示例#1
0
void
_pthread_exit_mask(void *status, sigset_t *mask)
{
    struct pthread *curthread = _get_curthread();

    /* Check if this thread is already in the process of exiting: */
    if (curthread->cancelling) {
        char msg[128];
        snprintf(msg, sizeof(msg), "Thread %p has called "
                 "pthread_exit() from a destructor. POSIX 1003.1 "
                 "1996 s16.2.5.2 does not allow this!", curthread);
        PANIC(msg);
    }

    /* Flag this thread as exiting. */
    curthread->cancelling = 1;
    curthread->no_cancel = 1;
    curthread->cancel_async = 0;
    curthread->cancel_point = 0;
    if (mask != NULL)
        __sys_sigprocmask(SIG_SETMASK, mask, NULL);
    if (curthread->unblock_sigcancel) {
        sigset_t set;

        curthread->unblock_sigcancel = 0;
        SIGEMPTYSET(set);
        SIGADDSET(set, SIGCANCEL);
        __sys_sigprocmask(SIG_UNBLOCK, mask, NULL);
    }

    /* Save the return value: */
    curthread->ret = status;
#ifdef _PTHREAD_FORCED_UNWIND

#ifdef PIC
    thread_uw_init();
#endif /* PIC */

#ifdef PIC
    if (uwl_forcedunwind != NULL) {
#else
    if (_Unwind_ForcedUnwind != NULL) {
#endif
        if (curthread->unwind_disabled) {
            if (message_printed == 0) {
                message_printed = 1;
                _thread_printf(2, "Warning: old _pthread_cleanup_push was called, "
                               "stack unwinding is disabled.\n");
            }
            goto cleanup;
        }
        thread_unwind();

    } else {
cleanup:
        while (curthread->cleanup != NULL) {
            __pthread_cleanup_pop_imp(1);
        }
        exit_thread();
    }

#else
    while (curthread->cleanup != NULL) {
        __pthread_cleanup_pop_imp(1);
    }

    exit_thread();
#endif /* _PTHREAD_FORCED_UNWIND */
}

static void
exit_thread(void)
{
    struct pthread *curthread = _get_curthread();

    /* Check if there is thread specific data: */
    if (curthread->specific != NULL) {
        /* Run the thread-specific data destructors: */
        _thread_cleanupspecific();
    }

    if (!_thr_isthreaded())
        exit(0);

    if (atomic_fetchadd_int(&_thread_active_threads, -1) == 1) {
        exit(0);
        /* Never reach! */
    }

    /* Tell malloc that the thread is exiting. */
    _malloc_thread_cleanup();

    THR_LOCK(curthread);
    curthread->state = PS_DEAD;
    if (curthread->flags & THR_FLAGS_NEED_SUSPEND) {
        curthread->cycle++;
        _thr_umtx_wake(&curthread->cycle, INT_MAX, 0);
    }
    if (!curthread->force_exit && SHOULD_REPORT_EVENT(curthread, TD_DEATH))
        _thr_report_death(curthread);
    /*
     * Thread was created with initial refcount 1, we drop the
     * reference count to allow it to be garbage collected.
     */
    curthread->refcount--;
    _thr_try_gc(curthread, curthread); /* thread lock released */

#if defined(_PTHREADS_INVARIANTS)
    if (THR_IN_CRITICAL(curthread))
        PANIC("thread exits with resources held!");
#endif
    /*
     * Kernel will do wakeup at the address, so joiner thread
     * will be resumed if it is sleeping at the address.
     */
    thr_exit(&curthread->tid);
    PANIC("thr_exit() returned");
    /* Never reach! */
}
示例#2
0
void
pthread_exit(void *status)
{
	struct pthread	*curthread = _get_curthread();
	pthread_t pthread;

	/* Check if this thread is already in the process of exiting: */
	if ((curthread->flags & PTHREAD_EXITING) != 0) {
		PANIC("Thread has called pthread_exit() from a destructor. POSIX 1003.1 1996 s16.2.5.2 does not allow this!");
	}

	/* Flag this thread as exiting: */
	curthread->flags |= PTHREAD_EXITING;

