remove deadlock

[Fu-XDU]

Because of unpredictable network connections during consensus, a deadlock can be caused as below.

At simple_pbft/pbft/network/proxy_server.go

func send(url string, msg []byte) {
	buff := bytes.NewBuffer(msg)
	http.Post("http://"+url, "application/json", buff)
}

http.Post will always wait until its response arrives. While http.Post is waiting, node.MsgDelivery is blocked so that resolveMsg() at simple_pbft/pbft/network/node.go can't deliver other msg. But the premise of the http.Post response’s arrival is that our node has processed the request msg of other nodes, so a deadlock is produced.

To resolve the deadlock, we can use go routine to make node processes other msg while waiting the post response.

func send(url string, msg []byte) {
	buff := bytes.NewBuffer(msg)
	go http.Post("http://"+url, "application/json", buff)
}