Closing a RandomAccessFile sometimes takes exactly 45 seconds

Question

In my program, closing a java.util.RandomAccessFile sometimes takes exactly 45 seconds (well, almost exactly: between 44.998 and 45.003 seconds). The program creates and closes lots of small files. Usually closing the file is very quick (between 0 and 0.1 seconds). If I debug the program, it's stuck in the native method RandomAccessFile.close0.

The same problem also occurs when using FileOutputStream instead of RandomAccessFile (in which case the program is blocked in the native method FileOutputStream.close0).

Has somebody an idea what that could be? Can you reproduce the problem on your system (I can reproduce it only on a Mac, not on Windows XP; I didn't test yet on Linux)?

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Update 2:

This only seems to happend on Mac OS X. I use JDK 1.6.0_22-b04. It happens on both 32-bit and 64-bit. On Windows XP it doesn't seem to occur.

My test case is:

import java.io.File;
import java.io.RandomAccessFile;
public class TestFileClose {
    public static void main(String... args) throws Exception {
        for (int i = 0; i < 100000; i++) {
            String name = "test" + i;
            RandomAccessFile r = new RandomAccessFile(name, "rw");
            r.write(0);
            long t = System.currentTimeMillis();
            r.close();
            long close = System.currentTimeMillis() - t;
            if (close > 200) {
                System.out.println("closing " + name +
                        " took " + close + " ms!");
            }
            if (i % 2000 == 0) {
                System.out.println("test " + i + "/100000");
            }
            new File(name).delete();
        }
    }
}

Example output on my machine:

test 0/100000
test 2000/100000
test 4000/100000
test 6000/100000
test 8000/100000
test 10000/100000
closing test10030 took 44998 ms!
test 12000/100000
test 14000/100000
test 16000/100000
closing test16930 took 44998 ms!
test 18000/100000
test 20000/100000

Answer 1

In my case, it turned out to be McAfee antivirus installed on my machine. I had to install it (company policy)...

The problem also showed up if I disabled the on-access scan.