--- /dev/null
+/*
+ * QEMU VNC display driver
+ *
+ * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
+ * Copyright (C) 2006 Fabrice Bellard
+ * Copyright (C) 2009 Red Hat, Inc
+ * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+
+#include "vnc.h"
+#include "vnc-jobs.h"
+#include "qemu/sockets.h"
+#include "block/aio.h"
+
+/*
+ * Locking:
+ *
+ * There are three levels of locking:
+ * - jobs queue lock: for each operation on the queue (push, pop, isEmpty?)
+ * - VncDisplay global lock: mainly used for framebuffer updates to avoid
+ * screen corruption if the framebuffer is updated
+ * while the worker is doing something.
+ * - VncState::output lock: used to make sure the output buffer is not corrupted
+ * if two threads try to write on it at the same time
+ *
+ * While the VNC worker thread is working, the VncDisplay global lock is held
+ * to avoid screen corruption (this does not block vnc_refresh() because it
+ * uses trylock()) but the output lock is not held because the thread works on
+ * its own output buffer.
+ * When the encoding job is done, the worker thread will hold the output lock
+ * and copy its output buffer in vs->output.
+ */
+
+struct VncJobQueue {
+ QemuCond cond;
+ QemuMutex mutex;
+ QemuThread thread;
+ Buffer buffer;
+ bool exit;
+ QTAILQ_HEAD(, VncJob) jobs;
+};
+
+typedef struct VncJobQueue VncJobQueue;
+
+/*
+ * We use a single global queue, but most of the functions are
+ * already reentrant, so we can easily add more than one encoding thread
+ */
+static VncJobQueue *queue;
+
+static void vnc_lock_queue(VncJobQueue *queue)
+{
+ qemu_mutex_lock(&queue->mutex);
+}
+
+static void vnc_unlock_queue(VncJobQueue *queue)
+{
+ qemu_mutex_unlock(&queue->mutex);
+}
+
+VncJob *vnc_job_new(VncState *vs)
+{
+ VncJob *job = g_malloc0(sizeof(VncJob));
+
+ job->vs = vs;
+ vnc_lock_queue(queue);
+ QLIST_INIT(&job->rectangles);
+ vnc_unlock_queue(queue);
+ return job;
+}
+
+int vnc_job_add_rect(VncJob *job, int x, int y, int w, int h)
+{
+ VncRectEntry *entry = g_malloc0(sizeof(VncRectEntry));
+
+ entry->rect.x = x;
+ entry->rect.y = y;
+ entry->rect.w = w;
+ entry->rect.h = h;
+
+ vnc_lock_queue(queue);
+ QLIST_INSERT_HEAD(&job->rectangles, entry, next);
+ vnc_unlock_queue(queue);
+ return 1;
+}
+
+void vnc_job_push(VncJob *job)
+{
+ vnc_lock_queue(queue);
+ if (queue->exit || QLIST_EMPTY(&job->rectangles)) {
+ g_free(job);
+ } else {
+ QTAILQ_INSERT_TAIL(&queue->jobs, job, next);
+ qemu_cond_broadcast(&queue->cond);
+ }
+ vnc_unlock_queue(queue);
+}
+
+static bool vnc_has_job_locked(VncState *vs)
+{
+ VncJob *job;
+
+ QTAILQ_FOREACH(job, &queue->jobs, next) {
+ if (job->vs == vs || !vs) {
+ return true;
+ }
+ }
+ return false;
+}
+
+bool vnc_has_job(VncState *vs)
+{
+ bool ret;
+
+ vnc_lock_queue(queue);
+ ret = vnc_has_job_locked(vs);
+ vnc_unlock_queue(queue);
+ return ret;
+}
+
+void vnc_jobs_clear(VncState *vs)
+{
+ VncJob *job, *tmp;
+
+ vnc_lock_queue(queue);
+ QTAILQ_FOREACH_SAFE(job, &queue->jobs, next, tmp) {
+ if (job->vs == vs || !vs) {
+ QTAILQ_REMOVE(&queue->jobs, job, next);
+ }
+ }
+ vnc_unlock_queue(queue);
+}
+
+void vnc_jobs_join(VncState *vs)
+{
+ vnc_lock_queue(queue);
+ while (vnc_has_job_locked(vs)) {
+ qemu_cond_wait(&queue->cond, &queue->mutex);
+ }
+ vnc_unlock_queue(queue);
+ vnc_jobs_consume_buffer(vs);
+}
+
+void vnc_jobs_consume_buffer(VncState *vs)
+{
+ bool flush;
+
+ vnc_lock_output(vs);
+ if (vs->jobs_buffer.offset) {
+ vnc_write(vs, vs->jobs_buffer.buffer, vs->jobs_buffer.offset);
+ buffer_reset(&vs->jobs_buffer);
+ }
+ flush = vs->csock != -1 && vs->abort != true;
+ vnc_unlock_output(vs);
+
+ if (flush) {
+ vnc_flush(vs);
+ }
+}
+
+/*
+ * Copy data for local use
+ */
+static void vnc_async_encoding_start(VncState *orig, VncState *local)
+{
+ local->vnc_encoding = orig->vnc_encoding;
+ local->features = orig->features;
+ local->vd = orig->vd;
+ local->lossy_rect = orig->lossy_rect;
