xref: /third_party/libwebsockets/lib/event-libs/libuv/libuv.c

/*
 * libwebsockets - small server side websockets and web server implementation
 *
 * Copyright (C) 2010 - 2021 Andy Green <andy@warmcat.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include "private-lib-core.h"
#include "private-lib-event-libs-libuv.h"

#define pt_to_priv_uv(_pt) ((struct lws_pt_eventlibs_libuv *)(_pt)->evlib_pt)
#define wsi_to_priv_uv(_w) ((struct lws_wsi_eventlibs_libuv *)(_w)->evlib_wsi)

static void
lws_uv_sultimer_cb(uv_timer_t *timer
#if UV_VERSION_MAJOR == 0
		, int status
#endif
)
{
	struct lws_pt_eventlibs_libuv *ptpr = lws_container_of(timer,
				struct lws_pt_eventlibs_libuv, sultimer);
	struct lws_context_per_thread *pt = ptpr->pt;
	lws_usec_t us;

	lws_context_lock(pt->context, __func__);
	lws_pt_lock(pt, __func__);
	us = __lws_sul_service_ripe(pt->pt_sul_owner, LWS_COUNT_PT_SUL_OWNERS,
				    lws_now_usecs());
	if (us)
		uv_timer_start(&pt_to_priv_uv(pt)->sultimer, lws_uv_sultimer_cb,
			       LWS_US_TO_MS((uint64_t)us), 0);
	lws_pt_unlock(pt);
	lws_context_unlock(pt->context);
}

static void
lws_uv_idle(uv_idle_t *handle
#if UV_VERSION_MAJOR == 0
		, int status
#endif
)
{	struct lws_pt_eventlibs_libuv *ptpr = lws_container_of(handle,
		struct lws_pt_eventlibs_libuv, idle);
	struct lws_context_per_thread *pt = ptpr->pt;
	lws_usec_t us;

	lws_service_do_ripe_rxflow(pt);

	lws_context_lock(pt->context, __func__);
	lws_pt_lock(pt, __func__);

	/*
	 * is there anybody with pending stuff that needs service forcing?
	 */
	if (!lws_service_adjust_timeout(pt->context, 1, pt->tid))
		/* -1 timeout means just do forced service */
		_lws_plat_service_forced_tsi(pt->context, pt->tid);

	/* account for sultimer */

	us = __lws_sul_service_ripe(pt->pt_sul_owner, LWS_COUNT_PT_SUL_OWNERS,
				    lws_now_usecs());
	if (us)
		uv_timer_start(&pt_to_priv_uv(pt)->sultimer, lws_uv_sultimer_cb,
			       LWS_US_TO_MS((uint64_t)us), 0);

	/* if there is nobody who needs service forcing, shut down idle */
	if (lws_service_adjust_timeout(pt->context, 1, pt->tid))
		uv_idle_stop(handle);

	lws_pt_unlock(pt);
	lws_context_unlock(pt->context);
}

static void
lws_io_cb(uv_poll_t *watcher, int status, int revents)
{
	struct lws *wsi = (struct lws *)((uv_handle_t *)watcher)->data;
	struct lws_context *context = wsi->a.context;
	struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
	struct lws_pt_eventlibs_libuv *ptpriv = pt_to_priv_uv(pt);
	struct lws_pollfd eventfd;

	lws_context_lock(pt->context, __func__);
	lws_pt_lock(pt, __func__);

	if (pt->is_destroyed)
		goto bail;

	if (!ptpriv->thread_valid) {
		/* record the thread id that gave us our first event */
		ptpriv->uv_thread = uv_thread_self();
		ptpriv->thread_valid = 1;
	}

#if defined(WIN32) || defined(_WIN32)
	eventfd.fd = watcher->socket;
#else
	eventfd.fd = watcher->io_watcher.fd;
#endif
	eventfd.events = 0;
	eventfd.revents = 0;

	if (status < 0) {
		/*
		 * At this point status will be an UV error, like UV_EBADF,
		 * we treat all errors as LWS_POLLHUP
		 *
		 * You might want to return; instead of servicing the fd in
		 * some cases */
		if (status == UV_EAGAIN)
			goto bail;

