我目前正在学习如何使用朋友建议我用于个人项目的lib ZeroMQ。
在阅读文档并规划如何将lib用于我的项目之后，我开始使用文档给出的代码测试项目。 我使用的测试是this one。 不幸的是，它不起作用。我做了一些小修改来测试它。 （我给出了我测试时的确切代码，很多，我很抱歉，但是没有我觉得它没有意义，也无法帮助我：/）。< / p>
我几乎没有改变文档给出的测试，只是添加了一些输出进行测试，我也删除了客户端的轮询（我认为问题来自这里，因为它阻止了无限循环，即使有一个超时）。
#include <vector>
#include <thread>
#include <memory>
#include <functional>
#include <zmq.h>
#include <zmq.hpp>
#include <zhelper.hpp>
// This is our client task class.
// It connects to the server, and then sends a request once per second
// It collects responses as they arrive, and it prints them out. We will
// run several client tasks in parallel, each with a different random ID.
// Attention! -- this random work well only on linux.
class client_task {
public:
client_task()
: ctx_(1),
client_socket_(ctx_, ZMQ_DEALER)
{}
void start() {
// generate random identity
char identity[10] = {};
sprintf(identity, "%04X-%04X", within(0x10000), within(0x10000));
printf("-> %s\n", identity);
client_socket_.setsockopt(ZMQ_IDENTITY, identity, strlen(identity));
client_socket_.connect("tcp://localhost:5570");
zmq_pollitem_t items;
items.socket = &client_socket_;
items.fd = 0;
items.events = ZMQ_POLLIN;
items.revents = 0;
int request_nbr = 0;
try {
while (true) {
for (int i = 0; i < 100; ++i) {
// 10 milliseconds
sleep(1);
std::cout << "ici" << std::endl;
if (items.revents & ZMQ_POLLIN) {
printf("\n%s ", identity);
s_dump(client_socket_);
}
char request_string[16] = {};
sprintf(request_string, "request #%d", ++request_nbr);
client_socket_.send(request_string, strlen(request_string));
}
}
}
catch (std::exception &e)
{}
}
private:
zmq::context_t ctx_;
zmq::socket_t client_socket_;
};
// Each worker task works on one request at a time and sends a random number
// of replies back, with random delays between replies:
class server_worker {
public:
server_worker(zmq::context_t &ctx, int sock_type)
: ctx_(ctx),
worker_(ctx_, sock_type)
{}
void work() {
worker_.connect("inproc://backend");
try {
while (true) {
zmq::message_t identity;
zmq::message_t msg;
zmq::message_t copied_id;
zmq::message_t copied_msg;
worker_.recv(&identity);
worker_.recv(&msg);
std::cout << "I never arrive here" << std::endl;
int replies = within(5);
for (int reply = 0; reply < replies; ++reply) {
std::cout << "LA" << std::endl;
s_sleep(within(1000) + 1);
copied_id.copy(&identity);
copied_msg.copy(&msg);
worker_.send(copied_id, ZMQ_SNDMORE);
worker_.send(copied_msg);
}
}
}
catch (std::exception &e) {}
}
private:
zmq::context_t &ctx_;
zmq::socket_t worker_;
};
// This is our server task.
// It uses the multithreaded server model to deal requests out to a pool
// of workers and route replies back to clients. One worker can handle
// one request at a time but one client can talk to multiple workers at
// once.
class server_task {
public:
server_task()
: ctx_(1),
frontend_(ctx_, ZMQ_ROUTER),
backend_(ctx_, ZMQ_DEALER)
{}
void run() {
frontend_.bind("tcp://*:5570");
backend_.bind("inproc://backend");
server_worker * worker = new server_worker(ctx_, ZMQ_DEALER);
std::thread worker_thread(std::bind(&server_worker::work, worker));
worker_thread.detach();
try {
zmq::proxy(&frontend_, &backend_, NULL);
}
catch (std::exception &e) {}
}
private:
zmq::context_t ctx_;
zmq::socket_t frontend_;
zmq::socket_t backend_;
};
// The main thread simply starts several clients and a server, and then
// waits for the server to finish.
int main (void)
{
client_task ct1;
client_task ct2;
client_task ct3;
server_task st;
std::thread t1(std::bind(&client_task::start, &ct1));
std::thread t2(std::bind(&client_task::start, &ct2));
std::thread t3(std::bind(&client_task::start, &ct3));
std::thread t4(std::bind(&server_task::run, &st));
t1.detach();
t2.detach();
t3.detach();
t4.detach();
std::cout << "ok" << std::endl;
getchar();
std::cout << "ok" << std::endl;
return 0;
}
我从这段代码得到的输出如下：
-> CC66-C879
-> 3292-E961
-> C4AA-55D1
ok
ici
ici
ici
... (infinite ici)
我真的不明白为什么它不起作用。 客户端中的轮询在非套接字上发送异常Socket操作。 对我来说，主要的问题是它是来自官方文档的测试，我无法使其工作。我使用套接字有什么问题？
感谢您的帮助
答案 0 :(得分：2)
我发现了问题。
官方文档中存在问题（一些明显的错误，比如zmq_pollitem_t数组的初始化），另一个问题导致我的测试不起作用。
对于zmq :: poll或zmq :: proxy，您需要在void *中转换套接字结构，并且您不能在套接字上使用指针。 ZMQ poll not working
经过那些修改后，它起作用了。我做了另一篇文章来解释为什么here
以下是没有我的附加测试输出的更正代码：
// Asynchronous client-to-server (DEALER to ROUTER)
//
// While this example runs in a single process, that is to make
// it easier to start and stop the example. Each task has its own
// context and conceptually acts as a separate process.
