一 rounter / Dealer
client <=> server (rounter<=>dealer) <=> work0, work1,...
Two requirements:
Server sends an instruction to the client, server response immediately recovered, server asynchronous processing instruction, returns the process result to the client periodically.
Three Solutions:
server using rounter / dealer mode, deal with two communication work, work0 responsible for an acknowledgment back, work1 responsible for the processing result back.
Four codes:
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <iostream>
#include <thread>
#include <zmq.h>
using namespace std;
int do_router(void* router, void* dealer) {
while (true) {
int more = 1;
zmq_msg_t message;
zmq_msg_init(&message);
int rc = zmq_msg_recv(&message, router, 0);
size_t more_size = sizeof(more);
zmq_getsockopt(router, ZMQ_RCVMORE, &more, &more_size);
zmq_msg_send(&message, dealer, more ? ZMQ_SNDMORE : 0);
printf("[%ld] router deliver request to dealer. rc = %d, more = %d\n", time(NULL), rc, more);
zmq_msg_close(&message);
if (!more) {
break; // Last message part
}
}
printf("[%ld]----------DoRouter----------\n\n", time(NULL));
return 0;
}
int do_dealer(void* router, void* dealer) {
while (true) {
int more = 1;
zmq_msg_t message;
zmq_msg_init(&message);
int rc = zmq_msg_recv(&message, dealer, 0);
size_t more_size = sizeof (more);
zmq_getsockopt(dealer, ZMQ_RCVMORE, &more, &more_size);
zmq_msg_send(&message, router, more ? ZMQ_SNDMORE : 0);
printf("[%ld] dealer deliver reply to router. rc = %d, more = %d\n", time(NULL), rc, more);
zmq_msg_close(&message);
if (!more) {
break; // Last message part
}
}
printf("[%ld]----------DoDealer----------\n\n", time(NULL));
return 0;
}
void work0() {
void* context = zmq_ctx_new();
void* worker = zmq_socket(context, ZMQ_REP);
const char *addr = "tcp://127.0.0.1:9999";
int rec = zmq_connect(worker, addr);
if (rec) {
printf("zmq_connect %s error:%d\n", addr, rec);
zmq_close(worker);
zmq_ctx_term(context);
return;
}
printf("worker zmq_connect %s done!\n", addr);
char buf[128] = {0};
char buf1[128] = "work0 ack now.";
while (true) {
cout << "I am work0." << endl;
rec = zmq_recv(worker, buf, sizeof(buf), 0);
printf("[%ld] work0 recv request(%s) from client, rec = %d, request.len = %zu\n", time(NULL), buf, rec, strlen(buf));
rec = zmq_send(worker, buf1, strlen(buf1), 0);
printf("[%ld] work0 send reply(%s) to client, rec = %d, reply.len = %zu\n", time(NULL), buf1, rec, strlen(buf1));
printf("[%ld]------------------------\n\n", time(NULL));
}
zmq_close(worker);
zmq_ctx_term(context);
printf("good bye and good luck!\n");
}
void work1() {
void* context = zmq_ctx_new();
void* worker = zmq_socket(context, ZMQ_REP);
const char *addr = "tcp://127.0.0.1:9999";
int rec = zmq_connect(worker, addr);
if (rec) {
printf("zmq_connect %s error:%d\n", addr, rec);
zmq_close(worker);
zmq_ctx_term(context);
return;
}
printf("worker zmq_connect %s done!\n", addr);
char buf[128] = {0};
char buf1[128] = {"work1 process ok."};
while (true) {
rec = zmq_recv(worker, buf, sizeof(buf), 0);
cout << "I am work1." << endl;
printf("[%ld] work1 recv request(%s) from client, rec = %d, request.len = %zu\n", time(NULL), buf, rec, strlen(buf));
sleep(6);
rec = zmq_send(worker, buf1, strlen(buf1), 0);
