text: /*
   * libwebsockets - small server side websockets and web server implementation
   *
   * Copyright (C) 2010-2018 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 "core/private.h"
  
  int
  lws_callback_as_writeable(struct lws *wsi)
  {
  	struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
  	int n, m;
  
  	lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_C_WRITEABLE_CB, 1);
  #if defined(LWS_WITH_STATS)
  	if (wsi->active_writable_req_us) {
  		uint64_t ul = lws_time_in_microseconds() -
  			      wsi->active_writable_req_us;
  
  		lws_stats_atomic_bump(wsi->context, pt,
  				      LWSSTATS_MS_WRITABLE_DELAY, ul);
  		lws_stats_atomic_max(wsi->context, pt,
  				     LWSSTATS_MS_WORST_WRITABLE_DELAY, ul);
  		wsi->active_writable_req_us = 0;
  	}
  #endif
  
  	n = wsi->role_ops->writeable_cb[lwsi_role_server(wsi)];
  
  	m = user_callback_handle_rxflow(wsi->protocol->callback,
  					wsi, (enum lws_callback_reasons) n,
  					wsi->user_space, NULL, 0);
  
  	return m;
  }
  
  LWS_VISIBLE int
  lws_handle_POLLOUT_event(struct lws *wsi, struct lws_pollfd *pollfd)
  {
  	volatile struct lws *vwsi = (volatile struct lws *)wsi;
  	int n;
  
  	// lwsl_notice("%s: %p\n", __func__, wsi);
  
  	vwsi->leave_pollout_active = 0;
  	vwsi->handling_pollout = 1;
  	/*
  	 * if another thread wants POLLOUT on us, from here on while
  	 * handling_pollout is set, he will only set leave_pollout_active.
  	 * If we are going to disable POLLOUT, we will check that first.
  	 */
  	wsi->could_have_pending = 0; /* clear back-to-back write detection */
  
  	/*
  	 * user callback is lowest priority to get these notifications
  	 * actually, since other pending things cannot be disordered
  	 *
  	 * Priority 1: pending truncated sends are incomplete ws fragments
  	 *	       If anything else sent first the protocol would be
  	 *	       corrupted.
  	 *
  	 *	       These are post- any compression transform
  	 */
  
  	if (lws_has_buffered_out(wsi)) {
  		//lwsl_notice("%s: completing partial\n", __func__);
  		if (lws_issue_raw(wsi, NULL, 0) < 0) {
  			lwsl_info("%s signalling to close\n", __func__);
  			goto bail_die;
  		}
  		/* leave POLLOUT active either way */
  		goto bail_ok;
  	} else
  		if (lwsi_state(wsi) == LRS_FLUSHING_BEFORE_CLOSE) {
  			wsi->socket_is_permanently_unusable = 1;
  			goto bail_die; /* retry closing now */
  		}
  
  	/* Priority 2: pre- compression transform */
  
  #if defined(LWS_WITH_HTTP_STREAM_COMPRESSION)
  	if (wsi->http.comp_ctx.buflist_comp ||
  	    wsi->http.comp_ctx.may_have_more) {
  		enum lws_write_protocol wp = LWS_WRITE_HTTP;
  
  		lwsl_info("%s: completing comp partial (buflist_comp %p, may %d)\n",
  				__func__, wsi->http.comp_ctx.buflist_comp,
  				wsi->http.comp_ctx.may_have_more
  				);
  
  		if (wsi->role_ops->write_role_protocol(wsi, NULL, 0, &wp) < 0) {
  			lwsl_info("%s signalling to close\n", __func__);
  			goto bail_die;
  		}
  		lws_callback_on_writable(wsi);
  
  		goto bail_ok;
  	}
  #endif
  
  #ifdef LWS_WITH_CGI
  	/*
  	 * A cgi master's wire protocol remains h1 or h2.  He is just getting
  	 * his data from his child cgis.
  	 */
  	if (wsi->http.cgi) {
  		/* also one shot */
  		if (pollfd)
  			if (lws_change_pollfd(wsi, LWS_POLLOUT, 0)) {
  				lwsl_info("failed at set pollfd\n");
  				return 1;
  			}
  		goto user_service_go_again;
  	}
  #endif
  
  	/* if we got here, we should have wire protocol ops set on the wsi */
  	assert(wsi->role_ops);
  
  	if (!wsi->role_ops->handle_POLLOUT)
  		goto bail_ok;
  
  	switch ((wsi->role_ops->handle_POLLOUT)(wsi)) {
  	case LWS_HP_RET_BAIL_OK:
  		goto bail_ok;
  	case LWS_HP_RET_BAIL_DIE:
  		goto bail_die;
  	case LWS_HP_RET_USER_SERVICE:
  		break;
  	default:
  		assert(0);
  	}
  
