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authoraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2009-03-20 15:59:24 +0000
committeraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2009-03-20 15:59:24 +0000
commitc522d0e2dee3774884a731691a702126901a1a88 (patch)
tree3a214688f7148c604774d5f04f8ec985c7b61d1f
parent23decc87cc5e52eb3021cf05b64347b884698b17 (diff)
vnc: throttle screen updates. (Gerd Hoffmann)
This patch makes the vnc server code skip screen refreshes in case there is data in the output buffer. This reduces the refresh rate to throttle the bandwidth needed in case the network link is saturated. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6862 c046a42c-6fe2-441c-8c8c-71466251a162
-rw-r--r--vnc.c11
-rw-r--r--vnc.h1
2 files changed, 11 insertions, 1 deletions
diff --git a/vnc.c b/vnc.c
index de9edea2d3..6d9321584b 100644
--- a/vnc.c
+++ b/vnc.c
@@ -657,6 +657,7 @@ static void send_framebuffer_update(VncState *vs, int x, int y, int w, int h)
static void vnc_copy(VncState *vs, int src_x, int src_y, int dst_x, int dst_y, int w, int h)
{
+ vs->force_update = 1;
vnc_update_client(vs);
vnc_write_u8(vs, 0); /* msg id */
@@ -710,6 +711,12 @@ static void vnc_update_client(void *opaque)
int saved_offset;
int has_dirty = 0;
+ if (vs->output.offset && !vs->audio_cap && !vs->force_update) {
+ /* kernel send buffers are full -> drop frames to throttle */
+ qemu_mod_timer(vs->timer, qemu_get_clock(rt_clock) + VNC_REFRESH_INTERVAL);
+ return;
+ }
+
vga_hw_update();
/*
@@ -745,7 +752,7 @@ static void vnc_update_client(void *opaque)
server_row += ds_get_linesize(vs->ds);
}
- if (!has_dirty && !vs->audio_cap) {
+ if (!has_dirty && !vs->audio_cap && !vs->force_update) {
qemu_mod_timer(vs->timer, qemu_get_clock(rt_clock) + VNC_REFRESH_INTERVAL);
return;
}
@@ -789,6 +796,7 @@ static void vnc_update_client(void *opaque)
vs->output.buffer[saved_offset] = (n_rectangles >> 8) & 0xFF;
vs->output.buffer[saved_offset + 1] = n_rectangles & 0xFF;
vnc_flush(vs);
+ vs->force_update = 0;
}
@@ -1407,6 +1415,7 @@ static void framebuffer_update_request(VncState *vs, int incremental,
int i;
vs->need_update = 1;
+ vs->force_update = 1;
if (!incremental) {
for (i = 0; i < h; i++) {
vnc_set_bits(vs->guest.dirty[y_position + i],
diff --git a/vnc.h b/vnc.h
index ce9aa49900..3ae95f3d74 100644
--- a/vnc.h
+++ b/vnc.h
@@ -121,6 +121,7 @@ struct VncState
VncDisplay *vd;
int need_update;
+ int force_update;
uint32_t features;
int absolute;
int last_x;