[Android WebView] Terminate execution of stuck JS code on navigation requests

android_webview/renderer/aw_execution_termination_filter.h

Index: android_webview/renderer/aw_execution_termination_filter.h
diff --git a/android_webview/renderer/aw_execution_termination_filter.h b/android_webview/renderer/aw_execution_termination_filter.h
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+// Copyright 2014 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 ANDROID_WEBVIEW_RENDERER_AW_EXECUTION_TERMINATION_FILTER_H_
+#define ANDROID_WEBVIEW_RENDERER_AW_EXECUTION_TERMINATION_FILTER_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "base/timer/timer.h"
+#include "ipc/message_filter.h"
+
+namespace base {
+class MessageLoopProxy;
+}
+
+namespace v8 {
+class Isolate;
+}
+
+namespace android_webview {
+
+// The purpose of AwExecutionTerminationFilter is to attempt to terminate
+// any JavaScript code that is stuck in a loop before doing a navigation
+// originating from a Andoird WebView URL loading functions.
+//
+// This is how it works. AwExecutionTerminationFilter is created on render
+// thread. It listens on IO thread for navigation requests coming from
+// AwContents.loadUrl calls. On each such a request, it posts a delayed
+// cancellable task on the IO thread's message loop and, at the same time, posts
+// a cancellation task on the render thread's message loop. If render thread
+// is not stuck, the cancellation task runs and cancels the delayed task.
+// Otherwise, the delayed task runs and terminates execution of JS code
+// from the IO thread.
+class AwExecutionTerminationFilter : public IPC::MessageFilter {
+ public:
+  AwExecutionTerminationFilter(
+      const scoped_refptr<base::MessageLoopProxy>& io_message_loop,
+      const scoped_refptr<base::MessageLoopProxy>& main_message_loop);
+
+  void SetRenderThreadIsolate(v8::Isolate* isolate);
+
+ private:
+  virtual ~AwExecutionTerminationFilter();
+
+  // IPC::MessageFilter methods.
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+
+  void OnCheckRenderThreadResponsiveness();
+  void StopTimerOnMainThread();
+  void StopTimer();
+  void TerminateExecution();
+
+  const scoped_refptr<base::MessageLoopProxy> io_message_loop_;
+  const scoped_refptr<base::MessageLoopProxy> main_message_loop_;
+
+  v8::Isolate* render_thread_isolate_;
+  base::OneShotTimer<AwExecutionTerminationFilter> termination_timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(AwExecutionTerminationFilter);
+};
+
+}  // namespace android_webview
+
+#endif  // ANDROID_WEBVIEW_RENDERER_AW_EXECUTION_TERMINATION_FILTER_H_