Move the initialisation to __init__()

penelopeysm · penelopeysm · commit 0b5ef17da1fc · 2025-11-08T22:56:05.000Z
diff --git a/src/DynamicPPL.jl b/src/DynamicPPL.jl
@@ -205,8 +205,12 @@ include("test_utils.jl")
 include("experimental.jl")
 include("deprecated.jl")
 
-if isdefined(Base.Experimental, :register_error_hint)
-    function __init__()
+function __init__()
+    # This has to be in the `__init__()` function, if it's placed at the top level it
+    # always evaluates to false.
+    DynamicPPL.set_threadsafe_eval!(Threads.nthreads() > 1)
+
+    if isdefined(Base.Experimental, :register_error_hint)
         # Better error message if users forget to load JET.jl
         Base.Experimental.register_error_hint(MethodError) do io, exc, argtypes, _
             requires_jet =
diff --git a/src/model.jl b/src/model.jl
@@ -1,4 +1,4 @@
-const USE_THREADSAFE_EVAL = Ref(Threads.nthreads() > 1)
+USE_THREADSAFE_EVAL = Ref(true)
 
 """
     DynamicPPL.set_threadsafe_eval!(val::Bool)

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-const USE_THREADSAFE_EVAL = Ref(Threads.nthreads() > 1)`
	`1`	`+USE_THREADSAFE_EVAL = Ref(true)`
`2`	`2`
`3`	`3`	`"""`
`4`	`4`	`DynamicPPL.set_threadsafe_eval!(val::Bool)`