From 17ef45244b4791bc00a76094e07d98e7f1ebd3a2 Mon Sep 17 00:00:00 2001
From: Christopher Kohlhoff <chris@kohlhoff.com>
Date: Mon, 21 Apr 2008 01:36:28 +0000
Subject: [PATCH] Enhance example to make it clear that invocation hooking can
 be used with asynchronous operations.

[SVN r44665]
---
 example/invocation/prioritised_handlers.cpp | 23 +++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/example/invocation/prioritised_handlers.cpp b/example/invocation/prioritised_handlers.cpp
index 657eb5f6..82dc4a3e 100644
--- a/example/invocation/prioritised_handlers.cpp
+++ b/example/invocation/prioritised_handlers.cpp
@@ -13,6 +13,8 @@
 #include <iostream>
 #include <queue>
 
+using boost::asio::ip::tcp;
+
 class handler_priority_queue
 {
 public:
@@ -108,12 +110,12 @@ void asio_handler_invoke(Function f,
 
 //----------------------------------------------------------------------
 
-void high_priority_handler()
+void high_priority_handler(const boost::system::error_code& /*ec*/)
 {
   std::cout << "High priority handler\n";
 }
 
-void middle_priority_handler()
+void middle_priority_handler(const boost::system::error_code& /*ec*/)
 {
   std::cout << "Middle priority handler\n";
 }
@@ -129,9 +131,22 @@ int main()
 
   handler_priority_queue pri_queue;
 
+  // Post a completion handler to be run immediately.
   io_service.post(pri_queue.wrap(0, low_priority_handler));
-  io_service.post(pri_queue.wrap(100, high_priority_handler));
-  io_service.post(pri_queue.wrap(42, middle_priority_handler));
+
+  // Start an asynchronous accept that will complete immediately.
+  tcp::endpoint endpoint(boost::asio::ip::address_v4::loopback(), 0);
+  tcp::acceptor acceptor(io_service, endpoint);
+  tcp::socket server_socket(io_service);
+  acceptor.async_accept(server_socket,
+      pri_queue.wrap(100, high_priority_handler));
+  tcp::socket client_socket(io_service);
+  client_socket.connect(acceptor.local_endpoint());
+
+  // Set a deadline timer to expire immediately.
+  boost::asio::deadline_timer timer(io_service);
+  timer.expires_at(boost::posix_time::neg_infin);
+  timer.async_wait(pri_queue.wrap(42, middle_priority_handler));
 
   while (io_service.run_one())
   {