Here you can find the source of getMmapBufferUsage()
public static long getMmapBufferUsage()
//package com.java2s; /**//from ww w . j a va 2 s .c om * Copyright (C) 2014-2016 LinkedIn Corp. (pinot-core@linkedin.com) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.util.concurrent.atomic.AtomicLong; public class Main { private static final AtomicLong MMAP_BUFFER_USAGE = new AtomicLong(0L); /** * Returns the number of bytes of memory mapped files. */ public static long getMmapBufferUsage() { return MMAP_BUFFER_USAGE.get(); } }