ThreadGroup.java: Merged with classpath.
2000-06-20 Bryce McKinlay <bryce@albatross.co.nz> * java/lang/ThreadGroup.java: Merged with classpath. * prims.cc (_Jv_RunMain): Don't use ain_group'. * gnu/gcj/runtime/FirstThread.java: Remove ThreadGroup constructor argument. * java/lang/Thread.java (Thread): Bootstrap initial thread from ThreadGroup.root if Thread.currentThread is null. Honour the ThreadGroup's max priority setting. From-SVN: r34615
This commit is contained in:
Bryce McKinlay
Bryce McKinlay
parent
83fb52d8bb
commit
6dfd8a7790
5 changed files with 477 additions and 311 deletions
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@ -1,212 +1,437 @@
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// ThreadGroup.java - ThreadGroup class.
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/* Copyright (C) 1998, 1999, 2000 Free Software Foundation
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This file is part of libgcj.
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/* java.lang.ThreadGroup
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Copyright (C) 1998, 2000 Free Software Foundation, Inc.
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This file is part of libgcj.
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This software is copyrighted work licensed under the terms of the
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Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
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details. */
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package java.lang;
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import java.util.Enumeration;
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import java.util.Vector;
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/**
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* @author Tom Tromey <tromey@cygnus.com>
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* @date August 25, 1998
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*/
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import java.util.Enumeration;
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/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
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* "The Java Language Specification", ISBN 0-201-63451-1
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* plus online API docs for JDK 1.2 beta from http://www.javasoft.com.
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* Status: Complete for 1.1. Parts from the JDK 1.0 spec only are
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* not implemented. Parts of the 1.2 spec are also not implemented.
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* Status: Complete for 1.2. Parts from the JDK 1.0 spec only are
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* not implemented.
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*/
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/**
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* ThreadGroup allows you to group Threads together. There is a
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* hierarchy of ThreadGroups, and only the initial ThreadGroup has
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* no parent. A Thread may access information about its own
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* ThreadGroup, but not its parents or others outside the tree.
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*
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* @author John Keiser
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* @author Tom Tromey
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* @version 1.2.0, June 20, 2000
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* @since JDK1.0
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*/
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public class ThreadGroup
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{
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public int activeCount ()
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/* The Initial, top-level ThreadGroup. */
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static ThreadGroup root = new ThreadGroup();
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private ThreadGroup parent;
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private String name;
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private Vector threads = new Vector();
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private Vector groups = new Vector();
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private boolean daemon_flag = false;
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private boolean destroyed_flag = false;
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int maxpri = Thread.MAX_PRIORITY;
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private ThreadGroup()
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{
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int ac = threads.size();
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Enumeration e = groups.elements();
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while (e.hasMoreElements())
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name = "main";
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}
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/** Create a new ThreadGroup using the given name and the
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* current thread's ThreadGroup as a parent.
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* @param name the name to use for the ThreadGroup.
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*/
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public ThreadGroup(String name)
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{
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this (Thread.currentThread().getThreadGroup(), name);
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}
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/** Create a new ThreadGroup using the given name and
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* parent group.
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* @param name the name to use for the ThreadGroup.
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* @param parent the ThreadGroup to use as a parent.
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* @exception NullPointerException if parent is null.
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* @exception SecurityException if you cannot change
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* the intended parent group.
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*/
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public ThreadGroup(ThreadGroup parent, String name)
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{
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parent.checkAccess();
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this.parent = parent;
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if (parent.destroyed_flag)
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throw new IllegalArgumentException ();
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this.name = name;
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maxpri = parent.maxpri;
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daemon_flag = parent.daemon_flag;
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parent.add(this);
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}
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/** Get the name of this ThreadGroup.
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* @return the name of this ThreadGroup.
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*/
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public final String getName()
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{
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return name;
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}
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/** Get the parent of this ThreadGroup.
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* @return the parent of this ThreadGroup.
