[HTTPASYNC-77] Client leaks file descriptors if .execute() not called

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.0.1
• Fix Version/s: 4.0.2
• Labels: performance
• Environment: Ubuntu 12.04, possibly others
• Assignee: Unassigned
• Reporter: Paul Draper
• Created: 31/May/14 16:32
• Updated: 31/May/14 23:04
• Resolved: 31/May/14 18:20

Description

This leaks one anon_inode and two pipes:

CloseableHttpAsyncClient client = HttpAsyncClients.createDefault();
client.start();
client.close();

This does not:

CloseableHttpAsyncClient client = HttpAsyncClients.createDefault();
client.start();
client.execute(new HttpGet("https://issues.apache.org/jira/"), null);
client.close();

Full sample code (for Linux):

import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
import org.apache.http.impl.nio.client.HttpAsyncClients;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.lang.management.ManagementFactory;
import java.util.concurrent.ExecutionException;

public class Benchmark {

    public static void main(String[] args) throws ExecutionException, InterruptedException, IOException  {
        printFileDescriptorCounts();
        for(int i = 0; i < 20; i++) {
            CloseableHttpAsyncClient client = HttpAsyncClients.createDefault();
            client.start();
            // uncomment the next line to fix the leak
            // client.execute(new HttpGet("http://stackoverflow.com/questions/23966483"), null);
            client.close();
            printFileDescriptorCounts();
        }
    }

    // not portable -- Linux only
    private static void printFileDescriptorCounts() throws IOException {
        String processId = ManagementFactory.getRuntimeMXBean().getName().split("@")[0];
        String cmd = String.format("lsof -p %s | grep 'anon_inode\\|pipe' | awk '{ print $NF; }' | sort | uniq -c", processId);
        Process process = Runtime.getRuntime().exec(new String[]{"/bin/sh", "-c", cmd});
        BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()));
        try {
            for(String line; (line = br.readLine()) != null; ) {
                System.out.print(line.replace("\n", "\t"));
            }
            System.out.println();
        } finally {
            br.close();
            process.destroy();
        }
    }

}