예제 #1
0
int
_pthread_detach(pthread_t pthread)
{
	struct pthread *curthread = _get_curthread();
	int rval;

	if (pthread == NULL)
		return (EINVAL);

	if ((rval = _thr_find_thread(curthread, pthread,
			/*include dead*/1)) != 0) {
		return (rval);
	}

	/* Check if the thread is already detached or has a joiner. */
	if ((pthread->flags & THR_FLAGS_DETACHED) != 0 ||
	    (pthread->joiner != NULL)) {
		THR_THREAD_UNLOCK(curthread, pthread);
		return (EINVAL);
	}

	/* Flag the thread as detached. */
	pthread->flags |= THR_FLAGS_DETACHED;
	_thr_try_gc(curthread, pthread); /* thread lock released */

	return (0);
}
예제 #2
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! */
}
예제 #3
0
/*
 * Cancellation behavior:
 *   if the thread is canceled, joinee is not recycled.
 */
static int
join_common(pthread_t pthread, void **thread_return,
	const struct timespec *abstime)
{
	struct pthread *curthread = _get_curthread();
	struct timespec ts, ts2, *tsp;
	void *tmp;
	long tid;
	int ret = 0;

	if (pthread == NULL)
		return (EINVAL);

	if (pthread == curthread)
		return (EDEADLK);

	if ((ret = _thr_find_thread(curthread, pthread, 1)) != 0)
		return (ESRCH);

	if ((pthread->flags & THR_FLAGS_DETACHED) != 0) {
		ret = EINVAL;
	} else if (pthread->joiner != NULL) {
		/* Multiple joiners are not supported. */
		ret = ENOTSUP;
	}
	if (ret) {
		THR_THREAD_UNLOCK(curthread, pthread);
		return (ret);
	}
	/* Set the running thread to be the joiner: */
	pthread->joiner = curthread;

	THR_THREAD_UNLOCK(curthread, pthread);

	THR_CLEANUP_PUSH(curthread, backout_join, pthread);
	_thr_cancel_enter(curthread);

	tid = pthread->tid;
	while (pthread->tid != TID_TERMINATED) {
		_thr_testcancel(curthread);
		if (abstime != NULL) {
			clock_gettime(CLOCK_REALTIME, &ts);
			TIMESPEC_SUB(&ts2, abstime, &ts);
			if (ts2.tv_sec < 0) {
				ret = ETIMEDOUT;
				break;
			}
			tsp = &ts2;
		} else
			tsp = NULL;
		ret = _thr_umtx_wait(&pthread->tid, tid, tsp);
		if (ret == ETIMEDOUT)
			break;
	}

	_thr_cancel_leave(curthread, 0);
	THR_CLEANUP_POP(curthread, 0);

	if (ret == ETIMEDOUT) {
		THR_THREAD_LOCK(curthread, pthread);
		pthread->joiner = NULL;
		THR_THREAD_UNLOCK(curthread, pthread);
	} else {
		ret = 0;
		tmp = pthread->ret;
		THR_THREAD_LOCK(curthread, pthread);
		pthread->flags |= THR_FLAGS_DETACHED;
		pthread->joiner = NULL;
		_thr_try_gc(curthread, pthread); /* thread lock released */

		if (thread_return != NULL)
			*thread_return = tmp;
	}
	return (ret);
}
예제 #4
0
int
_pthread_create(pthread_t * thread, const pthread_attr_t * attr,
	       void *(*start_routine) (void *), void *arg)
{
	struct pthread *curthread, *new_thread;
	struct thr_param param;
	struct sched_param sched_param;
	struct rtprio rtp;
	sigset_t set, oset;
	cpuset_t *cpusetp;
	int i, cpusetsize, create_suspended, locked, old_stack_prot, ret;

	cpusetp = NULL;
	ret = cpusetsize = 0;
	_thr_check_init();

	/*
	 * Tell libc and others now they need lock to protect their data.
	 */
	if (_thr_isthreaded() == 0) {
		_malloc_first_thread();
		if (_thr_setthreaded(1))
			return (EAGAIN);
	}

	curthread = _get_curthread();
	if ((new_thread = _thr_alloc(curthread)) == NULL)
		return (EAGAIN);

	memset(&param, 0, sizeof(param));

	if (attr == NULL || *attr == NULL)
		/* Use the default thread attributes: */
		new_thread->attr = _pthread_attr_default;
	else {
		new_thread->attr = *(*attr);
		cpusetp = new_thread->attr.cpuset;
		cpusetsize = new_thread->attr.cpusetsize;
		new_thread->attr.cpuset = NULL;
		new_thread->attr.cpusetsize = 0;
	}
	if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
		/* inherit scheduling contention scope */
		if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
			new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
		else
			new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;

