Translated Lazy Pirate examples to C++

examples/C++/lpclient.cpp

@@ -1,13 +1,70 @@
-No-one has translated the lpclient example into C++ yet.  Be the first to create
-lpclient in C++ and get one free Internet!  If you're the author of the C++
-binding, this is a great way to get people to use 0MQ in C++.
-
-To submit a new translation email it to zeromq-dev@lists.zeromq.org.  Please:
-
-* Stick to identical functionality and naming used in examples so that readers
-  can easily compare languages.
-* You MUST place your name as author in the examples so readers can contact you.
-* You MUST state in the email that you license your code under the MIT/X11
-  license.
-
-Subscribe to the email list at http://lists.zeromq.org/mailman/listinfo/zeromq-dev.
+//
+//  Lazy Pirate client
+//  Use zmq_poll to do a safe request-reply
+//  To run, start piserver and then randomly kill/restart it
+//
+#include "zhelpers.hpp"
+
+#define REQUEST_TIMEOUT     2500    //  msecs, (> 1000!)
+#define REQUEST_RETRIES     3       //  Before we abandon
+//  Helper function that returns a new configured socket
+//  connected to the Hello World server
+//
+static zmq::socket_t * s_client_socket(zmq::context_t & context) {
+   printf("I: connecting to server...\n");
+   zmq::socket_t * client = new zmq::socket_t(context, ZMQ_REQ);
+   client->connect("tcp://localhost:5555");
+
+   //  Configure socket to not wait at close time
+   int linger = 0;
+   client->setsockopt(ZMQ_LINGER, &linger, sizeof(linger));
+   return client;
+}
+
+int main() {
+   zmq::context_t context(1);
+
+   zmq::socket_t * client = s_client_socket(context);
+
+   printf("I: connecting to server...\n");
+
+   int sequence = 0;
+   int retries_left = REQUEST_RETRIES;
+   while (retries_left) {
+      //  We send a request, then we work to get a reply
+      char request[10];
+      sprintf(request, "%d", ++sequence);
+      s_send(*client, request);
+      sleep(1);
+      int expect_reply = 1;
+      while (expect_reply) {
+         //  Poll socket for a reply, with timeout
+         zmq::pollitem_t items[] = { { *client, 0, ZMQ_POLLIN, 0 } };
+         zmq::poll(&items[0], 1, REQUEST_TIMEOUT * 1000);
+         //  If we got a reply, process it
+         if (items[0].revents & ZMQ_POLLIN) {
+            //  We got a reply from the server, must match sequence
+            std::string *reply = s_recv(*client);
+            if (atoi(reply->c_str()) == sequence) {
+               printf("I: server replied OK (%s)\n", reply->c_str());
+               retries_left = REQUEST_RETRIES;
+               expect_reply = 0;
+            } else
+               printf("E: malformed reply from server: %s\n", reply->c_str());
+
+            delete reply;
+         } else if (--retries_left == 0) {
+            printf("E: server seems to be offline, abandoning\n");
+            break;
+         } else {
+            printf("W: no response from server, retrying...\n");
+            //  Old socket will be confused; close it and open a new one
+            delete client;
+            client = s_client_socket(context);
+            //  Send request again, on new socket
+            s_send(*client, request);
+         }
+      }
+   }
+   return 0;
+}

examples/C++/lpserver.cpp

@@ -1,13 +1,39 @@
-No-one has translated the lpserver example into C++ yet.  Be the first to create
-lpserver in C++ and get one free Internet!  If you're the author of the C++
-binding, this is a great way to get people to use 0MQ in C++.
-
-To submit a new translation email it to zeromq-dev@lists.zeromq.org.  Please:
-
-* Stick to identical functionality and naming used in examples so that readers
-  can easily compare languages.
-* You MUST place your name as author in the examples so readers can contact you.
-* You MUST state in the email that you license your code under the MIT/X11
-  license.
-
-Subscribe to the email list at http://lists.zeromq.org/mailman/listinfo/zeromq-dev.
+//
+// Lazy Pirate server
+// Binds REQ socket to tcp://*:5555
+// Like hwserver except:
+// - echoes request as-is
+// - randomly runs slowly, or exits to simulate a crash.
+//
+#include "zhelpers.hpp"
+
+int main ()
+{
+    srandom ((unsigned) time (NULL));
+
+    zmq::context_t context(1);
+    zmq::socket_t server(context, ZMQ_REP);
+    server.bind("tcp://*:5555");
+
+    int cycles = 0;
+    while (1) {
+        std::string *request = s_recv (server);
+        cycles++;
+
+        // Simulate various problems, after a few cycles
+        if (cycles > 3 && within (3) == 0) {
+            printf ("I: simulating a crash\n");
+            break;
+        }
+        else
+        if (cycles > 3 && within (3) == 0) {
+            printf ("I: simulating CPU overload\n");
+            sleep (5);
+        }
+        printf ("I: normal request (%s)\n", request->c_str());
+        sleep (1); // Do some heavy work
+        s_send (server, *request);
+        delete request;
+    }
+    return 0;
+}