[webkit-changes] [WebKit/WebKit] 0072dc: ImageBufferIOSurfaceBackend context setup and tear...

[Kimmo Kinnunen]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 0072dcd9a13bfa4235b0184fe629e657a60c9b4a
      https://github.com/WebKit/WebKit/commit/0072dcd9a13bfa4235b0184fe629e657a60c9b4a
  Author: Kimmo Kinnunen <kkinnunen at apple.com>
  Date:   2023-02-23 (Thu, 23 Feb 2023)

  Changed paths:
    M Source/WebCore/platform/graphics/ImageBufferBackend.cpp
    M Source/WebCore/platform/graphics/ImageBufferBackend.h
    M Source/WebCore/platform/graphics/cg/IOSurfacePool.cpp
    M Source/WebCore/platform/graphics/cg/ImageBufferCGBackend.cpp
    M Source/WebCore/platform/graphics/cg/ImageBufferCGBackend.h
    M Source/WebCore/platform/graphics/cg/ImageBufferCGBitmapBackend.cpp
    M Source/WebCore/platform/graphics/cg/ImageBufferCGBitmapBackend.h
    M Source/WebCore/platform/graphics/cg/ImageBufferIOSurfaceBackend.cpp
    M Source/WebCore/platform/graphics/cg/ImageBufferIOSurfaceBackend.h
    M Source/WebCore/platform/graphics/cocoa/IOSurface.h
    M Source/WebCore/platform/graphics/cocoa/IOSurface.mm

  Log Message:
  -----------
  ImageBufferIOSurfaceBackend context setup and teardown functions are redundant and error-prone
https://bugs.webkit.org/show_bug.cgi?id=240452
rdar://93412550

Reviewed by Simon Fraser.

Make all ImageBufferCGBackend hold the GraphicsContextCG.
Avoid holding GraphicsContext in IOSurface, as the only caller was
ImageBufferIOSurfaceBackend.

ImageBufferBackend::applyBaseTransformToContext() invoked a virtual
function context(). This was called from the middle of the inheritance
chain, from a constructor. If a class later in the inheritance chain
would override context(), the call would not be invoked correctly.
Currently no class suffered from this, but in future some might.

ImageBufferIOSurfaceBackend call to applyBaseTransformToContext() would
also recurse through context() back to applyBaseTransformToContext() in
non-intuitive way through overridden ::context() which would re-enter
applyBaseTransformToContext(). Based on current knowledge doubly
invoking the logic did not cause any harm.

* Source/WebCore/platform/graphics/ImageBufferBackend.cpp:
(WebCore::ImageBufferBackend::applyBaseTransformToContext const): Deleted.
* Source/WebCore/platform/graphics/ImageBufferBackend.h:
* Source/WebCore/platform/graphics/cg/IOSurfacePool.cpp:
(WebCore::IOSurfacePool::willAddSurface):
* Source/WebCore/platform/graphics/cg/ImageBufferCGBackend.cpp:
(WebCore::ImageBufferCGBackend::applyBaseTransform const):
* Source/WebCore/platform/graphics/cg/ImageBufferCGBackend.h:
* Source/WebCore/platform/graphics/cg/ImageBufferCGBitmapBackend.cpp:
(WebCore::ImageBufferCGBitmapBackend::ImageBufferCGBitmapBackend):
* Source/WebCore/platform/graphics/cg/ImageBufferCGBitmapBackend.h:
* Source/WebCore/platform/graphics/cg/ImageBufferIOSurfaceBackend.cpp:
(WebCore::ImageBufferIOSurfaceBackend::ImageBufferIOSurfaceBackend):
(WebCore::ImageBufferIOSurfaceBackend::context const):
(WebCore::ImageBufferIOSurfaceBackend::releaseGraphicsContext):
* Source/WebCore/platform/graphics/cg/ImageBufferIOSurfaceBackend.h:
* Source/WebCore/platform/graphics/cocoa/IOSurface.h:
* Source/WebCore/platform/graphics/cocoa/IOSurface.mm:
(WebCore::IOSurface::create):
(WebCore::IOSurface::releasePlatformContext):
(WebCore::IOSurface::ensureGraphicsContext): Deleted.
(WebCore::IOSurface::releaseGraphicsContext): Deleted.

Canonical link: https://commits.webkit.org/260734@main