		new_thread->attr.prio = curthread->attr.prio;
		new_thread->attr.sched_policy = curthread->attr.sched_policy;
	}

	new_thread->tid = TID_TERMINATED;

	old_stack_prot = _rtld_get_stack_prot();
	if (create_stack(&new_thread->attr) != 0) {
		/* Insufficient memory to create a stack: */
		_thr_free(curthread, new_thread);
		return (EAGAIN);
	}
	/*
	 * Write a magic value to the thread structure
	 * to help identify valid ones:
	 */
	new_thread->magic = THR_MAGIC;
	new_thread->start_routine = start_routine;
	new_thread->arg = arg;
	new_thread->cancel_enable = 1;
	new_thread->cancel_async = 0;
	/* Initialize the mutex queue: */
	for (i = 0; i < TMQ_NITEMS; i++)
		TAILQ_INIT(&new_thread->mq[i]);

	/* Initialise hooks in the thread structure: */
	if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) {
		new_thread->flags = THR_FLAGS_NEED_SUSPEND;
		create_suspended = 1;
	} else {
		create_suspended = 0;
	}

	new_thread->state = PS_RUNNING;

	if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
		new_thread->flags |= THR_FLAGS_DETACHED;

	/* Add the new thread. */
	new_thread->refcount = 1;
	_thr_link(curthread, new_thread);

	/*
	 * Handle the race between __pthread_map_stacks_exec and
	 * thread linkage.
	 */
	if (old_stack_prot != _rtld_get_stack_prot())
		_thr_stack_fix_protection(new_thread);

	/* Return thread pointer eariler so that new thread can use it. */
	(*thread) = new_thread;
	if (SHOULD_REPORT_EVENT(curthread, TD_CREATE) || cpusetp != NULL) {
		THR_THREAD_LOCK(curthread, new_thread);
		locked = 1;
	} else
		locked = 0;
	param.start_func = (void (*)(void *)) thread_start;
	param.arg = new_thread;
	param.stack_base = new_thread->attr.stackaddr_attr;
	param.stack_size = new_thread->attr.stacksize_attr;
	param.tls_base = (char *)new_thread->tcb;
	param.tls_size = sizeof(struct tcb);
	param.child_tid = &new_thread->tid;
	param.parent_tid = &new_thread->tid;
	param.flags = 0;
	if (new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM)
		param.flags |= THR_SYSTEM_SCOPE;
	if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED)
		param.rtp = NULL;
	else {
		sched_param.sched_priority = new_thread->attr.prio;
		_schedparam_to_rtp(new_thread->attr.sched_policy,
			&sched_param, &rtp);
		param.rtp = &rtp;
	}

	/* Schedule the new thread. */
	if (create_suspended) {
		SIGFILLSET(set);
		SIGDELSET(set, SIGTRAP);
		__sys_sigprocmask(SIG_SETMASK, &set, &oset);
		new_thread->sigmask = oset;
		SIGDELSET(new_thread->sigmask, SIGCANCEL);
	}

	ret = thr_new(&param, sizeof(param));

	if (ret != 0) {
		ret = errno;
		/*
		 * Translate EPROCLIM into well-known POSIX code EAGAIN.
		 */
		if (ret == EPROCLIM)
			ret = EAGAIN;
	}

	if (create_suspended)
		__sys_sigprocmask(SIG_SETMASK, &oset, NULL);

	if (ret != 0) {
		if (!locked)
			THR_THREAD_LOCK(curthread, new_thread);
		new_thread->state = PS_DEAD;
		new_thread->tid = TID_TERMINATED;
		new_thread->flags |= THR_FLAGS_DETACHED;
		new_thread->refcount--;
		if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
			new_thread->cycle++;
			_thr_umtx_wake(&new_thread->cycle, INT_MAX, 0);
		}
		_thr_try_gc(curthread, new_thread); /* thread lock released */
		atomic_add_int(&_thread_active_threads, -1);
	} else if (locked) {
		if (cpusetp != NULL) {
			if (cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID,
				TID(new_thread), cpusetsize, cpusetp)) {
				ret = errno;
				/* kill the new thread */
				new_thread->force_exit = 1;
				new_thread->flags |= THR_FLAGS_DETACHED;
				_thr_try_gc(curthread, new_thread);
				 /* thread lock released */
				goto out;
			}
		}

		_thr_report_creation(curthread, new_thread);
		THR_THREAD_UNLOCK(curthread, new_thread);
	}
out:
	if (ret)
		(*thread) = 0;
	return (ret);
}