close(sig)
				return

			default:
				syscall.Kill(syscall.Getpid(), syscall.SIGUSR1)
				runtime.Gosched()
			}
		}
	}()

	for range sig {
		// Receive signals until the sender closes sig.
	}
}

func testCancel(t *testing.T, ignore bool) {
	// Ask to be notified on c1 when a SIGWINCH is received.
	c1 := make(chan os.Signal, 1)
	Notify(c1, syscall.SIGWINCH)
	defer Stop(c1)

	c.sendx++
	if c.sendx == c.dataqsiz {
		c.sendx = 0
	}
	c.qcount++
	selunlock(scases, lockorder)
	goto retc

recv:
	// can receive from sleeping sender (sg)
	recv(c, sg, cas.elem, func() { selunlock(scases, lockorder) }, 2)
	if debugSelect {
		print("syncrecv: cas0=", cas0, " c=", c, "\n")
	}
	recvOK = true
	goto retc

rclose:

//   - oobn is the number of control data bytes read into oob; this may be interpreted using [ParseSocketControlMessage]
//   - recvflags is flags returned by recvmsg
//   - from is the address of the sender
//
// If the underlying socket type is not SOCK_DGRAM, a received message
// containing oob data and a single '\0' of non-control data is treated as if

      }
      flowControlListener.receivingConnectionWindowChanged(readBytes)
    }
  }

  /**
   * Returns a new server-initiated stream.
   *
   * @param associatedStreamId the stream that triggered the sender to create this stream.
   * @param out true to create an output stream that we can use to send data to the remote peer.
   *     Corresponds to `FLAG_FIN`.
   */
  @Throws(IOException::class)
  fun pushStream(

		// Returning error here is too noisy.
		return nil
	case c.outQueue <- msg:
		return nil
	}
}

// queueMsg queues a message, with an optional payload.
// sender should not reference msg.Payload
func (c *Connection) queueMsg(msg message, payload sender) error {
	// Add baseflags.
	msg.Flags.Set(c.baseFlags)
	// This cannot encode subroute.
	msg.Flags.Clear(FlagSubroute)
	if payload != nil {

	// Start two goroutines ping-ponging on a channel send.
	// At any given time, at least one of these goroutines is runnable:
	// if the channel buffer is full, the receiver is runnable,
	// and if it is not full, the sender is runnable.
	//
	// In addition, the AfterFunc callback should become runnable after
	// the indicated delay.
	//
	// Even if GOMAXPROCS=1, we expect the runtime to eventually schedule

  Scope root = Scope::NewRootScope().ExitOnError();

  Output recv_a = ops::_Recv(root.WithOpName("recv_a"), DT_BOOL, "tensor_a",
                             "sender", 0, "receiver");
  Output recv_b = ops::_Recv(root.WithOpName("recv_b"), DT_BOOL, "tensor_b",
                             "sender", 0, "receiver");
  Output const_a = ops::Const(root.WithOpName("const_a"), 42);

  ops::ControlTrigger ctrl_trigger_a(root.WithOpName("ctrl_trigger_a"));

	if !isZeroTime(modtime) {
		w.Header().Set("Last-Modified", modtime.UTC().Format(TimeFormat))
	}
}

func writeNotModified(w ResponseWriter) {
	// RFC 7232 section 4.1:
	// a sender SHOULD NOT generate representation metadata other than the
	// above listed fields unless said metadata exists for the purpose of
	// guiding cache updates (e.g., Last-Modified might be useful if the

	}

	// Sender sending more than they'd declared?
	if st.declBodyBytes != -1 && st.bodyBytes+int64(len(data)) > st.declBodyBytes {
		if !sc.inflow.take(f.Length) {
			return sc.countError("data_flow", http2streamError(id, http2ErrCodeFlowControl))
		}
		sc.sendWindowUpdate(nil, int(f.Length)) // conn-level

		if err != nil {
			return nil, nil, nil, err
		}
	}

	return hello, keyShareKeys, ech, nil
}

type echContext struct {
	config          *echConfig
	hpkeContext     *hpke.Sender
	encapsulatedKey []byte
	innerHello      *clientHelloMsg
	innerTranscript hash.Hash
	kdfID           uint16
	aeadID          uint16
	echRejected     bool
}