		eventfd.events |= LWS_POLLHUP;
		eventfd.revents |= LWS_POLLHUP;
	} else {
		if (revents & UV_READABLE) {
			eventfd.events |= LWS_POLLIN;
			eventfd.revents |= LWS_POLLIN;
		}
		if (revents & UV_WRITABLE) {
			eventfd.events |= LWS_POLLOUT;
			eventfd.revents |= LWS_POLLOUT;
		}
	}

	lws_pt_unlock(pt);
	lws_context_unlock(pt->context);

	lws_service_fd_tsi(context, &eventfd, wsi->tsi);

	if (pt->destroy_self) {
		lws_context_destroy(pt->context);
		return;
	}

	uv_idle_start(&ptpriv->idle, lws_uv_idle);
	return;

bail:
	lws_pt_unlock(pt);
	lws_context_unlock(pt->context);
}

/*
 * This does not actually stop the event loop.  The reason is we have to pass
 * libuv handle closures through its event loop.  So this tries to close all
 * wsi, and set a flag; when all the wsi closures are finalized then we
 * actually stop the libuv event loops.
 */
static void
lws_libuv_stop(struct lws_context *context)
{
	if (context->requested_stop_internal_loops) {
		lwsl_cx_err(context, "ignoring");
		return;
	}

	context->requested_stop_internal_loops = 1;
	lws_context_destroy(context);
}

static void
lws_uv_signal_handler(uv_signal_t *watcher, int signum)
{
	struct lws_context_per_thread *pt = (struct lws_context_per_thread *)
							watcher->data;

	if (pt->context->eventlib_signal_cb) {
		pt->context->eventlib_signal_cb((void *)watcher, signum);

		return;
	}

	lwsl_cx_err(pt->context, "internal signal handler caught signal %d",
				 signum);
	lws_libuv_stop(pt->context);
}

static int
lws_uv_finalize_pt(struct lws_context_per_thread *pt)
{
	pt->event_loop_pt_unused = 1;

	lwsl_cx_info(pt->context, "thr %d", (int)(pt - pt->context->pt));

	lws_context_lock(pt->context, __func__);

	if (!--pt->context->undestroyed_threads) {
		struct lws_vhost *vh = pt->context->vhost_list;

		/*
		 * eventually, we emptied all the pts...
		 */

		lwsl_cx_debug(pt->context, "all pts down now");

		/* protocols may have initialized libuv objects */

		while (vh) {
			lws_vhost_destroy1(vh);
			vh = vh->vhost_next;
		}

		if (!pt->count_event_loop_static_asset_handles &&
		    pt->event_loop_foreign) {
			lwsl_cx_info(pt->context, "resuming context_destroy");
			lws_context_unlock(pt->context);
			lws_context_destroy(pt->context);
			/*
			 * For foreign, we're being called from the foreign
			 * thread context the loop is associated with, we must
			 * return to it cleanly even though we are done with it.
			 */
			return 1;
		}
	} else
		lwsl_cx_debug(pt->context, "still %d undestroyed",
					   pt->context->undestroyed_threads);

	lws_context_unlock(pt->context);

	return 0;
}

// static void lws_uv_walk_cb(uv_handle_t *handle, void *arg)
// {
//      if (!uv_is_closing(handle))
//	      lwsl_err("%s: handle %p still alive on loop\n", __func__, handle);
// }


static const int sigs[] = { SIGINT, SIGTERM, SIGSEGV, SIGFPE, SIGHUP };

/*
 * Closing Phase 2: Close callback for a static UV asset
 */

static void
lws_uv_close_cb_sa(uv_handle_t *handle)
{
	struct lws_context_per_thread *pt =
			LWS_UV_REFCOUNT_STATIC_HANDLE_TO_PT(handle);
	struct lws_pt_eventlibs_libuv *ptpriv = pt_to_priv_uv(pt);
	struct lws_context *context = pt->context;
#if !defined(LWS_WITH_NO_LOGS) && defined(_DEBUG)
	int tsi = (int)(pt - &context->pt[0]);
#endif

	lwsl_cx_info(context, "thr %d: sa left %d: dyn left: %d (rk %d)",
			      tsi,
			      pt->count_event_loop_static_asset_handles - 1,
			      ptpriv->extant_handles,
			      context->requested_stop_internal_loops);

	/* any static assets left? */

	if (LWS_UV_REFCOUNT_STATIC_HANDLE_DESTROYED(handle) ||
	    ptpriv->extant_handles)
		return;

