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Tidy thread-safeness

From: Andy Quick <ac.quick@sympatico.ca>
Date: Sat, 26 Jun 1999 22:18:09 -0400
Message-ID: <000d01bec044$0b585500$6dceacce@quick>
To: <html-tidy@w3.org>
Dave,

This is a concern I have about your claim that the tidy parser is
thread-safe.  My concern is that some functions in parser.c reference
the static data item 'SeenBodyEndTag'.  Shouldn't this data item be
contained in an object that is instantiated for each thread? (such as
Lexer - maybe this doesn't make logical sense, but makes sense for
thread-safeness) I am assuming that you mean multiple threads in the
same process can call main.

I have built Java Tidy as a JavaBean.  The main class, Tidy, defines
a static 'main' method that is used for command line invocation.  It also
defines a method 'parse' that takes input and output stream arguments.
Since Java Tidy is a Bean, it can be instantiated in multiple threads
like this:

<CODE>
import java.io.IOException;
import java.io.FileOutputStream;
import java.io.FileInputStream;
import java.io.PrintWriter;
import java.io.FileWriter;
import org.w3c.tidy.Tidy;

public class Test16 implements Runnable {

    private String url;
    private String outFileName;
    private String errOutFileName;
    private boolean xmlOut;

    public Test16(String url, String outFileName,
                  String errOutFileName, boolean xmlOut)
    {
        this.url = url;
        this.outFileName = outFileName;
        this.errOutFileName = errOutFileName;
        this.xmlOut = xmlOut;
    }

    public void run()
    {
        FileInputStream in;
        FileOutputStream out;
        Tidy tidy = new Tidy();  // create instance of Tidy JavaBean

        tidy.setXmlOut(xmlOut);  // set XmlOut property
        try {
            tidy.setErrout(new PrintWriter(new FileWriter(errOutFileName), true));
            in = new FileInputStream(url);
            out = new FileOutputStream(outFileName);
            tidy.parse(in, out);
        }
        catch ( IOException e ) {
            System.out.println( this.toString() + e.toString() );
        }
    }

    public static void main( String[] args ) {
        Test16 t1 = new Test16(args[0], args[1], args[2], true);
        Test16 t2 = new Test16(args[3], args[4], args[5], false);
        Thread th1 = new Thread(t1);
        Thread th2 = new Thread(t2);

        th1.start(); // produces xml
        th2.start(); // produces html
    }

}
</CODE>

However, since 'SeenBodyEndTag' is a static data item in class ParserImpl,
I don't think Java Tidy is fully thread-safe because of this.

Andy Quick
Received on Saturday, 26 June 1999 22:24:27 GMT

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