1 |
|
|
/* $OpenBSD: cmd-wait-for.c,v 1.16 2016/10/16 19:04:05 nicm Exp $ */ |
2 |
|
|
|
3 |
|
|
/* |
4 |
|
|
* Copyright (c) 2013 Nicholas Marriott <nicholas.marriott@gmail.com> |
5 |
|
|
* Copyright (c) 2013 Thiago de Arruda <tpadilha84@gmail.com> |
6 |
|
|
* |
7 |
|
|
* Permission to use, copy, modify, and distribute this software for any |
8 |
|
|
* purpose with or without fee is hereby granted, provided that the above |
9 |
|
|
* copyright notice and this permission notice appear in all copies. |
10 |
|
|
* |
11 |
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
12 |
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
13 |
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
14 |
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
15 |
|
|
* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER |
16 |
|
|
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING |
17 |
|
|
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
18 |
|
|
*/ |
19 |
|
|
|
20 |
|
|
#include <sys/types.h> |
21 |
|
|
|
22 |
|
|
#include <stdlib.h> |
23 |
|
|
#include <string.h> |
24 |
|
|
|
25 |
|
|
#include "tmux.h" |
26 |
|
|
|
27 |
|
|
/* |
28 |
|
|
* Block or wake a client on a named wait channel. |
29 |
|
|
*/ |
30 |
|
|
|
31 |
|
|
static enum cmd_retval cmd_wait_for_exec(struct cmd *, struct cmdq_item *); |
32 |
|
|
|
33 |
|
|
const struct cmd_entry cmd_wait_for_entry = { |
34 |
|
|
.name = "wait-for", |
35 |
|
|
.alias = "wait", |
36 |
|
|
|
37 |
|
|
.args = { "LSU", 1, 1 }, |
38 |
|
|
.usage = "[-L|-S|-U] channel", |
39 |
|
|
|
40 |
|
|
.flags = 0, |
41 |
|
|
.exec = cmd_wait_for_exec |
42 |
|
|
}; |
43 |
|
|
|
44 |
|
|
struct wait_item { |
45 |
|
|
struct cmdq_item *item; |
46 |
|
|
TAILQ_ENTRY(wait_item) entry; |
47 |
|
|
}; |
48 |
|
|
|
49 |
|
|
struct wait_channel { |
50 |
|
|
const char *name; |
51 |
|
|
int locked; |
52 |
|
|
int woken; |
53 |
|
|
|
54 |
|
|
TAILQ_HEAD(, wait_item) waiters; |
55 |
|
|
TAILQ_HEAD(, wait_item) lockers; |
56 |
|
|
|
57 |
|
|
RB_ENTRY(wait_channel) entry; |
58 |
|
|
}; |
59 |
|
|
RB_HEAD(wait_channels, wait_channel); |
60 |
|
|
static struct wait_channels wait_channels = RB_INITIALIZER(wait_channels); |
61 |
|
|
|
62 |
|
|
static int wait_channel_cmp(struct wait_channel *, struct wait_channel *); |
63 |
|
|
RB_GENERATE_STATIC(wait_channels, wait_channel, entry, wait_channel_cmp); |
64 |
|
|
|
65 |
|
|
static int |
66 |
|
|
wait_channel_cmp(struct wait_channel *wc1, struct wait_channel *wc2) |
67 |
|
|
{ |
68 |
|
|
return (strcmp(wc1->name, wc2->name)); |
69 |
|
|
} |
70 |
|
|
|
71 |
|
|
static enum cmd_retval cmd_wait_for_signal(struct cmdq_item *, const char *, |
72 |
|
|
struct wait_channel *); |
73 |
|
|
static enum cmd_retval cmd_wait_for_wait(struct cmdq_item *, const char *, |
74 |
|
|
struct wait_channel *); |
75 |
|
|
static enum cmd_retval cmd_wait_for_lock(struct cmdq_item *, const char *, |
76 |
|
|
struct wait_channel *); |
77 |
|
|
static enum cmd_retval cmd_wait_for_unlock(struct cmdq_item *, const char *, |
78 |
|
|
struct wait_channel *); |
