Skip to content

Commit

Permalink
make FTE thread-safe
Browse files Browse the repository at this point in the history
  • Loading branch information
@t-bltg
t-bltg committed Oct 31, 2024
1 parent d279973 commit 461250f
Show file tree
Hide file tree
Showing 2 changed files with 63 additions and 26 deletions.
67 changes: 42 additions & 25 deletions ext/FreeTypeExt.jl
View file
Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,7 @@ using FreeType

const REGULAR_STYLES = "regular", "normal", "medium", "standard", "roman", "book"
const FT_LIB = FT_Library[C_NULL]
const LIB_LOCK = ReentrantLock()
const VALID_FONTPATHS = String[]

struct FontExtent{T}
Expand All @@ -23,16 +24,21 @@ end

mutable struct FTFont
ft_ptr::FT_Face
lock::ReentrantLock # lock this for the duration of any FT operation on ft_ptr
function FTFont(ft_ptr::FT_Face)
face = new(ft_ptr)
finalizer(
face -> (face.ft_ptr != C_NULL && FT_LIB[1] != C_NULL) && FT_Done_Face(face),
face,
)
face = new(ft_ptr, ReentrantLock())
finalizer(safe_free, face)
face
end
end
FTFont(path::String) = FTFont(newface(path))

function safe_free(face::FTFont)
@lock face.lock begin
(face.ft_ptr != C_NULL && FT_LIB[1] != C_NULL) && FT_Done_Face(face)
end
end

FTFont(path::String) = FTFont(new_face(path))
FTFont(::Nothing) = nothing

family_name(font::FTFont) = lowercase(ft_property(font, :family_name))
Expand All @@ -43,9 +49,9 @@ Base.propertynames(font::FTFont) = fieldnames(FT_FaceRec)
Base.cconvert(::Type{FT_Face}, font::FTFont) = font
Base.unsafe_convert(::Type{FT_Face}, font::FTFont) = font.ft_ptr

function ft_property(font::FTFont, fieldname::Symbol)
fontrect = unsafe_load(font.ft_ptr)
if (field = getfield(fontrect, fieldname)) isa Ptr{FT_String}
function ft_property(face::FTFont, fieldname::Symbol)
font_rect = @lock face.lock unsafe_load(face.ft_ptr)
if (field = getfield(font_rect, fieldname)) isa Ptr{FT_String}
field == C_NULL && return ""
unsafe_string(field)
else
Expand All @@ -60,10 +66,10 @@ Base.show(io::IO, font::FTFont) = print(

check_error(err, error_msg) = err == 0 || error("$error_msg with error: $err")

function newface(facename, faceindex::Real = 0, ftlib = FT_LIB)
function new_face(name, index::Real = 0, ftlib = FT_LIB)
face = Ref{FT_Face}()
err = FT_New_Face(ftlib[1], facename, Int32(faceindex), face)
check_error(err, "Couldn't load font $facename")
err = @lock LIB_LOCK FT_New_Face(ftlib[1], name, Int32(index), face)
check_error(err, "Couldn't load font $name")
face[]
end

Expand Down Expand Up @@ -201,18 +207,23 @@ FontExtent(func::Function, ext::FontExtent) = FontExtent(
)

function set_pixelsize(face::FTFont, size::Integer)
check_error(FT_Set_Pixel_Sizes(face, size, size), "Couldn't set pixelsize")
@lock face.lock check_error(
FT_Set_Pixel_Sizes(face, size, size),
"Couldn't set pixelsize",
)
size
end

glyph_index(face::FTFont, glyphname::String)::UInt64 = FT_Get_Name_Index(face, glyphname)
glyph_index(face::FTFont, char::Char)::UInt64 = FT_Get_Char_Index(face, char)
glyph_index(face::FTFont, glyphname::String)::UInt64 =
@lock face.lock FT_Get_Name_Index(face, glyphname)
glyph_index(face::FTFont, char::Char)::UInt64 =
@lock face.lock FT_Get_Char_Index(face, char)
glyph_index(face::FTFont, idx::Integer) = UInt64(idx)

