8330572: jdk.internal.net.http.HttpConnection calls an expensive checkOpen() when returning a HTTP/1.1 connection to the pool

Reviewed-by: dfuchs, djelinski

Author: jaikiran

src/java.net.http/share/classes/jdk/internal/net/http/HttpConnection.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -409,7 +409,7 @@ void closeOrReturnToCache(HttpHeaders hdrs) {
                 .map((s) -> !s.equalsIgnoreCase("close"))
                 .orElse(true);
 
-        if (keepAlive && checkOpen()) {
+        if (keepAlive && isOpen()) {
             Log.logTrace("Returning connection to the pool: {0}", this);
             pool.returnToPool(this);
         } else {