	/*
	 * So we believe nothing of ours left on the loop.  Let's sanity
	 * check it to count what's still on the loop
	 */

	// uv_walk(pt_to_priv_uv(pt)->io_loop, lws_uv_walk_cb, NULL);

	/*
	 * That's it... all wsi were down, and now every
	 * static asset lws had a UV handle for is down.
	 *
	 * Stop the loop so we can get out of here.
	 */

	lwsl_cx_info(context, "thr %d: seen final static handle gone", tsi);

	if (!pt->event_loop_foreign)
		lws_context_destroy(context);

	lws_uv_finalize_pt(pt);

	lwsl_cx_info(context, "all done");
}

/*
 * These must be called by protocols that want to use libuv objects directly...
 *
 * .... when the libuv object is created...
 */

void
lws_libuv_static_refcount_add(uv_handle_t *h, struct lws_context *context,
				int tsi)
{
	struct lws_context_per_thread *pt = &context->pt[tsi];

	LWS_UV_REFCOUNT_STATIC_HANDLE_NEW(h, pt);
}

/*
 * ... and in the close callback when the object is closed.
 */

void
lws_libuv_static_refcount_del(uv_handle_t *h)
{
	lws_uv_close_cb_sa(h);
}

void
lws_libuv_stop_without_kill(const struct lws_context *context, int tsi)
{
	if (pt_to_priv_uv(&context->pt[tsi])->io_loop)
		uv_stop(pt_to_priv_uv(&context->pt[tsi])->io_loop);
}

uv_loop_t *
lws_uv_getloop(struct lws_context *context, int tsi)
{
	if (pt_to_priv_uv(&context->pt[tsi])->io_loop)
		return pt_to_priv_uv(&context->pt[tsi])->io_loop;

	return NULL;
}

int
lws_libuv_check_watcher_active(struct lws *wsi)
{
	uv_handle_t *h = (uv_handle_t *)wsi_to_priv_uv(wsi)->w_read.pwatcher;

	if (!h)
		return 0;

	return uv_is_active(h);
}

static int
elops_init_context_uv(struct lws_context *context,
		      const struct lws_context_creation_info *info)
{
	int n;

	context->eventlib_signal_cb = info->signal_cb;

	for (n = 0; n < context->count_threads; n++)
		pt_to_priv_uv(&context->pt[n])->w_sigint.context = context;

	return 0;
}

static int
elops_destroy_context1_uv(struct lws_context *context)
{
	struct lws_context_per_thread *pt;
	int n, m = 0;

	for (n = 0; n < context->count_threads; n++) {
		int budget = 10000;
		pt = &context->pt[n];

		/* only for internal loops... */

		if (!pt->event_loop_foreign) {

			while (budget-- && (m = uv_run(pt_to_priv_uv(pt)->io_loop,
						  UV_RUN_NOWAIT)))
					;
			if (m)
				lwsl_cx_info(context, "tsi %d: unclosed", n);

		}
	}

	/* call destroy2 if internal loop */
	return !context->pt[0].event_loop_foreign;
}

static int
elops_destroy_context2_uv(struct lws_context *context)
{
	struct lws_context_per_thread *pt;
	int n, internal = 0;

	for (n = 0; n < context->count_threads; n++) {
		pt = &context->pt[n];

		/* only for internal loops... */

		if (!pt->event_loop_foreign && pt_to_priv_uv(pt)->io_loop) {
			internal = 1;
			if (!context->evlib_finalize_destroy_after_int_loops_stop)
				uv_stop(pt_to_priv_uv(pt)->io_loop);
			else {
#if UV_VERSION_MAJOR > 0
				uv_loop_close(pt_to_priv_uv(pt)->io_loop);
#endif
				lws_free_set_NULL(pt_to_priv_uv(pt)->io_loop);
			}
		}
	}

	return internal;
}

static int
elops_wsi_logical_close_uv(struct lws *wsi)
{
	if (!lws_socket_is_valid(wsi->desc.sockfd) &&
	    wsi->role_ops && strcmp(wsi->role_ops->name, "raw-file") &&
	    !wsi_to_priv_uv(wsi)->w_read.pwatcher)
		return 0;