	/* Save the return value: */
	curthread->ret = status;

	while (curthread->cleanup != NULL) {
		pthread_cleanup_pop(1);
	}
	if (curthread->attr.cleanup_attr != NULL) {
		curthread->attr.cleanup_attr(curthread->attr.arg_attr);
	}
	/* Check if there is thread specific data: */
	if (curthread->specific_data != NULL) {
		/* Run the thread-specific data destructors: */
		_thread_cleanupspecific();
	}

	/*
	 * Lock the garbage collector mutex to ensure that the garbage
	 * collector is not using the dead thread list.
	 */
	if (pthread_mutex_lock(&_gc_mutex) != 0)
		PANIC("Cannot lock gc mutex");

	/* Add this thread to the list of dead threads. */
	TAILQ_INSERT_HEAD(&_dead_list, curthread, dle);

	/*
	 * Signal the garbage collector thread that there is something
	 * to clean up.
	 */
	if (pthread_cond_signal(&_gc_cond) != 0)
		PANIC("Cannot signal gc cond");

	/*
	 * Avoid a race condition where a scheduling signal can occur
	 * causing the garbage collector thread to run.  If this happens,
	 * the current thread can be cleaned out from under us.
	 */
	_thread_kern_sig_defer();

	/* Unlock the garbage collector mutex: */
	if (pthread_mutex_unlock(&_gc_mutex) != 0)
		PANIC("Cannot unlock gc mutex");

	/* Check if there is a thread joining this one: */
	if (curthread->joiner != NULL) {
		pthread = curthread->joiner;
		curthread->joiner = NULL;

		switch (pthread->suspended) {
		case SUSP_JOIN:
			/*
			 * The joining thread is suspended.  Change the
			 * suspension state to make the thread runnable when it
			 * is resumed:
			 */
			pthread->suspended = SUSP_NO;
			break;
		case SUSP_NO:
			/* Make the joining thread runnable: */
			PTHREAD_NEW_STATE(pthread, PS_RUNNING);
			break;
		default:
			PANIC("Unreachable code reached");
		}

		/* Set the return value for the joining thread: */
		pthread->join_status.ret = curthread->ret;
		pthread->join_status.error = 0;
		pthread->join_status.thread = NULL;

		/* Make this thread collectable by the garbage collector. */
		PTHREAD_ASSERT(((curthread->attr.flags & PTHREAD_DETACHED) ==
		    0), "Cannot join a detached thread");
		curthread->attr.flags |= PTHREAD_DETACHED;
	}

	/* Remove this thread from the thread list: */
	TAILQ_REMOVE(&_thread_list, curthread, tle);

	/* This thread will never be re-scheduled. */
	_thread_kern_sched_state(PS_DEAD, __FILE__, __LINE__);

	/* This point should not be reached. */
	PANIC("Dead thread has resumed");
}
示例#3
0
void
_pthread_exit(void *status)
{
	struct pthread *curthread = _get_curthread();
	kse_critical_t crit;
	struct kse *curkse;

	/* Check if this thread is already in the process of exiting: */
	if ((curthread->flags & THR_FLAGS_EXITING) != 0) {
		char msg[128];
		snprintf(msg, sizeof(msg), "Thread %p has called "
		    "pthread_exit() from a destructor. POSIX 1003.1 "
		    "1996 s16.2.5.2 does not allow this!", curthread);
		PANIC(msg);
	}

	/*
	 * Flag this thread as exiting.  Threads should now be prevented
	 * from joining to this thread.
	 */
	THR_SCHED_LOCK(curthread, curthread);
	curthread->flags |= THR_FLAGS_EXITING;
	THR_SCHED_UNLOCK(curthread, curthread);
	
