src/lib/platform/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 using namespace CEC;
  37
  38 CMutex::CMutex(void)
  39 {
  40   pthread_mutex_init(&m_mutex, NULL);
  41 }
  42
  43 CMutex::~CMutex(void)
  44 {
  45   pthread_mutex_destroy(&m_mutex);
  46 }
  47
  48 bool CMutex::TryLock(void)
  49 {
  50   return (pthread_mutex_trylock(&m_mutex) == 0);
  51 }
  52
  53 bool CMutex::Lock(void)
  54 {
  55   return (pthread_mutex_lock(&m_mutex) == 0);
  56 }
  57
  58 void CMutex::Unlock(void)
  59 {
  60   pthread_mutex_unlock(&m_mutex);
  61 }
  62
  63 CLockObject::CLockObject(CMutex *mutex, bool bTryLock /* = false */) :
  64   m_mutex(mutex)
  65 {
  66   if (m_mutex)
  67     m_bLocked = bTryLock ? m_mutex->TryLock() : m_mutex->Lock();
  68 }
  69
  70 CLockObject::~CLockObject(void)
  71 {
  72   Leave();
  73   m_mutex = NULL;
  74 }
  75
  76 void CLockObject::Leave(void)
  77 {
  78   if (m_mutex && m_bLocked)
  79   {
  80     m_bLocked = false;
  81     m_mutex->Unlock();
  82   }
  83 }
  84
  85 void CLockObject::Lock(void)
  86 {
  87   if (m_mutex)
  88     m_bLocked = m_mutex->Lock();
  89 }
  90
  91 CCondition::CCondition(void)
  92 {
  93   pthread_cond_init(&m_cond, NULL);
  94 }
  95
  96 CCondition::~CCondition(void)
  97 {
  98   pthread_cond_broadcast(&m_cond);
  99   pthread_cond_destroy(&m_cond);
 100 }
 101
 102 void CCondition::Broadcast(void)
 103 {
 104   pthread_cond_broadcast(&m_cond);
 105 }
 106
 107 void CCondition::Signal(void)
 108 {
 109   pthread_cond_signal(&m_cond);
 110 }
 111
 112 bool CCondition::Wait(CMutex *mutex, uint32_t iTimeout /* = 0 */)
 113 {
 114   bool bReturn(false);
 115   sched_yield();
 116   if (mutex)
 117   {
 118     if (iTimeout > 0)
 119     {
 120       struct timespec abstime;
 121       struct timeval now;
 122       gettimeofday(&now, NULL);
 123       iTimeout       += now.tv_usec / 1000;
 124       abstime.tv_sec  = now.tv_sec + (time_t)(iTimeout / 1000);
 125       abstime.tv_nsec = (int32_t)((iTimeout % (uint32_t)1000) * (uint32_t)1000000);
 126       bReturn         = (pthread_cond_timedwait(&m_cond, &mutex->m_mutex, &abstime) == 0);
 127     }
 128     else
 129     {
 130       bReturn         = (pthread_cond_wait(&m_cond, &mutex->m_mutex) == 0);
 131     }
 132   }
 133
 134   return bReturn;
 135 }
 136
 137 void CCondition::Sleep(uint32_t iTimeout)
 138 {
 139   CCondition w;
 140   CMutex m;
 141   CLockObject lock(&m);
 142   w.Wait(&m, iTimeout);
 143 }
 144
 145 CThread::CThread(void) :
 146     m_bStop(false),
 147     m_bRunning(false)
 148 {
 149 }
 150
 151 CThread::~CThread(void)
 152 {
 153   StopThread();
 154 }
 155
 156 bool CThread::CreateThread(bool bWait /* = true */)
 157 {
 158   bool bReturn(false);
 159
 160   CLockObject lock(&m_threadMutex);
 161   m_bStop = false;
 162   if (!m_bRunning && pthread_create(&m_thread, NULL, (void *(*) (void *))&CThread::ThreadHandler, (void *)this) == 0)
 163   {
 164     if (bWait)
 165       m_threadCondition.Wait(&m_threadMutex);
 166     bReturn = true;
 167   }
 168
 169   return bReturn;
 170 }
 171
 172 void *CThread::ThreadHandler(CThread *thread)
 173 {
 174   void *retVal = NULL;
 175
 176   if (thread)
 177   {
 178     CLockObject lock(&thread->m_threadMutex);
 179     thread->m_bRunning = true;
 180     lock.Leave();
 181     thread->m_threadCondition.Broadcast();
 182
 183     retVal = thread->Process();
 184
 185     lock.Lock();
 186     thread->m_bRunning = false;
 187     lock.Leave();
 188     thread->m_threadCondition.Broadcast();
 189   }
 190
 191   return retVal;
 192 }
 193
 194 bool CThread::StopThread(bool bWaitForExit /* = true */)
 195 {
 196   bool bReturn(true);
 197   m_bStop = true;
 198
 199   m_threadCondition.Broadcast();
 200
 201   void *retVal;
 202   if (bWaitForExit && m_bRunning)
 203     bReturn = (pthread_join(m_thread, &retVal) == 0);
 204
 205   return bReturn;
 206 }
 207
 208 bool CThread::Sleep(uint32_t iTimeout)
 209 {
 210   CLockObject lock(&m_threadMutex);
 211   return m_bStop ? false : m_threadCondition.Wait(&m_threadMutex, iTimeout);
 212 }