Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' 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 "vnc.h"
30 #include "vnc-jobs.h"
31 #include "qemu/sockets.h"
32
33 /*
34 * Locking:
35 *
36 * There are three levels of locking:
37 * - jobs queue lock: for each operation on the queue (push, pop, isEmpty?)
38 * - VncDisplay global lock: mainly used for framebuffer updates to avoid
39 * screen corruption if the framebuffer is updated
40 * while the worker is doing something.
41 * - VncState::output lock: used to make sure the output buffer is not corrupted
42 * if two threads try to write on it at the same time
43 *
44 * While the VNC worker thread is working, the VncDisplay global lock is held
45 * to avoid screen corruption (this does not block vnc_refresh() because it
46 * uses trylock()) but the output lock is not held because the thread works on
47 * its own output buffer.
48 * When the encoding job is done, the worker thread will hold the output lock
49 * and copy its output buffer in vs->output.
50 */
51
52 struct VncJobQueue {
53 QemuCond cond;
54 QemuMutex mutex;
55 QemuThread thread;
56 Buffer buffer;
57 bool exit;
58 QTAILQ_HEAD(, VncJob) jobs;
59 };
60
61 typedef struct VncJobQueue VncJobQueue;
62
63 /*
64 * We use a single global queue, but most of the functions are
65 * already reentrant, so we can easily add more than one encoding thread
66 */
67 static VncJobQueue *queue;
68
69 static void vnc_lock_queue(VncJobQueue *queue)
70 {
71 qemu_mutex_lock(&queue->mutex);
72 }
73
74 static void vnc_unlock_queue(VncJobQueue *queue)
75 {
76 qemu_mutex_unlock(&queue->mutex);
77 }
78
79 VncJob *vnc_job_new(VncState *vs)
80 {
81 VncJob *job = g_malloc0(sizeof(VncJob));
82
83 job->vs = vs;
84 vnc_lock_queue(queue);
85 QLIST_INIT(&job->rectangles);
86 vnc_unlock_queue(queue);
87 return job;
88 }
89
90 int vnc_job_add_rect(VncJob *job, int x, int y, int w, int h)
91 {
92 VncRectEntry *entry = g_malloc0(sizeof(VncRectEntry));
93
94 entry->rect.x = x;
95 entry->rect.y = y;
96 entry->rect.w = w;
97 entry->rect.h = h;
98
99 vnc_lock_queue(queue);
100 QLIST_INSERT_HEAD(&job->rectangles, entry, next);
101 vnc_unlock_queue(queue);
102 return 1;
103 }
104
105 void vnc_job_push(VncJob *job)
106 {
107 vnc_lock_queue(queue);
108 if (queue->exit || QLIST_EMPTY(&job->rectangles)) {
109 g_free(job);
110 } else {
111 QTAILQ_INSERT_TAIL(&queue->jobs, job, next);
112 qemu_cond_broadcast(&queue->cond);
113 }
114 vnc_unlock_queue(queue);
115 }
116
117 static bool vnc_has_job_locked(VncState *vs)
118 {
119 VncJob *job;
120
121 QTAILQ_FOREACH(job, &queue->jobs, next) {
122 if (job->vs == vs || !vs) {
123 return true;
124 }
125 }
126 return false;
127 }
128
129 bool vnc_has_job(VncState *vs)
130 {
131 bool ret;
132
133 vnc_lock_queue(queue);
134 ret = vnc_has_job_locked(vs);
135 vnc_unlock_queue(queue);
136 return ret;
137 }
138
139 void vnc_jobs_clear(VncState *vs)
140 {
141 VncJob *job, *tmp;
142
143 vnc_lock_queue(queue);
144 QTAILQ_FOREACH_SAFE(job, &queue->jobs, next, tmp) {
145 if (job->vs == vs || !vs) {
146 QTAILQ_REMOVE(&queue->jobs, job, next);
147 }
148 }
149 vnc_unlock_queue(queue);
150 }
151
152 void vnc_jobs_join(VncState *vs)
153 {
154 vnc_lock_queue(queue);
155 while (vnc_has_job_locked(vs)) {
156 qemu_cond_wait(&queue->cond, &queue->mutex);
157 }
158 vnc_unlock_queue(queue);
159 vnc_jobs_consume_buffer(vs);
160 }
161
162 void vnc_jobs_consume_buffer(VncState *vs)
163 {
164 bool flush;
165
166 vnc_lock_output(vs);
167 if (vs->jobs_buffer.offset) {
168 vnc_write(vs, vs->jobs_buffer.buffer, vs->jobs_buffer.offset);
169 buffer_reset(&vs->jobs_buffer);
170 }
171 flush = vs->csock != -1 && vs->abort != true;
172 vnc_unlock_output(vs);
173
174 if (flush) {
175 vnc_flush(vs);
176 }
177 }
178
179 /*
180 * Copy data for local use
181 */
182 static void vnc_async_encoding_start(VncState *orig, VncState *local)
183 {
184 local->vnc_encoding = orig->vnc_encoding;
185 local->features = orig->features;
186 local->vd = orig->vd;
187 local->lossy_rect = orig->lossy_rect;
188 local->write_pixels = orig->write_pixels;
189 local->client_pf = orig->client_pf;
190 local->client_be = orig->client_be;
191 local->tight = orig->tight;
192 local->zlib = orig->zlib;
193 local->hextile = orig->hextile;
