/ray/src/lib/threads/condition.cc

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/*
 * lib/threads/condition.cc
 * 
 * Implementing a thread condition; an object that threads can block 
 * on, if they find a certain condition to be false. 
 * 
 * Copyright (c) 2004 by Wolfgang Wieser ] wwieser (a) gmx <*> de [ 
 * 
 * This file may be distributed and/or modified under the terms of the 
 * GNU General Public License version 2 as published by the Free Software 
 * Foundation. (See COPYING.GPL for details.)
 * 
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 * 
 */

#include "condition.h"

#if USE_PRIVATE__PTHREADS
#if TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# if HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  include <time.h>
# endif
#endif
#else  /* !USE_PRIVATE__PTHREADS */
# include <glib/gmain.h>   /* for g_get_current_time */
# include <glib/gtimer.h>  /* for g_time_val_add */
#endif  /* USE_PRIVATE__PTHREADS */


inline int WaitCondition::wait(ConditionMutex &m,long msec)
{
    if(msec<0)  msec=0;
    
#if USE_PRIVATE__PTHREADS
    // Compute absolute time of wait endtime: 
    timeval tv;
    gettimeofday(&tv,NULL);
    tv.tv_sec+=msec/1000;
    tv.tv_usec+=(msec%1000)*1000;
    if(tv.tv_usec>1000000)
    {  tv.tv_usec-=1000000;  ++tv.tv_sec;  }
    
    timespec tspec;
    tspec.tv_sec=tv.tv_sec;
    tspec.tv_nsec=1000*tv.tv_usec;
    
    // Actually wait: 
    switch(pthread_cond_timedwait(&c,&m.m,&tspec))
    {
        case ETIMEDOUT:  return(1);
        case EINTR:      return(2);
    }
    return(0);
#else
    GTimeVal tv;
    g_get_current_time(&tv);
    g_time_val_add(&tv,1000*msec);
    if(g_cond_timed_wait(c,m.m,&tv))
    {  /* "woken up in time" */  return(0);  }
    return(1);
#endif
}


WaitCondition::WaitCondition()
{
#if USE_PRIVATE__PTHREADS
    //pthread_condattr_t attr;
    //pthread_condattr_init(&attr);
    pthread_cond_init(&c,/*&attr*/NULL);  // <-- NULL = "all defaults"
    //pthread_condattr_destroy(&attr);
#else
    // We must make sure that g_thread_init() has been called before. 
    c=g_cond_new();
#endif
}

WaitCondition::~WaitCondition()
{
#if USE_PRIVATE__PTHREADS
    pthread_cond_destroy(&c);
#else
    // We must make sure that g_thread_init() has been called before. 
    g_cond_free(c);
#endif
}

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