Line data    Source code

       1             : /*
       2             :  * Copyright (c) 2013 Juniper Networks, Inc. All rights reserved.
       3             :  * Copyright Contributors to the OpenSDN project
       4             :  */
       5             : 
       6             : #ifndef SRC_IO_EVENT_MANAGER_H_
       7             : #define SRC_IO_EVENT_MANAGER_H_
       8             : 
       9             : #pragma once
      10             : 
      11             : #include <tbb/spin_mutex.h>
      12             : #include <boost/asio/io_service.hpp>
      13             : 
      14             : #include "base/util.h"
      15             : 
      16             : //
      17             : // Wrapper around boost::io_service.
      18             : //
      19             : // The mutex and the related assertions in Run, RunOnce and Poll are used
      20             : // to detect the case where multiple threads are running the EventManager.
      21             : // This typically happens in unit tests that inadvertently call RunOnce or
      22             : // Poll directly or indirectly after having started a ServerThread (which
      23             : // calls Run).
      24             : //
      25             : class EventManager {
      26             : public:
      27             :     EventManager();
      28             : 
      29             :     // Run until shutdown.
      30             :     void Run();
      31             : 
      32             :     // Run at most once.
      33             :     size_t RunOnce();
      34             : 
      35             :     // Run all ready handlers, without blocking.
      36             :     size_t Poll();
      37             : 
      38             :     void Shutdown();
      39             : 
      40             :     // Information whether mutex is already acquired
      41             :     bool IsRunning() const;
      42             : 
      43      435341 :     boost::asio::io_context *io_service() { return &io_service_; }
      44             : 
      45             : private:
      46             :     // Atomic mutex lock operation and changing the running_ flag
      47             :     void Lock();
      48             : 
      49             :     // Atomic mutex unlock operation and changing the running_ flag
      50             :     void Unlock();
      51             : 
      52             :     boost::asio::io_context io_service_;
      53             :     bool shutdown_;
      54             :     tbb::spin_mutex io_mutex_;
      55             :     bool running_;
      56             :     tbb::spin_mutex guard_running_;
      57             : 
      58             :     DISALLOW_COPY_AND_ASSIGN(EventManager);
      59             : };
      60             : 
      61             : #endif  // SRC_IO_EVENT_MANAGER_H_