From 6e46cc84fbd94abd0c44f8ca3309f6ddf8c1ce8d Mon Sep 17 00:00:00 2001
From: Teo Camarasu <teofilcamarasu@gmail.com>
Date: Wed, 17 Dec 2025 17:07:21 +0000
Subject: [PATCH] Make atomicModifyStrip strict

Previously we could end up with thunks in our mutable variable
---
 thread-utils-context/src/Control/Concurrent/Thread/Storage.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/thread-utils-context/src/Control/Concurrent/Thread/Storage.hs b/thread-utils-context/src/Control/Concurrent/Thread/Storage.hs
index 8020593..70fae2c 100644
--- a/thread-utils-context/src/Control/Concurrent/Thread/Storage.hs
+++ b/thread-utils-context/src/Control/Concurrent/Thread/Storage.hs
@@ -98,7 +98,7 @@ atomicModifyStripe (ThreadStorageMap arr#) tid f = IO $ \s -> go s
         let (updatedIntMap, result) = f intMap 
         in case casArray# arr# stripe# intMap updatedIntMap s1 of
              (# s2, outcome, old #) -> case outcome of
-               0# -> (# s2, result #)
+               0# -> updatedIntMap `seq` (# s2, result #)
                1# -> go s2
                _ -> error "Got impossible result in atomicModifyStripe"