zero mq asynchronous server side is getting core dump - zeromq

Question

This is first post in the forum and need help.
I have implemented the ZeroMQ server part much same as documented here
https://github.com/egalli64/thisthread/blob/master/zmq/d2r.cpp.
Below is my code
#include <string>
#include <boost/thread.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/random.hpp>
#include "zmq2.h"
#include <pthread.h>
#include <unistd.h>
#include <cassert>
#include <string>
#include <iostream>
#include <zmq.hpp>
boost::mutex mio;
void *worker(void *arg)
{
std::cout << "in worker" << std::endl;
zmq::context_t *context = (zmq::context_t *) arg;
zmq::Socket skWorker(*context, ZMQ_DEALER);
std::cout << "in worker2" << std::endl;
skWorker.connect("inproc://backend");
std::cout<< "Worker started" << std::endl;
while(true)
{
std::cout << "in while" << std::endl;
zmq::Frames frames = skWorker.blockingRecv(2, false);
if(frames.size() == 1)
{
std::cout << "in if" << std::endl;
break;
}
// send a few replies
for(int i =0; i < 10; ++i)
{
boost::this_thread::sleep(boost::posix_time::millisec(100 * 10));
std::cout << "worker reply" << std::endl;
skWorker.send(frames);
}
}
std::cout << "terminating worker" << std::endl;
return (NULL);
}
void dumpId(const char* tag, const std::string& msg)
{
boost::lock_guard<boost::mutex> lock(mio);
std::string id = boost::lexical_cast<std::string>(boost::this_thread::get_id());
std::cout << id << ' ' << tag << ' ' << msg << std::endl;
}
int main()
{
zmq::context_t context(1);
zmq::Socket client(context, ZMQ_ROUTER);
client.bind("tcp://*:5555");
zmq::Socket workers(context, ZMQ_DEALER);
workers.bind("inproc://workers");
for (int thread_nbr = 0; thread_nbr != 2; thread_nbr++)
{
pthread_t threads;
pthread_create(&threads, NULL, worker, (void *) &context);
}
std::cout << " server started" << std::endl;
zmq_pollitem_t items [] =
{
{ client, 0, ZMQ_POLLIN, 0 },
{ workers, 0, ZMQ_POLLIN, 0 }
};
while(true)
{
if(zmq_poll(items, 2, 3000 * 1000) < 1) // 3 secs
break;
if(items[0].revents & ZMQ_POLLIN)
{
zmq::Frames frames = client.blockingRecv(2);
dumpId("Received on frontend", frames[0]);
workers.send(frames);
items[0].revents = 0; // cleanup
}
if(items[1].revents & ZMQ_POLLIN)
{
zmq::Frames frames = workers.blockingRecv(2);
dumpId("Received on backend", frames[0]);
client.send(frames);
items[1].revents = 0; // cleanup
}
}
std::cout <<"Nothing happened for a while" << std::endl;
// send a terminator to each worker
for(int i = 0; i < 2; ++i)
workers.send("");
std::cout << "Server shutdown" << std::endl;
}
After running the its getting core dumped.
Below is the output
in workerin worker server started
in worker2
in worker2
terminate called after throwing an instance of 'zmq::error_t'
terminate called recursively
Aborted (core dumped)
Could some one let me know where I m doing wrong.......
Thanks in advance....