vnc: threaded VNC server

Implement a threaded VNC server using the producer-consumer model.
The main thread will push encoding jobs (a list a rectangles to update)
in a queue, and the VNC worker thread will consume that queue and send
framebuffer updates to the output buffer.

The threaded VNC server can be enabled with ./configure --enable-vnc-thread.

If you don't want it, just use ./configure --disable-vnc-thread and a syncrhonous
queue of job will be used (which as exactly the same behavior as the old queue).
If you disable the VNC thread, all thread related code will not be built and there will
be no overhead.

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 73 insertions, 0 deletions

diff --git a/ui/vnc-jobs-sync.c b/ui/vnc-jobs-sync.c
new file mode 100644
index 0000000000..49b77afcc9
--- /dev/null
+++ b/ui/vnc-jobs-sync.c
@@ -0,0 +1,73 @@
+/*
+ * 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"
+
+void vnc_jobs_clear(VncState *vs)
+{
+}
+
+void vnc_jobs_join(VncState *vs)
+{
+}
+
+VncJob *vnc_job_new(VncState *vs)
+{
+    vs->job.vs = vs;
+    vs->job.rectangles = 0;
+
+    vnc_write_u8(vs, VNC_MSG_SERVER_FRAMEBUFFER_UPDATE);
+    vnc_write_u8(vs, 0);
+    vs->job.saved_offset = vs->output.offset;
+    vnc_write_u16(vs, 0);
+    return &vs->job;
+}
+
+void vnc_job_push(VncJob *job)
+{
+    VncState *vs = job->vs;
+
+    vs->output.buffer[job->saved_offset] = (job->rectangles >> 8) & 0xFF;
+    vs->output.buffer[job->saved_offset + 1] = job->rectangles & 0xFF;
+    vnc_flush(job->vs);
+}
+
+int vnc_job_add_rect(VncJob *job, int x, int y, int w, int h)
+{
+    int n;
+
+    n = vnc_send_framebuffer_update(job->vs, x, y, w, h);
+    if (n >= 0)
+        job->rectangles += n;
+    return n;
+}
+
+bool vnc_has_job(VncState *vs)
+{
+    return false;
+}