--- a/src/hotspot/share/jfr/utilities/jfrTryLock.hpp	Mon Nov 25 12:32:40 2019 +0100
+++ b/src/hotspot/share/jfr/utilities/jfrTryLock.hpp	Mon Nov 25 12:33:15 2019 +0100
@@ -36,7 +36,7 @@
   bool _has_lock;
 
  public:
-  JfrTryLock(volatile int* lock) : _lock(lock), _has_lock(Atomic::cmpxchg(1, lock, 0) == 0) {}
+  JfrTryLock(volatile int* lock) : _lock(lock), _has_lock(Atomic::cmpxchg(lock, 0, 1) == 0) {}
 
   ~JfrTryLock() {
     if (_has_lock) {