  	/* one shot */
  
  	if (pollfd) {
  		int eff = vwsi->leave_pollout_active;
  
  		if (!eff) {
  			if (lws_change_pollfd(wsi, LWS_POLLOUT, 0)) {
  				lwsl_info("failed at set pollfd\n");
  				goto bail_die;
  			}
  		}
  
  		vwsi->handling_pollout = 0;
  
  		/* cannot get leave_pollout_active set after the above */
  		if (!eff && wsi->leave_pollout_active) {
  			/*
  			 * got set inbetween sampling eff and clearing
  			 * handling_pollout, force POLLOUT on
  			 */
  			lwsl_debug("leave_pollout_active\n");
  			if (lws_change_pollfd(wsi, 0, LWS_POLLOUT)) {
  				lwsl_info("failed at set pollfd\n");
  				goto bail_die;
  			}
  		}
  
  		vwsi->leave_pollout_active = 0;
  	}
  
  	if (lwsi_role_client(wsi) && !wsi->hdr_parsing_completed &&
  	     lwsi_state(wsi) != LRS_H2_WAITING_TO_SEND_HEADERS &&
  	     lwsi_state(wsi) != LRS_ISSUE_HTTP_BODY)
  		goto bail_ok;
  
  
  #ifdef LWS_WITH_CGI
  user_service_go_again:
  #endif
  
  	if (wsi->role_ops->perform_user_POLLOUT) {
  		if (wsi->role_ops->perform_user_POLLOUT(wsi) == -1)
  			goto bail_die;
  		else
  			goto bail_ok;
  	}
  	
  	lwsl_debug("%s: %p: non mux: wsistate 0x%x, ops %s\n", __func__, wsi,
  		   wsi->wsistate, wsi->role_ops->name);
  
  	vwsi = (volatile struct lws *)wsi;
  	vwsi->leave_pollout_active = 0;
  
  	n = lws_callback_as_writeable(wsi);
  	vwsi->handling_pollout = 0;
  
  	if (vwsi->leave_pollout_active)
  		lws_change_pollfd(wsi, 0, LWS_POLLOUT);
  
  	return n;
  
  	/*
  	 * since these don't disable the POLLOUT, they are always doing the
  	 * right thing for leave_pollout_active whether it was set or not.
  	 */
  
  bail_ok:
  	vwsi->handling_pollout = 0;
  	vwsi->leave_pollout_active = 0;
  
  	return 0;
  
  bail_die:
  	vwsi->handling_pollout = 0;
  	vwsi->leave_pollout_active = 0;
  
  	return -1;
  }
  
  static int
  __lws_service_timeout_check(struct lws *wsi, time_t sec)
  {
  	struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
  #if defined(LWS_ROLE_H1) || defined(LWS_ROLE_H2)
  	int n = 0;
  #endif
  
  	(void)n;
  
  	/*
  	 * if we went beyond the allowed time, kill the
  	 * connection
  	 */
  	if (lws_compare_time_t(wsi->context, sec, wsi->pending_timeout_set) >
  			       wsi->pending_timeout_limit) {
  
  #if defined(LWS_ROLE_H1) || defined(LWS_ROLE_H2)
  		if (wsi->desc.sockfd != LWS_SOCK_INVALID &&
  		    wsi->position_in_fds_table >= 0)
  			n = pt->fds[wsi->position_in_fds_table].events;
  #endif
  
  		lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_C_TIMEOUTS, 1);
  
  		/* no need to log normal idle keepalive timeout */
  //		if (wsi->pending_timeout != PENDING_TIMEOUT_HTTP_KEEPALIVE_IDLE)
  #if defined(LWS_ROLE_H1) || defined(LWS_ROLE_H2)
  			lwsl_info("wsi %p: TIMEDOUT WAITING on %d "
  				  "(did hdr %d, ah %p, wl %d, pfd "
  				  "events %d) %llu vs %llu\n",
  				  (void *)wsi, wsi->pending_timeout,
  				  wsi->hdr_parsing_completed, wsi->http.ah,
  				  pt->http.ah_wait_list_length, n,
  				  (unsigned long long)sec,
  				  (unsigned long long)wsi->pending_timeout_limit);
  #if defined(LWS_WITH_CGI)
  		if (wsi->http.cgi)
  			lwsl_notice("CGI timeout: %s\n", wsi->http.cgi->summary);
  #endif
  #else
  		lwsl_info("wsi %p: TIMEDOUT WAITING on %d ", (void *)wsi,
  			  wsi->pending_timeout);
  #endif
  