function kerning(face::FTFont, glyphspecs...)
i1, i2 = glyph_index.(Ref(face), glyphspecs)
kerning2d = Ref{FT_Vector}()
err = FT_Get_Kerning(face, i1, i2, FT_KERNING_DEFAULT, kerning2d)
err = @lock face.lock FT_Get_Kerning(face, i1, i2, FT_KERNING_DEFAULT, kerning2d)
# can error if font has no kerning! Since that's somewhat expected, we just return 0
err == 0 || return SVector(0.0, 0.0)
divisor = 64 # 64 since metrics are in 1/64 units (units to 26.6 fractional pixels)
Expand All @@ -221,14 +232,14 @@ end

function load_glyph(face::FTFont, glyph)
gi = glyph_index(face, glyph)
err = FT_Load_Glyph(face, gi, FT_LOAD_RENDER)
err = @lock face.lock FT_Load_Glyph(face, gi, FT_LOAD_RENDER)
check_error(err, "Could not load glyph $(repr(glyph)) from $face to render.")
end

function load_glyph(face::FTFont, glyph, pixelsize::Integer; set_pix = true)
set_pix && set_pixelsize(face, pixelsize)
load_glyph(face, glyph)
gl = unsafe_load(ft_property(face, :glyph))
gl = @lock face.lock unsafe_load(ft_property(face, :glyph))
@assert gl.format == FT_GLYPH_FORMAT_BITMAP
gl
end
Expand Down Expand Up @@ -414,16 +425,22 @@ function UnicodePlots.render_string!(
end

function ft_init()
FT_LIB[1] != C_NULL && error("Freetype already initialized. init() called two times ?")
FT_Init_FreeType(FT_LIB) == 0
@lock LIB_LOCK begin
FT_LIB[1] != C_NULL &&
error("Freetype already initialized. init() called two times ?")
FT_Init_FreeType(FT_LIB) == 0
end
end

function ft_done()
FT_LIB[1] == C_NULL &&
error("Library == CNULL. done() called before init(), or done called two times ?")
err = FT_Done_FreeType(FT_LIB[1])
FT_LIB[1] = C_NULL
err == 0
@lock LIB_LOCK begin
FT_LIB[1] == C_NULL && error(
"Library == CNULL. done() called before init(), or done called two times ?",
)
err = FT_Done_FreeType(FT_LIB[1])
FT_LIB[1] = C_NULL
err == 0
end
end

add_recursive(result, path) =
Expand Down
22 changes: 21 additions & 1 deletion test/tst_freetype.jl
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,8 @@ const FTE = if isdefined(Base, :get_extension)
else
UnicodePlots.FreeTypeExt
end
push!(FTE.VALID_FONTPATHS, joinpath(@__DIR__, "fonts"))
const FT_DIR = joinpath(@__DIR__, "fonts")
push!(FTE.VALID_FONTPATHS, FT_DIR)

@testset "init and done" begin
@test_throws ErrorException FTE.ft_init()
Expand Down Expand Up @@ -247,4 +248,23 @@ end
@test FTE.fallback_fonts() isa Tuple
end

@testset "thread safety" begin
mktempdir() do dir
n = 100
fontfiles = map(1:n) do i
p = joinpath(dir, "hack_regular_$i.ttf")
cp(joinpath(FT_DIR, "hack_regular.ttf"), p)
p
end
Threads.@threads for f in fontfiles
fo = FTE.FTFont(f)
Threads.@threads for i = 1:n
FTE.load_glyph(fo, i)
FTE.load_glyph(fo, i, 64)
FTE.render_face(fo, i, 16)
end
end
end
end

pop!(FTE.VALID_FONTPATHS)

0 comments on commit 461250f

Please sign in to comment.