lib/libuv.c

/*
 * libwebsockets - small server side websockets and web server implementation
 *
 * Copyright (C) 2010-2016 Andy Green <andy@warmcat.com>
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation:
 *  version 2.1 of the License.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 *  MA  02110-1301  USA
 */

#include "private-libwebsockets.h"

void
lws_feature_status_libuv(struct lws_context_creation_info *info)
{
	if (lws_check_opt(info->options, LWS_SERVER_OPTION_LIBUV))
		lwsl_notice("libuv support compiled in and enabled\n");
	else
		lwsl_notice("libuv support compiled in but disabled\n");
}

static void
lws_uv_idle(uv_idle_t *handle
#if UV_VERSION_MAJOR == 0
		, int status
#endif
)
{
	struct lws_context_per_thread *pt = lws_container_of(handle,
					struct lws_context_per_thread, uv_idle);

	lwsl_debug("%s\n", __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_tsi(pt->context, -1, pt->tid);
		/* still somebody left who wants forced service? */
		if (!lws_service_adjust_timeout(pt->context, 1, pt->tid))
			/* yes... come back again later */
			lwsl_debug("%s: done again\n", __func__);
			return;
	}

	/* there is nobody who needs service forcing, shut down idle */
	uv_idle_stop(handle);

	lwsl_debug("%s: done stop\n", __func__);
}

static void
lws_io_cb(uv_poll_t *watcher, int status, int revents)
{
	struct lws_io_watcher *lws_io = lws_container_of(watcher,
					struct lws_io_watcher, uv_watcher);
	struct lws *wsi = lws_container_of(lws_io, struct lws, w_read);
	struct lws_context *context = lws_io->context;
	struct lws_pollfd eventfd;

#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)
			return;

		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_service_fd(context, &eventfd);

	uv_idle_start(&context->pt[(int)wsi->tsi].uv_idle, lws_uv_idle);
}

LWS_VISIBLE void
lws_uv_sigint_cb(uv_signal_t *watcher, int signum)
{
	lwsl_info("internal signal handler caught signal %d\n", signum);
	lws_libuv_stop(watcher->data);
}

LWS_VISIBLE int
lws_uv_sigint_cfg(struct lws_context *context, int use_uv_sigint,
		  uv_signal_cb cb)
{
	context->use_ev_sigint = use_uv_sigint;
	if (cb)
		context->lws_uv_sigint_cb = cb;
	else
		context->lws_uv_sigint_cb = &lws_uv_sigint_cb;

	return 0;
}

static void
lws_uv_timeout_cb(uv_timer_t *timer
#if UV_VERSION_MAJOR == 0
		, int status
#endif
)
{
	struct lws_context_per_thread *pt = lws_container_of(timer,
			struct lws_context_per_thread, uv_timeout_watcher);

	lwsl_debug("%s\n", __func__);

	lws_service_fd_tsi(pt->context, NULL, pt->tid);
}

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

LWS_VISIBLE int
lws_uv_initloop(struct lws_context *context, uv_loop_t *loop, int tsi)
{
	struct lws_context_per_thread *pt = &context->pt[tsi];
	struct lws_vhost *vh = context->vhost_list;
	int status = 0, n;

	if (!loop) {
		loop = lws_malloc(sizeof(*loop));
#if UV_VERSION_MAJOR > 0
		uv_loop_init(loop);
#else
		lwsl_err("This libuv is too old to work...\n");
		return 1;
#endif
		pt->ev_loop_foreign = 0;
	} else
		pt->ev_loop_foreign = 1;

	pt->io_loop_uv = loop;
	uv_idle_init(loop, &pt->uv_idle);

	if (pt->context->use_ev_sigint) {
		assert(ARRAY_SIZE(sigs) <= ARRAY_SIZE(pt->signals));
		for (n = 0; n < ARRAY_SIZE(sigs); n++) {
			uv_signal_init(loop, &pt->signals[n]);
			pt->signals[n].data = pt->context;
			uv_signal_start(&pt->signals[n],
					context->lws_uv_sigint_cb, sigs[n]);
		}
	}

	/*
	 * 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.
	 */
	while (vh) {
		if (vh->lserv_wsi) {
			vh->lserv_wsi->w_read.context = context;
			n = uv_poll_init_socket(pt->io_loop_uv,
				     &vh->lserv_wsi->w_read.uv_watcher,
				     vh->lserv_wsi->sock);
			if (n) {
				lwsl_err("uv_poll_init failed %d, sockfd=%p\n",
					n, (void *)(long)vh->lserv_wsi->sock);

				return -1;
			}
			uv_poll_start(&vh->lserv_wsi->w_read.uv_watcher,
				      UV_READABLE, lws_io_cb);
		}
		vh = vh->vhost_next;
	}

	uv_timer_init(pt->io_loop_uv, &pt->uv_timeout_watcher);
	uv_timer_start(&pt->uv_timeout_watcher, lws_uv_timeout_cb, 1000, 1000);

	return status;
}

void lws_uv_close_cb(uv_handle_t *handle)
{

}

void lws_uv_walk_cb(uv_handle_t *handle, void *arg)
{
	uv_close(handle, lws_uv_close_cb);
}