	if (wsi->listener || wsi->event_pipe) {
		lwsl_wsi_debug(wsi, "%d %d stop listener / pipe poll",
				    wsi->listener,
				    wsi->event_pipe);
		if (wsi_to_priv_uv(wsi)->w_read.pwatcher)
			uv_poll_stop(wsi_to_priv_uv(wsi)->w_read.pwatcher);
	}
	lwsl_wsi_debug(wsi, "lws_libuv_closehandle");
	/*
	 * libuv has to do his own close handle processing asynchronously
	 */
	lws_libuv_closehandle(wsi);

	return 1; /* do not complete the wsi close, uv close cb will do it */
}

static int
elops_check_client_connect_ok_uv(struct lws *wsi)
{
	if (lws_libuv_check_watcher_active(wsi)) {
		lwsl_wsi_warn(wsi, "Waiting for libuv watcher to close");
		return 1;
	}

	return 0;
}

static void
lws_libuv_closewsi_m(uv_handle_t* handle)
{
	lws_sockfd_type sockfd = (lws_sockfd_type)(lws_intptr_t)handle->data;

	lwsl_debug("%s: sockfd %d\n", __func__, sockfd);
	compatible_close(sockfd);
	lws_free(handle);
}

static void
elops_close_handle_manually_uv(struct lws *wsi)
{
	uv_handle_t *h = (uv_handle_t *)wsi_to_priv_uv(wsi)->w_read.pwatcher;

	lwsl_wsi_debug(wsi, "lws_libuv_closehandle");

	/*
	 * the "manual" variant only closes the handle itself and the
	 * related fd.  handle->data is the fd.
	 */
	h->data = (void *)(lws_intptr_t)wsi->desc.sockfd;

	/*
	 * We take responsibility to close / destroy these now.
	 * Remove any trace from the wsi.
	 */

	wsi->desc.sockfd = LWS_SOCK_INVALID;
	wsi_to_priv_uv(wsi)->w_read.pwatcher = NULL;
	wsi->told_event_loop_closed = 1;

	uv_close(h, lws_libuv_closewsi_m);
}

static int
elops_accept_uv(struct lws *wsi)
{
	struct lws_context_per_thread *pt = &wsi->a.context->pt[(int)wsi->tsi];
	struct lws_pt_eventlibs_libuv *ptpriv = pt_to_priv_uv(pt);
	struct lws_io_watcher_libuv *w_read = &wsi_to_priv_uv(wsi)->w_read;
	int n;

	if (!ptpriv->thread_valid) {
		/* record the thread id that gave us our first event */
		ptpriv->uv_thread = uv_thread_self();
		ptpriv->thread_valid = 1;
	}

	w_read->context = wsi->a.context;

	w_read->pwatcher = lws_malloc(sizeof(*w_read->pwatcher), "uvh");
	if (!w_read->pwatcher)
		return -1;

	if (wsi->role_ops->file_handle)
		n = uv_poll_init(pt_to_priv_uv(pt)->io_loop, w_read->pwatcher,
			     (int)(lws_intptr_t)wsi->desc.filefd);
	else
		n = uv_poll_init_socket(pt_to_priv_uv(pt)->io_loop,
				    w_read->pwatcher, wsi->desc.sockfd);

	if (n) {
		lwsl_wsi_err(wsi, "uv_poll_init failed %d, sockfd=%p", n,
				  (void *)(lws_intptr_t)wsi->desc.sockfd);
		lws_free(w_read->pwatcher);
		w_read->pwatcher = NULL;
		return -1;
	}

	((uv_handle_t *)w_read->pwatcher)->data = (void *)wsi;

	ptpriv->extant_handles++;

	lwsl_wsi_debug(wsi, "thr %d: sa left %d: dyn left: %d",
			    (int)(pt - &pt->context->pt[0]),
			    pt->count_event_loop_static_asset_handles,
			    ptpriv->extant_handles);

	return 0;
}

static void
elops_io_uv(struct lws *wsi, unsigned int flags)
{
	struct lws_context_per_thread *pt = &wsi->a.context->pt[(int)wsi->tsi];
	struct lws_io_watcher_libuv *w = &(wsi_to_priv_uv(wsi)->w_read);
	int current_events = w->actual_events & (UV_READABLE | UV_WRITABLE);

	lwsl_wsi_debug(wsi, "%d", flags);