printf("[%ld] work1 send reply(%s) to client, rec = %d, reply.len = %zu\n", time(NULL), buf1, rec, strlen(buf1));
printf("[%ld]------------------------\n\n", time(NULL));
}
zmq_close(worker);
zmq_ctx_term(context);
printf("good bye and good luck!\n");
}
void client() {
void* context = zmq_ctx_new();
void* client = zmq_socket(context, ZMQ_REQ);
const char *addr = "tcp://127.0.0.1:8888";
int rec = zmq_connect(client, addr);
if (rec) {
printf("zmq_connect %s error:%d\n", addr, rec);
zmq_close(client);
zmq_ctx_term(context);
return;
}
printf("worker zmq_connect %s done!\n", addr);
char buf[128] = "hello I am a client.";
char buf1[128] = "";
while (true) {
rec = zmq_send(client, buf, strlen(buf), 0);
printf("[%ld] client send request(%s) from client, rec = %d, request.len = %zu\n", time(NULL), buf, rec, strlen(buf));
sleep(2);
rec = zmq_recv(client, buf1, sizeof(buf1), 0);
printf("[%ld] client recv reply(%s) from server, rec = %d, reply.len = %zu\n", time(NULL), buf, rec, strlen(buf));
printf("[%ld]------------------------\n\n", time(NULL));
}
zmq_close(client);
zmq_ctx_term(context);
printf("good bye and good luck!\n");
}
int main(int argc, char** argv) {
if (argc < 5) {
printf("usage : %s router_ip router_port dealer_ip dealer_port\n", argv[0]);
return -1;
}
int major, minor, patch;
zmq_version (&major, &minor, &patch);
printf ("Current 0MQ version is %d.%d.%d\n", major, minor, patch);
printf("===========================================\n\n");
char addr[128] = {0};
void* context = zmq_ctx_new();
snprintf(addr, sizeof(addr), "tcp://%s:%s", argv[1], argv[2]);
void* router = zmq_socket(context, ZMQ_ROUTER);
int rc = zmq_bind(router, addr);
printf("[%ld] router bind %s %s.\n", time(NULL), addr, (rc ? "error" : "ok"));
if (rc) {
printf("[%ld] router bind error : %s\n", time(NULL), zmq_strerror(zmq_errno()));
zmq_close(router);
zmq_ctx_term(context);
return -2;
}
snprintf(addr, sizeof(addr), "tcp://%s:%s", argv[3], argv[4]);
void* dealer = zmq_socket(context, ZMQ_DEALER);
rc = zmq_bind(dealer, addr);
printf("[%ld] dealer bind %s %s.\n", time(NULL), addr, (rc ? "error" : "ok"));
if (rc) {
printf("[%ld] dealer bind error : %s\n", time(NULL), zmq_strerror(zmq_errno()));
zmq_close(router);
zmq_close(dealer);
zmq_ctx_term(context);
return -3;
}
thread th0(work0);
thread th1(work1);
thread th2(client);
zmq_pollitem_t items [] = {
{router, 0, ZMQ_POLLIN, 0} , {dealer, 0, ZMQ_POLLIN, 0} };
while (true) {
rc = zmq_poll(items, sizeof(items) / sizeof(zmq_pollitem_t), 1000);
if (rc < 0) {
printf("[%ld] zmq_poll error: %d\n", time(NULL), rc);
break;
}
printf("[%ld] zmq_poll rc = %d\n", time(NULL), rc);
if (rc < 1) {
continue;
}
if (items[0].revents & ZMQ_POLLIN) {
/* router可读事件，说明有client请求过来了。 */
printf("[%ld] zmq_poll catch one router event!\n", time(NULL));
do_router(router, dealer);
}
else if (items[1].revents & ZMQ_POLLIN) {
/* dealer可读事件，说明有worker的应答数据到来了。 */
printf("[%ld] zmq_poll catch one dealer event!\n", time(NULL));
do_dealer(router, dealer);
}
else {
printf("[%ld] zmq_poll Don't Care this evnet!\n", time(NULL));
}
}
th0.join();
th1.join();
th2.join();
zmq_close(router);
zmq_close(dealer);
zmq_ctx_term(context);
printf("[%ld] good bye and good luck!\n", time(NULL));
return 0;
}