if(VM_HardwarePerformanceMonitors.verbose>=4) { VM.sysWriteln("VM_TraceWriter.writeHeader() write headerFilename \"",VM_HardwarePerformanceMonitors.hpm_info.headerFilename(),"\""); }
  private void writeHeader()  {    if(VM_HardwarePerformanceMonitors.verbose>=2){ VM.sysWriteln("VM_TraceWriter.writeHeader() PID ",pid); }    byte[] buffer   = new byte[32+(10*100)];	// temporary buffer    int    index    = 0;        // write version number     int version_number = VM_HardwarePerformanceMonitors.hpm_info.version_number;    VM_Magic.setIntAtOffset(buffer, index, version_number);    index += VM_HardwarePerformanceMonitors.SIZE_OF_INT;    // write name of header file    index = VM_HardwarePerformanceMonitors.writeStringToBuffer(buffer, index, VM_HardwarePerformanceMonitors.hpm_info.headerFilename().getBytes());    // write header to file.    writeFileOutputStream(buffer, index);  }