src/lib/platform/threads/mutex.h

   1 #pragma once
   2 /*
   3  * This file is part of the libCEC(R) library.
   4  *
   5  * libCEC(R) is Copyright (C) 2011 Pulse-Eight Limited.  All rights reserved.
   6  * libCEC(R) is an original work, containing original code.
   7  *
   8  * libCEC(R) is a trademark of Pulse-Eight Limited.
   9  *
  10  * This program is dual-licensed; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  *
  24  *
  25  * Alternatively, you can license this library under a commercial license,
  26  * please contact Pulse-Eight Licensing for more information.
  27  *
  28  * For more information contact:
  29  * Pulse-Eight Licensing       <license@pulse-eight.com>
  30  *     http://www.pulse-eight.com/
  31  *     http://www.pulse-eight.net/
  32  */
  33
  34 namespace PLATFORM
  35 {
  36   class PreventCopy
  37   {
  38   public:
  39     inline PreventCopy(void) {}
  40     inline ~PreventCopy(void) {}
  41
  42   private:
  43     inline PreventCopy(const PreventCopy &c) { *this = c; }
  44     inline PreventCopy &operator=(const PreventCopy &c){ *this = c; return *this; }
  45   };
  46
  47   class CCondition;
  48
  49   class CMutex : public PreventCopy
  50   {
  51     friend class CCondition;
  52   public:
  53     inline CMutex(void) :
  54       m_iLockCount(0)
  55     {
  56       MutexCreate(m_mutex);
  57     }
  58
  59     inline ~CMutex(void)
  60     {
  61       Clear();
  62       MutexDelete(m_mutex);
  63     }
  64
  65     inline bool TryLock(void)
  66     {
  67       if (MutexTryLock(m_mutex))
  68       {
  69         ++m_iLockCount;
  70         return true;
  71       }
  72       return false;
  73     }
  74
  75     inline bool Lock(void)
  76     {
  77       MutexLock(m_mutex);
  78       ++m_iLockCount;
  79       return true;
  80     }
  81
  82     inline void Unlock(void)
  83     {
  84       --m_iLockCount;
  85       MutexUnlock(m_mutex);
  86     }
  87
  88     inline bool Clear(void)
  89     {
  90       bool bReturn(false);
  91       if (TryLock())
  92       {
  93         unsigned int iLockCount = m_iLockCount;
  94         for (unsigned int iPtr = 0; iPtr < iLockCount; iPtr++)
  95           Unlock();
  96         bReturn = true;
  97       }
  98       return bReturn;
  99     }
 100
 101   private:
 102     mutex_t      m_mutex;
 103     unsigned int m_iLockCount;
 104   };
 105
 106   class CLockObject : public PreventCopy
 107   {
 108   public:
 109     inline CLockObject(CMutex &mutex, bool bClearOnExit = false) :
 110       m_mutex(mutex),
 111       m_bClearOnExit(bClearOnExit)
 112     {
 113       m_mutex.Lock();
 114     }
 115
 116     inline ~CLockObject(void)
 117     {
 118       if (m_bClearOnExit)
 119         Clear();
 120       else
 121         Unlock();
 122     }
 123
 124     inline bool TryLock(void)
 125     {
 126       return m_mutex.TryLock();
 127     }
 128
 129     inline void Unlock(void)
 130     {
 131       m_mutex.Unlock();
 132     }
 133
 134     inline bool Clear(void)
 135     {
 136       return m_mutex.Clear();
 137     }
 138
 139     inline bool Lock(void)
 140     {
 141       return m_mutex.Lock();
 142     }
 143
 144   private:
 145     CMutex &m_mutex;
 146     bool    m_bClearOnExit;
 147   };
 148
 149   class CCondition : public PreventCopy
 150   {
 151   public:
 152     inline CCondition(void)
 153     {
 154       ConditionCreate(m_condition);
 155     }
 156
 157     inline ~CCondition(void)
 158     {
 159       Broadcast();
 160       ConditionDelete(m_condition);
 161     }
 162
 163     inline void Broadcast(void)
 164     {
 165       ConditionBroadcast(m_condition);
 166     }
 167
 168     inline void Signal(void)
 169     {
 170       ConditionSignal(m_condition);
 171     }
 172
 173     inline bool Wait(CMutex &mutex, uint32_t iTimeout = 0)
 174     {
 175       return ConditionWait(m_condition, mutex.m_mutex, iTimeout);
 176     }
 177
 178     static void Sleep(uint32_t iTimeout)
 179     {
 180       CCondition w;
 181       CMutex m;
 182       CLockObject lock(m);
 183       w.Wait(m, iTimeout);
 184     }
 185
 186     condition_t m_condition;
 187   };
 188 }