  		/* cgi timeout */
  		if (wsi->pending_timeout != PENDING_TIMEOUT_HTTP_KEEPALIVE_IDLE)
  			/*
  			 * Since he failed a timeout, he already had a chance to
  			 * do something and was unable to... that includes
  			 * situations like half closed connections.  So process
  			 * this "failed timeout" close as a violent death and
  			 * don't try to do protocol cleanup like flush partials.
  			 */
  			wsi->socket_is_permanently_unusable = 1;
  		if (lwsi_state(wsi) == LRS_WAITING_SSL && wsi->protocol)
  			wsi->protocol->callback(wsi,
  				LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
  				wsi->user_space,
  				(void *)"Timed out waiting SSL", 21);
  
  		__lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS, "timeout");
  
  		return 1;
  	}
  
  	return 0;
  }
  
  int
  lws_rxflow_cache(struct lws *wsi, unsigned char *buf, int n, int len)
  {
  	struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
  	uint8_t *buffered;
  	size_t blen;
  	int ret = LWSRXFC_CACHED, m;
  
  	/* his RX is flowcontrolled, don't send remaining now */
  	blen = lws_buflist_next_segment_len(&wsi->buflist, &buffered);
  	if (blen) {
  		if (buf >= buffered && buf + len <= buffered + blen) {
  			/*
  			 * rxflow while we were spilling prev rxflow
  			 *
  			 * len indicates how much was unused, then... so trim
  			 * the head buflist to match that situation
  			 */
  
  			lws_buflist_use_segment(&wsi->buflist, blen - len);
  			lwsl_debug("%s: trim existing rxflow %d -> %d\n",
  					__func__, (int)blen, (int)len);
  
  			return LWSRXFC_TRIMMED;
  		}
  		ret = LWSRXFC_ADDITIONAL;
  	}
  
  	/* a new rxflow, buffer it and warn caller */
  
  	m = lws_buflist_append_segment(&wsi->buflist, buf + n, len - n);
  
  	if (m < 0)
  		return LWSRXFC_ERROR;
  	if (m) {
  		lwsl_debug("%s: added %p to rxflow list\n", __func__, wsi);
  		lws_dll2_add_head(&wsi->dll_buflist, &pt->dll_buflist_owner);
  	}
  
  	return ret;
  }
  
  /* this is used by the platform service code to stop us waiting for network
   * activity in poll() when we have something that already needs service
   */
  
  LWS_VISIBLE LWS_EXTERN int
  lws_service_adjust_timeout(struct lws_context *context, int timeout_ms, int tsi)
  {
  	struct lws_context_per_thread *pt = &context->pt[tsi];
  
  	/*
  	 * Figure out if we really want to wait in poll()... we only need to
  	 * wait if really nothing already to do and we have to wait for
  	 * something from network
  	 */
  #if defined(LWS_ROLE_WS) && !defined(LWS_WITHOUT_EXTENSIONS)
  	/* 1) if we know we are draining rx ext, do not wait in poll */
  	if (pt->ws.rx_draining_ext_list)
  		return 0;
  #endif
  
  #if defined(LWS_WITH_TLS)
  	/* 2) if we know we have non-network pending data,
  	 *    do not wait in poll */
  
  	if (pt->context->tls_ops &&
  	    pt->context->tls_ops->fake_POLLIN_for_buffered &&
  	    pt->context->tls_ops->fake_POLLIN_for_buffered(pt))
  			return 0;
  #endif
  
  	/*
  	 * 3) If there is any wsi with rxflow buffered and in a state to process
  	 *    it, we should not wait in poll
  	 */
  
  	lws_start_foreach_dll(struct lws_dll2 *, d, pt->dll_buflist_owner.head) {
  		struct lws *wsi = lws_container_of(d, struct lws, dll_buflist);
  
  		if (!lws_is_flowcontrolled(wsi) &&
  		     lwsi_state(wsi) != LRS_DEFERRING_ACTION)
  			return 0;
  
  	/*
  	 * 4) If any guys with http compression to spill, we shouldn't wait in
  	 *    poll but hurry along and service them
  	 */
  
  	} lws_end_foreach_dll(d);
  
  	return timeout_ms;
  }
  
  /*
   * POLLIN said there is something... we must read it, and either use it; or
   * if other material already in the buflist append it and return the buflist
   * head material.
   */
  int
  lws_buflist_aware_read(struct lws_context_per_thread *pt, struct lws *wsi,
  		       struct lws_tokens *ebuf)
  {
  	int n, prior = (int)lws_buflist_next_segment_len(&wsi->buflist, NULL);
  
  	ebuf->token = (char *)pt->serv_buf;
  	ebuf->len = lws_ssl_capable_read(wsi, pt->serv_buf,
  					 wsi->context->pt_serv_buf_size);
  
  	if (ebuf->len == LWS_SSL_CAPABLE_MORE_SERVICE && prior)
  		goto get_from_buflist;
  
  	if (ebuf->len <= 0)
  		return 0;
  
  	/* nothing in buflist already?  Then just use what we read */
  
  	if (!prior)
  		return 0;
  
