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// Copyright (c) 2011 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.
// This file defines a mapping between Automation Proxy objects and
// their associated app-side handles.
#pragma once
#include <map>
#include "base/basictypes.h"
#include "base/memory/ref_counted.h"
#include "base/synchronization/lock.h"
#include "ipc/ipc_channel.h"
// This represents a value that the app's AutomationProvider returns
// when asked for a resource (like a window or tab).
typedef int AutomationHandle;
class AutomationHandleTracker;
class AutomationMessageSender;
class AutomationResourceProxy
: public base::RefCountedThreadSafe<AutomationResourceProxy> {
AutomationResourceProxy(AutomationHandleTracker* tracker,
AutomationMessageSender* sender,
AutomationHandle handle);
// Marks this proxy object as no longer valid; this generally means
// that the corresponding resource on the app side is gone.
void Invalidate() {
is_valid_ = false;
tracker_ = NULL;
bool is_valid() const { return is_valid_; }
// Returns the handle that the app has generated to refer to this resource.
AutomationHandle handle() { return handle_; }
friend class AutomationHandleTracker;
friend class base::RefCountedThreadSafe<AutomationResourceProxy>;
virtual ~AutomationResourceProxy();
AutomationHandle handle_;
// Not owned by us, owned by the AutomationProxy object. May be NULL if the
// tracker has been destroyed (and hence the object is invalid).
AutomationHandleTracker* tracker_;
// Not owned by us.
AutomationMessageSender* sender_;
// True if the resource that this object is a proxy for on the app side
// still exists.
bool is_valid_;
// This class keeps track of the mapping between AutomationHandles and
// AutomationResourceProxy objects. This is important because (1) multiple
// AutomationResourceProxy objects can be generated for the same handle
// (2) handles can be invalidated by the app, and all the associated
// proxy objects then need to be invalidated, and (3) when a handle is no
// longer being used on this end, we need to tell the app that it can
// discard the handle.
class AutomationHandleTracker {
explicit AutomationHandleTracker();
// Adds the specified proxy object to the tracker.
void Add(AutomationResourceProxy* proxy);
// Removes a given proxy object from the mapping, and unregisters the
// handle on the app side if this was the last proxy object that was using
// that handle. This is a no-op if the proxy object is not currently
// in the tracker.
void Remove(AutomationResourceProxy* proxy);
// Marks all proxy objects related to a given handle invalid. This is
// used when a resource (like a window) on the app side is closed, meaning
// that no further operations can be completed using the handle that
// identified that resource.
void InvalidateHandle(AutomationHandle handle);
AutomationResourceProxy* GetResource(AutomationHandle handle);
void put_channel(IPC::Channel* channel) {
channel_ = channel;
std::map<AutomationHandle, scoped_refptr<AutomationResourceProxy> >
typedef std::pair<AutomationHandle, AutomationResourceProxy*> MapEntry;
HandleToObjectMap handle_to_object_;
base::Lock map_lock_;
IPC::Channel* channel_;