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(bool bRecursive /* = true */)
  39 {
  40   pthread_mutex_init(&m_mutex, bRecursive ? GetMutexAttribute() : 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 static pthread_mutexattr_t g_mutexAttr;
  64 pthread_mutexattr_t *CMutex::GetMutexAttribute()
  65 {
  66   static bool bAttributeInitialised = false;
  67   if (!bAttributeInitialised)
  68   {
  69     pthread_mutexattr_init(&g_mutexAttr);
  70     pthread_mutexattr_settype(&g_mutexAttr, PTHREAD_MUTEX_RECURSIVE);
  71     bAttributeInitialised = true;
  72   }
  73   return &g_mutexAttr;
  74 }
  75
  76 CLockObject::CLockObject(CMutex *mutex, bool bTryLock /* = false */) :
  77   m_mutex(mutex)
  78 {
  79   if (m_mutex)
  80     m_bLocked = bTryLock ? m_mutex->TryLock() : m_mutex->Lock();
  81 }
  82
  83 CLockObject::~CLockObject(void)
  84 {
  85   Leave();
  86   m_mutex = NULL;
  87 }
  88
  89 void CLockObject::Leave(void)
  90 {
  91   if (m_mutex && m_bLocked)
  92   {
  93     m_bLocked = false;
  94     m_mutex->Unlock();
  95   }
  96 }
  97
  98 void CLockObject::Lock(void)
  99 {
 100   if (m_mutex)
 101     m_bLocked = m_mutex->Lock();
 102 }
 103
 104 CCondition::CCondition(void)
 105 {
 106   pthread_cond_init(&m_cond, NULL);
 107 }
 108
 109 CCondition::~CCondition(void)
 110 {
 111   pthread_cond_broadcast(&m_cond);
 112   pthread_cond_destroy(&m_cond);
 113 }
 114
 115 void CCondition::Broadcast(void)
 116 {
 117   pthread_cond_broadcast(&m_cond);
 118 }
 119
 120 void CCondition::Signal(void)
 121 {
 122   pthread_cond_signal(&m_cond);
 123 }
 124
 125 bool CCondition::Wait(CMutex *mutex, uint32_t iTimeout /* = 0 */)
 126 {
 127   bool bReturn(false);
 128   sched_yield();
 129   if (mutex)
 130   {
 131     if (iTimeout > 0)
 132     {
 133       struct timespec abstime;
 134       struct timeval now;
 135       gettimeofday(&now, NULL);
 136       iTimeout       += now.tv_usec / 1000;
 137       abstime.tv_sec  = now.tv_sec + (time_t)(iTimeout / 1000);
 138       abstime.tv_nsec = (int32_t)((iTimeout % (uint32_t)1000) * (uint32_t)1000000);
 139       bReturn         = (pthread_cond_timedwait(&m_cond, &mutex->m_mutex, &abstime) == 0);
 140     }
 141     else
 142     {
 143       bReturn         = (pthread_cond_wait(&m_cond, &mutex->m_mutex) == 0);
 144     }
 145   }
 146
 147   return bReturn;
 148 }
 149
 150 void CCondition::Sleep(uint32_t iTimeout)
 151 {
 152   CCondition w;
 153   CMutex m;
 154   CLockObject lock(&m);
 155   w.Wait(&m, iTimeout);
 156 }
 157
 158 CThread::CThread(void) :
 159     m_bStop(false),
 160     m_bRunning(false)
 161 {
 162 }
 163
 164 CThread::~CThread(void)
 165 {
 166   StopThread();
 167 }
 168
 169 bool CThread::CreateThread(bool bWait /* = true */)
 170 {
 171   bool bReturn(false);
 172
 173   CLockObject lock(&m_threadMutex);
 174   m_bStop = false;
 175   if (!m_bRunning && pthread_create(&m_thread, NULL, (void *(*) (void *))&CThread::ThreadHandler, (void *)this) == 0)
 176   {
 177     if (bWait)
 178       m_threadCondition.Wait(&m_threadMutex);
 179     bReturn = true;
 180   }
 181
 182   return bReturn;
 183 }
 184
 185 void *CThread::ThreadHandler(CThread *thread)
 186 {
 187   void *retVal = NULL;
 188
 189   if (thread)
 190   {
 191     CLockObject lock(&thread->m_threadMutex);
 192     thread->m_bRunning = true;
 193     lock.Leave();
 194     thread->m_threadCondition.Broadcast();
 195
 196     retVal = thread->Process();
 197
 198     lock.Lock();
 199     thread->m_bRunning = false;
 200     lock.Leave();
 201     thread->m_threadCondition.Broadcast();
 202   }
 203
 204   return retVal;
 205 }
 206
 207 bool CThread::StopThread(bool bWaitForExit /* = true */)
 208 {
 209   bool bReturn(true);
 210   m_bStop = true;
 211
 212   m_threadCondition.Broadcast();
 213
 214   void *retVal;
 215   if (bWaitForExit && m_bRunning)
 216     bReturn = (pthread_join(m_thread, &retVal) == 0);
 217
 218   return bReturn;
 219 }
 220
 221 bool CThread::Sleep(uint32_t iTimeout)
 222 {
 223   CLockObject lock(&m_threadMutex);
 224   return m_bStop ? false : m_threadCondition.Wait(&m_threadMutex, iTimeout);
 225 }