src/Thread/Thread.hpp

   1 /*
   2 Copyright_License {
   3
   4   XCSoar Glide Computer - http://www.xcsoar.org/
   5   Copyright (C) 2000-2013 The XCSoar Project
   6   A detailed list of copyright holders can be found in the file "AUTHORS".
   7
   8   This program is free software; you can redistribute it and/or
   9   modify it under the terms of the GNU General Public License
  10   as published by the Free Software Foundation; either version 2
  11   of the License, or (at your option) any later version.
  12
  13   This program is distributed in the hope that it will be useful,
  14   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16   GNU General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with this program; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21 }
  22 */
  23
  24 #ifndef XCSOAR_THREAD_THREAD_HPP
  25 #define XCSOAR_THREAD_THREAD_HPP
  26
  27 #ifndef NDEBUG
  28 #include "Util/ListHead.hpp"
  29 #endif
  30
  31 #ifdef HAVE_POSIX
  32 #include <pthread.h>
  33 #else
  34 #include <windows.h>
  35 #endif
  36
  37 #include <assert.h>
  38
  39 /**
  40  * This class provides an OS independent view on a thread.
  41  */
  42 class Thread {
  43 #ifndef NDEBUG
  44   ListHead siblings;
  45 #endif
  46
  47 #ifdef HAVE_POSIX
  48   pthread_t handle;
  49   bool defined;
  50
  51 #ifndef NDEBUG
  52   /**
  53    * The thread is currently being created.  This is a workaround for
  54    * IsInside(), which may return false until pthread_create() has
  55    * initialised the #handle.
  56    */
  57   bool creating;
  58 #endif
  59
  60 #else
  61   HANDLE handle;
  62   DWORD id;
  63 #endif
  64
  65 public:
  66 #ifdef HAVE_POSIX
  67   Thread():defined(false) {
  68 #ifndef NDEBUG
  69     creating = false;
  70 #endif
  71   }
  72 #else
  73   Thread():handle(NULL) {}
  74 #endif
  75
  76 #ifndef NDEBUG
  77   virtual ~Thread() {
  78     /* all Thread objects must be destructed manually by calling
  79        Join(), to clean up */
  80     assert(!IsDefined());
  81   }
  82 #endif
  83
  84   Thread(const Thread &other) = delete;
  85   Thread &operator=(const Thread &other) = delete;
  86
  87   bool IsDefined() const {
  88 #ifdef HAVE_POSIX
  89     return defined;
  90 #else
  91     return handle != NULL;
  92 #endif
  93   }
  94
  95   /**
  96    * Check if this thread is the current thread.
  97    */
  98   bool IsInside() const {
  99 #ifdef HAVE_POSIX
 100 #ifdef NDEBUG
 101     const bool creating = false;
 102 #endif
 103
 104     return IsDefined() && (creating || pthread_equal(pthread_self(), handle));
 105 #else
 106     return GetCurrentThreadId() == id;
 107 #endif
 108   }
 109
 110   void SetLowPriority() {
 111 #ifndef HAVE_POSIX
 112     ::SetThreadPriority(handle, THREAD_PRIORITY_BELOW_NORMAL);
 113 #endif
 114   }
 115
 116   bool Start();
 117   void Join();
 118
 119 #ifndef HAVE_POSIX
 120   bool Join(unsigned timeout_ms);
 121 #endif
 122
 123 protected:
 124   virtual void Run() = 0;
 125
 126 private:
 127 #ifdef HAVE_POSIX
 128   static void *ThreadProc(void *lpParameter);
 129 #else
 130   static DWORD WINAPI ThreadProc(LPVOID lpParameter);
 131 #endif
 132 };
 133
 134 #ifndef NDEBUG
 135 gcc_pure
 136 bool
 137 ExistsAnyThread();
 138 #endif
 139
 140 #endif