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RE: Thread related queries
- To: <jaiprakash at inablers dot net>,<ecos-discuss at sources dot redhat dot com>
- Subject: RE: [ECOS] Thread related queries
- From: "Trenton D. Adams" <tadams at theone dot dnsalias dot com>
- Date: Mon, 27 Aug 2001 09:03:42 -0600
See "Thread Operations" in the eCos Reference guide. Then take a look
at "ecos/examples/twothreads.c" one directory below the root of your
repository. That is to say the directory with "packages", and "host"
directories in it.
-----Original Message-----
From: ecos-discuss-owner@sources.redhat.com
[mailto:ecos-discuss-owner@sources.redhat.com] On Behalf Of Jaiprakash
Sent: Saturday, August 25, 2001 5:35 AM
To: ecos-discuss@sources.redhat.com
Subject: [ECOS] Thread related queries
Hello,
I have the following queries regarding implementation of threading in
ecos:
1. Does ecos consider main() as a running thread or is it just an entry
point to the system.
2. What is Cyg_Idle_thread used for? its functionality is not clear.
3. I was trying to compare following piece of code on linux 6.2 and
ecos running on my board.
#include <pthread.h>
#include <signal.h>
#define NUM_THREADS 3
void *PrintThreadid(void *threadid)
{
int i;
for(;;){
printf("\nthread %d\n",threadid);
i = sleep(1);
if(i) {
printf("return value from sleep() %d", i);
}
}
}
int main()
{
pthread_t threads[NUM_THREADS];
int rc, t,i,j;
int *thread_return;
pthread_attr_t attr;
rc = pthread_attr_init(&attr);
if(rc){
printf("ERROR: return code from pthread_attr_init %d", rc);
}
printf("\n creating threads\n");
for(t=0;t < NUM_THREADS;t++){
rc = pthread_create(&threads[t], &attr, PrintThreadid, (void *)
t);
if (rc){
printf("ERROR; return code from pthread_create()%d ", rc);
}
}
printf("\n running main thread\n");
pthread_attr_destroy(&attr);
for(t=0;t < NUM_THREADS;t++){
rc = pthread_join(threads[t], (void *)&thread_return);
if(rc){
printf("ERROR: return code from pthread_join %d", rc);
}
printf("Completed join with thread %d thread_return = %d\n",t,
thread_return );
}
while(1) ;
}
On linux the control goes to main() once, later the threads keep
running continuously. But in ecos the main() seems to get more
timeslice (15 - 20 times more) than the three threads. My basic clock
tick is 0.5 secs and timeslicing is 2 ticks. can you give me some
inputs regarding the difference of behaviour eventhough i am using
pthread calls.
There is not much documentation regarding implementation of threading
in ecos.
Thanking you in advance.
Jaiprakash N