src/lib/util/threads.cpp

   1 /*
   2  * This file is part of the libCEC(R) library.
   3  *
   4  * libCEC(R) is Copyright (C) 2011 Pulse-Eight Limited.  All rights reserved.
   5  * libCEC(R) is an original work, containing original code.
   6  *
   7  * libCEC(R) is a trademark of Pulse-Eight Limited.
   8  *
   9  * This program is dual-licensed; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22  *
  23  *
  24  * Alternatively, you can license this library under a commercial license,
  25  * please contact Pulse-Eight Licensing for more information.
  26  *
  27  * For more information contact:
  28  * Pulse-Eight Licensing       <license@pulse-eight.com>
  29  *     http://www.pulse-eight.com/
  30  *     http://www.pulse-eight.net/
  31  */
  32
  33 #include "threads.h"
  34 #include "timeutils.h"
  35
  36 CMutex::CMutex(void)
  37 {
  38   pthread_mutex_init(&m_mutex, NULL);
  39   m_condition = new CCondition();
  40   m_bLocked = false;
  41 }
  42
  43 CMutex::~CMutex(void)
  44 {
  45   delete m_condition;
  46   pthread_mutex_destroy(&m_mutex);
  47 }
  48
  49 bool CMutex::TryLock(int64_t iTimeout)
  50 {
  51   m_bLocked = (pthread_mutex_trylock(&m_mutex) == 0);
  52   if (!m_bLocked)
  53   {
  54     if (m_condition->Wait(this, iTimeout))
  55       m_bLocked = (pthread_mutex_trylock(&m_mutex) == 0);
  56   }
  57
  58   return m_bLocked;
  59 }
  60
  61 bool CMutex::Lock(void)
  62 {
  63   m_bLocked = (pthread_mutex_lock(&m_mutex) == 0);
  64   return m_bLocked;
  65 }
  66
  67 void CMutex::Unlock(void)
  68 {
  69   pthread_mutex_unlock(&m_mutex);
  70   m_bLocked = false;
  71   m_condition->Signal();
  72 }
  73
  74 CLockObject::CLockObject(CMutex *mutex, int64_t iTimeout /* = -1 */) :
  75   m_mutex(mutex),
  76   m_bLocked(false)
  77 {
  78   if (iTimeout > 0)
  79     m_bLocked = m_mutex->TryLock(iTimeout);
  80   else
  81     m_bLocked = m_mutex->Lock();
  82 }
  83
  84 CLockObject::~CLockObject(void)
  85 {
  86   m_mutex->Unlock();
  87   m_bLocked = false;
  88   m_mutex = NULL;
  89 }
  90
  91 CCondition::CCondition(void)
  92 {
  93   pthread_cond_init(&m_cond, NULL);
  94   m_bSignaled = false;
  95 }
  96
  97 CCondition::~CCondition(void)
  98 {
  99   pthread_cond_broadcast(&m_cond);
 100   pthread_cond_destroy(&m_cond);
 101 }
 102
 103 void CCondition::Signal(void)
 104 {
 105   pthread_cond_broadcast(&m_cond);
 106 }
 107
 108 bool CCondition::Wait(CMutex *mutex, int64_t iTimeout)
 109 {
 110   struct timespec abstime;
 111   struct timeval now;
 112   if (gettimeofday(&now, NULL) == 0)
 113   {
 114     iTimeout       += now.tv_usec / 1000;
 115     abstime.tv_sec  = now.tv_sec + (time_t)(iTimeout / 1000);
 116     abstime.tv_nsec = (long)((iTimeout % (unsigned long)1000) * (unsigned long)1000000);
 117     m_bSignaled     = (pthread_cond_timedwait(&m_cond, &mutex->m_mutex, &abstime) == 0);
 118   }
 119
 120   bool bReturn = m_bSignaled;
 121   m_bSignaled = false;
 122
 123   return bReturn;
 124 }
 125
 126 void CCondition::Sleep(int iTimeout)
 127 {
 128   sched_yield();
 129   CCondition w;
 130   CMutex m;
 131   w.Wait(&m, iTimeout);
 132 }