10. Libevent receives and processes server messages

test.cpp

#include <iostream>
#include <thread>
#include <event2/event.h>
#include <event2/event.h>
#include <event2/thread.h>
#include<event2/listener.h>
#include <errno.h>
#include <string.h>
#ifndef _WIN32
#include <signal.h>
#else
#endif
using namespace std;

#define SPORT 8989

// Normal disconnection and timeout will enter 
void client_cb(evutil_socket_t s, short w, void* arg)
{
	event* ev = (event*)arg;
	// Timeout event judgment 
	if (w & EV_TIMEOUT)
	{
		cout << "time out" << endl;
		event_free(ev);
		evutil_closesocket(s);
		return;
	}

	char  buf[1024] = { 0 };
	int len = recv(s, buf, sizeof(buf) - 1, 0);
	if (len > 0)
	{
		cout << buf << endl;
		send(s, "ok", 2, 0);
	}
	else
	{
		
		// It needs to be cleaned up event
		cout << "." << flush;
		event_free(ev);
		evutil_closesocket(s);
		
	}
	
}

void listen_cb(evutil_socket_t s, short w, void* arg)
{
	cout << "listen_cb" << endl;

	sockaddr_in sin;
	socklen_t size = sizeof(sin);
	// Read connection information 
	evutil_socket_t client = accept(s, (sockaddr*)&sin, &size);
	char ip[16] = { 0 };
	evutil_inet_ntop(AF_INET, &sin.sin_addr,ip,sizeof(ip)-1);
	cout << "client ip :" << ip << endl;

	event_base* base = (event_base*)arg;

	// Client data read event 
	event* ev = event_new(base, client, EV_READ | EV_PERSIST, client_cb, event_self_cbarg());
	timeval t = { 10,0 };
	event_add(ev, &t);
}


int main(int argc, char** argv)
{
#ifdef _WIN32 
	// initialization socket library 
	WSADATA wsa;
	WSAStartup(MAKEWORD(2, 2), &wsa);
#else
	// Ignore the pipe signal , Send data to the closed socket
	if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
		return 1;
#endif

	event_base* base = event_base_new();

	//event The server 
	cout << "event server ->" << endl;

	// establish socket
	evutil_socket_t sock = socket(AF_INET, SOCK_STREAM, 0);
	if (sock <= 0)
	{
		cout << "socket error: " << strerror(errno) << endl;
		return -1;
	}

	// Set address multiplexing and non blocking 
	evutil_make_socket_nonblocking(sock);
	evutil_make_listen_socket_reuseable(sock);

	// Binding port and address 
	sockaddr_in sin;
	memset(&sin, 0, sizeof(sin));
	sin.sin_family = AF_INET;
	sin.sin_port = htons(SPORT);
	int re = ::bind(sock, (sockaddr*)&sin, sizeof(sin));
	if (re != 0)
	{
		cerr << "bind error: " << strerror(errno) << endl;
		return -1;
	}

	// Start listening 
	listen(sock, 10);

	// Accept connection Events 
	event* ev = event_new(base, sock, EV_READ | EV_PERSIST, listen_cb, base);
	event_add(ev, 0);


	// Enter the event main loop 
	event_base_dispatch(base);
	evutil_closesocket(sock);
	event_base_free(base);

	return 0;
}

linux Next makefile

test:test.cpp
        g++ $^ -o $@ -levent
        ./$@
clean:
        rm -rf test
        rm -rf *.o