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

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

	if (!pt->io_loop_uv)
		return;

	if (context->use_ev_sigint)
		uv_signal_stop(&pt->w_sigint.uv_watcher);
	for (m = 0; m < ARRAY_SIZE(sigs); m++)
		uv_signal_stop(&pt->signals[m]);
	if (!pt->ev_loop_foreign) {
		uv_stop(pt->io_loop_uv);
		uv_walk(pt->io_loop_uv, lws_uv_walk_cb, NULL);
		while (uv_run(pt->io_loop_uv, UV_RUN_NOWAIT));
#if UV_VERSION_MAJOR > 0
		m = uv_loop_close(pt->io_loop_uv);
		if (m == UV_EBUSY)
			lwsl_debug("%s: uv_loop_close: UV_EBUSY\n", __func__);
#endif
		lws_free(pt->io_loop_uv);
	}
}

void
lws_libuv_accept(struct lws *wsi, int accept_fd)
{
	struct lws_context *context = lws_get_context(wsi);
	struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];

	if (!LWS_LIBUV_ENABLED(context))
		return;

	lwsl_debug("%s: new wsi %p\n", __func__, wsi);

	wsi->w_read.context = context;

	uv_poll_init_socket(pt->io_loop_uv, &wsi->w_read.uv_watcher, accept_fd);
}

void
lws_libuv_io(struct lws *wsi, int flags)
{
	struct lws_context *context = lws_get_context(wsi);
	struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
#if defined(WIN32) || defined(_WIN32)
	int current_events = wsi->w_read.uv_watcher.events &
			     (UV_READABLE | UV_WRITABLE);
#else
	int current_events = wsi->w_read.uv_watcher.io_watcher.pevents &
			     (UV_READABLE | UV_WRITABLE);
#endif
	struct lws_io_watcher *w = &wsi->w_read;

	if (!LWS_LIBUV_ENABLED(context))
		return;

	lwsl_debug("%s: wsi: %p, flags:0x%x\n", __func__, wsi, flags);

	if (!pt->io_loop_uv) {
		lwsl_info("%s: no io loop yet\n", __func__);
		return;
	}

	assert((flags & (LWS_EV_START | LWS_EV_STOP)) &&
	       (flags & (LWS_EV_READ | LWS_EV_WRITE)));

	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->uv_watcher, 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->uv_watcher);
		else
			uv_poll_start(&w->uv_watcher, current_events,
				      lws_io_cb);
	}
}

int
lws_libuv_init_fd_table(struct lws_context *context)
{
	int n;

	if (!LWS_LIBUV_ENABLED(context))
		return 0;

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

	return 1;
}

LWS_VISIBLE void
lws_libuv_run(const struct lws_context *context, int tsi)
{
	if (context->pt[tsi].io_loop_uv && LWS_LIBUV_ENABLED(context))
		uv_run(context->pt[tsi].io_loop_uv, 0);
}

static void
lws_libuv_kill(const struct lws_context *context)
{
	int n;

	for (n = 0; n < context->count_threads; n++)
		if (context->pt[n].io_loop_uv && LWS_LIBUV_ENABLED(context))
			uv_stop(context->pt[n].io_loop_uv);
	// TODO uv_stop check foreign loop? or not?
}

/*
 * 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.
 */

LWS_VISIBLE void
lws_libuv_stop(struct lws_context *context)
{
	struct lws_context_per_thread *pt;
	int n, m;

	context->requested_kill = 1;

	m = context->count_threads;
	context->being_destroyed = 1;

	while (m--) {
		pt = &context->pt[m];

		for (n = 0; (unsigned int)n < context->pt[m].fds_count; n++) {
			struct lws *wsi = wsi_from_fd(context, pt->fds[n].fd);

			if (!wsi)
				continue;
			lws_close_free_wsi(wsi,
				LWS_CLOSE_STATUS_NOSTATUS_CONTEXT_DESTROY
				/* no protocol close */);
			n--;
		}
	}

	lwsl_info("%s: feels everything closed\n", __func__);
	if (context->count_wsi_allocated == 0)
		lws_libuv_kill(context);
}

