Replace counter with timestamp

Author: ppkarwasz

log4j-api-test/src/main/java/org/apache/logging/log4j/test/junit/TempLoggingDirectory.java

@@ -28,7 +28,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.atomic.AtomicInteger;
 import org.apache.logging.log4j.status.StatusLogger;
 import org.apache.logging.log4j.test.TestProperties;
 import org.junit.jupiter.api.extension.BeforeAllCallback;
@@ -46,8 +45,6 @@
 
 public class TempLoggingDirectory implements BeforeAllCallback, BeforeEachCallback, ParameterResolver {
 
-    private final AtomicInteger counter = new AtomicInteger();
-
     @Override
     public void beforeAll(ExtensionContext context) throws Exception {
         final List<Field> fields = AnnotationSupport.findAnnotatedFields(
@@ -155,8 +152,10 @@ private Path determinePerClassPath(ExtensionContext context) {
                 // Create a temporary directory that uses the simple class name as prefix
                 Path packagePath = basePath.resolve(dir);
                 Files.createDirectories(packagePath);
+                // Use a UNIX timestamp to (roughly) sort directories by execution time.
                 return Files.createTempDirectory(
-                        packagePath, String.format("%s_%02d_", clazz.getSimpleName(), counter.incrementAndGet()));
+                        packagePath,
+                        String.format("%s_%08x_", clazz.getSimpleName(), System.currentTimeMillis() / 1000));
             } catch (final IOException e) {
                 throw new ExtensionContextException("Failed to create temporary directory.", e);
             }

log4j-api-test/src/test/java/org/apache/logging/log4j/test/junit/TempLoggingDirectoryTest.java

@@ -27,7 +27,7 @@
 @UsingTestProperties
 public class TempLoggingDirectoryTest {
 
-    private static final Pattern PER_CLASS_PATH = Pattern.compile("TempLoggingDirectoryTest_\\d{2}_\\d+");
+    private static final Pattern PER_CLASS_PATH = Pattern.compile("TempLoggingDirectoryTest_[0-9a-f]{8,}_\\d+");
     private static final Path PER_TEST_PATH = Paths.get("testInjectedFields");
 
     @TempLoggingDir