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
This commit is contained in:
aliguori 2009-03-20 15:59:24 +00:00
parent 23decc87cc
commit c522d0e2de
2 changed files with 11 additions and 1 deletions

11
vnc.c
View File

@ -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],

1
vnc.h
View File

@ -121,6 +121,7 @@ struct VncState
VncDisplay *vd;
int need_update;
int force_update;
uint32_t features;
int absolute;
int last_x;