  	/* stash what we read */
  
  	n = lws_buflist_append_segment(&wsi->buflist, (uint8_t *)ebuf->token,
  				       ebuf->len);
  	if (n < 0)
  		return -1;
  	if (n) {
  		lwsl_debug("%s: added %p to rxflow list\n", __func__, wsi);
  		lws_dll2_add_head(&wsi->dll_buflist, &pt->dll_buflist_owner);
  	}
  
  	/* get the first buflist guy in line */
  
  get_from_buflist:
  
  	ebuf->len = (int)lws_buflist_next_segment_len(&wsi->buflist,
  						      (uint8_t **)&ebuf->token);
  
  	return 1; /* came from buflist */
  }
  
  int
  lws_buflist_aware_consume(struct lws *wsi, struct lws_tokens *ebuf, int used,
  			  int buffered)
  {
  	struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
  	int m;
  
  	/* it's in the buflist; we didn't use any */
  
  	if (!used && buffered)
  		return 0;
  
  	if (used && buffered) {
  		m = lws_buflist_use_segment(&wsi->buflist, used);
  		lwsl_info("%s: draining rxflow: used %d, next %d\n",
  			    __func__, used, m);
  		if (m)
  			return 0;
  
  		lwsl_info("%s: removed %p from dll_buflist\n", __func__, wsi);
  		lws_dll2_remove(&wsi->dll_buflist);
  
  		return 0;
  	}
  
  	/* any remainder goes on the buflist */
  
  	if (used != ebuf->len) {
  		m = lws_buflist_append_segment(&wsi->buflist,
  					       (uint8_t *)ebuf->token + used,
  					       ebuf->len - used);
  		if (m < 0)
  			return 1; /* OOM */
  		if (m) {
  			lwsl_debug("%s: added %p to rxflow list\n",
  				   __func__, wsi);
  			lws_dll2_add_head(&wsi->dll_buflist,
  					 &pt->dll_buflist_owner);
  		}
  	}
  
  	return 0;
  }
  
  void
  lws_service_do_ripe_rxflow(struct lws_context_per_thread *pt)
  {
  	struct lws_pollfd pfd;
  
  	if (!pt->dll_buflist_owner.head)
  		return;
  
  	/*
  	 * service all guys with pending rxflow that reached a state they can
  	 * accept the pending data
  	 */
  
  	lws_pt_lock(pt, __func__);
  
  	lws_start_foreach_dll_safe(struct lws_dll2 *, d, d1,
  				   pt->dll_buflist_owner.head) {
  		struct lws *wsi = lws_container_of(d, struct lws, dll_buflist);
  
  		pfd.events = LWS_POLLIN;
  		pfd.revents = LWS_POLLIN;
  		pfd.fd = -1;
  
  		lwsl_debug("%s: rxflow processing: %p fc=%d, 0x%x\n", __func__,
  				wsi, lws_is_flowcontrolled(wsi),
  			    wsi->wsistate);
  
  		if (!lws_is_flowcontrolled(wsi) &&
  		    lwsi_state(wsi) != LRS_DEFERRING_ACTION &&
  		    (wsi->role_ops->handle_POLLIN)(pt, wsi, &pfd) ==
  						   LWS_HPI_RET_PLEASE_CLOSE_ME)
  			lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS,
  					   "close_and_handled");
  
  	} lws_end_foreach_dll_safe(d, d1);
  
  	lws_pt_unlock(pt);
  }
  
  /*
   * guys that need POLLIN service again without waiting for network action
   * can force POLLIN here if not flowcontrolled, so they will get service.
   *
   * Return nonzero if anybody got their POLLIN faked
   */
  int
  lws_service_flag_pending(struct lws_context *context, int tsi)
  {
  	struct lws_context_per_thread *pt = &context->pt[tsi];
  	int forced = 0;
  
  	lws_pt_lock(pt, __func__);
  
  	/*
  	 * 1) If there is any wsi with a buflist and in a state to process
  	 *    it, we should not wait in poll
  	 */
  
  	lws_start_foreach_dll(struct lws_dll2 *, d, pt->dll_buflist_owner.head) {
  		struct lws *wsi = lws_container_of(d, struct lws, dll_buflist);
  
  		if (!lws_is_flowcontrolled(wsi) &&
  		     lwsi_state(wsi) != LRS_DEFERRING_ACTION) {
  			forced = 1;
  			break;
  		}
  	} lws_end_foreach_dll(d);
  
  #if defined(LWS_ROLE_WS)
  	forced |= role_ops_ws.service_flag_pending(context, tsi);
  #endif
  
