[Chromoting] Introducing refcount-based life time management of the message loops in the service (d…

remoting/host/chromoting_host_context.h

Index: remoting/host/chromoting_host_context.h
diff --git a/remoting/host/chromoting_host_context.h b/remoting/host/chromoting_host_context.h
index 2e3480d69d3a1c50f59421615d2aad0d494ce494..bfe6c7181e860ed3cb8370a43bba2c888b9b2697 100644
--- a/remoting/host/chromoting_host_context.h
+++ b/remoting/host/chromoting_host_context.h
@@ -5,17 +5,11 @@
 #ifndef REMOTING_HOST_CHROMOTING_HOST_CONTEXT_H_
 #define REMOTING_HOST_CHROMOTING_HOST_CONTEXT_H_
 
-#include <string>
-
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
-#include "base/threading/platform_thread.h"
+#include "base/single_thread_task_runner.h"
 #include "base/threading/thread.h"
 
-namespace base {
-class SingleThreadTaskRunner;
-}  // namespace base
-
 namespace net {
 class URLRequestContextGetter;
 }  // namespace net
@@ -38,6 +32,8 @@ class ChromotingHostContext {
   // this API.
   virtual bool Start();
 
+  void Stop();

[Sergey Ulanov, 2012/08/31 01:25:18]

Seems wrong to call this method Stop() given that it doesn't really stop the
threads. Maybe FreeThreads() or UnrefThreads()?

You essentially tie the lifetime of all threads to the lifetime of the main UI
thread: i.e. we really stop these threads only after the main thread message
loop quits. Why not stop them in the same manner we quit the main thread?

[alexeypa (please no reviews), 2012/08/31 19:57:36]

Done. ReleaseTaskRunners()
There is a lengthy comment in the declaration of AutoThreadTaskRunner and the
corresponding bug is http://crbug.com/145856. Basically the answer is that we
can't because the plugin main loop is stopped during shutdown and Thread::Stop()
has limitations that prevent us from stopping threads the way we would want them
to be stopped.

This CL is one step closer to the model that we will be able to stop the threads
earlier.

+
   // Task runner for the thread that is used for the UI. In the NPAPI
   // plugin this corresponds to the main plugin thread.
   virtual base::SingleThreadTaskRunner* ui_task_runner();
@@ -86,6 +82,14 @@ class ChromotingHostContext {
   // Thread for blocking IO operations.
   base::Thread file_thread_;
 
+  // Task runners wrapping the above threads. These should be declared after
+  // the corresponding threads to guarantee proper order of destruction.
+  scoped_refptr<base::SingleThreadTaskRunner> network_task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> capture_task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> encode_task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> desktop_task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> file_task_runner_;
+
   scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
 
   scoped_refptr<net::URLRequestContextGetter> url_request_context_getter_;