Bug 1806058 - Add blocklist for Accelerated Canvas2D. r=jrmuizel

Differential Revision: https://phabricator.services.mozilla.com/D164881

dom/canvas/DrawTargetWebgl.cpp

@@ -12,6 +12,7 @@
 #include "mozilla/gfx/AAStroke.h"
 #include "mozilla/gfx/Blur.h"
 #include "mozilla/gfx/DrawTargetSkia.h"
+#include "mozilla/gfx/gfxVars.h"
 #include "mozilla/gfx/Helpers.h"
 #include "mozilla/gfx/HelpersSkia.h"
 #include "mozilla/gfx/Logging.h"
@@ -716,7 +717,7 @@ bool DrawTargetWebgl::IsValid() const {
 
 already_AddRefed<DrawTargetWebgl> DrawTargetWebgl::Create(
     const IntSize& aSize, SurfaceFormat aFormat) {
-  if (!StaticPrefs::gfx_canvas_accelerated()) {
+  if (!gfxVars::UseAcceleratedCanvas2D()) {
     return nullptr;
   }
 

gfx/config/gfxFeature.h

@@ -45,7 +45,8 @@ namespace gfx {
   _(DMABUF_SURFACE_EXPORT, Feature, "WebGL DMABuf surface export")           \
   _(REUSE_DECODER_DEVICE, Feature, "Reuse decoder device")                   \
   _(BACKDROP_FILTER, Feature, "Backdrop filter")                             \
-  _(CANVAS_RENDERER_THREAD, Feature, "canvas renderer thread")
+  _(CANVAS_RENDERER_THREAD, Feature, "canvas renderer thread")               \
+  _(ACCELERATED_CANVAS2D, Feature, "Accelerated Canvas2D")
 /* Add new entries above this comment */
 
 enum class Feature : uint32_t {

gfx/config/gfxVars.h

@@ -94,7 +94,8 @@ class gfxVarReceiver;
   _(ReuseDecoderDevice, bool, false)                               \
   _(UseCanvasRenderThread, bool, false)                            \
   _(AllowBackdropFilter, bool, true)                               \
-  _(WebglOopAsyncPresentForceSync, bool, true)
+  _(WebglOopAsyncPresentForceSync, bool, true)                     \
+  _(UseAcceleratedCanvas2D, bool, false)
 
 /* Add new entries above this line. */
 

gfx/thebes/gfxPlatform.cpp

@@ -924,6 +924,7 @@ void gfxPlatform::Init() {
   gPlatform->InitWebGPUConfig();
   gPlatform->InitWindowOcclusionConfig();
   gPlatform->InitBackdropFilterConfig();
+  gPlatform->InitAcceleratedCanvas2DConfig();
 
 #if defined(XP_WIN)
   // When using WebRender, we defer initialization of the D3D11 devices until
@@ -3087,6 +3088,53 @@ void gfxPlatform::InitBackdropFilterConfig() {
           StaticPrefs::GetPrefName_layout_css_backdrop_filter_force_enabled()));
 }
 
+static void AcceleratedCanvas2DPrefChangeCallback(const char*, void*) {
+  FeatureState& feature = gfxConfig::GetFeature(Feature::ACCELERATED_CANVAS2D);
+
+  // Reset to track toggling prefs and ensure force-enable does not happen
+  // after blocklist.
+  feature.Reset();
+
+  // gfx.canvas.accelerated pref controls whether platform enables the feature,
+  // but it still allows blocklisting to override it later.
+  feature.SetDefaultFromPref(
+      StaticPrefs::GetPrefName_gfx_canvas_accelerated(), true,
+      StaticPrefs::GetPrefDefault_gfx_canvas_accelerated());
+
+  // gfx.canvas.accelerated.force-enabled overrides the blocklist.
+  if (StaticPrefs::gfx_canvas_accelerated_force_enabled()) {
+    feature.UserForceEnable("Force-enabled by pref");
+  }
+
+  // Check if blocklisted despite the default pref.
+  nsCString message;
+  nsCString failureId;
+  if (!gfxPlatform::IsGfxInfoStatusOkay(
+          nsIGfxInfo::FEATURE_ACCELERATED_CANVAS2D, &message, failureId)) {
+    feature.Disable(FeatureStatus::Blocklisted, message.get(), failureId);
+  }
+
+  gfxVars::SetUseAcceleratedCanvas2D(feature.IsEnabled());
+}
+
+void gfxPlatform::InitAcceleratedCanvas2DConfig() {
+  if (!XRE_IsParentProcess()) {
+    return;
+  }
+
+  // Decide during pref changes whether or not to enable acceleration. This
+  // allows easily toggling acceleration on and off to test performance.
+  AcceleratedCanvas2DPrefChangeCallback(nullptr, nullptr);
+
+  Preferences::RegisterCallback(
+      AcceleratedCanvas2DPrefChangeCallback,
+      nsDependentCString(StaticPrefs::GetPrefName_gfx_canvas_accelerated()));
+  Preferences::RegisterCallback(
+      AcceleratedCanvas2DPrefChangeCallback,
+      nsDependentCString(
+          StaticPrefs::GetPrefName_gfx_canvas_accelerated_force_enabled()));
+}
+
 bool gfxPlatform::CanUseHardwareVideoDecoding() {
   // this function is called from the compositor thread, so it is not
   // safe to init the prefs etc. from here.