79 |
|
|
|
80 |
|
|
static struct wait_channel *cmd_wait_for_add(const char *); |
81 |
|
|
static void cmd_wait_for_remove(struct wait_channel *); |
82 |
|
|
|
83 |
|
|
static struct wait_channel * |
84 |
|
|
cmd_wait_for_add(const char *name) |
85 |
|
|
{ |
86 |
|
|
struct wait_channel *wc; |
87 |
|
|
|
88 |
|
|
wc = xmalloc(sizeof *wc); |
89 |
|
|
wc->name = xstrdup(name); |
90 |
|
|
|
91 |
|
|
wc->locked = 0; |
92 |
|
|
wc->woken = 0; |
93 |
|
|
|
94 |
|
|
TAILQ_INIT(&wc->waiters); |
95 |
|
|
TAILQ_INIT(&wc->lockers); |
96 |
|
|
|
97 |
|
|
RB_INSERT(wait_channels, &wait_channels, wc); |
98 |
|
|
|
99 |
|
|
log_debug("add wait channel %s", wc->name); |
100 |
|
|
|
101 |
|
|
return (wc); |
102 |
|
|
} |
103 |
|
|
|
104 |
|
|
static void |
105 |
|
|
cmd_wait_for_remove(struct wait_channel *wc) |
106 |
|
|
{ |
107 |
|
|
if (wc->locked) |
108 |
|
|
return; |
109 |
|
|
if (!TAILQ_EMPTY(&wc->waiters) || !wc->woken) |
110 |
|
|
return; |
111 |
|
|
|
112 |
|
|
log_debug("remove wait channel %s", wc->name); |
113 |
|
|
|
114 |
|
|
RB_REMOVE(wait_channels, &wait_channels, wc); |
115 |
|
|
|
116 |
|
|
free((void *)wc->name); |
117 |
|
|
free(wc); |
118 |
|
|
} |
119 |
|
|
|
120 |
|
|
static enum cmd_retval |
121 |
|
|
cmd_wait_for_exec(struct cmd *self, struct cmdq_item *item) |
122 |
|
|
{ |
123 |
|
|
struct args *args = self->args; |
124 |
|
|
const char *name = args->argv[0]; |
125 |
|
|
struct wait_channel *wc, wc0; |
126 |
|
|
|
127 |
|
|
wc0.name = name; |
128 |
|
|
wc = RB_FIND(wait_channels, &wait_channels, &wc0); |
129 |
|
|
|
130 |
|
|
if (args_has(args, 'S')) |
131 |
|
|
return (cmd_wait_for_signal(item, name, wc)); |
132 |
|
|
if (args_has(args, 'L')) |
133 |
|
|
return (cmd_wait_for_lock(item, name, wc)); |
134 |
|
|
if (args_has(args, 'U')) |
135 |
|
|
return (cmd_wait_for_unlock(item, name, wc)); |
136 |
|
|
return (cmd_wait_for_wait(item, name, wc)); |
137 |
|
|
} |
138 |
|
|
|
139 |
|
|
static enum cmd_retval |
140 |
|
|
cmd_wait_for_signal(__unused struct cmdq_item *item, const char *name, |
141 |
|
|
struct wait_channel *wc) |
142 |
|
|
{ |
143 |
|
|
struct wait_item *wi, *wi1; |
144 |
|
|
|
145 |
|
|
if (wc == NULL) |
146 |
|
|
wc = cmd_wait_for_add(name); |
147 |
|
|
|
148 |
|
|
if (TAILQ_EMPTY(&wc->waiters) && !wc->woken) { |
149 |
|
|
log_debug("signal wait channel %s, no waiters", wc->name); |
150 |
|
|
wc->woken = 1; |
151 |
|
|
return (CMD_RETURN_NORMAL); |
152 |
|
|
} |
153 |
|
|
log_debug("signal wait channel %s, with waiters", wc->name); |
154 |
|
|
|
155 |
|
|
TAILQ_FOREACH_SAFE(wi, &wc->waiters, entry, wi1) { |
156 |
|
|
wi->item->flags &= ~CMDQ_WAITING; |
157 |
|
|
|
158 |
|
|
TAILQ_REMOVE(&wc->waiters, wi, entry); |
159 |
|
|
free(wi); |
160 |
|
|
} |
161 |
|
|
|
162 |
|
|
cmd_wait_for_remove(wc); |
163 |
|
|
return (CMD_RETURN_NORMAL); |
164 |
|
|
} |
165 |
|
|
|
166 |
|
|
static enum cmd_retval |
167 |
|
|
cmd_wait_for_wait(struct cmdq_item *item, const char *name, |
168 |
|
|
struct wait_channel *wc) |
169 |
|
|
{ |
170 |
|
|
struct client *c = item->client; |
