Refactoring libboostasio (part 2)

README.md

@@ -170,7 +170,7 @@ to RabbitMQ has to be set up.
 
 An example compilation command for an application using the TCP module:
 ```bash
-g++ -g -Wall -lamqcpp -lpthread -ldl my-amqp-cpp.c -o my-amqp-cpp
+g++ -std=c++17 -g -Wall -lamqcpp -lpthread -ldl my-amqp-cpp.c -o my-amqp-cpp
 ```
 
 HOW TO USE AMQP-CPP
@@ -710,7 +710,7 @@ it has a couple of open issues.
 
 | TCP Handler Impl        | Header File Location   |  Sample File Location     |
 | ----------------------- | ---------------------- | ------------------------- |
-| Boost asio (io_service) | include/libboostasio.h | examples/libboostasio.cpp |  
+| Boost asio              | include/libboostasio.h | examples/libboostasio.cpp |
 | libev                   | include/libev.h        | examples/libev.cpp        |
 | libevent                | include/libevent.h     | examples/libevent.cpp     |
 | libuv                   | include/libuv.h        | examples/libuv.cpp        |
@@ -770,7 +770,7 @@ class MyTcpHandler : public AMQP::TcpHandler
 ````
 
 If you enable heartbeats, it is your own responsibility to ensure that the
-```connection->heartbeat()``` method is called at least once during this period,
+`connection->heartbeat()` method is called at least once during this period,
 or that you call one of the other channel or connection methods to send data
 over the connection. Heartbeats are sent by the server too, RabbitMQ also ensures
 that _some data_ is sent over the connection from the server to the client 

examples/libboostasio.cpp

@@ -1,20 +1,19 @@
 /**
  *  LibBoostAsio.cpp
- * 
- *  Test program to check AMQP functionality based on Boost's asio io_service.
- * 
+ *
+ *  Test program to check AMQP functionality based on Boost's asio io_context.
+ *
  *  @author Gavin Smith <gavin.smith@coralbay.tv>
  *
- *  Compile with g++ -std=c++14 libboostasio.cpp -o boost_test -lpthread -lboost_system -lamqpcpp
+ *  Compile with:
+ *  g++ -std=c++17 -Wall  libboostasio.cpp -o boost_test  -lboost_system -lamqpcpp -lpthread -ldl
  */
 
 /**
  *  Dependencies
  */
-#include <boost/asio/io_service.hpp>
-#include <boost/asio/strand.hpp>
-#include <boost/asio/deadline_timer.hpp>
-
+#include <boost/asio/io_context.hpp>
+#include <boost/asio/signal_set.hpp>
 
 #include <amqpcpp.h>
 #include <amqpcpp/libboostasio.h>
@@ -25,32 +24,51 @@
  */
 int main()
 {
-
     // access to the boost asio handler
-    // note: we suggest use of 2 threads - normally one is fin (we are simply demonstrating thread safety).
-    boost::asio::io_service service(4);
+    boost::asio::io_context context;
+
+    // set of signal for process termination (CTRL-C, kill)
+    boost::asio::signal_set signals(context, SIGINT, SIGTERM);
+
+    // handler for libboostasio
+    AMQP::LibBoostAsioHandler handler(context);
 
-    // handler for libev
-    AMQP::LibBoostAsioHandler handler(service);
-
     // make a connection
     AMQP::TcpConnection connection(&handler, AMQP::Address("amqp://guest:guest@localhost/"));
-    
+
     // we need a channel too
     AMQP::TcpChannel channel(&connection);
-
+
+    channel.onReady([&signals, &connection]() {
+        std::cout << "hit CTRL-C to exit\n\nchannel ready\n";
+
+        // install the signals handler
+        signals.async_wait([&connection](const boost::system::error_code& ec, int /* signal_number */)
+        {
+            if (!ec) {
+                // now we gently close the connection
+                std::cerr << "\nclosing connection...\n";
+                connection.close();
+            }
+        });
+    });
+    channel.onError([](const char *message) {
+        std::cerr << "channel error: " << message << std::endl;
+    });
+
     // create a temporary queue
-    channel.declareQueue(AMQP::exclusive).onSuccess([&connection](const std::string &name, uint32_t messagecount, uint32_t consumercount) {
-
+    channel.declareQueue(AMQP::exclusive
+     ).onSuccess([](const std::string &name, uint32_t /* messagecount */, uint32_t /* consumercount */) {
+
         // report the name of the temporary queue
         std::cout << "declared queue " << name << std::endl;
-
-        // now we can close the connection
-        connection.close();
+
+    }).onError([](const char *message) {
+
+        // something went wrong creating the queue (or even before)
+        std::cerr << "declareQueue error: " << message << std::endl;
     });
-    
+
     // run the handler
-    // a t the moment, one will need SIGINT to stop.  In time, should add signal handling through boost API.
-    return service.run();
+    return context.run();
 }
-

include/amqpcpp/deferred.h

@@ -178,7 +178,7 @@ class Deferred
         // store pointer
         _next = deferred;
     }
-    
+
     /**
      *  Remove this object from the chain of deferreds
      */
@@ -282,9 +282,6 @@ class Deferred
      *  or fails. This function will be called
      *  either way.
      *
-     *  In the case of success, the provided
-     *  error parameter will be an empty string.
-     *
      *  Only one callback can be registered at at time.
      *  Successive calls to this function will clear
      *  callbacks registered before.