	/*
	 * To avoid signal-lost problem, if signals had already been
	 * delivered to us, handle it. we have already set EXITING flag
	 * so no new signals should be delivered to us.
	 * XXX this is not enough if signal was delivered just before
	 * thread called sigprocmask and masked it! in this case, we
	 * might have to re-post the signal by kill() if the signal
	 * is targeting process (not for a specified thread).
	 * Kernel has same signal-lost problem, a signal may be delivered
	 * to a thread which is on the way to call sigprocmask or thr_exit()!
	 */
	if (curthread->check_pending)
		_thr_sig_check_pending(curthread);
	/* Save the return value: */
	curthread->ret = status;
	while (curthread->cleanup != NULL) {
		_pthread_cleanup_pop(1);
	}
	if (curthread->attr.cleanup_attr != NULL) {
		curthread->attr.cleanup_attr(curthread->attr.arg_attr);
	}
	/* Check if there is thread specific data: */
	if (curthread->specific != NULL) {
		/* Run the thread-specific data destructors: */
		_thread_cleanupspecific();
	}
	if (!_kse_isthreaded())
		exit(0);
	crit = _kse_critical_enter();
	curkse = _get_curkse();
	KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock);
	/* Use thread_list_lock */
	_thread_active_threads--;
	if ((_thread_scope_system <= 0 && _thread_active_threads == 1) ||
	    (_thread_scope_system > 0 && _thread_active_threads == 0)) {
		KSE_LOCK_RELEASE(curkse, &_thread_list_lock);
		_kse_critical_leave(crit);
		exit(0);
		/* Never reach! */
	}
	KSE_LOCK_RELEASE(curkse, &_thread_list_lock);

	/* This thread will never be re-scheduled. */
	KSE_LOCK(curkse);
	THR_SET_STATE(curthread, PS_DEAD);
	_thr_sched_switch_unlocked(curthread);
	/* Never reach! */

	/* This point should not be reached. */
	PANIC("Dead thread has resumed");
}
示例#4
0
void
_pthread_exit(void *status)
{
	struct pthread *curthread = _get_curthread();

	/* Check if this thread is already in the process of exiting: */
	if (curthread->cancelling) {
		char msg[128];
		snprintf(msg, sizeof(msg), "Thread %p has called "
		    "pthread_exit() from a destructor. POSIX 1003.1 "
		    "1996 s16.2.5.2 does not allow this!", curthread);
		PANIC(msg);
	}

	/* Flag this thread as exiting. */
	curthread->cancelling = 1;
	
	_thr_exit_cleanup();

	/* Save the return value: */
	curthread->ret = status;
	while (curthread->cleanup != NULL) {
		_pthread_cleanup_pop(1);
	}

	/* Check if there is thread specific data: */
	if (curthread->specific != NULL) {
		/* Run the thread-specific data destructors: */
		_thread_cleanupspecific();
	}

	if (!_thr_isthreaded())
		exit(0);

	THREAD_LIST_LOCK(curthread);
	_thread_active_threads--;
	if (_thread_active_threads == 0) {
		THREAD_LIST_UNLOCK(curthread);
		exit(0);
		/* Never reach! */
	}
	THREAD_LIST_UNLOCK(curthread);

	/* Tell malloc that the thread is exiting. */
	_malloc_thread_cleanup();

	THREAD_LIST_LOCK(curthread);
	THR_LOCK(curthread);
	curthread->state = PS_DEAD;
	if (curthread->flags & THR_FLAGS_NEED_SUSPEND) {
		curthread->cycle++;
		_thr_umtx_wake(&curthread->cycle, INT_MAX, 0);
	}
	THR_UNLOCK(curthread);
	/*
	 * Thread was created with initial refcount 1, we drop the
	 * reference count to allow it to be garbage collected.
	 */
	curthread->refcount--;
	if (curthread->tlflags & TLFLAGS_DETACHED)
		THR_GCLIST_ADD(curthread);
	THREAD_LIST_UNLOCK(curthread);
	if (!curthread->force_exit && SHOULD_REPORT_EVENT(curthread, TD_DEATH))
		_thr_report_death(curthread);

	/*
	 * Kernel will do wakeup at the address, so joiner thread
	 * will be resumed if it is sleeping at the address.
	 */
	thr_exit(&curthread->tid);
#ifndef __AVM2__ // might exit if we're impersonating another thread!
	PANIC("thr_exit() returned");
#endif
	/* Never reach! */
}