	/* w->context is set after the loop is initialized */

	if (!pt_to_priv_uv(pt)->io_loop || !w->context) {
		lwsl_wsi_info(wsi, "no io loop yet");
		return;
	}

	if (!((flags & (LWS_EV_START | LWS_EV_STOP)) &&
	      (flags & (LWS_EV_READ | LWS_EV_WRITE)))) {
		lwsl_wsi_err(wsi, "assert: flags %d", flags);
		assert(0);
	}

	if (!w->pwatcher || wsi->told_event_loop_closed) {
		lwsl_wsi_info(wsi, "no watcher");

		return;
	}

	if (flags & LWS_EV_START) {
		if (flags & LWS_EV_WRITE)
			current_events |= UV_WRITABLE;

		if (flags & LWS_EV_READ)
			current_events |= UV_READABLE;

		uv_poll_start(w->pwatcher, current_events, lws_io_cb);
	} else {
		if (flags & LWS_EV_WRITE)
			current_events &= ~UV_WRITABLE;

		if (flags & LWS_EV_READ)
			current_events &= ~UV_READABLE;

		if (!(current_events & (UV_READABLE | UV_WRITABLE)))
			uv_poll_stop(w->pwatcher);
		else
			uv_poll_start(w->pwatcher, current_events, lws_io_cb);
	}

	w->actual_events = (uint8_t)current_events;
}

static int
elops_init_vhost_listen_wsi_uv(struct lws *wsi)
{
	struct lws_context_per_thread *pt;
	struct lws_pt_eventlibs_libuv *ptpriv;
	struct lws_io_watcher_libuv *w_read;
	int n;

	if (!wsi)
		return 0;

	w_read = &wsi_to_priv_uv(wsi)->w_read;

	if (w_read->context)
		return 0;

	pt = &wsi->a.context->pt[(int)wsi->tsi];
	ptpriv = pt_to_priv_uv(pt);
	if (!ptpriv->io_loop)
		return 0;

	w_read->context = wsi->a.context;

	w_read->pwatcher = lws_malloc(sizeof(*w_read->pwatcher), "uvh");
	if (!w_read->pwatcher)
		return -1;

	n = uv_poll_init_socket(pt_to_priv_uv(pt)->io_loop,
				w_read->pwatcher, wsi->desc.sockfd);
	if (n) {
		lwsl_wsi_err(wsi, "uv_poll_init failed %d, sockfd=%p", n,
				  (void *)(lws_intptr_t)wsi->desc.sockfd);

		return -1;
	}

	ptpriv->extant_handles++;

	lwsl_wsi_debug(wsi, "thr %d: sa left %d: dyn left: %d",
			    (int)(pt - &pt->context->pt[0]),
			    pt->count_event_loop_static_asset_handles,
			    ptpriv->extant_handles);

	((uv_handle_t *)w_read->pwatcher)->data = (void *)wsi;

	elops_io_uv(wsi, LWS_EV_START | LWS_EV_READ);

	return 0;
}

static void
elops_run_pt_uv(struct lws_context *context, int tsi)
{
	if (pt_to_priv_uv(&context->pt[tsi])->io_loop)
		uv_run(pt_to_priv_uv(&context->pt[tsi])->io_loop, 0);
}

static void
elops_destroy_pt_uv(struct lws_context *context, int tsi)
{
	struct lws_context_per_thread *pt = &context->pt[tsi];
	struct lws_pt_eventlibs_libuv *ptpriv = pt_to_priv_uv(pt);
	int m, ns;

	if (!lws_check_opt(context->options, LWS_SERVER_OPTION_LIBUV))
		return;

	if (!ptpriv->io_loop)
		return;

	if (pt->event_loop_destroy_processing_done) {
		if (!pt->event_loop_foreign) {
			lwsl_warn("%s: stopping event loop\n", __func__);
			uv_stop(pt_to_priv_uv(pt)->io_loop);
		}
		return;
	}

	pt->event_loop_destroy_processing_done = 1;
	// lwsl_cx_debug(context, "%d", tsi);

	if (!pt->event_loop_foreign) {

		uv_signal_stop(&pt_to_priv_uv(pt)->w_sigint.watcher);

		ns = LWS_ARRAY_SIZE(sigs);
		if (lws_check_opt(context->options,
				  LWS_SERVER_OPTION_UV_NO_SIGSEGV_SIGFPE_SPIN))
			ns = 2;

		for (m = 0; m < ns; m++) {
			uv_signal_stop(&pt_to_priv_uv(pt)->signals[m]);
			uv_close((uv_handle_t *)&pt_to_priv_uv(pt)->signals[m],
				 lws_uv_close_cb_sa);
		}
	} else
		lwsl_cx_debug(context, "not closing pt signals");