  #if defined(LWS_WITH_TLS)
  	/*
  	 * 2) For all guys with buffered SSL read data already saved up, if they
  	 * are not flowcontrolled, fake their POLLIN status so they'll get
  	 * service to use up the buffered incoming data, even though their
  	 * network socket may have nothing
  	 */
  	lws_start_foreach_dll_safe(struct lws_dll *, p, p1,
  				   pt->tls.dll_pending_tls_head.next) {
  		struct lws *wsi = lws_container_of(p, struct lws,
  						   tls.dll_pending_tls);
  
  		pt->fds[wsi->position_in_fds_table].revents |=
  			pt->fds[wsi->position_in_fds_table].events & LWS_POLLIN;
  		if (pt->fds[wsi->position_in_fds_table].revents & LWS_POLLIN) {
  			forced = 1;
  			/*
  			 * he's going to get serviced now, take him off the
  			 * list of guys with buffered SSL.  If he still has some
  			 * at the end of the service, he'll get put back on the
  			 * list then.
  			 */
  			__lws_ssl_remove_wsi_from_buffered_list(wsi);
  		}
  
  	} lws_end_foreach_dll_safe(p, p1);
  #endif
  
  	lws_pt_unlock(pt);
  
  	return forced;
  }
  
  static int
  lws_service_periodic_checks(struct lws_context *context,
  			    struct lws_pollfd *pollfd, int tsi)
  {
  	struct lws_context_per_thread *pt = &context->pt[tsi];
  	struct lws_timed_vh_protocol *tmr;
  	lws_sockfd_type our_fd = 0, tmp_fd;
  	struct lws *wsi;
  	int timed_out = 0;
  	time_t now;
  #if defined(LWS_ROLE_H1) || defined(LWS_ROLE_H2)
  	struct allocated_headers *ah;
  	int n, m;
  #endif
  
  	if (!context->protocol_init_done)
  		if (lws_protocol_init(context)) {
  			lwsl_err("%s: lws_protocol_init failed\n", __func__);
  			return -1;
  		}
  
  	time(&now);
  
  	/*
  	 * handle case that system time was uninitialized when lws started
  	 * at boot, and got initialized a little later
  	 */
  	if (context->time_up < 1464083026 && now > 1464083026)
  		context->time_up = now;
  
  	if (context->last_timeout_check_s &&
  	    now - context->last_timeout_check_s > 100) {
  		/*
  		 * There has been a discontiguity.  Any stored time that is
  		 * less than context->time_discontiguity should have context->
  		 * time_fixup added to it.
  		 *
  		 * Some platforms with no RTC will experience this as a normal
  		 * event when ntp sets their clock, but we can have started
  		 * long before that with a 0-based unix time.
  		 */
  
  		context->time_discontiguity = now;
  		context->time_fixup = now - context->last_timeout_check_s;
  
  		lwsl_notice("time discontiguity: at old time %llus, "
  			    "new time %llus: +%llus\n",
  			    (unsigned long long)context->last_timeout_check_s,
  			    (unsigned long long)context->time_discontiguity,
  			    (unsigned long long)context->time_fixup);
  
  		context->last_timeout_check_s = now - 1;
  	}
  
  	if (!lws_compare_time_t(context, context->last_timeout_check_s, now))
  		return 0;
  
  	context->last_timeout_check_s = now;
  
  #if defined(LWS_WITH_STATS)
  	if (!tsi && now - context->last_dump > 10) {
  		lws_stats_log_dump(context);
  		context->last_dump = now;
  	}
  #endif
  
  	lws_plat_service_periodic(context);
  	lws_check_deferred_free(context, tsi, 0);
  
  #if defined(LWS_WITH_PEER_LIMITS)
  	lws_peer_cull_peer_wait_list(context);
  #endif
  
  	/* retire unused deprecated context */
  #if !defined(LWS_PLAT_OPTEE) && !defined(LWS_WITH_ESP32)
  #if !defined(_WIN32)
  	if (context->deprecated && !context->count_wsi_allocated) {
  		lwsl_notice("%s: ending deprecated context\n", __func__);
  		kill(getpid(), SIGINT);
  		return 0;
  	}
  #endif
  #endif
  	/* global timeout check once per second */
  
  	if (pollfd)
  		our_fd = pollfd->fd;
  
  	/*
  	 * Phase 1: check every wsi on our pt's timeout check list
  	 */
  
  	lws_pt_lock(pt, __func__);
  
  	lws_start_foreach_dll_safe(struct lws_dll *, d, d1,
  				   context->pt[tsi].dll_timeout_head.next) {
  		wsi = lws_container_of(d, struct lws, dll_timeout);
  
  		tmp_fd = wsi->desc.sockfd;
  		if (__lws_service_timeout_check(wsi, now)) {
  			/* he did time out... */
  			if (tmp_fd == our_fd)
  				/* it was the guy we came to service! */
  				timed_out = 1;
  			/* he's gone, no need to mark as handled */
  		}
  	} lws_end_foreach_dll_safe(d, d1);
  
