asked on

How can get the thread ids

hi,

In my unix program I am creating a series of threads inwhich i am executing different functions on creation of new thread.I want to have the track of all these thread ids of the individual threads.I should able to stop any one of the thread and all the remaining threads should be running.

here i am sending my code what i have done. In that I want to stop first thread and the second thread shold be running as usual.Please help me

[ccode]

#include<pthread.h>
#include<errno.h>
#include<stdio.h>

void do_loop(int *data)
{
      int i;
      int j;
      printf("I am in do_loop\n");

      for (i = 0;i<10;i++)
      {
            for(j=0;j<500000;j++)
            {
                  printf("%d got\n ",*data);

                  printf("\nMy thread id %d\n",pthread_self());

                  sleep(20);
            }

      }

      //pthread_exit(NULL);
}

void do_loop1(int *data)
{
      int i;
      int j;
      printf("I am in do_loop1\n");

            for (i = 0;i<10;i++)
            {
                  for(j=0;j<500000;j++)
                  {

                  printf("%d got\n ",*data);                              printf("\nMy thread id %d\n",pthread_self());
sleep(20);
                                                            }

      }
}

int main(int argc,char *argv[])
{
//      int thread_id;
      pthread_t p_thread1;
      pthread_t p_thread2;
      int a=100;
      int b=111;
      int j;

       pthread_create(&p_thread1,pthread_attr_default,do_loop,&a);

       pthread_create(&p_thread2,pthread_attr_default,do_loop1,&b);

      sleep(10);
      for(j=0;j<500000;j++)
      {
            printf("I am in parent loop\n");
            printf("count j = %d",j);

            if(j==4)
                  pthread_cancel(pthread_self());

// here i want to cancel the specific thread

      //      pthread_cancel(p_thread1.pthread_id);
            sleep(20);
      }

      return 0;

}

[/ccode]

adinarayanak

ASKER

if I put the sleep(20) before second printf in any one of the do_loops then I am getting two different ids.but if i execute the prigram as it is given in the code,I am getting the same thread id for both.Why it is happening.

ASKER CERTIFIED SOLUTION

rdelfino

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adinarayanak

ASKER

if i modify the same program as

#include<pthread.h>
#include<errno.h>
#include<stdio.h>
void do_loop(int *data)
{
int i;
int j;
printf("I am in do_loop\n");

for (i = 0;i<10;i++)
{
for(j=0;j<500000;j++)
{
printf("%d got\n ",*data);

printf("\nMy thread id %d\n",pthread_self());

sleep(20);
}

}

}

int main(int argc,char *argv[])
{

pthread_t p_thread1;
pthread_t p_thread2;
int a=100;
int b=111;
int j;

pthread_create(&p_thread1,pthread_attr_default,do_loop,&a);

pthread_create(&p_thread2,pthread_attr_default,do_loop,&b);

sleep(10);
for(j=0;j<500000;j++)
{
printf("I am in parent loop\n");
printf("count j = %d",j);

if (j == 100);
{
// here you kill (cancel) the first thread you created from the
// parent thread
pthread_cancel(p_thread1);

sleep(20);
return 0;
}

}
return 0;
}

if i run this when the count j == 100 the program will be stopped.

I want one thread to be continuously executing and one thread to be terminated.

please do it

rdelfino

When the main thread finishes, the process die (and all threads within it).

All you gotta do is change the following lines

if (j == 100);
{
// here you kill (cancel) the first thread you created from the
// parent thread
pthread_cancel(p_thread1);

sleep(20);
return 0;
}

to these ones below

if (j == 100);
{
// here you kill (cancel) the first thread you created from the
// parent thread
pthread_cancel(p_thread1);

sleep(20);
//return 0;
}

adinarayanak

ASKER

It is fine.Can I display any one of the childrens' thread_id in the main loop.
If so how to do it.

waiting for u'r reply.

regards,
AdinarayanaK.

rdelfino

in the main thread, do the following after you created the 2 threads:

printf("thread1 id = %u\n", p_thread1);
printf("thread2 id = %u\n", p_thread2);

adinarayanak

ASKER

But it is giving the same id for both the threads.

Why it is so.

awaiting u'r reply.