1 /*
2 * libwebsockets - small server side websockets and web server implementation
3 *
4 * Copyright (C) 2010 - 2021 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
25 #include <private-lib-core.h>
26 #include "private-lib-event-libs-poll.h"
27
28 static int
elops_foreign_thread_poll(struct lws_context * cx,int tsi)29 elops_foreign_thread_poll(struct lws_context *cx, int tsi)
30 {
31 struct lws_context_per_thread *pt = &cx->pt[tsi];
32 volatile struct lws_context_per_thread *vpt =
33 (volatile struct lws_context_per_thread *)pt;
34
35 /*
36 * To avoid mandating a specific threading library, we can check
37 * probabilistically by seeing if the lws default wait is still asleep
38 * at the time we are checking, if it is then we cannot be being called
39 * by the event loop loop thread.
40 */
41
42 return vpt->inside_poll;
43 }
44
45 struct lws_event_loop_ops event_loop_ops_poll = {
46 .name = "poll",
47
48 .foreign_thread = elops_foreign_thread_poll,
49
50 .flags = LELOF_ISPOLL,
51 };
52
53 const lws_plugin_evlib_t evlib_poll = {
54 .hdr = {
55 "poll",
56 "lws_evlib_plugin",
57 "n/a",
58 LWS_PLUGIN_API_MAGIC
59 },
60
61 .ops = &event_loop_ops_poll
62 };
63