Bug 24345

Garbage collector looks into list of dead threads and freeing
resources only for threads with PTHREAD_DETACHED flag.
Unfortunattely pthread_join() doesn't set PTHREAD_DETACHED flag
on thread after fetching it return value. So, garbage collector
leave this thread in dead list and won't free() any resources
associated with it. This causes memory leak.

Fix: Should we simply set PTHREAD_DETACHED flag after sucessfuly
joining on thread ? But this is not solution for pthread_cancel(),
that also put threads in dead list w/o PTHREAD_DETACHED flag set.

How-To-Repeat: Simply start thread in joinable state, and then join on it.
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#ifndef _THREAD_SAFE
#define _THREAD_SAFE
#endif
#ifndef _REENTRANT
#define _REENTRANT
#endif
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <pthread.h>

unsigned long brk_value = 0;

void *check_leak(void *arg)
{
    unsigned long current_brk = (unsigned long) sbrk(0);
    if (current_brk > brk_value)
        if (brk_value != 0)
            fprintf(stdout, "Data segment grows up by 0x%lX bytes\n", current_brk - brk_value);
    brk_value = current_brk;
    pthread_exit(NULL);
}

int main()
{
    pthread_t tid;
    pthread_attr_t attr;
    pthread_attr_init(&attr);
    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
    for (;;) {
        if (pthread_create(&tid, &attr, check_leak, NULL)) {
            perror("pthread_create");
            exit(0);
        }
         else
            pthread_join(tid, NULL);
    }
}
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