src/lib/platform/util/buffer.h

   1 #pragma once
   2 /*
   3  * This file is part of the libCEC(R) library.
   4  *
   5  * libCEC(R) is Copyright (C) 2011-2013 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 #include "lib/platform/threads/mutex.h"
  35 #include <queue>
  36
  37 namespace PLATFORM
  38 {
  39   template<typename _BType>
  40     struct SyncedBuffer
  41     {
  42     public:
  43       SyncedBuffer(size_t iMaxSize = 100) :
  44           m_maxSize(iMaxSize),
  45           m_bHasMessages(false) {}
  46
  47       virtual ~SyncedBuffer(void)
  48       {
  49         Clear();
  50       }
  51
  52       void Clear(void)
  53       {
  54         CLockObject lock(m_mutex);
  55         while (!m_buffer.empty())
  56           m_buffer.pop();
  57         m_bHasMessages = true;
  58         m_condition.Broadcast();
  59       }
  60
  61       size_t Size(void)
  62       {
  63         CLockObject lock(m_mutex);
  64         return m_buffer.size();
  65       }
  66
  67       bool IsEmpty(void)
  68       {
  69         CLockObject lock(m_mutex);
  70         return m_buffer.empty();
  71       }
  72
  73       bool Push(_BType entry)
  74       {
  75         CLockObject lock(m_mutex);
  76         if (m_buffer.size() == m_maxSize)
  77           return false;
  78
  79         m_buffer.push(entry);
  80         m_bHasMessages = true;
  81         m_condition.Signal();
  82         return true;
  83       }
  84
  85       bool Pop(_BType &entry, uint32_t iTimeoutMs = 0)
  86       {
  87         bool bReturn(false);
  88         CLockObject lock(m_mutex);
  89
  90         // wait for a signal if the buffer is empty
  91         if (m_buffer.empty() && iTimeoutMs > 0)
  92         {
  93           if (!m_condition.Wait(m_mutex, m_bHasMessages, iTimeoutMs))
  94             return bReturn;
  95         }
  96
  97         // pop the first item
  98         m_bHasMessages = !m_buffer.empty();
  99         if (!m_buffer.empty())
 100         {
 101           entry = m_buffer.front();
 102           m_buffer.pop();
 103           bReturn = true;
 104         }
 105         return bReturn;
 106       }
 107
 108       bool Peek(_BType &entry)
 109       {
 110         bool bReturn(false);
 111         CLockObject lock(m_mutex);
 112         if (!m_buffer.empty())
 113         {
 114           entry = m_buffer.front();
 115           bReturn = true;
 116         }
 117         return bReturn;
 118       }
 119
 120     private:
 121       size_t             m_maxSize;
 122       std::queue<_BType> m_buffer;
 123       CMutex             m_mutex;
 124       CCondition<bool>   m_condition;
 125       bool               m_bHasMessages;
 126     };
 127 };