Question

I a have a C program which calls to threads.

iret1 = pthread_create( &thread1, NULL, readdata, NULL);
iret2 = pthread_create( &thread2, NULL, timer_func, NULL);
pthread_join(thread2, NULL);

Thread 2 returns after performing some function, after which I want to stop the execution of thread 1. How should I do this?

Answer 1

You can stop the thread using pthread_cancel:

pthread_cancel(thread1);

And in readdata:

/* call this when you are not ready to cancel the thread */
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
...
/* call this when you are ready to cancel the thread */
pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);

See the pthread_cancel man page for more information – there’s an example included.

If you don’t want to use pthread_cancel, you can use a global flag that is set by the main thread and read by thread 1. Also, you can use any of the IPC methods, like establishing a pipe between the threads.