Am 02.03.2011 23:01, schrieb Stefan Weil:
Am 02.03.2011 19:47, schrieb Peter Maydell:
On 2 March 2011 18:36, Stefan Weil <w...@mail.berlios.de> wrote:
No. I dont't think that the third parameter of bitmap_clear is
ok like that. See my patch for the correct value.
Wen's patch:
+ const size_t width = ds_get_width(vd->ds) / 16;
[...]
- bitmap_set(width_mask, 0, (ds_get_width(vd->ds) / 16));
- bitmap_clear(width_mask, (ds_get_width(vd->ds) / 16),
- VNC_DIRTY_WORDS * BITS_PER_LONG);
+ bitmap_set(width_mask, 0, width);
+ bitmap_clear(width_mask, width, VNC_DIRTY_WORDS * BITS_PER_LONG
- width);
Your patch:
bitmap_clear(width_mask, (ds_get_width(vd->ds) / 16),
- VNC_DIRTY_WORDS * BITS_PER_LONG);
+ (VNC_MAX_WIDTH - ds_get_width(vd->ds)) / 16);
Since ui/vnc.h has:
#define VNC_DIRTY_WORDS (VNC_MAX_WIDTH / (16 * BITS_PER_LONG))
the third parameter to bitmap_clear is the same value in
both cases, isn't it? Or is this a rounding bug?
-- PMM
Because of rounding effects, both values can be different.
The part missing in my patch is correct handling of another
rounding effect:
VNC_DIRTY_WORDS is exact for 32 bit long values (and the
"old" code which used uint32_t until some weeks ago), where
VNC_DIRTY_WORDS = 2560/16/32 = 5.
For 64 bit values, VNC_DIRTY_WORDS = 2560/16/64 = 2 (rounded)!
Stefan W.
Is bitmap_clear() really needed here? Meanwhile I think it is not,
so this might be a new patch variant...
