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, 87 insertions, 0 deletions

diff --git a/ui/vnc-jobs.h b/ui/vnc-jobs.h
new file mode 100644
index 0000000000..b8dab8169f
--- /dev/null
+++ b/ui/vnc-jobs.h
@@ -0,0 +1,87 @@
+/*
+ * QEMU VNC display driver
+ *
+ * From libvncserver/rfb/rfbproto.h
+ * Copyright (C) 2005 Rohit Kumar, Johannes E. Schindelin
+ * Copyright (C) 2000-2002 Constantin Kaplinsky.  All Rights Reserved.
+ * Copyright (C) 2000 Tridia Corporation.  All Rights Reserved.
+ * Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.
+ *
+ *
+ * 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.
+ */
+
+#ifndef VNC_JOBS_H
+#define VNC_JOBS_H
+
+/* Jobs */
+VncJob *vnc_job_new(VncState *vs);
+int vnc_job_add_rect(VncJob *job, int x, int y, int w, int h);
+void vnc_job_push(VncJob *job);
+bool vnc_has_job(VncState *vs);
+void vnc_jobs_clear(VncState *vs);
+void vnc_jobs_join(VncState *vs);
+
+#ifdef CONFIG_VNC_THREAD
+
+void vnc_start_worker_thread(void);
+bool vnc_worker_thread_running(void);
+void vnc_stop_worker_thread(void);
+
+#endif /* CONFIG_VNC_THREAD */
+
+/* Locks */
+static inline int vnc_trylock_display(VncDisplay *vd)
+{
+#ifdef CONFIG_VNC_THREAD
+    return qemu_mutex_trylock(&vd->mutex);
+#else
+    return 0;
+#endif
+}
+
+static inline void vnc_lock_display(VncDisplay *vd)
+{
+#ifdef CONFIG_VNC_THREAD
+    qemu_mutex_lock(&vd->mutex);
+#endif
+}
+
+static inline void vnc_unlock_display(VncDisplay *vd)
+{
+#ifdef CONFIG_VNC_THREAD
+    qemu_mutex_unlock(&vd->mutex);
+#endif
+}
+
+static inline void vnc_lock_output(VncState *vs)
+{
+#ifdef CONFIG_VNC_THREAD
+    qemu_mutex_lock(&vs->output_mutex);
+#endif
+}
+
+static inline void vnc_unlock_output(VncState *vs)
+{
+#ifdef CONFIG_VNC_THREAD
+    qemu_mutex_unlock(&vs->output_mutex);
+#endif
+}
+
+#endif /* VNC_JOBS_H */