Multiple socket reader in C

//
// Reading from multiple sockets
// This version uses a simple recv loop
//
#include "zhelpers.h"

int main (void)
{
// Prepare our context and sockets
void *context = zmq_ctx_new ();

// Connect to task ventilator
void *receiver = zmq_socket (context, ZMQ_PULL);
zmq_connect (receiver, "tcp://localhost:5557");

// Connect to weather server
void *subscriber = zmq_socket (context, ZMQ_SUB);
zmq_connect (subscriber, "tcp://localhost:5556");
zmq_setsockopt (subscriber, ZMQ_SUBSCRIBE, "10001 ", 6);

// Process messages from both sockets
// We prioritize traffic from the task ventilator
while (true) {
// Process any waiting tasks
int rc;
for (rc = 0; !rc; ) {
zmq_msg_t task;
zmq_msg_init (&task);
if ((rc = zmq_msg_recv (&task, receiver, ZMQ_DONTWAIT)) != -1) {
// process task
}
zmq_msg_close (&task);
}
// Process any waiting weather updates
for (rc = 0; !rc; ) {
zmq_msg_t update;
zmq_msg_init (&update);
if ((rc = zmq_msg_recv (&update, subscriber, ZMQ_DONTWAIT)) != -1) {
// process weather update
}
zmq_msg_close (&update);
}
// No activity, so sleep for 1 msec
s_sleep (1);
}
// We never get here but clean up anyhow
zmq_close (receiver);
zmq_close (subscriber);
zmq_ctx_destroy (context);
return 0;
}