Merge remote-tracking branch 'remotes/kraxel/tags/pull-vga-20170103-1' into staging
[qemu.git] / ui / vnc-jobs.c
1 /*
2 * QEMU VNC display driver
3 *
4 * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
5 * Copyright (C) 2006 Fabrice Bellard
6 * Copyright (C) 2009 Red Hat, Inc
7 * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a copy
10 * of this software and associated documentation files (the "Software"), to deal
11 * in the Software without restriction, including without limitation the rights
12 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13 * copies of the Software, and to permit persons to whom the Software is
14 * furnished to do so, subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25 * THE SOFTWARE.
26 */
27
28
29 #include "qemu/osdep.h"
30 #include "vnc.h"
31 #include "vnc-jobs.h"
32 #include "qemu/sockets.h"
33 #include "qemu/main-loop.h"
34 #include "block/aio.h"
35
36 /*
37 * Locking:
38 *
39 * There are three levels of locking:
40 * - jobs queue lock: for each operation on the queue (push, pop, isEmpty?)
41 * - VncDisplay global lock: mainly used for framebuffer updates to avoid
42 * screen corruption if the framebuffer is updated
43 * while the worker is doing something.
44 * - VncState::output lock: used to make sure the output buffer is not corrupted
45 * if two threads try to write on it at the same time
46 *
47 * While the VNC worker thread is working, the VncDisplay global lock is held
48 * to avoid screen corruption (this does not block vnc_refresh() because it
49 * uses trylock()) but the output lock is not held because the thread works on
50 * its own output buffer.
51 * When the encoding job is done, the worker thread will hold the output lock
52 * and copy its output buffer in vs->output.
53 */
54
55 struct VncJobQueue {
56 QemuCond cond;
57 QemuMutex mutex;
58 QemuThread thread;
59 bool exit;
60 QTAILQ_HEAD(, VncJob) jobs;
61 };
62
63 typedef struct VncJobQueue VncJobQueue;
64
65 /*
66 * We use a single global queue, but most of the functions are
67 * already reentrant, so we can easily add more than one encoding thread
68 */
69 static VncJobQueue *queue;
70
71 static void vnc_lock_queue(VncJobQueue *queue)
72 {
73 qemu_mutex_lock(&queue->mutex);
74 }
75
76 static void vnc_unlock_queue(VncJobQueue *queue)
77 {
78 qemu_mutex_unlock(&queue->mutex);
79 }
80
81 VncJob *vnc_job_new(VncState *vs)
82 {
83 VncJob *job = g_new0(VncJob, 1);
84
85 job->vs = vs;
86 vnc_lock_queue(queue);
87 QLIST_INIT(&job->rectangles);
88 vnc_unlock_queue(queue);
89 return job;
90 }
91
92 int vnc_job_add_rect(VncJob *job, int x, int y, int w, int h)
93 {
94 VncRectEntry *entry = g_new0(VncRectEntry, 1);
95
96 entry->rect.x = x;
97 entry->rect.y = y;
98 entry->rect.w = w;
99 entry->rect.h = h;
100
101 vnc_lock_queue(queue);
102 QLIST_INSERT_HEAD(&job->rectangles, entry, next);
103 vnc_unlock_queue(queue);
104 return 1;
105 }
106
107 void vnc_job_push(VncJob *job)
108 {
109 vnc_lock_queue(queue);
110 if (queue->exit || QLIST_EMPTY(&job->rectangles)) {
111 g_free(job);
112 } else {
113 QTAILQ_INSERT_TAIL(&queue->jobs, job, next);
