From d3075dd0df56c7d556da0a858c0239f4c05c3fa3 Mon Sep 17 00:00:00 2001
From: KristofferC <kristoffer.carlsson@juliacomputing.com>
Date: Fri, 5 Jan 2024 13:30:06 +0100
Subject: [PATCH 1/4] use a Dict instead of an IdDict for caching of the
 `cwstring` for Windows env variables

`IdDict` methods have a bunch of `nospecialize` annotations which specifically when using an `Array` value causes methods to be compiled that are very vulnerable to invalidations.
---
 base/env.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/base/env.jl b/base/env.jl
index 27594acff6b7f..2a5223ef142b7 100644
--- a/base/env.jl
+++ b/base/env.jl
@@ -3,7 +3,7 @@
 if Sys.iswindows()
     const ERROR_ENVVAR_NOT_FOUND = UInt32(203)
 
-    const env_dict = IdDict{String, Vector{Cwchar_t}}()
+    const env_dict = Dict{String, Vector{Cwchar_t}}()
     const env_lock = ReentrantLock()
 
     function memoized_env_lookup(str::AbstractString)

From 5a3a238182d0ebc69e70ae3a06e112618c903441 Mon Sep 17 00:00:00 2001
From: Kristoffer Carlsson <kcarlsson89@gmail.com>
Date: Fri, 5 Jan 2024 16:19:09 +0100
Subject: [PATCH 2/4] also lock on access

---
 base/env.jl | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/base/env.jl b/base/env.jl
index 2a5223ef142b7..48ab3f11b8061 100644
--- a/base/env.jl
+++ b/base/env.jl
@@ -11,10 +11,10 @@ if Sys.iswindows()
         # incurred allocations because we had to convert a String to a Vector{Cwchar_t} each time
         # an environment variable was looked up. This function memoizes that lookup process, storing
         # the String => Vector{Cwchar_t} pairs in env_dict
-        var = get(env_dict, str, nothing)
-        if isnothing(var)
-            var = @lock env_lock begin
-                env_dict[str] = cwstring(str)
+        @lock env_lock begin
+            var = get(env_dict, str, nothing)
+            if isnothing(var)
+                var = env_dict[str] = cwstring(str)
             end
         end
         var

From abdef50740c5c137064738e09eda3fa77b894caa Mon Sep 17 00:00:00 2001
From: Kristoffer Carlsson <kcarlsson89@gmail.com>
Date: Fri, 5 Jan 2024 21:56:59 +0100
Subject: [PATCH 3/4] webbrowser editing...

---
 base/env.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/base/env.jl b/base/env.jl
index 48ab3f11b8061..ac3c0c2794554 100644
--- a/base/env.jl
+++ b/base/env.jl
@@ -16,8 +16,8 @@ if Sys.iswindows()
             if isnothing(var)
                 var = env_dict[str] = cwstring(str)
             end
+            return var
         end
-        var
     end
 
     _getenvlen(var::Vector{UInt16}) = ccall(:GetEnvironmentVariableW,stdcall,UInt32,(Ptr{UInt16},Ptr{UInt16},UInt32),var,C_NULL,0)

From 0385eaa76dfe8b0bf001625cb5a5b4af8ea9557f Mon Sep 17 00:00:00 2001
From: Kristoffer Carlsson <kcarlsson89@gmail.com>
Date: Fri, 5 Jan 2024 21:58:06 +0100
Subject: [PATCH 4/4] nicer

---
 base/env.jl | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/base/env.jl b/base/env.jl
index ac3c0c2794554..1bebfd2623e61 100644
--- a/base/env.jl
+++ b/base/env.jl
@@ -14,7 +14,8 @@ if Sys.iswindows()
         @lock env_lock begin
             var = get(env_dict, str, nothing)
             if isnothing(var)
-                var = env_dict[str] = cwstring(str)
+                var = cwstring(str)
+                env_dict[str] = var
             end
             return var
         end