001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 */ 019package org.apache.reef.wake; 020 021import org.apache.reef.wake.metrics.Meter; 022 023import java.util.concurrent.atomic.AtomicBoolean; 024 025/** 026 * An {@link EStage} that implements metering. 027 * 028 * @param <T> type 029 */ 030public abstract class AbstractEStage<T> implements EStage<T> { 031 032 protected final AtomicBoolean closed; 033 protected final String name; 034 private final Meter inMeter; 035 036 /** 037 * outputs share a single meter. 038 */ 039 private final Meter outMeter; 040 041 /** 042 * Constructs an abstract estage. 043 * 044 * @param stageName the stage name 045 */ 046 public AbstractEStage(final String stageName) { 047 this.closed = new AtomicBoolean(false); 048 this.name = stageName; 049 this.inMeter = new Meter(stageName + "_in"); 050 this.outMeter = new Meter(stageName + "_out"); 051 } 052 053 /** 054 * Gets the input meter of this stage. 055 * 056 * @return the input meter 057 */ 058 public Meter getInMeter() { 059 return inMeter; 060 } 061 062 /** 063 * Gets the output meter of this stage. 064 * 065 * @return the output meter 066 */ 067 public Meter getOutMeter() { 068 return outMeter; 069 } 070 071 /** 072 * Updates the input meter. 073 * <p> 074 * Stages that want to meter their 075 * input must call this each time an event is input. 076 */ 077 protected void beforeOnNext() { 078 inMeter.mark(1); 079 } 080 081 /** 082 * Updates the output meter. 083 * <p> 084 * Stages that want to meter their 085 * output must call this each time an event is output. 086 */ 087 protected void afterOnNext() { 088 outMeter.mark(1); 089 } 090 091 /** 092 * Check if the stage can still accept messages. 093 * @return true if the stage is closed, false otherwise. 094 */ 095 public boolean isClosed() { 096 return closed.get(); 097 } 098 099 /** 100 * Get human readable representation of the class (used for logging). 101 * @return A string that contains stage name. 102 */ 103 @Override 104 public String toString() { 105 return String.format("Stage:%s:%s", this.getClass().getCanonicalName(), name); 106 } 107}