	uv_timer_stop(&pt_to_priv_uv(pt)->sultimer);
	uv_close((uv_handle_t *)&pt_to_priv_uv(pt)->sultimer, lws_uv_close_cb_sa);

	uv_idle_stop(&pt_to_priv_uv(pt)->idle);
	uv_close((uv_handle_t *)&pt_to_priv_uv(pt)->idle, lws_uv_close_cb_sa);
}

static int
elops_listen_init_uv(struct lws_dll2 *d, void *user)
{
	struct lws *wsi = lws_container_of(d, struct lws, listen_list);

	if (elops_init_vhost_listen_wsi_uv(wsi) == -1)
		return -1;

	return 0;
}

/*
 * This needs to be called after vhosts have been defined.
 *
 * If later, after server start, another vhost is added, this must be
 * called again to bind the vhost
 */

int
elops_init_pt_uv(struct lws_context *context, void *_loop, int tsi)
{
	struct lws_context_per_thread *pt = &context->pt[tsi];
	struct lws_pt_eventlibs_libuv *ptpriv = pt_to_priv_uv(pt);
	int status = 0, n, ns, first = 1;
	uv_loop_t *loop = (uv_loop_t *)_loop;

	ptpriv->pt = pt;

	if (!ptpriv->io_loop) {
		if (!loop) {
			loop = lws_malloc(sizeof(*loop), "libuv loop");
			if (!loop) {
				lwsl_cx_err(context, "OOM");
				return -1;
			}
#if UV_VERSION_MAJOR > 0
			uv_loop_init(loop);
#else
			lwsl_cx_err(context, "This libuv is too old to work...");
			return 1;
#endif
			pt->event_loop_foreign = 0;
		} else {
			lwsl_cx_notice(context, " Using foreign event loop...");
			pt->event_loop_foreign = 1;
		}

		ptpriv->io_loop = loop;
		uv_idle_init(loop, &ptpriv->idle);
		LWS_UV_REFCOUNT_STATIC_HANDLE_NEW(&ptpriv->idle, pt);
		uv_idle_start(&ptpriv->idle, lws_uv_idle);

		ns = LWS_ARRAY_SIZE(sigs);
		if (lws_check_opt(context->options,
				  LWS_SERVER_OPTION_UV_NO_SIGSEGV_SIGFPE_SPIN))
			ns = 2;

		if (!pt->event_loop_foreign) {
			assert(ns <= (int)LWS_ARRAY_SIZE(ptpriv->signals));
			for (n = 0; n < ns; n++) {
				uv_signal_init(loop, &ptpriv->signals[n]);
				LWS_UV_REFCOUNT_STATIC_HANDLE_NEW(
						&ptpriv->signals[n], pt);
				ptpriv->signals[n].data = pt;
				uv_signal_start(&ptpriv->signals[n],
						lws_uv_signal_handler, sigs[n]);
			}
		}
	} else
		first = 0;

	/*
	 * Initialize the accept wsi read watcher with all the listening sockets
	 * and register a callback for read operations
	 *
	 * We have to do it here because the uv loop(s) are not
	 * initialized until after context creation.
	 */
	lws_vhost_foreach_listen_wsi(context, context, elops_listen_init_uv);

	if (!first)
		return status;

	uv_timer_init(ptpriv->io_loop, &ptpriv->sultimer);
	LWS_UV_REFCOUNT_STATIC_HANDLE_NEW(&ptpriv->sultimer, pt);

	return status;
}

static void
lws_libuv_closewsi(uv_handle_t* handle)
{
	struct lws *wsi = (struct lws *)handle->data;
	struct lws_context *context = lws_get_context(wsi);
	struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
	struct lws_pt_eventlibs_libuv *ptpriv = pt_to_priv_uv(pt);
#if defined(LWS_WITH_SERVER)
	int lspd = 0;
#endif

	// lwsl_wsi_notice(wsi, "in");

	lws_context_lock(context, __func__);

