xbmc/platform/linux/FDEventMonitor.h

   1 /*
   2  *  Copyright (C) 2014-2018 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 "platform/Platform.h"
  12 #include "threads/CriticalSection.h"
  13 #include "threads/Thread.h"
  14
  15 #include <map>
  16 #include <vector>
  17
  18 #include <sys/epoll.h>
  19
  20 /**
  21  * Monitor a file descriptor with callback on poll() events.
  22  */
  23 class CFDEventMonitor : public IPlatformService, private CThread
  24 {
  25 public:
  26
  27   typedef void (*EventCallback)(int id, int fd, short revents, void *data);
  28
  29   struct MonitoredFD
  30   {
  31     int fd = -1; /**< File descriptor to be monitored */
  32     short events = 0; /**< Events to be monitored (see poll(2)) */
  33
  34     EventCallback callback = nullptr; /** Callback to be called on events */
  35     void *callbackData = nullptr; /** data parameter for EventCallback */
  36
  37     MonitoredFD(int fd_, short events_, EventCallback callback_, void *callbackData_) :
  38       fd(fd_), events(events_), callback(callback_), callbackData(callbackData_) {}
  39     MonitoredFD() = default;
  40   };
  41
  42   CFDEventMonitor();
  43   ~CFDEventMonitor() override;
  44
  45   void AddFD(const MonitoredFD& monitoredFD, int& id);
  46   void AddFDs(const std::vector<MonitoredFD>& monitoredFDs, std::vector<int>& ids);
  47
  48   void RemoveFD(int id);
  49   void RemoveFDs(const std::vector<int>& ids);
  50
  51 protected:
  52   void Process() override;
  53
  54 private:
  55   void AddFDLocked(const MonitoredFD& monitoredFD, int& id);
  56
  57   void AddPollDesc(int id, int fd, short events);
  58   void UpdatePollDescs();
  59
  60   void StartMonitoring();
  61   void InterruptPoll();
  62
  63   std::map<int, MonitoredFD> m_monitoredFDs;
  64
  65   /* these are kept synchronized */
  66   std::vector<int> m_monitoredFDbyPollDescs;
  67   std::vector<struct pollfd> m_pollDescs;
  68
  69   int m_nextID = 0;
  70   int m_wakeupfd = -1;
  71
  72   CCriticalSection m_mutex;
  73   CCriticalSection m_pollMutex;
  74 };