1/***
2    This file is part of PulseAudio.
3
4    Copyright 2022 Craig Howard
5
6    PulseAudio is free software; you can redistribute it and/or modify
7    it under the terms of the GNU Lesser General Public License as published
8    by the Free Software Foundation; either version 2.1 of the License,
9    or (at your option) any later version.
10
11    PulseAudio is distributed in the hope that it will be useful, but
12    WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14    General Public License for more details.
15
16    You should have received a copy of the GNU Lesser General Public License
17    along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
18***/
19
20#ifdef HAVE_CONFIG_H
21#include <config.h>
22#endif
23
24#include "restart-module.h"
25
26#include <pulse/timeval.h>
27#include <pulse/xmalloc.h>
28#include <pulse/mainloop.h>
29
30#include <pulsecore/core.h>
31#include <pulsecore/thread-mq.h>
32
33struct pa_restart_data {
34    init_cb do_init;
35    done_cb do_done;
36
37    pa_usec_t restart_usec;
38    pa_module *module;
39    pa_time_event *time_event;
40    pa_defer_event *defer_event;
41};
42
43static void do_reinit(pa_mainloop_api *mainloop, pa_restart_data *rd);
44
45static void call_init(pa_mainloop_api *mainloop, pa_time_event *e, const struct timeval *tv, void *userdata) {
46    pa_restart_data *rd = userdata;
47    int ret;
48
49    if (rd->time_event) {
50        mainloop->time_free(rd->time_event);
51        rd->time_event = NULL;
52    }
53
54    /* now that restart_usec has elapsed, we call do_init to restart the module */
55    ret = rd->do_init(rd->module);
56
57    /* if the init failed, we got here because the caller wanted to restart, so
58     * setup another restart */
59    if (ret < 0)
60        do_reinit(mainloop, rd);
61}
62
63static void defer_callback(pa_mainloop_api *mainloop, pa_defer_event *e, void *userdata) {
64    pa_restart_data *rd = userdata;
65
66    pa_assert(rd->defer_event == e);
67
68    mainloop->defer_enable(rd->defer_event, 0);
69    mainloop->defer_free(rd->defer_event);
70    rd->defer_event = NULL;
71
72    do_reinit(mainloop, rd);
73}
74
75static void do_reinit(pa_mainloop_api *mainloop, pa_restart_data *rd) {
76    struct timeval tv;
77
78    pa_assert_ctl_context();
79
80    /* call do_done on the module, which will effectively tear it down; all
81     * that remains is the pa_module */
82    rd->do_done(rd->module);
83
84    /* after restart_usec, call do_init to restart the module */
85    pa_gettimeofday(&tv);
86    pa_timeval_add(&tv, rd->restart_usec);
87    rd->time_event = mainloop->time_new(mainloop, &tv, call_init, rd);
88}
89
90pa_restart_data *pa_restart_module_reinit(pa_module *m, init_cb do_init, done_cb do_done, pa_usec_t restart_usec) {
91    pa_restart_data *rd;
92
93    pa_assert_ctl_context();
94    pa_assert(do_init);
95    pa_assert(do_done);
96    pa_assert(restart_usec);
97
98    pa_log_info("Starting reinit for %s", m->name);
99
100    rd = pa_xnew0(pa_restart_data, 1);
101    rd->do_init = do_init;
102    rd->do_done = do_done;
103    rd->restart_usec = restart_usec;
104    rd->module = m;
105
106    /* defer actually doing a reinit, so that we can safely exit whatever call
107     * chain we're in before we effectively reinit the module */
108    rd->defer_event = m->core->mainloop->defer_new(m->core->mainloop, defer_callback, rd);
109    m->core->mainloop->defer_enable(rd->defer_event, 1);
110
111    return rd;
112}
113
114void pa_restart_free(pa_restart_data *rd) {
115    pa_assert_ctl_context();
116    pa_assert(rd);
117
118    if (rd->defer_event) {
119        rd->module->core->mainloop->defer_enable(rd->defer_event, 0);
120        rd->module->core->mainloop->defer_free(rd->defer_event);
121    }
122
123    if (rd->time_event) {
124        pa_log_info("Cancel reinit for %s", rd->module->name);
125        rd->module->core->mainloop->time_free(rd->time_event);
126    }
127
128    pa_xfree(rd);
129}
130