FULL PRODUCT VERSION :
1.4.2_02

ADDITIONAL OS VERSION INFORMATION :
Windows 2003 Server

A DESCRIPTION OF THE PROBLEM :
Given the program

public class PatternProblem {
  
  private static Pattern pattern=null;
 
  public static void main(String[] args) throws InterruptedException {
    int threads = Integer.parseInt(args[0]);
    int loadPattern = Integer.parseInt(args[1]);
    if(loadPattern==1) {
      pattern = Pattern.compile("^\\p{Digit}");
    }
    TestThread[] tt = new TestThread [threads];
    for (int i = 0; i < tt.length; i++) {
      tt[i] = new TestThread();
    }
    for (int i = 0; i < tt.length; i++) {
      tt[i].start();
    }
    for (int i = 0; i < tt.length; i++) {
      tt[i].join();
    }
  }
}
 
class TestThread extends Thread {

  public void run () {
    String str = "1LALA";
    try {
      str = str.replaceAll("^\\p{Digit}", "R");
      str = str.replaceAll("[^\\p{Lower}\\p{Upper}\\p{Digit}]", "_");
    } catch (Exception e) {
      System.out.println(this.getName()+":"+e.getMessage());
    }
  }
 
}

regular PatternSyntaxException are returned when started with e.g. 10 threads and 0 for the loadPattern argument. on a multiprocessor machine.
When starting with loadPattern 1 the exception is never thrown.

This seems to trace back to the following JDK code (java.util.regex.Pattern)

private Node retrieveCategoryNode(String name) {
        if (categories == null) {
            int cns = categoryNodes.length;
            categories = new HashMap((int)(cns/.75) + 1);
            for (int x=0; x<cns; x++)
                categories.put(categoryNames[x], categoryNodes[x]);
        }
        Node n = (Node)categories.get(name);
        if (n != null)
            return n;
 
        return familyError(name, "Unknown character category {");
    }
...
   static HashMap categories = null;
...

THe initialization of the static categories HashMap is not protected which sometimes gives issues in a multithreaded application on a multiprocessor machine.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Execute the repro on a multiprocessor machine with with 10 for the first and 0 for the second run time argument.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
No PatternSyntaxException
ACTUAL -
Intermittent PatternSyntaxException

ERROR MESSAGES/STACK TRACES THAT OCCUR :
Stack trace as in
java.util.regex.PatternSyntaxException: Unknown character category {Digit} near index 9
^\p{Digit}
^
at java.util.regex.Pattern.error(Unknown Source)
at java.util.regex.Pattern.familyError(Unknown Source)
at java.util.regex.Pattern.retrieveCategoryNode(Unknown Source)
at java.util.regex.Pattern.family(Unknown Source)
at java.util.regex.Pattern.sequence(Unknown Source)
at java.util.regex.Pattern.expr(Unknown Source)
at java.util.regex.Pattern.compile(Unknown Source)
at java.util.regex.Pattern.<init>(Unknown Source)
at java.util.regex.Pattern.compile(Unknown Source)
at java.lang.String.replaceAll(Unknown Source)


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.regex.Pattern;



public class PatternProblem {
  
  private static Pattern pattern=null;

  public static void main(String[] args) throws InterruptedException {
    int threads = Integer.parseInt(args[0]);
    int loadPattern = Integer.parseInt(args[1]);
    if(loadPattern==1) {
      pattern = Pattern.compile("^\\p{Digit}");
    }
    TestThread[] tt = new TestThread [threads];
    for (int i = 0; i < tt.length; i++) {
      tt[i] = new TestThread();
    }
    for (int i = 0; i < tt.length; i++) {
      tt[i].start();
    }
    for (int i = 0; i < tt.length; i++) {
      tt[i].join();
    }
  }
}

class TestThread extends Thread {

  public void run () {
    String str = "1LALA";
    try {
      str = str.replaceAll("^\\p{Digit}", "R");
      str = str.replaceAll("[^\\p{Lower}\\p{Upper}\\p{Digit}]", "_");
    } catch (Exception e) {
      System.out.println(this.getName()+":"+e.getMessage());
    }
  }

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

CUSTOMER SUBMITTED WORKAROUND :
Adding
   pattern = Pattern.compile("^\\p{Digit}");
to the main thread before other threads are started
###@###.### 2005-03-10 09:23:36 GMT