src/hotspot/share/jfr/recorder/service/jfrPostBox.cpp

*** 137,147 ****
    return Atomic::load(&_messages) == 0;
  }
  
  int JfrPostBox::collect() {
    // get pending and reset to 0
!   const int messages = Atomic::xchg(0, &_messages);
    if (check_waiters(messages)) {
      _has_waiters = true;
      assert(JfrMsg_lock->owned_by_self(), "incrementing _msg_read_serial is protected by JfrMsg_lock");
      // Update made visible on release of JfrMsg_lock via fence instruction in Monitor::IUnlock.
      ++_msg_read_serial;
--- 137,147 ----
    return Atomic::load(&_messages) == 0;
  }
  
  int JfrPostBox::collect() {
    // get pending and reset to 0
!   const int messages = Atomic::xchg(&_messages, 0);
    if (check_waiters(messages)) {
      _has_waiters = true;
      assert(JfrMsg_lock->owned_by_self(), "incrementing _msg_read_serial is protected by JfrMsg_lock");
      // Update made visible on release of JfrMsg_lock via fence instruction in Monitor::IUnlock.
      ++_msg_read_serial;