((VM_HardwarePerformanceMonitor)producer).notifyAppStart(app);
hpm.notifyAppStart(app);
  public void notifyAppStart(String app)  {    if (VM_HardwarePerformanceMonitors.hpm_trace) {      if(VM_HardwarePerformanceMonitors.verbose>=2){ VM.sysWriteln("VM_TraceWriter.notifyAppStart(",app,") PID ",pid); }      if (trace_file == null) {	VM.sysWriteln("\n***VM_TraceWriter.notifyAppStart() pid ",pid," trace_file == null!***\n");	return;	//	VM.sysExit(-1);      }      ((VM_HardwarePerformanceMonitor)producer).notifyAppStart(app);    }  }