add another check before we execute the synchronized code to propagate

Author: mknet

log4j-jul/src/main/java/org/apache/logging/log4j/jul/Log4jBridgeHandler.java

@@ -175,15 +175,19 @@ public void publish(LogRecord record) {
             return;
         }
 
+        // Only execute synchronized code if we really have to
         if (this.installAsLevelPropagator) {
             synchronized(this) {
-                @SuppressWarnings("resource")    // no need to close the AutoCloseable ctx here
-                LoggerContext context = LoggerContext.getContext(false);
-                context.addPropertyChangeListener(this);
-                propagateLogLevels(context.getConfiguration());
-                // note: java.util.logging.LogManager.addPropertyChangeListener() could also
-                // be set here, but a call of JUL.readConfiguration() will be done on purpose
-                this.installAsLevelPropagator = false;
+                // Check again to make sure we still have to propagate  the levels at this point
+                if (this.installAsLevelPropagator) {
+                    @SuppressWarnings("resource")    // no need to close the AutoCloseable ctx here
+                    LoggerContext context = LoggerContext.getContext(false);
+                    context.addPropertyChangeListener(this);
+                    propagateLogLevels(context.getConfiguration());
+                    // note: java.util.logging.LogManager.addPropertyChangeListener() could also
+                    // be set here, but a call of JUL.readConfiguration() will be done on purpose
+                    this.installAsLevelPropagator = false;
+                }
             }
         }