chrome/test/automation/automation_handle_tracker.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // This file defines a mapping between Automation Proxy objects and
   6 // their associated app-side handles.
   7
   8 #ifndef CHROME_TEST_AUTOMATION_AUTOMATION_HANDLE_TRACKER_H__
   9 #define CHROME_TEST_AUTOMATION_AUTOMATION_HANDLE_TRACKER_H__
  10
  11 #include <map>
  12
  13 #include "base/basictypes.h"
  14 #include "base/memory/ref_counted.h"
  15 #include "base/synchronization/lock.h"
  16 #include "ipc/ipc_channel.h"
  17
  18 // This represents a value that the app's AutomationProvider returns
  19 // when asked for a resource (like a window or tab).
  20 typedef int AutomationHandle;
  21
  22 class AutomationHandleTracker;
  23 class AutomationMessageSender;
  24
  25 class AutomationResourceProxy
  26     : public base::RefCountedThreadSafe<AutomationResourceProxy> {
  27  public:
  28   AutomationResourceProxy(AutomationHandleTracker* tracker,
  29                           AutomationMessageSender* sender,
  30                           AutomationHandle handle);
  31
  32   // Marks this proxy object as no longer valid; this generally means
  33   // that the corresponding resource on the app side is gone.
  34   void Invalidate() {
  35     is_valid_ = false;
  36     tracker_ = NULL;
  37   }
  38
  39   bool is_valid() const { return is_valid_; }
  40
  41   // Returns the handle that the app has generated to refer to this resource.
  42   AutomationHandle handle() { return handle_; }
  43
  44  protected:
  45   friend class AutomationHandleTracker;
  46   friend class base::RefCountedThreadSafe<AutomationResourceProxy>;
  47
  48   virtual ~AutomationResourceProxy();
  49
  50   AutomationHandle handle_;
  51
  52   // Not owned by us, owned by the AutomationProxy object. May be NULL if the
  53   // tracker has been destroyed (and hence the object is invalid).
  54   AutomationHandleTracker* tracker_;
  55
  56   // Not owned by us.
  57   AutomationMessageSender* sender_;
  58
  59  private:
  60   // True if the resource that this object is a proxy for on the app side
  61   // still exists.
  62   bool is_valid_;
  63
  64   DISALLOW_COPY_AND_ASSIGN(AutomationResourceProxy);
  65 };
  66
  67 // This class keeps track of the mapping between AutomationHandles and
  68 // AutomationResourceProxy objects.  This is important because (1) multiple
  69 // AutomationResourceProxy objects can be generated for the same handle
  70 // (2) handles can be invalidated by the app, and all the associated
  71 // proxy objects then need to be invalidated, and (3) when a handle is no
  72 // longer being used on this end, we need to tell the app that it can
  73 // discard the handle.
  74 class AutomationHandleTracker {
  75  public:
  76   explicit AutomationHandleTracker();
  77   ~AutomationHandleTracker();
  78
  79   // Adds the specified proxy object to the tracker.
  80   void Add(AutomationResourceProxy* proxy);
  81
  82   // Removes a given proxy object from the mapping, and unregisters the
  83   // handle on the app side if this was the last proxy object that was using
  84   // that handle.  This is a no-op if the proxy object is not currently
  85   // in the tracker.
  86   void Remove(AutomationResourceProxy* proxy);
  87
  88   // Marks all proxy objects related to a given handle invalid.  This is
  89   // used when a resource (like a window) on the app side is closed, meaning
  90   // that no further operations can be completed using the handle that
  91   // identified that resource.
  92   void InvalidateHandle(AutomationHandle handle);
  93
  94   AutomationResourceProxy* GetResource(AutomationHandle handle);
  95
  96   void put_channel(IPC::Channel* channel) {
  97     channel_ = channel;
  98   }
  99
 100  private:
 101   typedef
 102     std::map<AutomationHandle, scoped_refptr<AutomationResourceProxy> >
 103         HandleToObjectMap;
 104   typedef std::pair<AutomationHandle, AutomationResourceProxy*> MapEntry;
 105
 106   HandleToObjectMap handle_to_object_;
 107
 108   base::Lock map_lock_;
 109   IPC::Channel* channel_;
 110   DISALLOW_COPY_AND_ASSIGN(AutomationHandleTracker);
 111 };
 112
 113 #endif  // CHROME_TEST_AUTOMATION_AUTOMATION_HANDLE_TRACKER_H__