  #if defined(LWS_ROLE_H1) || defined(LWS_ROLE_H2)
  	/*
  	 * Phase 2: double-check active ah timeouts independent of wsi
  	 *	    timeout status
  	 */
  
  	ah = pt->http.ah_list;
  	while (ah) {
  		int len;
  		char buf[256];
  		const unsigned char *c;
  
  		if (!ah->in_use || !ah->wsi || !ah->assigned ||
  		    (ah->wsi->vhost &&
  		     lws_compare_time_t(context, now, ah->assigned) <
  		     ah->wsi->vhost->timeout_secs_ah_idle + 360)) {
  			ah = ah->next;
  			continue;
  		}
  
  		/*
  		 * a single ah session somehow got held for
  		 * an unreasonable amount of time.
  		 *
  		 * Dump info on the connection...
  		 */
  		wsi = ah->wsi;
  		buf[0] = '\0';
  #if !defined(LWS_PLAT_OPTEE)
  		lws_get_peer_simple(wsi, buf, sizeof(buf));
  #else
  		buf[0] = '\0';
  #endif
  		lwsl_notice("ah excessive hold: wsi %p\n"
  			    "  peer address: %s\n"
  			    "  ah pos %u\n",
  			    wsi, buf, ah->pos);
  		buf[0] = '\0';
  		m = 0;
  		do {
  			c = lws_token_to_string(m);
  			if (!c)
  				break;
  			if (!(*c))
  				break;
  
  			len = lws_hdr_total_length(wsi, m);
  			if (!len || len > (int)sizeof(buf) - 1) {
  				m++;
  				continue;
  			}
  
  			if (lws_hdr_copy(wsi, buf, sizeof buf, m) > 0) {
  				buf[sizeof(buf) - 1] = '\0';
  
  				lwsl_notice("   %s = %s\n",
  					    (const char *)c, buf);
  			}
  			m++;
  		} while (1);
  
  		/* explicitly detach the ah */
  		lws_header_table_detach(wsi, 0);
  
  		/* ... and then drop the connection */
  
  		m = 0;
  		if (wsi->desc.sockfd == our_fd) {
  			m = timed_out;
  
  			/* it was the guy we came to service! */
  			timed_out = 1;
  		}
  
  		if (!m) /* if he didn't already timeout */
  			__lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS,
  					     "excessive ah");
  
  		ah = pt->http.ah_list;
  	}
  #endif
  	lws_pt_unlock(pt);
  
  #if 0
  	{
  		char s[300], *p = s;
  
  		for (n = 0; n < context->count_threads; n++)
  			p += sprintf(p, " %7lu (%5d), ",
  				     context->pt[n].count_conns,
  				     context->pt[n].fds_count);
  
  		lwsl_notice("load: %s\n", s);
  	}
  #endif
  	/*
  	 * Phase 3: vhost / protocol timer callbacks
  	 */
  
  	/* 3a: lock, collect, and remove vh timers that are pending */
  
  	lws_context_lock(context, "expired vh timers"); /* context ---------- */
  
  	n = 0;
  
  	/*
  	 * first, under the context lock, get a count of the number of
  	 * expired timers so we can allocate for them (or not, cleanly)
  	 */
  
  	lws_start_foreach_ll(struct lws_vhost *, v, context->vhost_list) {
  
  		if (v->timed_vh_protocol_list) {
  
  			lws_start_foreach_ll_safe(struct lws_timed_vh_protocol *,
  					q, v->timed_vh_protocol_list, next) {
  				if (now >= q->time && q->tsi_req == tsi)
  					n++;
  			} lws_end_foreach_ll_safe(q);
  		}
  
  	} lws_end_foreach_ll(v, vhost_next);
  
  	/* if nothing to do, unlock and move on to the next vhost */
  
  	if (!n) {
  		lws_context_unlock(context); /* ----------- context */
  		goto vh_timers_done;
  	}
  
  	/*
  	 * attempt to do the wsi and timer info allocation
  	 * first en bloc.  If it fails, we can just skip the rest and
  	 * the timers will still be pending next time.
  	 */
  
  	wsi = lws_zalloc(sizeof(*wsi), "cbwsi");
  	if (!wsi) {
  		/*
  		 * at this point, we haven't cleared any vhost
  		 * timers.  We can fail out and retry cleanly
  		 * next periodic check
  		 */
  		lws_context_unlock(context); /* ----------- context */
  		goto vh_timers_done;
  	}
  	wsi->context = context;
  
  	tmr = lws_zalloc(sizeof(*tmr) * n, "cbtmr");
  	if (!tmr) {
  		/* again OOM here can be handled cleanly */
  		lws_free(wsi);
  		lws_context_unlock(context); /* ----------- context */
  		goto vh_timers_done;
  	}
  
