add original source

source/listing_9.1.cpp

@@ -0,0 +1,53 @@
+class thread_pool
+{
+    std::atomic_bool done;
+    thread_safe_queue<std::function<void()> > work_queue;
+    std::vector<std::thread> threads;
+    join_threads joiner;
+
+    void worker_thread()
+    {
+        while(!done)
+        {
+            std::function<void()> task;
+            if(work_queue.try_pop(task))
+            {
+                task();
+            }
+            else
+            {
+                std::this_thread::yield();
+            }
+        }
+    }
+public:
+    thread_pool():
+        done(false),joiner(threads)
+    {
+        unsigned const thread_count=std::thread::hardware_concurrency();
+        try
+        {
+            for(unsigned i=0;i<thread_count;++i)
+            {
+                threads.push_back(
+                    std::thread(&thread_pool::worker_thread,this));
+            }
+        }
+        catch(...)
+        {
+            done=true;
+            throw;
+        }
+    }
+
+    ~thread_pool()
+    {
+        done=true;
+    }
+
+    template<typename FunctionType>
+    void submit(FunctionType f)
+    {
+        work_queue.push(std::function<void()>(f));
+    }
+};