mirror of
https://github.com/warmcat/libwebsockets.git
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bce1f01370
Introduce a generic lws_state object with notification handlers that may be registered in a chain. Implement one of those in the context to manage the "system state". Allow other pieces of lws and user code to register notification handlers on a context list. Handlers can object to or take over responsibility to move forward and retry system state changes if they know that some dependent action must succeed first. For example if the system time is invalid, we cannot move on to a state where anything can do tls until that has been corrected.
134 lines
3.4 KiB
C
134 lines
3.4 KiB
C
/*
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* libwebsockets - small server side websockets and web server implementation
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*
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* Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to
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* deal in the Software without restriction, including without limitation the
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* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
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* sell copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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#include "private-lib-core.h"
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void
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lws_state_reg_notifier(lws_state_manager_t *mgr,
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lws_state_notify_link_t *notify_link)
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{
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lws_dll2_add_head(¬ify_link->list, &mgr->notify_list);
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}
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void
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lws_state_reg_notifier_list(lws_state_manager_t *mgr,
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lws_state_notify_link_t **notify_link_array)
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{
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if (notify_link_array)
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while (*notify_link_array)
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lws_state_reg_notifier(mgr, *notify_link_array++);
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}
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#if defined(_DEBUG)
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static const char *
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_systnm(lws_state_manager_t *mgr, int state, char *temp8)
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{
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if (!mgr->state_names) {
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lws_snprintf(temp8, 8, "%d", state);
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return temp8;
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}
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return mgr->state_names[state];
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}
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#endif
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static int
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_report(lws_state_manager_t *mgr, int a, int b)
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{
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#if defined(_DEBUG)
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char temp8[8];
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#endif
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lws_start_foreach_dll(struct lws_dll2 *, d, mgr->notify_list.head) {
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lws_state_notify_link_t *l =
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lws_container_of(d, lws_state_notify_link_t, list);
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if (l->notify_cb(mgr, l, a, b)) {
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/* a dependency took responsibility for retry */
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#if defined(_DEBUG)
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lwsl_info("%s: %s: %s: rejected '%s' -> '%s'\n",
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__func__, mgr->name, l->name,
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_systnm(mgr, a, temp8),
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_systnm(mgr, b, temp8));
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#endif
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return 1;
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}
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} lws_end_foreach_dll(d);
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return 0;
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}
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static int
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_lws_state_transition(lws_state_manager_t *mgr, int target)
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{
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#if defined(_DEBUG)
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char temp8[8];
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#endif
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if (_report(mgr, mgr->state, target))
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return 1;
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#if defined(_DEBUG)
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lwsl_debug("%s: %s: changed %d '%s' -> %d '%s'\n", __func__, mgr->name,
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mgr->state, _systnm(mgr, mgr->state, temp8), target,
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_systnm(mgr, target, temp8));
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#endif
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mgr->state = target;
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/* Indicate success by calling the notifers again with both args same */
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_report(mgr, target, target);
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return 0;
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}
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int
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lws_state_transition_steps(lws_state_manager_t *mgr, int target)
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{
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int n = 0;
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#if defined(_DEBUG)
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int i = mgr->state;
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char temp8[8];
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#endif
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while (!n && mgr->state != target)
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n = _lws_state_transition(mgr, mgr->state + 1);
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#if defined(_DEBUG)
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lwsl_info("%s: %s -> %s\n", __func__, _systnm(mgr, i, temp8),
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_systnm(mgr, mgr->state, temp8));
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#endif
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return 0;
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}
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int
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lws_state_transition(lws_state_manager_t *mgr, int target)
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{
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if (mgr->state != target)
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_lws_state_transition(mgr, target);
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return 0;
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}
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