add original source

source/listing_c.1.cpp

@@ -0,0 +1,50 @@
+#include
+#include
+#include
+#include
+<mutex>
+<condition_variable>
+<queue>
+<memory>
+namespace messaging
+{
+    struct message_base
+    {
+        virtual ~message_base()
+        {}
+    };
+
+    template<typename Msg>
+    struct wrapped_message:
+        message_base
+    {
+        Msg contents;
+        explicit wrapped_message(Msg const& contents_):
+            contents(contents_)
+        {}
+    };
+
+    class queue
+    {
+        std::mutex m;
+        std::condition_variable c;
+        message_base
+        std::queue<std::shared_ptr<message_base> > q;
+    public:
+        template<typename T>
+        void push(T const& msg)
+        {
+            std::lock_guard<std::mutex> lk(m);
+            q.push(std::make_shared<wrapped_message<T> >(msg));
+            c.notify_all();
+        }
+        std::shared_ptr<message_base> wait_and_pop()
+        {
+            std::unique_lock<std::mutex> lk(m);
+            c.wait(lk,[&]{return !q.empty();});
+            auto res=q.front();
+            q.pop();
+            return res;
+        }
+    };
+}