90 lines
2.6 KiB
C++
90 lines
2.6 KiB
C++
// ------------------------------------------------------------------------
|
|
// kvu_threads.cpp: Various pthread related helper functions.
|
|
// Copyright (C) 2002,2004 Kai Vehmanen
|
|
//
|
|
// This program is free software; you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License as published by
|
|
// the Free Software Foundation; either version 2 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// This program is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU General Public License
|
|
// along with this program; if not, write to the Free Software
|
|
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
// ------------------------------------------------------------------------
|
|
|
|
#include <sys/time.h> /* gettimeofday() */
|
|
#include <errno.h> /* ETIMEDOUT */
|
|
|
|
#include "kvu_threads.h"
|
|
|
|
using std::string;
|
|
|
|
/**
|
|
* A variant of the standard pthread_mutex_lock. This routine is
|
|
* originally from Quasimodo CVS-tree, from the libpbd library, Written
|
|
* by Paul Davis. This version of the routine adds a second
|
|
* argument, 'spinlimit' which specifies the number of loops spent
|
|
* spinning, before blocking with the standard pthread_mutex_lock() call.
|
|
*/
|
|
int kvu_pthread_mutex_spinlock (pthread_mutex_t *mp, long int spinlimit)
|
|
{
|
|
int err = EBUSY;
|
|
unsigned int i;
|
|
|
|
i = spinlimit;
|
|
|
|
while (i > 0 && ((err = pthread_mutex_trylock (mp)) == EBUSY))
|
|
i--;
|
|
|
|
if (err == EBUSY) {
|
|
err = pthread_mutex_lock (mp);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* Waits for condition to occur.
|
|
*
|
|
* @return 0 on success,
|
|
* -ETIMEDOUT if timeout occured,
|
|
* other nonzero value on other errors
|
|
*/
|
|
int kvu_pthread_timed_wait(pthread_mutex_t* mutex, pthread_cond_t* cond, long int seconds)
|
|
{
|
|
struct timeval now;
|
|
gettimeofday(&now, 0);
|
|
struct timespec sleepcount;
|
|
sleepcount.tv_sec = now.tv_sec + seconds;
|
|
sleepcount.tv_nsec = now.tv_usec * 1000;
|
|
int ret = 0;
|
|
|
|
pthread_mutex_lock(mutex);
|
|
ret = pthread_cond_timedwait(cond,
|
|
mutex,
|
|
&sleepcount);
|
|
pthread_mutex_unlock(mutex);
|
|
|
|
return(ret);
|
|
}
|
|
|
|
/**
|
|
* Returns a string explaning the error code
|
|
* returned by kvu_pthread_timed_wait().
|
|
*/
|
|
string kvu_pthread_timed_wait_result(int result, const string& prefix)
|
|
{
|
|
if (result != 0) {
|
|
if (result == -ETIMEDOUT)
|
|
return(prefix + " failed; timeout");
|
|
else
|
|
return(prefix + " failed");
|
|
}
|
|
return(prefix + " ok");
|
|
}
|