  	/* so we have the allocation for n pending timers... */
  
  	m = 0;
  	lws_start_foreach_ll(struct lws_vhost *, v, context->vhost_list) {
  
  		if (v->timed_vh_protocol_list) {
  
  			lws_vhost_lock(v); /* vhost ------------------------- */
  
  			lws_start_foreach_ll_safe(struct lws_timed_vh_protocol *,
  					q, v->timed_vh_protocol_list, next) {
  
  				/* only do n */
  				if (m == n)
  					break;
  
  				if (now >= q->time && q->tsi_req == tsi) {
  
  					/*
  					 * tmr is an allocated array.
  					 * Ignore the linked-list.
  					 */
  					tmr[m].vhost = v;
  					tmr[m].protocol = q->protocol;
  					tmr[m++].reason = q->reason;
  
  					/* take the timer out now we took
  					 * responsibility */
  					__lws_timed_callback_remove(v, q);
  				}
  
  			} lws_end_foreach_ll_safe(q);
  
  			lws_vhost_unlock(v); /* ----------------------- vhost */
  		}
  
  	} lws_end_foreach_ll(v, vhost_next);
  	lws_context_unlock(context); /* ---------------------------- context */
  
  	/* 3b: call the vh timer callbacks outside any lock */
  
  	for (m = 0; m < n; m++) {
  
  		wsi->vhost = tmr[m].vhost; /* not a real bound wsi */
  		wsi->protocol = tmr[m].protocol;
  
  		lwsl_debug("%s: timed cb: vh %s, protocol %s, reason %d\n",
  			   __func__, tmr[m].vhost->name, tmr[m].protocol->name,
  			   tmr[m].reason);
  		tmr[m].protocol->callback(wsi, tmr[m].reason, NULL, NULL, 0);
  	}
  
  	lws_free(tmr);
  	lws_free(wsi);
  
  vh_timers_done:
  
  	/*
  	 * Phase 4: check for unconfigured vhosts due to required
  	 *	    interface missing before
  	 */
  
  	lws_context_lock(context, "periodic checks");
  	lws_start_foreach_llp(struct lws_vhost **, pv,
  			      context->no_listener_vhost_list) {
  		struct lws_vhost *v = *pv;
  		lwsl_debug("deferred iface: checking if on vh %s\n", (*pv)->name);
  		if (_lws_vhost_init_server(NULL, *pv) == 0) {
  			/* became happy */
  			lwsl_notice("vh %s: became connected\n", v->name);
  			*pv = v->no_listener_vhost_list;
  			v->no_listener_vhost_list = NULL;
  			break;
  		}
  	} lws_end_foreach_llp(pv, no_listener_vhost_list);
  	lws_context_unlock(context);
  
  	/*
  	 * Phase 5: role periodic checks
  	 */
  #if defined(LWS_ROLE_WS)
  	role_ops_ws.periodic_checks(context, tsi, now);
  #endif
  #if defined(LWS_ROLE_CGI)
  	role_ops_cgi.periodic_checks(context, tsi, now);
  #endif
  
  #if defined(LWS_WITH_TLS)
  	/*
  	 * Phase 6: check the remaining cert lifetime daily
  	 */
  
  	if (context->tls_ops &&
  	    context->tls_ops->periodic_housekeeping)
  		context->tls_ops->periodic_housekeeping(context, now);
  #endif
  
  	return 0;
  }
  
  LWS_VISIBLE int
  lws_service_fd_tsi(struct lws_context *context, struct lws_pollfd *pollfd,
  		   int tsi)
  {
  	struct lws_context_per_thread *pt = &context->pt[tsi];
  	struct lws *wsi;
  
  	if (!context || context->being_destroyed1)
  		return -1;
  
  	/* the case there's no pollfd to service, we just want to do periodic */
  	if (!pollfd) {
  		lws_service_periodic_checks(context, pollfd, tsi);
  		return -2;
  	}
  
  	assert(lws_socket_is_valid(pollfd->fd));
  
  	/* no, here to service a socket descriptor */
  	wsi = wsi_from_fd(context, pollfd->fd);
  	if (!wsi)
  		/* not lws connection ... leave revents alone and return */
  		return 0;
  
  #if LWS_MAX_SMP > 1
  	if (wsi->undergoing_init_from_other_pt)
  		/*
  		 * Temporary situation that other service thread is initializing
  		 * this wsi right now for use on our service thread.
  		 */
  		return 0;
  #endif
  
  	/*
  	 * so that caller can tell we handled, past here we need to
  	 * zero down pollfd->revents after handling
  	 */
  
