granicus.if.org Git - icinga2/blob - lib/base/io-engine.hpp

   1 /******************************************************************************
   2  * Icinga 2                                                                   *
   3  * Copyright (C) 2012-2018 Icinga Development Team (https://icinga.com/)      *
   4  *                                                                            *
   5  * This program is free software; you can redistribute it and/or              *
   6  * modify it under the terms of the GNU General Public License                *
   7  * as published by the Free Software Foundation; either version 2             *
   8  * of the License, or (at your option) any later version.                     *
   9  *                                                                            *
  10  * This program is distributed in the hope that it will be useful,            *
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of             *
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              *
  13  * GNU General Public License for more details.                               *
  14  *                                                                            *
  15  * You should have received a copy of the GNU General Public License          *
  16  * along with this program; if not, write to the Free Software Foundation     *
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.             *
  18  ******************************************************************************/
  19
  20 #ifndef IO_ENGINE_H
  21 #define IO_ENGINE_H
  22
  23 #include "base/lazy-init.hpp"
  24 #include <atomic>
  25 #include <exception>
  26 #include <memory>
  27 #include <thread>
  28 #include <vector>
  29 #include <boost/asio/deadline_timer.hpp>
  30 #include <boost/asio/io_service.hpp>
  31 #include <boost/asio/spawn.hpp>
  32
  33 namespace icinga
  34 {
  35
  36 /**
  37  * Scope lock for CPU-bound work done in an I/O thread
  38  *
  39  * @ingroup base
  40  */
  41 class CpuBoundWork
  42 {
  43 public:
  44         CpuBoundWork(boost::asio::yield_context yc);
  45         CpuBoundWork(const CpuBoundWork&) = delete;
  46         CpuBoundWork(CpuBoundWork&&) = delete;
  47         CpuBoundWork& operator=(const CpuBoundWork&) = delete;
  48         CpuBoundWork& operator=(CpuBoundWork&&) = delete;
  49         ~CpuBoundWork();
  50
  51         void Done();
  52
  53 private:
  54         bool m_Done;
  55 };
  56
  57 /**
  58  * Scope break for CPU-bound work done in an I/O thread
  59  *
  60  * @ingroup base
  61  */
  62 class IoBoundWorkSlot
  63 {
  64 public:
  65         IoBoundWorkSlot(boost::asio::yield_context yc);
  66         IoBoundWorkSlot(const IoBoundWorkSlot&) = delete;
  67         IoBoundWorkSlot(IoBoundWorkSlot&&) = delete;
  68         IoBoundWorkSlot& operator=(const IoBoundWorkSlot&) = delete;
  69         IoBoundWorkSlot& operator=(IoBoundWorkSlot&&) = delete;
  70         ~IoBoundWorkSlot();
  71
  72 private:
  73         boost::asio::yield_context yc;
  74 };
  75
  76 /**
  77  * Async I/O engine
  78  *
  79  * @ingroup base
  80  */
  81 class IoEngine
  82 {
  83         friend CpuBoundWork;
  84         friend IoBoundWorkSlot;
  85
  86 public:
  87         IoEngine(const IoEngine&) = delete;
  88         IoEngine(IoEngine&&) = delete;
  89         IoEngine& operator=(const IoEngine&) = delete;
  90         IoEngine& operator=(IoEngine&&) = delete;
  91         ~IoEngine();
  92
  93         static IoEngine& Get();
  94
  95         boost::asio::io_service& GetIoService();
  96
  97 private:
  98         IoEngine();
  99
 100         void RunEventLoop();
 101
 102         static LazyInit<std::unique_ptr<IoEngine>> m_Instance;
 103
 104         boost::asio::io_service m_IoService;
 105         boost::asio::io_service::work m_KeepAlive;
 106         std::vector<std::thread> m_Threads;
 107         boost::asio::deadline_timer m_AlreadyExpiredTimer;
 108         std::atomic_int_fast32_t m_CpuBoundSemaphore;
 109 };
 110
 111 class TerminateIoThread : public std::exception
 112 {
 113 };
 114
 115 /**
 116  * Condition variable which doesn't block I/O threads
 117  *
 118  * @ingroup base
 119  */
 120 class AsioConditionVariable
 121 {
 122 public:
 123         AsioConditionVariable(boost::asio::io_service& io, bool init = false);
 124
 125         void Set();
 126         void Clear();
 127         void Wait(boost::asio::yield_context yc);
 128
 129 private:
 130         boost::asio::deadline_timer m_Timer;
 131 };
 132
 133 }
 134
 135 #endif /* IO_ENGINE_H */