import javax.management.*;

import javax.management.openmbean.CompositeData;

import com.sun.management.GcInfo;

import com.sun.management.GarbageCollectionNotificationInfo;

sclass GCPause {

  long start, duration;

  S name, cause, action;

  toString {

    ret "GCPause duration=" + duration + " ms, start=" + start + " (VM time). " + renderStructs(+name, +cause, +action);

  }

}

static new Flag collectGCPauses_started;

static L<GCPause> collectGCPauses_list;

static void collectGCPauses() {

  collectGCPauses(1000);

}

static void collectGCPauses(int bufferSize) {

  if (!collectGCPauses_started.raise()) ret;

  collectGCPauses_list = synchroList(LatestList(bufferSize));

  onGCNotification(voidfunc(GarbageCollectionNotificationInfo info) {

    GcInfo gcInfo = info.getGcInfo();

    GCPause pause = nu(GCPause,

      start := gcInfo.getStartTime(),

      duration := gcInfo.getDuration(),

      name := info.getGcName(),

      cause := info.getGcCause(),

      action := info.getGcAction());

    collectGCPauses_list.add(pause);

  });

}