1 /*
2 * libwebsockets - small server side websockets and web server implementation
3 *
4 * Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to
8 * deal in the Software without restriction, including without limitation the
9 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10 * sell copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22 * IN THE SOFTWARE.
23 */
24
25struct lws_state_notify_link;
26struct lws_state_manager;
27
28#if defined(LWS_WITH_SYS_STATE)
29
30typedef int (*lws_state_notify_t)(struct lws_state_manager *mgr,
31 struct lws_state_notify_link *link,
32 int current, int target);
33
34typedef struct lws_state_notify_link {
35 lws_dll2_t list;
36 lws_state_notify_t notify_cb;
37 const char *name;
38} lws_state_notify_link_t;
39
40typedef struct lws_state_manager {
41 lws_dll2_owner_t notify_list;
42 struct lws_context *context;
43 void *parent;
44#if defined(LWS_WITH_SYS_SMD)
45 lws_smd_class_t smd_class;
46#endif
47 /**< optional opaque pointer to owning object... useful to make such
48 * a pointer available to a notification callback. Ignored by lws */
49 const char **state_names;
50 const char *name;
51 int state;
52} lws_state_manager_t;
53
54/**
55 * lws_state_reg_notifier() - add dep handler for state notifications
56 *
57 * \param context: the lws_context
58 * \param nl: the handler to add to the notifier linked-list
59 *
60 * Add \p notify_link to the context's list of notification handlers for system
61 * state changes. The handlers can defeat or take over responsibility for
62 * retrying the change after they have initiated some dependency.
63 */
64
65LWS_EXTERN LWS_VISIBLE void
66lws_state_reg_notifier(lws_state_manager_t *mgr, lws_state_notify_link_t *nl);
67
68/**
69 * lws_state_reg_deregister() - deregister a notifier
70 *
71 * \param nl: notification hardler to deregister
72 *
73 * Remove a notification handler from its state manager
74 */
75
76LWS_EXTERN LWS_VISIBLE void
77lws_state_reg_deregister(lws_state_notify_link_t *nl);
78
79/**
80 * lws_state_reg_notifier_list() - add dep handlers for state notifications
81 *
82 * \param context: the lws_context
83 * \param nl: list of notification handlers
84 *
85 * Add a NULL-terminated list of notification handler pointers to a notification
86 * manager object
87 */
88
89LWS_EXTERN LWS_VISIBLE void
90lws_state_reg_notifier_list(lws_state_manager_t *mgr,
91 lws_state_notify_link_t * const *nl);
92
93/**
94 * lws_state_transition_steps() - move to state via starting any deps
95 *
96 * \param mgr: the state manager object
97 * \param target: the state we wish to move to
98 *
99 * Advance state by state towards state \p target. At each state, notifiers
100 * may veto the change and be triggered to perform dependencies, stopping the
101 * advance towards the target state.
102 */
103LWS_EXTERN LWS_VISIBLE int
104lws_state_transition_steps(lws_state_manager_t *mgr, int target);
105
106/**
107 * lws_state_transition() - move to state via starting any deps
108 *
109 * \param mgr: the state manager object
110 * \param target: the state we wish to move to
111 *
112 * Jump to state target atomically. Notifiers may veto it.
113 */
114LWS_EXTERN LWS_VISIBLE int
115lws_state_transition(lws_state_manager_t *mgr, int target);
116
117#else
118
119#endif
120