test/exit_group/main.c
static void *futex_wait_thread_func(void *_) {
    int my_private_futex = 0;
    syscall(SYS_futex, &my_private_futex, FUTEX_WAIT, my_private_futex, NULL);
    return NULL;
}
// Type 3: a thead that waits on a futex FOREVER
Type 3: a thead that waits on a futex FOREVER
Type 3 : a thead that waits on a futex FOREVER
static void *futex_wait_thread_func(void *_) {
    int my_private_futex = 0;
    syscall(SYS_futex, &my_private_futex, FUTEX_WAIT, my_private_futex, NULL);
    return NULL;
}
static void * futex_wait_thread_func ( void * _ ) { int my_private_futex = 0 ; syscall ( SYS_futex , & my_private_futex , FUTEX_WAIT , my_private_futex , NULL ) ; return NULL ; }
Type 3: a thead that waits on a futex FOREVER
Type 3 : a thead that waits on a futex FOREVER