[webkit-changes] [WebKit/WebKit] 90e92d: Cherry-pick 261124 at main (06b9ec1834d2). https://bu...

[Žan Doberšek]

  Branch: refs/heads/webkitglib/2.40
  Home:   https://github.com/WebKit/WebKit
  Commit: 90e92d2420f19938b3f5299080f9ded2da6fde6f
      https://github.com/WebKit/WebKit/commit/90e92d2420f19938b3f5299080f9ded2da6fde6f
  Author: Žan Doberšek <zdobersek at igalia.com>
  Date:   2023-03-03 (Fri, 03 Mar 2023)

  Changed paths:
    M Source/WebCore/page/scrolling/nicosia/ScrollingTreeNicosia.cpp
    M Source/WebCore/page/scrolling/nicosia/ScrollingTreeNicosia.h
    M Source/WebKit/Shared/CoordinatedGraphics/threadedcompositor/ThreadedCompositor.cpp
    M Source/WebKit/Shared/CoordinatedGraphics/threadedcompositor/ThreadedCompositor.h
    M Source/WebKit/Shared/CoordinatedGraphics/threadedcompositor/ThreadedDisplayRefreshMonitor.cpp
    M Source/WebKit/Shared/CoordinatedGraphics/threadedcompositor/ThreadedDisplayRefreshMonitor.h
    M Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/LayerTreeHost.cpp

  Log Message:
  -----------
  Cherry-pick 261124 at main (06b9ec1834d2). https://bugs.webkit.org/show_bug.cgi?id=252467

    [CoordinatedGraphics] Provide scheduled display-update events for better scrolling handling
    https://bugs.webkit.org/show_bug.cgi?id=252467

    Reviewed by Carlos Garcia Campos.

    In ThreadedCompositor, a timer is established on the composition thread that is
    used to mimic display updates at the desired update frequency. This is necessary
    in order to provide opportunities for update producers like the scrolling thread
    to actually enact the desired composition changes, like scrolling, independently
    of the main thread.

    The timer is put on the composition thread, matching the compositing-thread
    update timer in priority. Its delay is based on the established frequency of the
    display updates.

    ThreadedCompositor::displayUpdateFired() method is added and is dispatched upon
    every firing of the timer. It notifies the scrolling thread(s) for the given
    display ID through the EventDispatcher instance on the WebProcess singleton,
    and the next firing of the timer is then scheduled.

    When ThreadedCompositor enters into the composition phase, the display update
    timer is stopped, and the displayUpdateFired() dispatcher is invoked manually
    when the frame-complete signal is returned from the embedder's environment. This
    allows aligning the display update timer with the environment's vsync signals
    without disturbing the composition itself.

    The target update frequency logic is pulled from ThreadedDisplayRefreshMonitor
    into ThreadedCompositor, with the desired DisplayUpdate object now also kept in
    that class. In order for ThreadedDisplayRefreshMonitor to use a sensible
    DisplayUpdate object for each of its own dispatches, the DisplayUpdate object
    is passed through the requiresDisplayRefreshCallback() method to the monitor,
    where it's then stored for next invocation on the main thread, if it occurs.

    ScrollingTreeNicosia::applyLayerPositionsInternal() override is provided,
    establishing an update scope when running on the scrolling thread. This will
    cause the applied positions to actually go through composition whenever the
    scrolling is being handled on the scrolling thread, meaning outside of the usual
    update process.

    * Source/WebCore/page/scrolling/nicosia/ScrollingTreeNicosia.cpp:
    (WebCore::ScrollingTreeNicosia::applyLayerPositionsInternal):
    * Source/WebCore/page/scrolling/nicosia/ScrollingTreeNicosia.h:
    * Source/WebKit/Shared/CoordinatedGraphics/threadedcompositor/ThreadedCompositor.cpp:
    (WebKit::m_displayRefreshMonitor):
    (WebKit::ThreadedCompositor::renderLayerTree):
    (WebKit::ThreadedCompositor::sceneUpdateFinished):
    (WebKit::ThreadedCompositor::frameComplete):
    (WebKit::ThreadedCompositor::targetRefreshRateDidChange):
    (WebKit::ThreadedCompositor::displayUpdateFired):
    * Source/WebKit/Shared/CoordinatedGraphics/threadedcompositor/ThreadedCompositor.h:
    * Source/WebKit/Shared/CoordinatedGraphics/threadedcompositor/ThreadedDisplayRefreshMonitor.cpp:
    (WebKit::ThreadedDisplayRefreshMonitor::ThreadedDisplayRefreshMonitor):
    (WebKit::ThreadedDisplayRefreshMonitor::requiresDisplayRefreshCallback):
    (WebKit::ThreadedDisplayRefreshMonitor::invalidate):
    (WebKit::ThreadedDisplayRefreshMonitor::displayRefreshCallback):
    (WebKit::ThreadedDisplayRefreshMonitor::setTargetRefreshRate): Deleted.
    * Source/WebKit/Shared/CoordinatedGraphics/threadedcompositor/ThreadedDisplayRefreshMonitor.h:
    * Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/LayerTreeHost.cpp:
    (WebKit::LayerTreeHost::displayDidRefresh):

    Canonical link: https://commits.webkit.org/261124@main