CareerCup

since we haven't created the thread and we are asking the parent to wait for it...it will do nothing imo...i tried it on linux

Wouldnt the process calling pthread_join need the thread handle to identify the child to wait on?. If there are no children then on wat thread the pthread_join would be called?

thread_join is an API which causes the calling thread to wait till a particular thread be executed.

Let say we have two threads available in a process.
1- Main thread : - Generates another thread
2- Both threads are independent and start executes in parallel.
3- If let say Main thread get CPU and it doesn't execute "join" API , it might cause process to exit without waiting for the newly generated thread completes its execution.

int main()
{
create_thread(); //We have 2 threads now main thread + child thread;
main thread completes the execution;
//thread_join(); wait for child thread execution
exit(0);
}

Let me know if i am not clear enough :)

my question is parent will keep on waiting or after some time it will exit

Hey, that's what i tried to explain in my previous mail!!!
Read it carefully.
Parent thread might exit if u don't use thread_join() [might ... becoz it depends onthread scheduler...which thread is scheduled to execute]

@swetank but suppose parent executes thread join when will parent exit when it has not childs

I think deadlock...

source: hxxp://sourceware.org/pthreads-win32/manual/pthread_join.html (note the hxxp instead of http)

int pthread_join(pthread_t th, void **thread_return);

Return Value

On success, the return value of th is stored in the location pointed to by thread_return, and 0 is returned. On error, a non-zero error code is returned.
Errors

ESRCH
No thread could be found corresponding to that specified by th.

I got a seg fault as the value of th was not initialized