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  1. JDK
  2. JDK-6798062

Memory Leak on using getFiles of FileSystemView

    Details

    • Subcomponent:
    • Resolved In Build:
      b55
    • CPU:
      x86
    • OS:
      windows_xp, windows_vista
    • Verification:
      Not verified

      Backports

        Description

        FULL PRODUCT VERSION :
        tested on jre 1.6_10

        ADDITIONAL OS VERSION INFORMATION :
        Windows Vista 64Bit business..

        though problem seems to appear on more os

        A DESCRIPTION OF THE PROBLEM :
        On using FileSystemView.getFiles() to retrieve all children of a directory the used memory shown by the OS rises. Though Heap and non Heap memory shown by jconsole stay the same.


        STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
        SSCCE given below ... just run it



        EXPECTED VERSUS ACTUAL BEHAVIOR :
        EXPECTED -
        Simple demo should just print ount current ammount of files on the disc...
        And not use much memory.
        ACTUAL -
        Memory usage of the java process rose by about 200 MiB per minute.

        REPRODUCIBILITY :
        This bug can be reproduced always.

        ---------- BEGIN SOURCE ----------

        import java.io.File;
        import javax.swing.filechooser.FileSystemView;


        public class LeakTest {

        private static long counter = 0;

        private static FileSystemView view = FileSystemView.getFileSystemView();

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

        while (true) {
        for (File f : File.listRoots()) {
        if (f.isDirectory()) {
        countFiles(f);
        System.out.println("found: "+counter);
        }
        }
        System.out.println("found Total: "+counter);
        counter = 0;
        Thread.sleep(1000);
        }



        }

        private static void countFiles(File root) {

        for (File f :view.getFiles(root, false)) {
        if (f.isDirectory()) {
        countFiles(f);
        } else {
        counter++;
        }
        }
        }

        }
        ---------- END SOURCE ----------

        CUSTOMER SUBMITTED WORKAROUND :
        Not a very good one:
        Using the following method gives nearly the same behaviour... though FileSystemViews list files still shows different kind of files as visible then File.isHidden()
        i.e. $Recycle.bin on Windows

        private static File[] getFiles(File parent,boolean useHidden) {
        File[] files = parent.listFiles();
        if (files == null) return new File[0];

        if (useHidden) {
        int length = files.length;
        for (int i = 0; i < length; i++) {
        if (files[i].isHidden()) {
        length--;
        System.arraycopy(files, i+1, files, i, length-i );
        }
        }
        if (length != files.length) {
        File[] onlyVisible = new File[length];
        System.arraycopy(files, 0, onlyVisible, 0, length);
        return onlyVisible;
        }
        }
        return files;

        }

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                • Assignee:
                  rupashka Pavel Porvatov (Inactive)
                  Reporter:
                  igor Igor Nekrestyanov (Inactive)
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                  • Created:
                    Updated:
                    Resolved:
                    Imported:
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