xbmc/utils/EventStreamDetail.h

   1 /*
   2  *  Copyright (C) 2016-2018 Team Kodi
   3  *  This file is part of Kodi - https://kodi.tv
   4  *
   5  *  SPDX-License-Identifier: GPL-2.0-or-later
   6  *  See LICENSES/README.md for more information.
   7  */
   8
   9 #pragma once
  10
  11 #include "threads/CriticalSection.h"
  12
  13 #include <mutex>
  14
  15 namespace detail
  16 {
  17
  18 template<typename Event>
  19 class ISubscription
  20 {
  21 public:
  22   virtual void HandleEvent(const Event& event) = 0;
  23   virtual void Cancel() = 0;
  24   virtual bool IsOwnedBy(void* obj) = 0;
  25   virtual ~ISubscription() = default;
  26 };
  27
  28 template<typename Event, typename Owner>
  29 class CSubscription : public ISubscription<Event>
  30 {
  31 public:
  32   typedef void (Owner::*Fn)(const Event&);
  33   CSubscription(Owner* owner, Fn fn);
  34   void HandleEvent(const Event& event) override;
  35   void Cancel() override;
  36   bool IsOwnedBy(void *obj) override;
  37
  38 private:
  39   Owner* m_owner;
  40   Fn m_eventHandler;
  41   CCriticalSection m_criticalSection;
  42 };
  43
  44 template<typename Event, typename Owner>
  45 CSubscription<Event, Owner>::CSubscription(Owner* owner, Fn fn)
  46     : m_owner(owner), m_eventHandler(fn)
  47 {}
  48
  49 template<typename Event, typename Owner>
  50 bool CSubscription<Event, Owner>::IsOwnedBy(void* obj)
  51 {
  52   std::unique_lock<CCriticalSection> lock(m_criticalSection);
  53   return obj != nullptr && obj == m_owner;
  54 }
  55
  56 template<typename Event, typename Owner>
  57 void CSubscription<Event, Owner>::Cancel()
  58 {
  59   std::unique_lock<CCriticalSection> lock(m_criticalSection);
  60   m_owner = nullptr;
  61 }
  62
  63 template<typename Event, typename Owner>
  64 void CSubscription<Event, Owner>::HandleEvent(const Event& event)
  65 {
  66   std::unique_lock<CCriticalSection> lock(m_criticalSection);
  67   if (m_owner)
  68     (m_owner->*m_eventHandler)(event);
  69 }
  70 }