1 files changed, 40 insertions, 1 deletions
diff --git a/libjava/classpath/java/lang/ThreadGroup.java b/libjava/classpath/java/lang/ThreadGroup.java
index 7fbef88..00f2f8e 100644
--- a/libjava/classpath/java/lang/ThreadGroup.java
+++ b/libjava/classpath/java/lang/ThreadGroup.java
@@ -66,7 +66,7 @@ public class ThreadGroup implements UncaughtExceptionHandler
   static boolean had_uncaught_exception;
 
   /** The parent thread group. */
-  private final ThreadGroup parent;
+  final ThreadGroup parent;
 
   /** The group name, non-null. */
   final String name;
@@ -749,4 +749,43 @@ public class ThreadGroup implements UncaughtExceptionHandler
           parent.removeGroup(this);
       }
   }
+
+  /*
+   * Helper method for the VM. Find a Thread by its Id.
+   *
+   * @param id The Thread Id.
+   * @return Thread object or null if thread doesn't exist.
+   */
+  static Thread getThreadFromId(long id)
+  {
+    return root.getThreadFromIdImpl(id);
+  }
+
+  private Thread getThreadFromIdImpl(long id)
+  {
+    synchronized (threads)
+      {
+        for (int i = 0; i < threads.size(); i++)
+          {
+            Thread t = (Thread) threads.get(i);
+            if (t.getId() == id)
+              return t;
+          }
+      }
+    Vector groups = this.groups;
+    if (groups != null)
+      {
+        synchronized (groups)
+          {
+            for (int i = 0; i < groups.size(); i++)
+              {
+                ThreadGroup g = (ThreadGroup) groups.get(i);
+                Thread t = g.getThreadFromIdImpl(id);
+                if (t != null)
+                  return t;
+              }
+          }
+      }
+    return null;
+  }
 } // class ThreadGroup