114 qemu_cond_broadcast(&queue->cond);
115 }
116 vnc_unlock_queue(queue);
117 }
118
119 static bool vnc_has_job_locked(VncState *vs)
120 {
121 VncJob *job;
122
123 QTAILQ_FOREACH(job, &queue->jobs, next) {
124 if (job->vs == vs || !vs) {
125 return true;
126 }
127 }
128 return false;
129 }
130
131 bool vnc_has_job(VncState *vs)
132 {
133 bool ret;
134
135 vnc_lock_queue(queue);
136 ret = vnc_has_job_locked(vs);
137 vnc_unlock_queue(queue);
138 return ret;
139 }
140
141 void vnc_jobs_clear(VncState *vs)
142 {
143 VncJob *job, *tmp;
144
145 vnc_lock_queue(queue);
146 QTAILQ_FOREACH_SAFE(job, &queue->jobs, next, tmp) {
147 if (job->vs == vs || !vs) {
148 QTAILQ_REMOVE(&queue->jobs, job, next);
149 }
150 }
151 vnc_unlock_queue(queue);
152 }
153
154 void vnc_jobs_join(VncState *vs)
155 {
156 vnc_lock_queue(queue);
157 while (vnc_has_job_locked(vs)) {
158 qemu_cond_wait(&queue->cond, &queue->mutex);
159 }
160 vnc_unlock_queue(queue);
161 vnc_jobs_consume_buffer(vs);
162 }
163
164 void vnc_jobs_consume_buffer(VncState *vs)
165 {
166 bool flush;
167
168 vnc_lock_output(vs);
169 if (vs->jobs_buffer.offset) {
170 if (vs->ioc != NULL && buffer_empty(&vs->output)) {
171 if (vs->ioc_tag) {
172 g_source_remove(vs->ioc_tag);
173 }
174 vs->ioc_tag = qio_channel_add_watch(
175 vs->ioc, G_IO_IN | G_IO_OUT, vnc_client_io, vs, NULL);
176 }
177 buffer_move(&vs->output, &vs->jobs_buffer);
178 }
179 flush = vs->ioc != NULL && vs->abort != true;
180 vnc_unlock_output(vs);
181
182 if (flush) {
183 vnc_flush(vs);
184 }
185 }
186
187 /*
188 * Copy data for local use
189 */
190 static void vnc_async_encoding_start(VncState *orig, VncState *local)
191 {
192 buffer_init(&local->output, "vnc-worker-output");
193 local->sioc = NULL; /* Don't do any network work on this thread */
194 local->ioc = NULL; /* Don't do any network work on this thread */
195
196 local->vnc_encoding = orig->vnc_encoding;
197 local->features = orig->features;
198 local->vd = orig->vd;
199 local->lossy_rect = orig->lossy_rect;
200 local->write_pixels = orig->write_pixels;
201 local->client_pf = orig->client_pf;
202 local->client_be = orig->client_be;
203 local->tight = orig->tight;
204 local->zlib = orig->zlib;
205 local->hextile = orig->hextile;
206 local->zrle = orig->zrle;
207 }
208
209 static void vnc_async_encoding_end(VncState *orig, VncState *local)
210 {
211 orig->tight = local->tight;
212 orig->zlib = local->zlib;
213 orig->hextile = local->hextile;
214 orig->zrle = local->zrle;
215 orig->lossy_rect = local->lossy_rect;
216 }
217
218 static int vnc_worker_thread_loop(VncJobQueue *queue)
219 {
220 VncJob *job;
221 VncRectEntry *entry, *tmp;
222 VncState vs = {};
223 int n_rectangles;
224 int saved_offset;
225
226 vnc_lock_queue(queue);
227 while (QTAILQ_EMPTY(&queue->jobs) && !queue->exit) {
228 qemu_cond_wait(&queue->cond, &queue->mutex);
229 }
230 /* Here job can only be NULL if queue->exit is true */
231 job = QTAILQ_FIRST(&queue->jobs);
232 vnc_unlock_queue(queue);
233
234 if (queue->exit) {
235 return -1;
236 }
237
238 vnc_lock_output(job->vs);
