Bug 1824200 - Make mFTFace an atomic pointer. r=lsalzman, a=dsmith (47354b33) · Commits · The Tor Project / Applications / Tor Browser

gfx/thebes/gfxFcPlatformFontList.cpp

+33 −17

Original line number	Diff line number	Diff line
		@@ -336,7 +336,8 @@ gfxFontconfigFontEntry::gfxFontconfigFontEntry(const nsACString& aFaceName,
		SlantStyleRange aStyle,
		RefPtr<SharedFTFace>&& aFace)
		: gfxFT2FontEntryBase(aFaceName),
		mFTFace(std::move(aFace)),
		mFontPattern(CreatePatternForFace(aFace->GetFace())),
		mFTFace(aFace.forget().take()),
		mFTFaceInitialized(true),
		mIgnoreFcCharmap(true),
		mHasVariationsInitialized(false) {
		@@ -344,8 +345,6 @@ gfxFontconfigFontEntry::gfxFontconfigFontEntry(const nsACString& aFaceName,
		mStyleRange = aStyle;
		mStretchRange = aStretch;
		mIsDataUserFont = true;

		mFontPattern = CreatePatternForFace(mFTFace->GetFace());
		}

		gfxFontconfigFontEntry::gfxFontconfigFontEntry(const nsACString& aFaceName,
		@@ -405,12 +404,17 @@ gfxFontconfigFontEntry::~gfxFontconfigFontEntry() {
		// InitializeVarFuncs must have been called in order for mMMVar to be
		// non-null here, so we don't need to do it again.
		if (sDoneVar) {
		MOZ_ASSERT(mFTFace, "How did mMMVar get set without a face?");
		(*sDoneVar)(mFTFace->GetFace()->glyph->library, mMMVar);
		auto ftFace = GetFTFace();
		MOZ_ASSERT(ftFace, "How did mMMVar get set without a face?");
		(*sDoneVar)(ftFace->GetFace()->glyph->library, mMMVar);
		} else {
		free(mMMVar);
		}
		}
		if (mFTFaceInitialized) {
		auto face = mFTFace.exchange(nullptr);
		NS_IF_RELEASE(face);
		}
		}

		nsresult gfxFontconfigFontEntry::ReadCMAP(FontInfoData* aFontInfoData) {
		@@ -923,9 +927,12 @@ gfxFont* gfxFontconfigFontEntry::CreateFontInstance(
		RefPtr<UnscaledFontFontconfig> unscaledFont =
		mUnscaledFontCache.Lookup(file, index);
		if (!unscaledFont) {
		unscaledFont = mFTFace->GetData() ? new UnscaledFontFontconfig(mFTFace)
		// Here, we use the original mFTFace, not a potential clone with variation
		// settings applied.
		auto ftFace = GetFTFace();
		unscaledFont = ftFace->GetData() ? new UnscaledFontFontconfig(ftFace)
		: new UnscaledFontFontconfig(
		std::move(file), index, mFTFace);
		std::move(file), index, ftFace);
		mUnscaledFontCache.Add(unscaledFont);
		}

		@@ -936,17 +943,25 @@ gfxFont* gfxFontconfigFontEntry::CreateFontInstance(
		return newFont;
		}

		const RefPtr<SharedFTFace>& gfxFontconfigFontEntry::GetFTFace() {
		SharedFTFace* gfxFontconfigFontEntry::GetFTFace() {
		if (!mFTFaceInitialized) {
		RefPtr<SharedFTFace> face = CreateFaceForPattern(mFontPattern);
		if (face) {
		if (mFTFace.compareExchange(nullptr, face.get())) {
		Unused << face.forget(); // The reference is now owned by mFTFace.
		mFTFaceInitialized = true;
		mFTFace = CreateFaceForPattern(mFontPattern);
		} else {
		// We lost a race to set mFTFace! Just discard our new face.
		}
		}
		}
		return mFTFace;
		}

		FTUserFontData* gfxFontconfigFontEntry::GetUserFontData() {
		if (mFTFace && mFTFace->GetData()) {
		return static_cast<FTUserFontData*>(mFTFace->GetData());
		auto face = GetFTFace();
		if (face && face->GetData()) {
		return static_cast<FTUserFontData*>(face->GetData());
		}
		return nullptr;
		}
		@@ -972,9 +987,9 @@ bool gfxFontconfigFontEntry::HasVariations() {
		mHasVariations = true;
		}
		} else {
		if (GetFTFace()) {
		if (auto ftFace = GetFTFace()) {
		mHasVariations =
		mFTFace->GetFace()->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS;
		ftFace->GetFace()->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS;
		}
		}

		@@ -990,10 +1005,11 @@ FT_MM_Var* gfxFontconfigFontEntry::GetMMVar() {
		if (!sGetVar) {
		return nullptr;
		}
		if (!GetFTFace()) {
		auto ftFace = GetFTFace();
		if (!ftFace) {
		return nullptr;
		}
		if (FT_Err_Ok != (*sGetVar)(mFTFace->GetFace(), &mMMVar)) {
		if (FT_Err_Ok != (*sGetVar)(ftFace->GetFace(), &mMMVar)) {
		mMMVar = nullptr;
		}
		return mMMVar;

gfx/thebes/gfxFcPlatformFontList.h

+7 −4

Original line number	Diff line number	Diff line
		@@ -94,7 +94,7 @@ class gfxFontconfigFontEntry final : public gfxFT2FontEntryBase {
		nsresult ReadCMAP(FontInfoData* aFontInfoData = nullptr) override;
		bool TestCharacterMap(uint32_t aCh) override;

		const RefPtr<mozilla::gfx::SharedFTFace>& GetFTFace();
		mozilla::gfx::SharedFTFace* GetFTFace();
		FTUserFontData* GetUserFontData();

		FT_MM_Var* GetMMVar() override;
		@@ -120,9 +120,12 @@ class gfxFontconfigFontEntry final : public gfxFT2FontEntryBase {
		// pattern for a single face of a family
		RefPtr<FcPattern> mFontPattern;

		// FTFace - initialized when needed
		RefPtr<mozilla::gfx::SharedFTFace> mFTFace;
		bool mFTFaceInitialized;
		// FTFace - initialized when needed. Once mFTFaceInitialized is true,
		// the face can be accessed without locking.
		// Note that mFTFace owns a reference to the SharedFTFace, but is not
		// a RefPtr because we need it to be an atomic.
		mozilla::Atomic<mozilla::gfx::SharedFTFace*> mFTFace;
		mozilla::Atomic<bool> mFTFaceInitialized;

		// Whether TestCharacterMap should check the actual cmap rather than asking
		// fontconfig about character coverage.