gfx/thebes/gfxPlatform.h

@@ -818,6 +818,7 @@ class gfxPlatform : public mozilla::layers::MemoryPressureListener {
   virtual void InitWebGPUConfig();
   virtual void InitWindowOcclusionConfig();
   void InitBackdropFilterConfig();
+  void InitAcceleratedCanvas2DConfig();
 
   virtual void GetPlatformDisplayInfo(mozilla::widget::InfoObject& aObj) {}
 

modules/libpref/init/StaticPrefList.yaml

@@ -5576,7 +5576,7 @@
 #endif
 
 - name: gfx.canvas.accelerated
-  type: RelaxedAtomicBool
+  type: bool
 #if defined(XP_MACOSX) || defined(XP_LINUX) && !defined(ANDROID)
   value: @IS_NIGHTLY_BUILD@
 #else
@@ -5584,6 +5584,12 @@
 #endif
   mirror: always
 
+# Whether to attempt to enable Accelerated Canvas2D regardless of blocklisting.
+- name: gfx.canvas.accelerated.force-enabled
+  type: bool
+  value: false
+  mirror: always
+
 - name: gfx.canvas.accelerated.async-present
   type: RelaxedAtomicBool
   value: true

widget/GfxInfoBase.cpp

@@ -260,6 +260,9 @@ static const char* GetPrefNameForFeature(int32_t aFeature) {
     case nsIGfxInfo::FEATURE_BACKDROP_FILTER:
       name = BLOCKLIST_PREF_BRANCH "backdrop.filter";
       break;
+    case nsIGfxInfo::FEATURE_ACCELERATED_CANVAS2D:
+      name = BLOCKLIST_PREF_BRANCH "accelerated-canvas2d";
+      break;
     default:
       MOZ_ASSERT_UNREACHABLE("Unexpected nsIGfxInfo feature?!");
       break;
@@ -533,6 +536,9 @@ static int32_t BlocklistFeatureToGfxFeature(const nsAString& aFeature) {
   if (aFeature.EqualsLiteral("BACKDROP_FILTER")) {
     return nsIGfxInfo::FEATURE_BACKDROP_FILTER;
   }
+  if (aFeature.EqualsLiteral("ACCELERATED_CANVAS2D")) {
+    return nsIGfxInfo::FEATURE_ACCELERATED_CANVAS2D;
+  }
 
   // If we don't recognize the feature, it may be new, and something
   // this version doesn't understand.  So, nothing to do.  This is

widget/nsIGfxInfo.idl

@@ -180,8 +180,10 @@ interface nsIGfxInfo : nsISupports
   const long FEATURE_REUSE_DECODER_DEVICE = 41;
   /* Whether to allow backdrop filter, starting in 105. */
   const long FEATURE_BACKDROP_FILTER = 42;
+  /* Whether to use Accelerated Canvas2D, starting in 110. */
+  const long FEATURE_ACCELERATED_CANVAS2D = 43;
   /* the maximum feature value. */
-  const long FEATURE_MAX_VALUE = FEATURE_BACKDROP_FILTER;
+  const long FEATURE_MAX_VALUE = FEATURE_ACCELERATED_CANVAS2D;
 
   /*
    * A set of return values from GetFeatureStatus