239 if (job->vs->ioc == NULL || job->vs->abort == true) {
240 vnc_unlock_output(job->vs);
241 goto disconnected;
242 }
243 if (buffer_empty(&job->vs->output)) {
244 /*
245 * Looks like a NOP as it obviously moves no data. But it
246 * moves the empty buffer, so we don't have to malloc a new
247 * one for vs.output
248 */
249 buffer_move_empty(&vs.output, &job->vs->output);
250 }
251 vnc_unlock_output(job->vs);
252
253 /* Make a local copy of vs and switch output buffers */
254 vnc_async_encoding_start(job->vs, &vs);
255
256 /* Start sending rectangles */
257 n_rectangles = 0;
258 vnc_write_u8(&vs, VNC_MSG_SERVER_FRAMEBUFFER_UPDATE);
259 vnc_write_u8(&vs, 0);
260 saved_offset = vs.output.offset;
261 vnc_write_u16(&vs, 0);
262
263 vnc_lock_display(job->vs->vd);
264 QLIST_FOREACH_SAFE(entry, &job->rectangles, next, tmp) {
265 int n;
266
267 if (job->vs->ioc == NULL) {
268 vnc_unlock_display(job->vs->vd);
269 /* Copy persistent encoding data */
270 vnc_async_encoding_end(job->vs, &vs);
271 goto disconnected;
272 }
273
274 n = vnc_send_framebuffer_update(&vs, entry->rect.x, entry->rect.y,
275 entry->rect.w, entry->rect.h);
276
277 if (n >= 0) {
278 n_rectangles += n;
279 }
280 g_free(entry);
281 }
282 vnc_unlock_display(job->vs->vd);
283
284 /* Put n_rectangles at the beginning of the message */
285 vs.output.buffer[saved_offset] = (n_rectangles >> 8) & 0xFF;
286 vs.output.buffer[saved_offset + 1] = n_rectangles & 0xFF;
287
288 vnc_lock_output(job->vs);
289 if (job->vs->ioc != NULL) {
290 buffer_move(&job->vs->jobs_buffer, &vs.output);
291 /* Copy persistent encoding data */
292 vnc_async_encoding_end(job->vs, &vs);
293
294 qemu_bh_schedule(job->vs->bh);
295 } else {
296 buffer_reset(&vs.output);
297 /* Copy persistent encoding data */
298 vnc_async_encoding_end(job->vs, &vs);
299 }
300 vnc_unlock_output(job->vs);
301
302 disconnected:
303 vnc_lock_queue(queue);
304 QTAILQ_REMOVE(&queue->jobs, job, next);
305 vnc_unlock_queue(queue);
306 qemu_cond_broadcast(&queue->cond);
307 g_free(job);
308 return 0;
309 }
310
311 static VncJobQueue *vnc_queue_init(void)
312 {
313 VncJobQueue *queue = g_new0(VncJobQueue, 1);
314
315 qemu_cond_init(&queue->cond);
316 qemu_mutex_init(&queue->mutex);
317 QTAILQ_INIT(&queue->jobs);
318 return queue;
319 }
320
321 static void vnc_queue_clear(VncJobQueue *q)
322 {
323 qemu_cond_destroy(&queue->cond);
324 qemu_mutex_destroy(&queue->mutex);
325 g_free(q);
326 queue = NULL; /* Unset global queue */
327 }
328
329 static void *vnc_worker_thread(void *arg)
330 {
331 VncJobQueue *queue = arg;
332
333 qemu_thread_get_self(&queue->thread);
334
335 while (!vnc_worker_thread_loop(queue)) ;
336 vnc_queue_clear(queue);
337 return NULL;
338 }
339
340 static bool vnc_worker_thread_running(void)
341 {
342 return queue; /* Check global queue */
343 }
344
345 void vnc_start_worker_thread(void)
346 {
347 VncJobQueue *q;
348
349 if (vnc_worker_thread_running())
350 return ;
351
352 q = vnc_queue_init();
353 qemu_thread_create(&q->thread, "vnc_worker", vnc_worker_thread, q,
354 QEMU_THREAD_DETACHED);
355 queue = q; /* Set global queue */
356 }