When running on Linux (only tried on Linux), the following code seems to leak 1 anon_inode, and 2 pipe file descriptors, according to lsof:
CloseableHttpAsyncClient client = HttpAsyncClients.createDefault();
client.start();
client.close();
If, however, client.execute() is called one or more times, the leak does not happen.
CloseableHttpAsyncClient client = HttpAsyncClients.createDefault();
client.start();
client.execute(new HttpGet("http://stackoverflow.com/questions/23966483"), null);
client.close();
Full sample code:
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();
//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();
}
}
}
I see
3 pipe
1 anon_inode 5 pipe
2 anon_inode 7 pipe
3 anon_inode 9 pipe
4 anon_inode 11 pipe
5 anon_inode 13 pipe
6 anon_inode 15 pipe
7 anon_inode 17 pipe
8 anon_inode 19 pipe
9 anon_inode 21 pipe
10 anon_inode 23 pipe
11 anon_inode 25 pipe
12 anon_inode 27 pipe
13 anon_inode 29 pipe
14 anon_inode 31 pipe
15 anon_inode 33 pipe
16 anon_inode 35 pipe
17 anon_inode 37 pipe
18 anon_inode 39 pipe
19 anon_inode 41 pipe
20 anon_inode 43 pipe
If I uncomment the execute line, the leak disappears.
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
3 pipe
(1) Is the intended/expected behavior, or is this a bug?
(2) Why/how does this happen?