171 |
|
|
struct wait_item *wi; |
172 |
|
|
|
173 |
|
|
if (c == NULL || c->session != NULL) { |
174 |
|
|
cmdq_error(item, "not able to wait"); |
175 |
|
|
return (CMD_RETURN_ERROR); |
176 |
|
|
} |
177 |
|
|
|
178 |
|
|
if (wc == NULL) |
179 |
|
|
wc = cmd_wait_for_add(name); |
180 |
|
|
|
181 |
|
|
if (wc->woken) { |
182 |
|
|
log_debug("wait channel %s already woken (%p)", wc->name, c); |
183 |
|
|
cmd_wait_for_remove(wc); |
184 |
|
|
return (CMD_RETURN_NORMAL); |
185 |
|
|
} |
186 |
|
|
log_debug("wait channel %s not woken (%p)", wc->name, c); |
187 |
|
|
|
188 |
|
|
wi = xcalloc(1, sizeof *wi); |
189 |
|
|
wi->item = item; |
190 |
|
|
TAILQ_INSERT_TAIL(&wc->waiters, wi, entry); |
191 |
|
|
|
192 |
|
|
return (CMD_RETURN_WAIT); |
193 |
|
|
} |
194 |
|
|
|
195 |
|
|
static enum cmd_retval |
196 |
|
|
cmd_wait_for_lock(struct cmdq_item *item, const char *name, |
197 |
|
|
struct wait_channel *wc) |
198 |
|
|
{ |
199 |
|
|
struct wait_item *wi; |
200 |
|
|
|
201 |
|
|
if (item->client == NULL || item->client->session != NULL) { |
202 |
|
|
cmdq_error(item, "not able to lock"); |
203 |
|
|
return (CMD_RETURN_ERROR); |
204 |
|
|
} |
205 |
|
|
|
206 |
|
|
if (wc == NULL) |
207 |
|
|
wc = cmd_wait_for_add(name); |
208 |
|
|
|
209 |
|
|
if (wc->locked) { |
210 |
|
|
wi = xcalloc(1, sizeof *wi); |
211 |
|
|
wi->item = item; |
212 |
|
|
TAILQ_INSERT_TAIL(&wc->lockers, wi, entry); |
213 |
|
|
return (CMD_RETURN_WAIT); |
214 |
|
|
} |
215 |
|
|
wc->locked = 1; |
216 |
|
|
|
217 |
|
|
return (CMD_RETURN_NORMAL); |
218 |
|
|
} |
219 |
|
|
|
220 |
|
|
static enum cmd_retval |
221 |
|
|
cmd_wait_for_unlock(struct cmdq_item *item, const char *name, |
222 |
|
|
struct wait_channel *wc) |
223 |
|
|
{ |
224 |
|
|
struct wait_item *wi; |
225 |
|
|
|
226 |
|
|
if (wc == NULL || !wc->locked) { |
227 |
|
|
cmdq_error(item, "channel %s not locked", name); |
228 |
|
|
return (CMD_RETURN_ERROR); |
229 |
|
|
} |
230 |
|
|
|
231 |
|
|
if ((wi = TAILQ_FIRST(&wc->lockers)) != NULL) { |
232 |
|
|
wi->item->flags &= ~CMDQ_WAITING; |
233 |
|
|
TAILQ_REMOVE(&wc->lockers, wi, entry); |
234 |
|
|
free(wi); |
235 |
|
|
} else { |
236 |
|
|
wc->locked = 0; |
237 |
|
|
cmd_wait_for_remove(wc); |
238 |
|
|
} |
239 |
|
|
|
240 |
|
|
return (CMD_RETURN_NORMAL); |
241 |
|
|
} |
242 |
|
|
|
243 |
|
|
void |
244 |
|
|
cmd_wait_for_flush(void) |
245 |
|
|
{ |
246 |
|
|
struct wait_channel *wc, *wc1; |
247 |
|
|
struct wait_item *wi, *wi1; |
248 |
|
|
|
249 |
|
|
RB_FOREACH_SAFE(wc, wait_channels, &wait_channels, wc1) { |
250 |
|
|
TAILQ_FOREACH_SAFE(wi, &wc->waiters, entry, wi1) { |
251 |
|
|
wi->item->flags &= ~CMDQ_WAITING; |
252 |
|
|
TAILQ_REMOVE(&wc->waiters, wi, entry); |
253 |
|
|
free(wi); |
254 |
|
|
} |
255 |
|
|
wc->woken = 1; |
256 |
|
|
TAILQ_FOREACH_SAFE(wi, &wc->lockers, entry, wi1) { |
257 |
|
|
wi->item->flags &= ~CMDQ_WAITING; |
258 |
|
|
TAILQ_REMOVE(&wc->lockers, wi, entry); |
259 |
|
|
free(wi); |
260 |
|
|
} |
261 |
|
|
wc->locked = 0; |
262 |
|
|
cmd_wait_for_remove(wc); |
263 |
|
|
} |
264 |
|
|
} |