CODEWITHSUNDEEP
javatools.jar
lovelywib
lovelywib

Reputation: 579

java compiler with java.lang.NullPointerException: Inflater has been closed

I've googled around on internet, but haven't found a problem exactly matching mine. So, I decided to post here.

Recently, our ANT building is throwing the following exception intermittently. And it's becoming more and more frequent.

The issue looks like related to:

However, the test case runs pretty OK on our JVM (IBM Java 7.1). So, the bug mentioned above shouldn't be the cause anymore.

I looked into the source code of the compiler, though I'm not quite good at it.

ZipFileIndex.class

public class ZipFileIndex
{
    .......
    private SoftReference<Inflater> inflaterRef;
    ......

    private int inflate(byte[] paramArrayOfByte1, byte[] paramArrayOfByte2)
    {
        Inflater localInflater = this.inflaterRef == null ? null : (Inflater)this.inflaterRef.get();

        if (localInflater == null) {
          this.inflaterRef = new SoftReference(localInflater = new Inflater(true));
        }
        localInflater.reset();
        localInflater.setInput(paramArrayOfByte1);
        try {
            return localInflater.inflate(paramArrayOfByte2); } catch (DataFormatException localDataFormatException) {
        }
        return -1;
    }

......
}

Inflater.class

......

public void reset() {
    synchronized (zsRef) {
        ensureOpen();
        reset(zsRef.address());
        buf = defaultBuf;
        finished = false;
        needDict = false;
        off = len = 0;
    }
}

......

public void end() {
    synchronized (zsRef) {
        long addr = zsRef.address();
        zsRef.clear();
        if (addr != 0) {
            end(addr);
            buf = null;
        }
    }
}

/**
 * Closes the decompressor when garbage is collected.
 */
protected void finalize() {
    end();
}

private void ensureOpen () {
    assert Thread.holdsLock(zsRef);
    if (zsRef.address() == 0)
        throw new NullPointerException("Inflater has been closed");
}

......

The "SoftReference" is very suspicous. Our ANT building can easily reach above 1024m, and I can still see the exception when setting MAX HeapSize to 1024m. (now I've changed it to 2048m, fingers crossed).

If this.inflaterRef is being collected right after initialization:

  1. Inflater.finalized() called
  2. zsRef is cleared, so zsRef.address() is set to 0
  3. Then Inflater.ensureOpen() is called
  4. exceptions thrown.

Here are my questions:

  1. Has anyone seen this exception before? If so, is there any good solution for it.
  2. Is my analysis correct?
  3. Is there a good way to insert some logging code to tools.jar? So, we can know what exactly happens before and after this exception. Decompile and recompile?
  4. Any idea to make this exception always happen?

Here is the stack trace*

An exception has occurred in the compiler (1.7.0-internal). Please file a bug at the Java Developer Connection (http://java.sun.com/webapps/bugreport) after checking the Bug Parade for duplicates. Include your program and the following diagnostic in your report. Thank you. java.lang.NullPointerException: Inflater has been closed at java.util.zip.Inflater.ensureOpen(Inflater.java:413) at java.util.zip.Inflater.reset(Inflater.java:375) at com.sun.tools.javac.file.ZipFileIndex.inflate(ZipFileIndex.java:467) at com.sun.tools.javac.file.ZipFileIndex.readBytes(ZipFileIndex.java:403) at com.sun.tools.javac.file.ZipFileIndex.read(ZipFileIndex.java:372) at com.sun.tools.javac.file.ZipFileIndex.read(ZipFileIndex.java:372) at com.sun.tools.javac.file.ZipFileIndexArchive$ZipFileIndexFileObject.openInputStream(ZipFileIndexArchive.java:163) at com.sun.tools.javac.jvm.ClassReader.fillIn(ClassReader.java:2219) at com.sun.tools.javac.jvm.ClassReader.complete(ClassReader.java:2151) at com.sun.tools.javac.code.Symbol.complete(Symbol.java:433) at com.sun.tools.javac.code.Symbol$ClassSymbol.complete(Symbol.java:833) at com.sun.tools.javac.jvm.ClassReader.loadClass(ClassReader.java:2332) at com.sun.tools.javac.comp.Resolve.loadClass(Resolve.java:1074) at com.sun.tools.javac.comp.Resolve.findIdentInPackage(Resolve.java:1239) at com.sun.tools.javac.comp.Attr.selectSym(Attr.java:2404) at com.sun.tools.javac.comp.Attr.visitSelect(Attr.java:2295) at com.sun.tools.javac.tree.JCTree$JCFieldAccess.accept(JCTree.java:1689)

Upvotes: 2

Views: 2223

Answers (1)

lovelywib
lovelywib

Reputation: 579

In the past week, with ANT_OPTS setting to -Xms512m -Xmx2048m, the problem hasn't happened again.

BTW, it doesn't work when setting JAVA_OPTS to -Xms512m -Xmx2048m for ANT.

Upvotes: 0

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