r.next = nil
		r.prev = nil
		if r.Done != nil {
			r.Done <- r
		}
		r = next
	}

	clnts.Lock()
	if clnt.prev != nil {
		clnt.prev.next = clnt.next
		clnt.prev = nil
	} else {
		clnts.clntList = clnt.next
	}

	if clnt.next != nil {
		clnt.next.prev = clnt.prev
		clnt.next = nil
	} else {
		clnts.clntLast = clnt.prev
	}
	clnts.Unlock()

	if sop, ok := (interface{}(clnt)).(StatsOps); ok {
		sop.statsUnregister()
	}
}
Exemplo n.º 2
0
func (conn *Conn) recv() {
	var err error
	var n int

	buf := make([]byte, conn.Msize*8)
	pos := 0
	for {
		if len(buf) < int(conn.Msize) {
			b := make([]byte, conn.Msize*8)
			copy(b, buf[0:pos])
			buf = b
			b = nil
		}

		n, err = conn.conn.Read(buf[pos:])
		if err != nil || n == 0 {
			conn.close()
			return
		}

		pos += n
		for pos > 4 {
			sz, _ := ninep.Gint32(buf)
			if sz > conn.Msize {
				log.Println("bad client connection: ", conn.conn.RemoteAddr())
				conn.conn.Close()
				conn.close()
				return
			}
			if pos < int(sz) {
				if len(buf) < int(sz) {
					b := make([]byte, conn.Msize*8)
					copy(b, buf[0:pos])
					buf = b
					b = nil
				}

				break
			}
			fc, err, fcsize := ninep.Unpack(buf, conn.Dotu)
			if err != nil {
				log.Println(fmt.Sprintf("invalid packet : %v %v", err, buf))
				conn.conn.Close()
				conn.close()
				return
			}

			tag := fc.Tag
			req := new(Req)
			select {
			case req.Rc = <-conn.rchan:
				break
			default:
				req.Rc = ninep.NewFcall(conn.Msize)
			}

			req.Conn = conn
			req.Tc = fc
			//			req.Rc = rc
			if conn.Debuglevel > 0 {
				conn.logFcall(req.Tc)
				if conn.Debuglevel&DbgPrintPackets != 0 {
					log.Println(">->", conn.Id, fmt.Sprint(req.Tc.Pkt))
				}

				if conn.Debuglevel&DbgPrintFcalls != 0 {
					log.Println(">>>", conn.Id, req.Tc.String())
				}
			}

			conn.Lock()
			conn.nreqs++
			conn.tsz += uint64(fc.Size)
			conn.npend++
			if conn.npend > conn.maxpend {
				conn.maxpend = conn.npend
			}

			req.next = conn.Reqs[tag]
			conn.Reqs[tag] = req
			process := req.next == nil
			if req.next != nil {
				req.next.prev = req
			}
			conn.Unlock()
			if process {
				// Tversion may change some attributes of the
				// connection, so we block on it. Otherwise,
				// we may loop back to reading and that is a race.
				// This fix brought to you by the race detector.
				if req.Tc.Type == ninep.Tversion {
					req.process()
				} else {
					go req.process()
				}
			}

			buf = buf[fcsize:]
			pos -= fcsize
		}
	}
}