+ local->write_pixels = orig->write_pixels;
+ local->client_pf = orig->client_pf;
+ local->client_be = orig->client_be;
+ local->tight = orig->tight;
+ local->zlib = orig->zlib;
+ local->hextile = orig->hextile;
+ local->zrle = orig->zrle;
+ local->output = queue->buffer;
+ local->csock = -1; /* Don't do any network work on this thread */
+
+ buffer_reset(&local->output);
+}
+
+static void vnc_async_encoding_end(VncState *orig, VncState *local)
+{
+ orig->tight = local->tight;
+ orig->zlib = local->zlib;
+ orig->hextile = local->hextile;
+ orig->zrle = local->zrle;
+ orig->lossy_rect = local->lossy_rect;
+
+ queue->buffer = local->output;
+}
+
+static int vnc_worker_thread_loop(VncJobQueue *queue)
+{
+ VncJob *job;
+ VncRectEntry *entry, *tmp;
+ VncState vs;
+ int n_rectangles;
+ int saved_offset;
+
+ vnc_lock_queue(queue);
+ while (QTAILQ_EMPTY(&queue->jobs) && !queue->exit) {
+ qemu_cond_wait(&queue->cond, &queue->mutex);
+ }
+ /* Here job can only be NULL if queue->exit is true */
+ job = QTAILQ_FIRST(&queue->jobs);
+ vnc_unlock_queue(queue);
+
+ if (queue->exit) {
+ return -1;
+ }
+
+ vnc_lock_output(job->vs);
+ if (job->vs->csock == -1 || job->vs->abort == true) {
+ vnc_unlock_output(job->vs);
+ goto disconnected;
+ }
+ vnc_unlock_output(job->vs);
+
+ /* Make a local copy of vs and switch output buffers */
+ vnc_async_encoding_start(job->vs, &vs);
+
+ /* Start sending rectangles */
+ n_rectangles = 0;
+ vnc_write_u8(&vs, VNC_MSG_SERVER_FRAMEBUFFER_UPDATE);
+ vnc_write_u8(&vs, 0);
+ saved_offset = vs.output.offset;
+ vnc_write_u16(&vs, 0);
+
+ vnc_lock_display(job->vs->vd);
+ QLIST_FOREACH_SAFE(entry, &job->rectangles, next, tmp) {
+ int n;
+
+ if (job->vs->csock == -1) {
+ vnc_unlock_display(job->vs->vd);
+ /* Copy persistent encoding data */
+ vnc_async_encoding_end(job->vs, &vs);
+ goto disconnected;
+ }
+
+ n = vnc_send_framebuffer_update(&vs, entry->rect.x, entry->rect.y,
+ entry->rect.w, entry->rect.h);
+
+ if (n >= 0) {
+ n_rectangles += n;
+ }
+ g_free(entry);
+ }
+ vnc_unlock_display(job->vs->vd);
+
+ /* Put n_rectangles at the beginning of the message */
+ vs.output.buffer[saved_offset] = (n_rectangles >> 8) & 0xFF;
+ vs.output.buffer[saved_offset + 1] = n_rectangles & 0xFF;
+
+ vnc_lock_output(job->vs);
+ if (job->vs->csock != -1) {
+ buffer_reserve(&job->vs->jobs_buffer, vs.output.offset);
+ buffer_append(&job->vs->jobs_buffer, vs.output.buffer,
+ vs.output.offset);
+ /* Copy persistent encoding data */
+ vnc_async_encoding_end(job->vs, &vs);
+
+ qemu_bh_schedule(job->vs->bh);
+ } else {
+ /* Copy persistent encoding data */
+ vnc_async_encoding_end(job->vs, &vs);
+ }
+ vnc_unlock_output(job->vs);
+
+disconnected:
+ vnc_lock_queue(queue);
+ QTAILQ_REMOVE(&queue->jobs, job, next);
+ vnc_unlock_queue(queue);
+ qemu_cond_broadcast(&queue->cond);
+ g_free(job);
+ return 0;
+}
+
+static VncJobQueue *vnc_queue_init(void)
+{
+ VncJobQueue *queue = g_malloc0(sizeof(VncJobQueue));
+
+ qemu_cond_init(&queue->cond);
+ qemu_mutex_init(&queue->mutex);
+ QTAILQ_INIT(&queue->jobs);
+ return queue;
+}
+
+static void vnc_queue_clear(VncJobQueue *q)
+{
+ qemu_cond_destroy(&queue->cond);
+ qemu_mutex_destroy(&queue->mutex);
+ buffer_free(&queue->buffer);
+ g_free(q);
+ queue = NULL; /* Unset global queue */
+}
+
+static void *vnc_worker_thread(void *arg)
+{
+ VncJobQueue *queue = arg;
+
+ qemu_thread_get_self(&queue->thread);
+
+ while (!vnc_worker_thread_loop(queue)) ;
+ vnc_queue_clear(queue);
+ return NULL;
+}
+
+static bool vnc_worker_thread_running(void)
+{
+ return queue; /* Check global queue */
+}
+
+void vnc_start_worker_thread(void)
+{
+ VncJobQueue *q;
+
+ if (vnc_worker_thread_running())
+ return ;
+
+ q = vnc_queue_init();
+ qemu_thread_create(&q->thread, "vnc_worker", vnc_worker_thread, q,
+ QEMU_THREAD_DETACHED);
+ queue = q; /* Set global queue */
+}
Code Review / kvmfornfv.git / blobdiff