[IO-760] FileUtils.iterateFiles create Too many open files

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Information Provided
• Affects Version/s: 2.11.0
• Component/s: Utilities

Environment

Commons-io 2.11.0

Java 11

Linux

Language

Java

• Assignee: Unassigned
• Reporter: thierry Martinez
• Created: 02/Feb/22 14:26
• Updated: 02/Feb/22 16:41
• Resolved: 02/Feb/22 16:27

Description

When i use FileUtils.iterateFiles and i decide to not iterate on all results, something is not closed correctly.

This code create "Too Many Open files":

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.util.Iterator;
import org.apache.commons.io.FileUtils;public class FileUtilsTest {
    static long step=0;
    public static void main(String[] argv) throws IOException {
        
        /*
         * create test directory
         */
        File tmpDirectory = Files.createTempDirectory("pipo").toFile();
        try {
            /*
             * add one file
             */
            new File(tmpDirectory, "first").createNewFile();            /*
             * try until TooManyOpenFiles Exception
             */
            while(true) {
                /*
                 * Iterate only to find first entry
                 */
                Iterator<File> candidates = FileUtils.iterateFiles(tmpDirectory, null, false);
                if (!candidates.hasNext()) {
                    throw new RuntimeException("one file must exists");
                }
                System.out.print("\rend step:"+(++step));
            }
        } finally {
            FileUtils.deleteDirectory(tmpDirectory);
        }
    }}
 

Exception trace:

java -cp Bug-all.jar FileUtilsTest
end step:2044
Exception in thread "main" java.io.UncheckedIOException: /tmp/pipo4192501847009771344
        at org.apache.commons.io.FileUtils.iterateFiles(FileUtils.java:1927)
        at FileUtilsTest.main(FileUtilsTest.java:28)
Caused by: java.nio.file.FileSystemException: /tmp/pipo4192501847009771344: Too many open files
        at java.base/sun.nio.fs.UnixException.translateToIOException(UnixException.java:100)
        at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:111)
        at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:116)
        at java.base/sun.nio.fs.UnixFileSystemProvider.newDirectoryStream(UnixFileSystemProvider.java:432)
        at java.base/java.nio.file.Files.newDirectoryStream(Files.java:472)
        at java.base/java.nio.file.FileTreeWalker.visit(FileTreeWalker.java:300)
        at java.base/java.nio.file.FileTreeWalker.walk(FileTreeWalker.java:322)
        at java.base/java.nio.file.FileTreeIterator.<init>(FileTreeIterator.java:71)
        at java.base/java.nio.file.Files.walk(Files.java:3825)
        at org.apache.commons.io.file.PathUtils.walk(PathUtils.java:1044)
        at org.apache.commons.io.FileUtils.streamFiles(FileUtils.java:2971)
        at org.apache.commons.io.FileUtils.iterateFiles(FileUtils.java:1925)
        ... 1 more