TickCounter gc0;
TickCounter gc1;
public PerfCounterGcCpuUsageMonitor(long pid) {
JStatData jd = JStatData.connect(pid);
gc0 = (TickCounter) jd.getAllCounters().get("sun.gc.collector.0.time");
gc1 = (TickCounter) jd.getAllCounters().get("sun.gc.collector.1.time");
}