add original source

source/listing_9.13.cpp

@@ -0,0 +1,38 @@
+std::mutex config_mutex;
+std::vector<interruptible_thread> background_threads;
+
+void background_thread(int disk_id)
+{
+    while(true)
+    {
+        interruption_point();
+        fs_change fsc=get_fs_changes(disk_id);
+        if(fsc.has_changes())
+        {
+            update_index(fsc);
+        }
+    }
+}
+
+void start_background_processing()
+{
+    background_threads.push_back(
+        interruptible_thread(background_thread,disk_1));
+    background_threads.push_back(
+        interruptible_thread(background_thread,disk_2));
+}
+
+int main()
+{
+    start_background_processing();
+    process_gui_until_exit();
+    std::unique_lock<std::mutex> lk(config_mutex);
+    for(unsigned i=0;i<background_threads.size();++i)
+    {
+        background_threads[i].interrupt();
+    }
+    for(unsigned i=0;i<background_threads.size();++i)
+    {
+        background_threads[i].join();
+    }
+}