194 local->zrle = orig->zrle;
195 local->output = queue->buffer;
196 local->csock = -1; /* Don't do any network work on this thread */
197
198 buffer_reset(&local->output);
199 }
200
201 static void vnc_async_encoding_end(VncState *orig, VncState *local)
202 {
203 orig->tight = local->tight;
204 orig->zlib = local->zlib;
205 orig->hextile = local->hextile;
206 orig->zrle = local->zrle;
207 orig->lossy_rect = local->lossy_rect;
208
209 queue->buffer = local->output;
210 }
211
212 static int vnc_worker_thread_loop(VncJobQueue *queue)
213 {
214 VncJob *job;
215 VncRectEntry *entry, *tmp;
216 VncState vs;
217 int n_rectangles;
218 int saved_offset;
219
220 vnc_lock_queue(queue);
221 while (QTAILQ_EMPTY(&queue->jobs) && !queue->exit) {
222 qemu_cond_wait(&queue->cond, &queue->mutex);
223 }
224 /* Here job can only be NULL if queue->exit is true */
225 job = QTAILQ_FIRST(&queue->jobs);
226 vnc_unlock_queue(queue);
227
228 if (queue->exit) {
229 return -1;
230 }
231
232 vnc_lock_output(job->vs);
233 if (job->vs->csock == -1 || job->vs->abort == true) {
234 vnc_unlock_output(job->vs);
235 goto disconnected;
236 }
237 vnc_unlock_output(job->vs);
238
239 /* Make a local copy of vs and switch output buffers */
240 vnc_async_encoding_start(job->vs, &vs);
241
242 /* Start sending rectangles */
243 n_rectangles = 0;
244 vnc_write_u8(&vs, VNC_MSG_SERVER_FRAMEBUFFER_UPDATE);
245 vnc_write_u8(&vs, 0);
246 saved_offset = vs.output.offset;
247 vnc_write_u16(&vs, 0);
248
249 vnc_lock_display(job->vs->vd);
250 QLIST_FOREACH_SAFE(entry, &job->rectangles, next, tmp) {
251 int n;
252
253 if (job->vs->csock == -1) {
254 vnc_unlock_display(job->vs->vd);
255 /* Copy persistent encoding data */
256 vnc_async_encoding_end(job->vs, &vs);
257 goto disconnected;
258 }
259
260 n = vnc_send_framebuffer_update(&vs, entry->rect.x, entry->rect.y,
261 entry->rect.w, entry->rect.h);
262
263 if (n >= 0) {
264 n_rectangles += n;
265 }
266 g_free(entry);
267 }
268 vnc_unlock_display(job->vs->vd);
269
270 /* Put n_rectangles at the beginning of the message */
271 vs.output.buffer[saved_offset] = (n_rectangles >> 8) & 0xFF;
272 vs.output.buffer[saved_offset + 1] = n_rectangles & 0xFF;
273
274 vnc_lock_output(job->vs);
275 if (job->vs->csock != -1) {
276 buffer_reserve(&job->vs->jobs_buffer, vs.output.offset);
277 buffer_append(&job->vs->jobs_buffer, vs.output.buffer,
278 vs.output.offset);
279 /* Copy persistent encoding data */
280 vnc_async_encoding_end(job->vs, &vs);
281
282 qemu_bh_schedule(job->vs->bh);
283 } else {
284 /* Copy persistent encoding data */
285 vnc_async_encoding_end(job->vs, &vs);
286 }
287 vnc_unlock_output(job->vs);
288
289 disconnected:
290 vnc_lock_queue(queue);
291 QTAILQ_REMOVE(&queue->jobs, job, next);
292 vnc_unlock_queue(queue);
293 qemu_cond_broadcast(&queue->cond);
294 g_free(job);
295 return 0;
296 }
297
298 static VncJobQueue *vnc_queue_init(void)
299 {
300 VncJobQueue *queue = g_malloc0(sizeof(VncJobQueue));
301
302 qemu_cond_init(&queue->cond);
303 qemu_mutex_init(&queue->mutex);
304 QTAILQ_INIT(&queue->jobs);
305 return queue;
306 }
307
308 static void vnc_queue_clear(VncJobQueue *q)
309 {
310 qemu_cond_destroy(&queue->cond);
311 qemu_mutex_destroy(&queue->mutex);
312 buffer_free(&queue->buffer);
313 g_free(q);
314 queue = NULL; /* Unset global queue */
315 }
316
317 static void *vnc_worker_thread(void *arg)
318 {
319 VncJobQueue *queue = arg;
320
321 qemu_thread_get_self(&queue->thread);
322
323 while (!vnc_worker_thread_loop(queue)) ;
324 vnc_queue_clear(queue);
325 return NULL;
326 }
327
328 static bool vnc_worker_thread_running(void)
329 {
330 return queue; /* Check global queue */
331 }
332
333 void vnc_start_worker_thread(void)
334 {
335 VncJobQueue *q;
336
337 if (vnc_worker_thread_running())
338 return ;
339
340 q = vnc_queue_init();
341 qemu_thread_create(&q->thread, "vnc_worker", vnc_worker_thread, q,
342 QEMU_THREAD_DETACHED);
343 queue = q; /* Set global queue */
344 }
345
346 void vnc_stop_worker_thread(void)
347 {
348 if (!vnc_worker_thread_running())
349 return ;
350
351 /* Remove all jobs and wake up the thread */
352 vnc_lock_queue(queue);
353 queue->exit = true;
354 vnc_unlock_queue(queue);
355 vnc_jobs_clear(NULL);
356 qemu_cond_broadcast(&queue->cond);
357 }