  	/* handle session socket closed */
  
  	if ((!(pollfd->revents & pollfd->events & LWS_POLLIN)) &&
  	    (pollfd->revents & LWS_POLLHUP)) {
  		wsi->socket_is_permanently_unusable = 1;
  		lwsl_debug("Session Socket %p (fd=%d) dead\n",
  			   (void *)wsi, pollfd->fd);
  
  		goto close_and_handled;
  	}
  
  #ifdef _WIN32
  	if (pollfd->revents & LWS_POLLOUT)
  		wsi->sock_send_blocking = FALSE;
  #endif
  
  	if ((!(pollfd->revents & pollfd->events & LWS_POLLIN)) &&
  	    (pollfd->revents & LWS_POLLHUP)) {
  		lwsl_debug("pollhup\n");
  		wsi->socket_is_permanently_unusable = 1;
  		goto close_and_handled;
  	}
  
  #if defined(LWS_WITH_TLS)
  	if (lwsi_state(wsi) == LRS_SHUTDOWN &&
  	    lws_is_ssl(wsi) && wsi->tls.ssl) {
  		switch (__lws_tls_shutdown(wsi)) {
  		case LWS_SSL_CAPABLE_DONE:
  		case LWS_SSL_CAPABLE_ERROR:
  			goto close_and_handled;
  
  		case LWS_SSL_CAPABLE_MORE_SERVICE_READ:
  		case LWS_SSL_CAPABLE_MORE_SERVICE_WRITE:
  		case LWS_SSL_CAPABLE_MORE_SERVICE:
  			goto handled;
  		}
  	}
  #endif
  	wsi->could_have_pending = 0; /* clear back-to-back write detection */
  
  	/* okay, what we came here to do... */
  
  	/* if we got here, we should have wire protocol ops set on the wsi */
  	assert(wsi->role_ops);
  
  	// lwsl_notice("%s: %s: wsistate 0x%x\n", __func__, wsi->role_ops->name,
  	//	    wsi->wsistate);
  
  	switch ((wsi->role_ops->handle_POLLIN)(pt, wsi, pollfd)) {
  	case LWS_HPI_RET_WSI_ALREADY_DIED:
  		return 1;
  	case LWS_HPI_RET_HANDLED:
  		break;
  	case LWS_HPI_RET_PLEASE_CLOSE_ME:
  close_and_handled:
  		lwsl_debug("%p: Close and handled\n", wsi);
  		lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS,
  				   "close_and_handled");
  #if defined(_DEBUG) && defined(LWS_WITH_LIBUV)
  		/*
  		 * confirm close has no problem being called again while
  		 * it waits for libuv service to complete the first async
  		 * close
  		 */
  		if (context->event_loop_ops == &event_loop_ops_uv)
  			lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS,
  					   "close_and_handled uv repeat test");
  #endif
  		/*
  		 * pollfd may point to something else after the close
  		 * due to pollfd swapping scheme on delete on some platforms
  		 * we can't clear revents now because it'd be the wrong guy's
  		 * revents
  		 */
  		return 1;
  	default:
  		assert(0);
  	}
  #if defined(LWS_WITH_TLS)
  handled:
  #endif
  	pollfd->revents = 0;
  
  	/* check the timeout situation if we didn't in the last second */
  	lws_service_periodic_checks(context, pollfd, tsi);
  
  	lws_pt_lock(pt, __func__);
  	__lws_hrtimer_service(pt);
  	lws_pt_unlock(pt);
  
  	return 0;
  }
  
  LWS_VISIBLE int
  lws_service_fd(struct lws_context *context, struct lws_pollfd *pollfd)
  {
  	return lws_service_fd_tsi(context, pollfd, 0);
  }
  
  LWS_VISIBLE int
  lws_service(struct lws_context *context, int timeout_ms)
  {
  	struct lws_context_per_thread *pt = &context->pt[0];
  	int n;
  
  	if (!context)
  		return 1;
  
  	pt->inside_service = 1;
  
  	if (context->event_loop_ops->run_pt) {
  		/* we are configured for an event loop */
  		context->event_loop_ops->run_pt(context, 0);
  
  		pt->inside_service = 0;
  
  		return 1;
  	}
  	n = lws_plat_service(context, timeout_ms);
  
  	pt->inside_service = 0;
  
  	return n;
  }
  
  LWS_VISIBLE int
  lws_service_tsi(struct lws_context *context, int timeout_ms, int tsi)
  {
  	struct lws_context_per_thread *pt = &context->pt[tsi];
  	int n;
  
  	pt->inside_service = 1;
  #if LWS_MAX_SMP > 1
  	pt->self = pthread_self();
  #endif
  
  	if (context->event_loop_ops->run_pt) {
  		/* we are configured for an event loop */
  		context->event_loop_ops->run_pt(context, tsi);
  
  		pt->inside_service = 0;
  
  		return 1;
  	}
  
  	n = _lws_plat_service_tsi(context, timeout_ms, tsi);
  
  	pt->inside_service = 0;
  
  	return n;
  }
  