Fixing a problem, where a hung renderer process is not killed when navigating away

content/public/browser/render_process_host.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_PUBLIC_BROWSER_RENDER_PROCESS_HOST_H_
 #define CONTENT_PUBLIC_BROWSER_RENDER_PROCESS_HOST_H_
 
 #include "base/basictypes.h"
 #include "base/id_map.h"
 #include "base/process.h"
@@ skipping 95 matching lines @@
 
   // Returns the process object associated with the child process.  In certain
   // tests or single-process mode, this will actually represent the current
   // process.
   //
   // NOTE: this is not necessarily valid immediately after calling Init, as
   // Init starts the process asynchronously.  It's guaranteed to be valid after
   // the first IPC arrives.
   virtual base::ProcessHandle GetHandle() = 0;
 
+  // Returns true if the process can be killed if it is unresponsive. This will
+  // only be the case if there is only one view using this renderer process.
+  virtual bool AllowTerminateOnUnresponsive() const = 0;

[Charlie Reis, 2012/03/01 21:08:17]

We should move this to below SuddenTerminationAllowed and make the name more
consistent (with Allowed at the end).

I'm trying to decide if something like TerminateAfterLeavingAllowed() is a
better name, or if we want it to be more generic, like
IsUsedByMultipleViews()...  It's possible there may be other uses for this
check.

[nasko, 2012/03/01 22:50:15]

Done.

[Charlie Reis, 2012/03/02 00:16:43]

Upon reflection, I'm leaning toward something like IsSharedByMultipleViews(). 
This is information about a process state (is it shared or not?) that might
useful for many policy decisions-- whether to kill if leaving in an unresponsive
state, whether we should prerender in this tab, and possibly others.

[nasko, 2012/03/02 18:40:36]

This makes sense, especially if we want the prerendering to use this type of
information.

+
   // Transport DIB functions ---------------------------------------------------
 
   // Return the TransportDIB for the given id. On Linux, this can involve
   // mapping shared memory. On Mac, the shared memory is created in the browser
   // process and the cached metadata is returned. On Windows, this involves
   // duplicating the handle from the remote process.  The RenderProcessHost
   // still owns the returned DIB.
   virtual TransportDIB* GetTransportDIB(TransportDIB::Id dib_id) = 0;
 
   // Returns the user browser context associated with this renderer process.
@@ skipping 103 matching lines @@
 
   // Returns the current max number of renderer processes used by the content
   // module.
   static size_t GetMaxRendererProcessCount();
 };
 
 }  // namespace content.
 
 #endif  // CONTENT_PUBLIC_BROWSER_RENDER_PROCESS_HOST_H_