diff -r f082177c5023 -r 10ecdb5d3574 src/hotspot/share/jfr/recorder/checkpoint/jfrMetadataEvent.cpp
--- a/src/hotspot/share/jfr/recorder/checkpoint/jfrMetadataEvent.cpp	Thu Sep 05 16:46:50 2019 +0200
+++ b/src/hotspot/share/jfr/recorder/checkpoint/jfrMetadataEvent.cpp	Mon Sep 09 13:26:35 2019 +0200
@@ -29,21 +29,11 @@
 #include "oops/klass.inline.hpp"
 #include "oops/oop.inline.hpp"
 #include "oops/typeArrayOop.inline.hpp"
-#include "runtime/semaphore.hpp"
 #include "runtime/thread.inline.hpp"
 
 static jbyteArray _metadata_blob = NULL;
 static u8 metadata_id = 0;
 static u8 last_written_metadata_id = 0;
-static Semaphore metadata_mutex_semaphore(1);
-
-void JfrMetadataEvent::lock() {
-  metadata_mutex_semaphore.wait();
-}
-
-void JfrMetadataEvent::unlock() {
-  metadata_mutex_semaphore.signal();
-}
 
 static void write_metadata_blob(JfrChunkWriter& chunkwriter, jbyteArray metadata_blob) {
   if (metadata_blob != NULL) {