fix(concatMap): deadlock on inner upstream subscription

Forwarding signals must not happen under locking conditions!
smallrye · Jan 26, 2024 · f18296b · f18296b
1 parent 796003c
commit f18296b
Showing 1 changed file with 4 additions and 7 deletions.
diff --git a/implementation/src/main/java/io/smallrye/mutiny/operators/multi/MultiConcatMapOp.java b/implementation/src/main/java/io/smallrye/mutiny/operators/multi/MultiConcatMapOp.java
@@ -103,13 +103,10 @@ public void onSubscribe(Flow.Subscription subscription) {
         private void innerOnSubscribe(Flow.Subscription subscription) {
             stateLock.lock();
             innerUpstream = subscription;
-            try {
-                long n = demand;
-                if (n > 0L) {
-                    subscription.request(n);
-                }
-            } finally {
-                stateLock.unlock();
+            long n = demand;
+            stateLock.unlock();
+            if (n > 0L) {
+                subscription.request(n);
             }
         }