RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 12:28:12 +00:00
Code Issues Activity Actions

WindowServer: Coalesce flushing buffers into one ioctl() call

Browse source 
We regularily need to flush many rectangles, so instead of making many
expensive ioctl() calls to the framebuffer driver, collect the
rectangles and only make one call. And if we have too many rectangles
then it may be cheaper to just update the entire region, in which case
we simply convert them all into a union and just flush that one
rectangle instead.
This commit is contained in:
Tom 2021-06-26 11:04:01 -06:00 • committed by Andreas Kling
parent 56cd0f929e
commit 38af4c29e6
7 changed files with 123 additions and 31 deletions
Download patch file Download diff file Expand all files Collapse all files

81
Userland/Services/WindowServer/Screen.cpp
View file

@ -25,6 +25,11 @@ Gfx::IntRect Screen::s_bounding_screens_rect {};
ScreenLayout Screen::s_layout;
Vector<int, default_scale_factors_in_use_count> Screen::s_scale_factors_in_use;
struct ScreenFBData {
Vector<FBRect, 32> pending_flush_rects;
bool too_many_pending_flush_rects { false };
};
ScreenInput& ScreenInput::the()
{
static ScreenInput s_the;
@ -105,6 +110,7 @@ void Screen::update_scale_factors_in_use()
Screen::Screen(ScreenLayout::Screen& screen_info)
: m_virtual_rect(screen_info.location, { screen_info.resolution.width() / screen_info.scale_factor, screen_info.resolution.height() / screen_info.scale_factor })
, m_framebuffer_data(adopt_own(*new ScreenFBData()))
, m_info(screen_info)
{
open_device();
@ -130,6 +136,7 @@ bool Screen::open_device()
}
m_can_set_buffer = (fb_set_buffer(m_framebuffer_fd, 0) == 0);
m_can_device_flush_buffers = true; // If the device can't do it we revert to false
set_resolution(true);
return true;
}
@ -316,14 +323,72 @@ void ScreenInput::on_receive_keyboard_data(::KeyEvent kernel_event)
Core::EventLoop::current().post_event(WindowManager::the(), move(message));
}
void Screen::flush_display(const Gfx::IntRect& flush_region)
void Screen::queue_flush_display_rect(Gfx::IntRect const& flush_region)
{
FBRect rect {
.x = (static_cast<unsigned>(flush_region.x()) - m_virtual_rect.left()) * scale_factor(),
.y = (static_cast<unsigned>(flush_region.y()) - m_virtual_rect.top()) * scale_factor(),
.width = static_cast<unsigned>(flush_region.width()) * scale_factor(),
.height = static_cast<unsigned>(flush_region.height() * scale_factor())
};
fb_flush_buffer(m_framebuffer_fd, &rect);
// NOTE: we don't scale until in Screen::flush_display so that when
// there are too many rectangles that we end up throwing away, we didn't
// waste accounting for scale factor!
auto& fb_data = *m_framebuffer_data;
if (fb_data.too_many_pending_flush_rects) {
// We already have too many, just make sure we extend it if needed
VERIFY(!fb_data.pending_flush_rects.is_empty());
if (fb_data.pending_flush_rects.size() == 1) {
auto& union_rect = fb_data.pending_flush_rects[0];
auto new_union = flush_region.united(Gfx::IntRect((int)union_rect.x, (int)union_rect.y, (int)union_rect.width, (int)union_rect.height));
union_rect.x = new_union.left();
union_rect.y = new_union.top();
union_rect.width = new_union.width();
union_rect.height = new_union.height();
} else {
// Convert all the rectangles into one union
auto new_union = flush_region;
for (auto& flush_rect : fb_data.pending_flush_rects)
new_union = new_union.united(Gfx::IntRect((int)flush_rect.x, (int)flush_rect.y, (int)flush_rect.width, (int)flush_rect.height));
fb_data.pending_flush_rects.resize(1, true);
auto& union_rect = fb_data.pending_flush_rects[0];
union_rect.x = new_union.left();
union_rect.y = new_union.top();
union_rect.width = new_union.width();
union_rect.height = new_union.height();
}
return;
}
VERIFY(fb_data.pending_flush_rects.size() < fb_data.pending_flush_rects.capacity());
fb_data.pending_flush_rects.append({ (unsigned)flush_region.left(),
(unsigned)flush_region.top(),
(unsigned)flush_region.width(),
(unsigned)flush_region.height() });
if (fb_data.pending_flush_rects.size() == fb_data.pending_flush_rects.capacity()) {
// If we get one more rectangle then we need to convert it to a single union rectangle
fb_data.too_many_pending_flush_rects = true;
}
}
void Screen::flush_display()
{
VERIFY(m_can_device_flush_buffers);
auto& fb_data = *m_framebuffer_data;
if (fb_data.pending_flush_rects.is_empty())
return;
// Now that we have a final set of rects, apply the scale factor
auto scale_factor = this->scale_factor();
for (auto& flush_rect : fb_data.pending_flush_rects) {
flush_rect.x *= scale_factor;
flush_rect.y *= scale_factor;
flush_rect.width *= scale_factor;
flush_rect.height *= scale_factor;
}
if (fb_flush_buffers(m_framebuffer_fd, fb_data.pending_flush_rects.data(), (unsigned)fb_data.pending_flush_rects.size()) < 0) {
int err = errno;
if (err == ENOTSUP)
m_can_device_flush_buffers = false;
else
dbgln("Screen #{}: Error ({}) flushing display: {}", index(), err, strerror(err));
}
fb_data.too_many_pending_flush_rects = false;
fb_data.pending_flush_rects.clear_with_capacity();
}
}