Fix flaky IOUtilitiesProtocolValidationTest performance test

- Add warmup iterations for JIT compilation before timing
- Increase threshold from 100ms to 500ms for CI environments

Co-Authored-By: Claude Opus 4 <noreply@anthropic.com>

Author: Claude4.0o

changelog.md

@@ -1,5 +1,10 @@
 ### Revision History
 
+#### 4.91.0 (unreleased)
+* **MAINTENANCE**: Fixed flaky `IOUtilitiesProtocolValidationTest.testProtocolValidationPerformance` test
+  * Added warmup iterations to allow JIT compilation before timing
+  * Increased threshold from 100ms to 500ms for CI environments with variable performance
+
 #### 4.90.0 2026-02-02
 * **BUG FIX**: `DeepEquals` - URL comparison now uses string representation instead of `URL.equals()`
   * Java's `URL.equals()` performs DNS resolution which causes flaky CI failures

src/test/java/com/cedarsoftware/util/IOUtilitiesProtocolValidationTest.java

@@ -344,14 +344,20 @@ public void testProtocolValidationPerformance() throws Exception {
         // Test that protocol validation doesn't significantly impact performance
         URL url = new URL("https://example.com");
         URLConnection connection = url.openConnection();
-        
+
+        // Warmup iterations to allow JIT compilation
+        for (int i = 0; i < 100; i++) {
+            validateUrlProtocolMethod.invoke(null, connection);
+        }
+
         long startTime = System.nanoTime();
         for (int i = 0; i < 1000; i++) {
             validateUrlProtocolMethod.invoke(null, connection);
         }
         long endTime = System.nanoTime();
-        
+
         long durationMs = (endTime - startTime) / 1_000_000;
-        assertTrue(durationMs < 100, "Protocol validation should be fast (took " + durationMs + "ms for 1000 calls)");
+        // Use generous threshold for CI environments with variable performance
+        assertTrue(durationMs < 500, "Protocol validation should be fast (took " + durationMs + "ms for 1000 calls)");
     }
 }