LWS_VISIBLE uv_loop_t *
lws_uv_getloop(struct lws_context *context, int tsi)
{
	if (context->pt[tsi].io_loop_uv && LWS_LIBUV_ENABLED(context))
		return context->pt[tsi].io_loop_uv;

	return NULL;
}

static void
lws_libuv_closewsi(uv_handle_t* handle)
{
	struct lws *n = NULL, *wsi = (struct lws *)(((char *)handle) -
			  (char *)(&n->w_read.uv_watcher));
	struct lws_context *context = lws_get_context(wsi);

	lws_close_free_wsi_final(wsi);

	if (context->requested_kill && context->count_wsi_allocated == 0)
		lws_libuv_kill(context);
}

void
lws_libuv_closehandle(struct lws *wsi)
{
	struct lws_context *context = lws_get_context(wsi);

	/* required to defer actual deletion until libuv has processed it */

	uv_close((uv_handle_t*)&wsi->w_read.uv_watcher, lws_libuv_closewsi);

	if (context->requested_kill && context->count_wsi_allocated == 0)
		lws_libuv_kill(context);
}

#if defined(LWS_WITH_PLUGINS) && (UV_VERSION_MAJOR > 0)

LWS_VISIBLE int
lws_plat_plugins_init(struct lws_context * context, const char *d)
{
	struct lws_plugin_capability lcaps;
	struct lws_plugin *plugin;
	lws_plugin_init_func initfunc;
	int m, ret = 0;
	void *v;
	uv_dirent_t dent;
	uv_fs_t req;
	char path[256];
	uv_loop_t loop;
	uv_lib_t lib;

	lib.errmsg = NULL;
	lib.handle = NULL;

	uv_loop_init(&loop);

	if (!uv_fs_scandir(&loop, &req, d, 0, NULL)) {
		lwsl_err("Scandir on %s failed\n", d);
		return 1;
	}

	lwsl_notice("  Plugins:\n");

	while (uv_fs_scandir_next(&req, &dent) != UV_EOF) {
		if (strlen(dent.name) < 7)
			continue;

		lwsl_notice("   %s\n", dent.name);

		snprintf(path, sizeof(path) - 1, "%s/%s", d, dent.name);
		if (uv_dlopen(path, &lib)) {
			uv_dlerror(&lib);
			lwsl_err("Error loading DSO: %s\n", lib.errmsg);
			goto bail;
		}
		/* we could open it, can we get his init function? */
		m = snprintf(path, sizeof(path) - 1, "init_%s",
			     dent.name + 3 /* snip lib... */);
		path[m - 3] = '\0'; /* snip the .so */
		if (uv_dlsym(&lib, path, &v)) {
			uv_dlerror(&lib);
			lwsl_err("Failed to get init on %s: %s",
					dent.name, lib.errmsg);
			goto bail;
		}
		initfunc = (lws_plugin_init_func)v;
		lcaps.api_magic = LWS_PLUGIN_API_MAGIC;
		m = initfunc(context, &lcaps);
		if (m) {
			lwsl_err("Initializing %s failed %d\n", dent.name, m);
			goto skip;
		}

		plugin = lws_malloc(sizeof(*plugin));
		if (!plugin) {
			lwsl_err("OOM\n");
			goto bail;
		}
		plugin->list = context->plugin_list;
		context->plugin_list = plugin;
		strncpy(plugin->name, dent.name, sizeof(plugin->name) - 1);
		plugin->name[sizeof(plugin->name) - 1] = '\0';
		plugin->lib = lib;
		plugin->caps = lcaps;
		context->plugin_protocol_count += lcaps.count_protocols;
		context->plugin_extension_count += lcaps.count_extensions;

		continue;

skip:
		uv_dlclose(&lib);
	}

bail:
	uv_fs_req_cleanup(&req);
	uv_loop_close(&loop);

	return ret;

}

LWS_VISIBLE int
lws_plat_plugins_destroy(struct lws_context * context)
{
	struct lws_plugin *plugin = context->plugin_list, *p;
	lws_plugin_destroy_func func;
	char path[256];
	void *v;
	int m;

	if (!plugin)
		return 0;

	lwsl_notice("%s\n", __func__);

	while (plugin) {
		p = plugin;
		m = snprintf(path, sizeof(path) - 1, "destroy_%s", plugin->name + 3);
		path[m - 3] = '\0';

		if (uv_dlsym(&plugin->lib, path, &v)) {
			uv_dlerror(&plugin->lib);
			lwsl_err("Failed to get init on %s: %s",
					plugin->name, plugin->lib.errmsg);
		} else {
			func = (lws_plugin_destroy_func)v;
			m = func(context);
			if (m)
				lwsl_err("Destroying %s failed %d\n",
						plugin->name, m);
		}

		uv_dlclose(&p->lib);
		plugin = p->list;
		p->list = NULL;
		free(p);
	}

	context->plugin_list = NULL;

	return 0;
}

#endif