Ok, after having clicked ion the send button, I also discovered that
NPTL uses INHERIT_SCHED by default in the pthread attributes
http://sources.redhat.com/bugzilla/show_bug.cgi?id=145
I added it to the original examples, and I obtained the following
(basically it is similar to the Case 1 depicted before...)
Linux Real-Time Threads
[EMAIL PROTECTED] xenomai-demos]# ./ex_rr
LOW priority thread!!!
...........###########............############...........###########...........###########............############...........###########............############...........###########...........###########............############...........###########...........###########............############...........###########...........###########............############...........###########............############...........###########...........###########............############...........###########...........###########............############...........###########...........###########.....#####LOW
priority thread!!!
[EMAIL PROTECTED]
xenomai-demos]#
--> that's fine;
Xenomai Threads:
[EMAIL PROTECTED] xenomai-demos]# ./rt_ex_rr
LOW priority thread!!!
.....###................................................................................###############################################################################...............................................................................################################################################################................................................................................###############################################################################........................................................###########################################################............................................................................................................................................................................................................................................................................................................LOW
priority thread!!!
[EMAIL PROTECTED]
xenomai-demos]#
That is not what should be :-(
Again, in this case there may be an additional influence of using the
stdio with mutexes and so on...
bye
Paolo
/*
* Linux FIFO/RR scheduler demo
*
* This demo creates a few tasks scheduled with the SCHED_FIFO or the
* SCHED_RR scheduler
*
* Copyright (C) 2002 by Paolo Gai
*
* 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 <stdio.h>
#include <pthread.h>
#include <stdlib.h>
/* for sched_param.c */
#include <sched.h>
void *low(void *arg)
{
printf("LOW priority thread!!!\n");
return NULL;
}
void *medium(void *arg)
{
int i,j;
for (i=0; i<300; i++) {
for (j=0; j<1000000; j++) ;
printf((char *)arg);
}
return NULL;
}
void my_create(int policy)
{
pthread_t th1, th2, th3;
pthread_attr_t medium_attr, low_attr;
struct sched_param medium_policy, low_policy;
pthread_attr_init(&medium_attr);
pthread_attr_setinheritsched(&medium_attr, PTHREAD_EXPLICIT_SCHED);
pthread_attr_setschedpolicy(&medium_attr, policy);
medium_policy.sched_priority = 2;
pthread_attr_setschedparam(&medium_attr, &medium_policy);
pthread_attr_init(&low_attr);
pthread_attr_setinheritsched(&medium_attr, PTHREAD_EXPLICIT_SCHED);
pthread_attr_setschedpolicy(&low_attr, SCHED_FIFO);
low_policy.sched_priority = 1;
pthread_attr_setschedparam(&low_attr, &low_policy);
pthread_create(&th1, &medium_attr, medium, (char *)".");
pthread_create(&th2, &medium_attr, medium, (char *)"#");
pthread_create(&th3, &low_attr, low, NULL);
pthread_attr_destroy(&medium_attr);
pthread_attr_destroy(&low_attr);
pthread_join(th1, NULL);
pthread_join(th2, NULL);
pthread_join(th3, NULL);
}
void *high(void *arg)
{
/* first experiment:
- two medium priority thread scheduled with RR
- one low priority thread scheduled with FIFO
*/
my_create(SCHED_RR);
/* second experiment:
- two medium priority thread scheduled with FIFO
- one low priority thread scheduled with FIFO
*/
my_create(SCHED_FIFO);
return NULL;
}
int main()
{
pthread_t mythread;
pthread_attr_t myattr;
struct sched_param myparam;
int err;
int parameter;
void *returnvalue;
/* initializes the thread attribute */
pthread_attr_init(&myattr);
pthread_attr_setinheritsched(&myattr, PTHREAD_EXPLICIT_SCHED);
pthread_attr_setschedpolicy(&myattr, SCHED_FIFO);
myparam.sched_priority = 3;
pthread_attr_setschedparam(&myattr, &myparam);
err = pthread_create(&mythread, &myattr, high, (void *)¶meter);
if (err) {
perror("ERROR");
exit(1);
}
pthread_attr_destroy(&myattr);
/* wait the end of the thread we just created */
pthread_join(mythread, &returnvalue);
return 0;
}
_______________________________________________
Xenomai-help mailing list
Xenomai-help@gna.org
https://mail.gna.org/listinfo/xenomai-help
