Revert "Change length of ThreadSafeVarInfo logps to maxthreadid()"

This reverts commit 027ccdc.

maxthreadid() causes failures with Mooncake, even on 1.11, so this is
not safe to change

Author: penelopeysm

HISTORY.md

@@ -6,8 +6,6 @@ Added compatibility with DifferentiationInterface.jl 0.7, and also with JET.jl 0
 
 The JET compatibility entry should only affect you if you are using DynamicPPL on the Julia 1.12 pre-release.
 
-The array of log probabilities stored in `ThreadSafeVarInfo` is now of length `Threads.maxthreadid()`, rather than `Threads.nthreads()`.
-
 ## 0.36.3
 
 Moved the `bijector(model)`, where `model` is a `DynamicPPL.Model`, function from the Turing main repo.

src/threadsafe.jl

@@ -9,7 +9,7 @@ struct ThreadSafeVarInfo{V<:AbstractVarInfo,L} <: AbstractVarInfo
     logps::L
 end
 function ThreadSafeVarInfo(vi::AbstractVarInfo)
-    return ThreadSafeVarInfo(vi, [Ref(zero(getlogp(vi))) for _ in 1:Threads.maxthreadid()])
+    return ThreadSafeVarInfo(vi, [Ref(zero(getlogp(vi))) for _ in 1:Threads.nthreads()])
 end
 ThreadSafeVarInfo(vi::ThreadSafeVarInfo) = vi
 

test/threadsafe.jl

@@ -5,7 +5,7 @@
 
         @test threadsafe_vi.varinfo === vi
         @test threadsafe_vi.logps isa Vector{typeof(Ref(getlogp(vi)))}
-        @test length(threadsafe_vi.logps) == Threads.maxthreadid()
+        @test length(threadsafe_vi.logps) == Threads.nthreads()
         @test all(iszero(x[]) for x in threadsafe_vi.logps)
     end