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I am using Sphinx to parse grammar files.

I have a function that loads all the grammar files. This function is called at the start of the program and every time the user requests a reload. When called initially it works. The StackOverflowError arises when subsequent calls are made to this function. The particular line in the function that causes the error is the gram.listRuleNames() line, specifically the method of RuleGrammar listRuleNames().

Does anyone have an idea as to why this is occurring?

The function:

BaseRecognizer recognizer;

public static void main(String[] args) {
    recognizer = new BaseRecognizer();
    recognizer.allocate();
    LoadAllGrammars();
    Thread.sleep(1000);
    LoadAllGrammars();
    recognizer.deallocate();
}

private static void LoadAllGrammars() throws IOException {
    RuleGrammar[] gramss = recognizer.listRuleGrammars();
    for (RuleGrammar rg : gramss) {
        recognizer.deleteRuleGrammar(rg);
    }

    recognizer.commitChanges();

    RuleGrammar gram = null;

    URL dir = new File("grams").toURI().toURL();

    gram = recognizer.loadJSGF(dir, "main", true, true, null);

    String[] names = gram.listRuleNames();

    //the rest of the code in the function is irrelevant to the question
}

The error:

 Exception in thread "Thread-23" java.lang.StackOverflowError
    at java.util.HashMap$KeyIterator.<init>(Unknown Source)
    at java.util.HashMap.newKeyIterator(Unknown Source)
    at java.util.HashMap$KeySet.iterator(Unknown Source)
    at java.util.AbstractCollection.toArray(Unknown Source)
    at com.sun.speech.engine.recognition.BaseRuleGrammar.listRuleNames(BaseRuleGrammar.java:266)
    at com.sun.speech.engine.recognition.BaseRecognizer.loadFullQualifiedRules(BaseRecognizer.java:958)
    at com.sun.speech.engine.recognition.BaseRecognizer.loadImports(BaseRecognizer.java:938)
    at com.sun.speech.engine.recognition.BaseRecognizer.loadFullQualifiedRules(BaseRecognizer.java:980)

After some debugging I have noticed that recognizer.deleteRuleGrammar(rg) isn't deleting the old grammars.

I have narrowed it down to the line loadJSGF() which when called twice results in the StackOverflowError. I would think it has something to do with the recognizer not deleting the old grammars.

noahnu
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  • I am guessing its the for loop which is creating **a lot of** `Rule` object. – Shiplu Mokaddim Dec 31 '12 at 03:50
  • It works the first time the function is run, also according to the error (and the lack of lines being printed) it doesn't even get to the loop. – noahnu Dec 31 '12 at 04:50
  • Please provide the sample code to reproduce your problem. – Nikolay Shmyrev Jan 04 '13 at 14:59
  • I removed all references to my GrammarParser class and added a main function so you can reproduce my problem. – noahnu Jan 04 '13 at 18:47
  • HashMap is not thread safe; are you doing something concurrently? I do see no sign here, but possible. More likely you constructed something recursively in your data in your class. – Joop Eggen Jan 06 '13 at 18:04

0 Answers0