#include <vector>
#include <thread>
#include <memory>
#include <functional>
#include <zmq.h>
#include <zmq.hpp>
#include <zhelper.hpp>
// This is our client task class.
// It connects to the server, and then sends a request once per second
// It collects responses as they arrive, and it prints them out. We will
// run several client tasks in parallel, each with a different random ID.
// Attention! -- this random work well only on linux.
class client_task {
public:
client_task()
: ctx_(1),
client_socket_(ctx_, ZMQ_DEALER)
{}
void start() {
// generate random identity
char identity[10] = {};
sprintf(identity, "%04X-%04X", within(0x10000), within(0x10000));
printf("-> %s\n", identity);
client_socket_.setsockopt(ZMQ_IDENTITY, identity, strlen(identity));
client_socket_.connect("tcp://localhost:5555");
zmq_pollitem_t items[1];
items[0].socket = static_cast<void *> (client_socket_);
items[0].fd = 0;
items[0].events = ZMQ_POLLIN;
items[0].revents = 0;
int request_nbr = 0;
try {
while (true) {
for (int i = 0 ; i < 100; ++i) {
zmq::poll(items, 1, 10);
if (items[0].revents & ZMQ_POLLIN) {
printf("\n%s =>", identity);
s_dump(client_socket_);
}
}
char request_string[16] = {};
sprintf(request_string, "request #%d", ++request_nbr);
client_socket_.send(request_string, strlen(request_string));
}
}
catch (std::exception &e)
{
std::cout << "exception : " << zmq_errno() << " "<< e.what() << std::endl;
if (zmq_errno() == EINTR)
std::cout << "lol"<< std::endl;
}
}
private:
zmq::context_t ctx_;
zmq::socket_t client_socket_;
};
// Each worker task works on one request at a time and sends a random number
// of replies back, with random delays between replies:
class server_worker {
public:
server_worker(zmq::context_t &ctx, int sock_type)
: ctx_(ctx),
worker_(ctx_, sock_type)
{}
void work() {
worker_.connect("inproc://backend");
try {
while (true) {
zmq::message_t identity;
zmq::message_t msg;
zmq::message_t copied_id;
zmq::message_t copied_msg;
worker_.recv(&identity);
worker_.recv(&msg);
int replies = within(5);
for (int reply = 0; reply < replies; ++reply) {
s_sleep(within(1000) + 1);
copied_id.copy(&identity);
copied_msg.copy(&msg);
worker_.send(copied_id, ZMQ_SNDMORE);
worker_.send(copied_msg);
}
}
}
catch (std::exception &e)
{
std::cout << "Error in worker : " << e.what() << std::endl;
}
}
private:
zmq::context_t &ctx_;
zmq::socket_t worker_;
};
// This is our server task.
// It uses the multithreaded server model to deal requests out to a pool
// of workers and route replies back to clients. One worker can handle
// one request at a time but one client can talk to multiple workers at
// once.
class server_task {
public:
server_task()
: ctx_(1),
frontend_(ctx_, ZMQ_ROUTER),
backend_(ctx_, ZMQ_DEALER)
{}
void run() {
frontend_.bind("tcp://*:5555");
backend_.bind("inproc://backend");
server_worker * worker = new server_worker(ctx_, ZMQ_DEALER);
std::thread worker_thread(std::bind(&server_worker::work, worker));
worker_thread.detach();
try {
zmq::proxy(static_cast<void *>(frontend_), static_cast<void *> (backend_), NULL);
}
catch (std::exception &e)
{
std::cout << "Error in Server : " << e.what() << std::endl;
}
}
private:
zmq::context_t ctx_;
zmq::socket_t frontend_;
zmq::socket_t backend_;
};
// The main thread simply starts several clients and a server, and then
// waits for the server to finish.
int main (void)
{
client_task ct1;
client_task ct2;
client_task ct3;
server_task st;
std::thread t4(std::bind(&server_task::run, &st));
t4.detach();
std::thread t1(std::bind(&client_task::start, &ct1));
std::thread t2(std::bind(&client_task::start, &ct2));
std::thread t3(std::bind(&client_task::start, &ct3));
t1.detach();
t2.detach();
t3.detach();
getchar();
return 0;
}