リークの確認テスト

Leak.java

public class Leak {

	public static void main(String[] args) throws Exception {

		File tmpDir = new File("mytmp");
		if (!tmpDir.exists()) {
			tmpDir.mkdirs();
		}
		
		// 無理やりPIDを取得。Linuxのみ。
		RuntimeMXBean bean = ManagementFactory.getRuntimeMXBean();
		int pid = Integer.parseInt(bean.getName().split("@")[0]);
		
		for (int i = 0; i < 100; i++) {
			String sessionId = makeSessionId();
			File file = File.createTempFile(sessionId, ".pipeout", tmpDir);
			BufferedReader br = new BufferedReader(new FileReader(file));
			// OPENしっぱなし
			
			if (i % 10 == 0) {
				System.gc();
				System.out.println("exec GC.");
			}
			
			System.out.printf("%d, %d%n", i, getLsof(pid).size());
			TimeUnit.MILLISECONDS.sleep(100);
			
		}
	}
	
	// Hiveの処理をそのまま
	private static String makeSessionId() {
		GregorianCalendar gc = new GregorianCalendar();
		String userid = "tamtam";
		return userid
				+ "_"
				+ String.format("%1$4d%2$02d%3$02d%4$02d%5$02d",
						gc.get(Calendar.YEAR), gc.get(Calendar.MONTH) + 1,
						gc.get(Calendar.DAY_OF_MONTH),
						gc.get(Calendar.HOUR_OF_DAY), gc.get(Calendar.MINUTE));
	}

	// ここ手抜き処理なので、終了処理とかいい加減です。
	// 真似しちゃだめ。
	public static List<String> getLsof(int pid) throws Exception {
		
		LinkedList<String> list = new LinkedList<String>();
		
		ProcessBuilder pb = new ProcessBuilder();
		pb.command("lsof", "-p", String.valueOf(pid));
		Process p = pb.start();
		
		BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream(), "utf-8"));
		String line = null;
		while ((line = br.readLine()) != null) {
			list.add(line);
		}
		br.close();
		
		p.waitFor();
		p.destroy();
		
		return list;
	}
}

Result.txt

exec GC.
0, 34
1, 35
2, 36
3, 37
4, 38
5, 39
6, 40
7, 41
8, 42
9, 43
exec GC.
10, 34
11, 35
12, 36
13, 37
14, 38
15, 39
16, 40
17, 41
18, 42
19, 43
exec GC.
20, 34
21, 35
22, 36
23, 37
24, 38
25, 39
26, 40
27, 41
28, 42
29, 43
exec GC.
30, 34
31, 35
32, 36
33, 37
34, 38
35, 39
36, 40
37, 41
38, 42
39, 43
exec GC.
40, 34
41, 35
42, 36
43, 37
44, 38
45, 39
46, 40
47, 41
48, 42
49, 43
exec GC.
50, 34
51, 35
52, 36
53, 37
54, 38
55, 39
56, 40
57, 41
58, 42
59, 43
exec GC.
60, 34
61, 35
62, 36
63, 37
64, 38
65, 39
66, 40
67, 41
68, 42
69, 43
exec GC.
70, 34
71, 35
72, 36
73, 37
74, 38
75, 39
76, 40
77, 41
78, 42
79, 43
exec GC.
80, 34
81, 35
82, 36
83, 37
84, 38
85, 39
86, 40
87, 41
88, 42
89, 43
exec GC.
90, 34
91, 35
92, 36
93, 37
94, 38
95, 39
96, 40
97, 41
98, 42
99, 43