gc_stop_the_world.c

/* stop all other threads by sending them SIG_STOP_FOR_GC */
    for(p=all_threads; p; p=p->next) {
        gc_assert(p->os_thread != 0);
        FSHOW_SIGNAL((stderr,"/gc_stop_the_world: thread=%lu, state=%x\n",
                      p->os_thread, thread_state(p)));
        if((p!=th) && ((thread_state(p)==STATE_RUNNING))) {
            FSHOW_SIGNAL((stderr,"/gc_stop_the_world: suspending thread %lu\n",
                          p->os_thread));
            /* We already hold all_thread_lock, P can become DEAD but
             * cannot exit, ergo it's safe to use pthread_kill. */
            status=pthread_kill(p->os_thread,SIG_STOP_FOR_GC);
            if (status==ESRCH) {
                /* This thread has exited. */
                gc_assert(thread_state(p)==STATE_DEAD);
            } else if (status) {
                lose("cannot send suspend thread=%lu: %d, %s\n",
                     p->os_thread,status,strerror(status));
            }
        }
    }