1    :  // Copyright 2013 Google Inc. All Rights Reserved.
   2    :  //
   3    :  // Licensed under the Apache License, Version 2.0 (the "License");
   4    :  // you may not use this file except in compliance with the License.
   5    :  // You may obtain a copy of the License at
   6    :  //
   7    :  //     http://www.apache.org/licenses/LICENSE-2.0
   8    :  //
   9    :  // Unless required by applicable law or agreed to in writing, software
  10    :  // distributed under the License is distributed on an "AS IS" BASIS,
  11    :  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12    :  // See the License for the specific language governing permissions and
  13    :  // limitations under the License.
  14    :  //
  15    :  // Declares a utility class to get DLL load/unload notifications on supporting
  16    :  // systems - Vista and up.
  17    :  
  18    :  #ifndef SYZYGY_AGENT_COMMON_DLL_NOTIFICATIONS_H_
  19    :  #define SYZYGY_AGENT_COMMON_DLL_NOTIFICATIONS_H_
  20    :  
  21    :  #include <windows.h>
  22    :  
  23    :  #include "base/callback.h"
  24    :  #include "base/strings/string_piece.h"
  25    :  
  26    :  // Forward decl.
  27  m :  union _LDR_DLL_NOTIFICATION_DATA;
  28    :  
  29  m :  namespace agent {
  30  m :  namespace common {
  31    :  
  32    :  // A wrapper class that assists with getting DLL load and unload notifications.
  33  m :  class DllNotificationWatcher {
  34  m :   public:
  35  m :    enum EventType {
  36  m :      kDllLoaded,
  37  m :      kDllUnloaded,
  38  m :    };
  39  m :    typedef base::Callback<void(EventType type,
  40  m :                                HMODULE module,
  41  m :                                size_t module_size,
  42  m :                                const base::StringPiece16& dll_path,
  43  m :                                const base::StringPiece16& dll_base_name)>
  44  m :        CallbackType;
  45    :  
  46  m :    DllNotificationWatcher();
  47  m :    ~DllNotificationWatcher();
  48    :  
  49    :    // Initialize for notifications to @p callback.
  50    :    // @returns true on success, false on failure.
  51    :    // @note this will return false on systems that don't implement this
  52    :    //     mechanism, Windows XP and earlier.
  53  m :    bool Init(const CallbackType& callback);
  54    :  
  55    :    // Uninitialize and unregister from further callbacks.
  56    :    // @note From observation, the registration and unregistration are done under
  57    :    //     loader's lock, so there's no danger of callbacks after this function
  58    :    //     returns.
  59  m :    void Reset();
  60    :  
  61  m :   private:
  62  m :    static void CALLBACK NotificationFunction(
  63  m :        ULONG reason,
  64  m :        const union _LDR_DLL_NOTIFICATION_DATA* data,
  65  m :        void* context);
  66    :  
  67  m :    CallbackType callback_;
  68  m :    void* cookie_;
  69  m :  };
  70    :  
  71  m :  }  // namespace common
  72  m :  }  // namespace agent
  73    :  
  74    :  #endif  // SYZYGY_AGENT_COMMON_DLL_NOTIFICATIONS_H_