OncePerX: Improve initializer type for DataType constructors (#58265)

Generalized from JuliaData/Parsers.jl#197

Author: topolarity

base/lock.jl

@@ -735,7 +735,9 @@ mutable struct OncePerProcess{T, F} <: Function
         return once
     end
 end
+OncePerProcess{T}(initializer::Type{U}) where {T, U} = OncePerProcess{T, Type{U}}(initializer)
 OncePerProcess{T}(initializer::F) where {T, F} = OncePerProcess{T, F}(initializer)
+OncePerProcess(initializer::Type{U}) where U = OncePerProcess{Base.promote_op(initializer), Type{U}}(initializer)
 OncePerProcess(initializer) = OncePerProcess{Base.promote_op(initializer), typeof(initializer)}(initializer)
 @inline function (once::OncePerProcess{T,F})() where {T,F}
     state = (@atomic :acquire once.state)
@@ -842,7 +844,9 @@ mutable struct OncePerThread{T, F} <: Function
         return once
     end
 end
+OncePerThread{T}(initializer::Type{U}) where {T, U} = OncePerThread{T,Type{U}}(initializer)
 OncePerThread{T}(initializer::F) where {T, F} = OncePerThread{T,F}(initializer)
+OncePerThread(initializer::Type{U}) where U = OncePerThread{Base.promote_op(initializer), Type{U}}(initializer)
 OncePerThread(initializer) = OncePerThread{Base.promote_op(initializer), typeof(initializer)}(initializer)
 @inline (once::OncePerThread{T,F})() where {T,F} = once[Threads.threadid()]
 @inline function getindex(once::OncePerThread{T,F}, tid::Integer) where {T,F}
@@ -961,8 +965,10 @@ false
 mutable struct OncePerTask{T, F} <: Function
     const initializer::F
 
+    OncePerTask{T}(initializer::Type{U}) where {T, U} = new{T,Type{U}}(initializer)
     OncePerTask{T}(initializer::F) where {T, F} = new{T,F}(initializer)
     OncePerTask{T,F}(initializer::F) where {T, F} = new{T,F}(initializer)
+    OncePerTask(initializer::Type{U}) where U = new{Base.promote_op(initializer), Type{U}}(initializer)
     OncePerTask(initializer) = new{Base.promote_op(initializer), typeof(initializer)}(initializer)
 end
 @inline function (once::OncePerTask{T,F})() where {T,F}

test/threads.jl

@@ -447,6 +447,12 @@ let once = OncePerProcess(() -> return [nothing])
     @atomic once.state = 0x01
     @test x === once()
 end
+let once1 = OncePerProcess(BigFloat), once2 = OncePerProcess{BigFloat}(BigFloat)
+    # Using a type as a constructor should create a OncePerProcess with
+    # Type{...} as its initializer (rather than DataType)
+    @test typeof(once1) <: OncePerProcess{BigFloat,Type{BigFloat}}
+    @test typeof(once2) <: OncePerProcess{BigFloat,Type{BigFloat}}
+end
 let once = OncePerProcess{Int}(() -> error("expected"))
     @test_throws ErrorException("expected") once()
     @test_throws ErrorException("OncePerProcess initializer failed previously") once()
@@ -551,6 +557,12 @@ let e = Base.Event(true),
     @test_throws ArgumentError once[-1]
 
 end
+let once1 = OncePerThread(BigFloat), once2 = OncePerThread{BigFloat}(BigFloat)
+    # Using a type as a constructor should create a OncePerThread with
+    # Type{...} as its initializer (rather than DataType)
+    @test typeof(once1) <: OncePerThread{BigFloat,Type{BigFloat}}
+    @test typeof(once2) <: OncePerThread{BigFloat,Type{BigFloat}}
+end
 let once = OncePerThread{Int}(() -> error("expected"))
     @test_throws ErrorException("expected") once()
     @test_throws ErrorException("OncePerThread initializer failed previously") once()
@@ -563,6 +575,12 @@ let once = OncePerTask(() -> return [nothing])
     delete!(task_local_storage(), once)
     @test x !== once() === once()
 end
+let once1 = OncePerTask(BigFloat), once2 = OncePerTask{BigFloat}(BigFloat)
+    # Using a type as a constructor should create a OncePerTask with
+    # Type{...} as its initializer (rather than DataType)
+    @test typeof(once1) <: OncePerTask{BigFloat,Type{BigFloat}}
+    @test typeof(once2) <: OncePerTask{BigFloat,Type{BigFloat}}
+end
 let once = OncePerTask{Int}(() -> error("expected"))
     @test_throws ErrorException("expected") once()
     @test_throws ErrorException("expected") once()