ml.shifu.guagua.util.JMap Maven / Gradle / Ivy
/**
* Copyright [2013-2014] eBay Software Foundation
*
* 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.
*/
package ml.shifu.guagua.util;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.lang.management.ManagementFactory;
import java.nio.charset.Charset;
import java.util.Date;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Helper to run jmap and print the output. Copy from Apache Giraph.
*/
public class JMap {
private static final Logger LOG = LoggerFactory.getLogger(JMap.class);
/** The command to run */
public static final String CMD = "jmap ";
/** Arguments to pass in to command */
public static final String ARGS = " -histo ";
/** Do not construct */
protected JMap() {
}
/**
* Get the process ID of the current running process
*
* @return Integer process ID
*/
public static int getProcessId() {
String processId = ManagementFactory.getRuntimeMXBean().getName();
if(processId.contains("@")) {
processId = processId.substring(0, processId.indexOf("@"));
}
return Integer.parseInt(processId);
}
/**
* Run jmap, print numLines of output from it to stderr.
*
* @param numLines
* Number of lines to print
*/
public static void heapHistogramDump(int numLines) {
heapHistogramDump(numLines, System.err);
}
/**
* Run jmap, print numLines of output from it to stream passed in.
*
* @param numLines
* Number of lines to print
* @param printStream
* Stream to print to
*/
public static void heapHistogramDump(int numLines, PrintStream printStream) {
BufferedReader in = null;
try {
Process p = Runtime.getRuntime().exec(CMD + ARGS + getProcessId());
in = new BufferedReader(new InputStreamReader(p.getInputStream(), Charset.defaultCharset()));
printStream.println("JMap histo dump at " + new Date());
String line = in.readLine();
for(int i = 0; i < numLines && line != null; ++i) {
printStream.println("--\t" + line);
line = in.readLine();
}
} catch (IOException e) {
LOG.error("IOException in dump heap", e);
} finally {
if(in != null) {
try {
in.close();
} catch (IOException e) {
LOG.error("Error in closing input stream", e);
}
}
}
}
}