	/*
	 * We get called back here for every wsi that closes
	 */

#if defined(LWS_WITH_SERVER)
	if (wsi->role_ops && !strcmp(wsi->role_ops->name, "listen") &&
	    wsi->a.context->deprecated) {
		lspd = 1;
		context->deprecation_pending_listen_close_count--;
		if (!context->deprecation_pending_listen_close_count)
			lspd = 2;
	}
#endif

	lws_pt_lock(pt, __func__);

	lwsl_wsi_info(wsi, "thr %d: sa left %d: dyn left: %d (rk %d)",
			   (int)(pt - &pt->context->pt[0]),
			   pt->count_event_loop_static_asset_handles,
			   ptpriv->extant_handles - 1,
			   context->requested_stop_internal_loops);

	__lws_close_free_wsi_final(wsi);
	assert(ptpriv->extant_handles);
	ptpriv->extant_handles--;
	lws_pt_unlock(pt);

	/* it's our job to close the handle finally */
	lws_free(handle);

#if defined(LWS_WITH_SERVER)
	if (lspd == 2 && context->deprecation_cb) {
		lwsl_cx_notice(context, "calling deprecation callback");
		context->deprecation_cb();
	}
#endif

	/*
	 * eventually, we closed all the wsi...
	 */

	if (context->requested_stop_internal_loops &&
	    !ptpriv->extant_handles &&
	    !pt->count_event_loop_static_asset_handles) {

		/*
		 * we closed everything on this pt
		 */

		lws_context_unlock(context);
		lws_uv_finalize_pt(pt);

		return;
	}

	lws_context_unlock(context);
}

void
lws_libuv_closehandle(struct lws *wsi)
{
	uv_handle_t* handle;
	struct lws_io_watcher_libuv *w_read = &wsi_to_priv_uv(wsi)->w_read;

	if (!w_read->pwatcher)
		return;

	if (wsi->told_event_loop_closed)
		return;

//	lwsl_wsi_debug(wsi, "in");

	wsi->told_event_loop_closed = 1;

	/*
	 * The normal close path attaches the related wsi as the
	 * handle->data.
	 */

	handle = (uv_handle_t *)w_read->pwatcher;

	/* ensure we can only do this once */

	w_read->pwatcher = NULL;

	uv_close(handle, lws_libuv_closewsi);
}

static int
elops_foreign_thread_uv(struct lws_context *cx, int tsi)
{
	struct lws_context_per_thread *pt = &cx->pt[tsi];
	struct lws_pt_eventlibs_libuv *ptpriv = pt_to_priv_uv(pt);
	uv_thread_t th = uv_thread_self();

	if (!ptpriv->thread_valid)
		/*
		 * We can't judge it until we get the first event from the loop
		 */
		return 0;

	/*
	 * This is the same thread that gave us the first event on this loop?
	 * Return 0 if so.
	 */

	return !uv_thread_equal(&th, &ptpriv->uv_thread);
}

static const struct lws_event_loop_ops event_loop_ops_uv = {
	/* name */			"libuv",
	/* init_context */		elops_init_context_uv,
	/* destroy_context1 */		elops_destroy_context1_uv,
	/* destroy_context2 */		elops_destroy_context2_uv,
	/* init_vhost_listen_wsi */	elops_init_vhost_listen_wsi_uv,
	/* init_pt */			elops_init_pt_uv,
	/* wsi_logical_close */		elops_wsi_logical_close_uv,
	/* check_client_connect_ok */	elops_check_client_connect_ok_uv,
	/* close_handle_manually */	elops_close_handle_manually_uv,
	/* accept */			elops_accept_uv,
	/* io */			elops_io_uv,
	/* run_pt */			elops_run_pt_uv,
	/* destroy_pt */		elops_destroy_pt_uv,
	/* destroy wsi */		NULL,
	/* foreign_thread */		elops_foreign_thread_uv,

	/* flags */			0,

	/* evlib_size_ctx */	sizeof(struct lws_context_eventlibs_libuv),
	/* evlib_size_pt */	sizeof(struct lws_pt_eventlibs_libuv),
	/* evlib_size_vh */	0,
	/* evlib_size_wsi */	sizeof(struct lws_io_watcher_libuv),
};

#if defined(LWS_WITH_EVLIB_PLUGINS)
LWS_VISIBLE
#endif
const lws_plugin_evlib_t evlib_uv = {
	.hdr = {
		"libuv event loop",
		"lws_evlib_plugin",
		LWS_BUILD_HASH,
		LWS_PLUGIN_API_MAGIC
	},

	.ops	= &event_loop_ops_uv
};