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*/
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public final ThreadGroup getParent()
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{
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return parent;
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}
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/** Set the maximum priority for Threads in this ThreadGroup. setMaxPriority
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* can only be used to reduce the current maximum. If maxpri
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* is greater than the current Maximum, the current value is not changed.
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* Calling this does not effect threads already in this ThreadGroup.
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* @param maxpri the new maximum priority for this ThreadGroup.
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* @exception SecurityException if you cannoy modify this ThreadGroup.
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*/
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public final void setMaxPriority(int maxpri)
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{
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checkAccess();
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if (maxpri < this.maxpri
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&& maxpri >= Thread.MIN_PRIORITY
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&& maxpri <= Thread.MAX_PRIORITY)
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{
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ThreadGroup g = (ThreadGroup) e.nextElement();
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ac += g.activeCount();
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}
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return ac;
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this.maxpri = maxpri;
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}
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}
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public int activeGroupCount ()
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/** Get the maximum priority of Threads in this ThreadGroup.
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* @return the maximum priority of Threads in this ThreadGroup.
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*/
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public final int getMaxPriority()
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{
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int ac = groups.size();
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Enumeration e = groups.elements();
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while (e.hasMoreElements())
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return maxpri;
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}
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/** Set whether this ThreadGroup is a daemon group. A daemon
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* group will be destroyed when its last thread is stopped and
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* its last thread group is destroyed.
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* @specnote The Java API docs indicate that the group is destroyed
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* when either of those happen, but that doesn't make
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* sense.
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* @param daemon whether this ThreadGroup should be a daemon group.
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* @exception SecurityException if you cannoy modify this ThreadGroup.
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*/
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public final void setDaemon (boolean daemon)
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{
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checkAccess();
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daemon_flag = daemon;
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}
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/** Tell whether this ThreadGroup is a daemon group. A daemon
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* group will be destroyed when its last thread is stopped and
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* its last thread group is destroyed.
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* @specnote The Java API docs indicate that the group is destroyed
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* when either of those happen, but that doesn't make
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* sense.
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* @return whether this ThreadGroup is a daemon group.
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*/
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public final boolean isDaemon()
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{
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return daemon_flag;
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}
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/** Tell whether this ThreadGroup has been destroyed or not.
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* @return whether this ThreadGroup has been destroyed or not.
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*/
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public boolean isDestroyed()
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{
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return destroyed_flag;
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}
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/** Check whether this ThreadGroup is an ancestor of the
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* specified ThreadGroup, or if they are the same.
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*
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* @param g the group to test on.
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* @return whether this ThreadGroup is a parent of the
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* specified group.
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*/
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public final boolean parentOf(ThreadGroup tg)
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{
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while (tg != null)
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{
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ThreadGroup g = (ThreadGroup) e.nextElement();
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ac += g.activeGroupCount();
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if (tg == this)
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return true;
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tg = tg.parent;
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}
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return ac;
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return false;
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}
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// Deprecated in 1.2.
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public boolean allowThreadSuspension (boolean allow)
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/** Return the total number of active threads in this ThreadGroup
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* and all its descendants.<P>
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*
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* This cannot return an exact number, since the status of threads
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* may change after they were counted. But it should be pretty
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* close.<P>
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*
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* @return the number of active threads in this ThreadGroup and
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* its descendants.
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*/
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public synchronized int activeCount()
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{
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// There is no way for a Java program to determine whether this
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// has any effect whatsoever. We don't need it.
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return true;
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}
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public final void checkAccess ()
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{
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SecurityManager s = System.getSecurityManager();
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if (s != null)
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s.checkAccess(this);
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}
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// This is called to remove a ThreadGroup from our internal list.
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private final void remove (ThreadGroup g)
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{
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groups.removeElement(g);
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if (daemon_flag && groups.size() == 0 && threads.size() == 0)
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int total = threads.size();
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for (int i=0; i < groups.size(); i++)
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{
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// We inline destroy to avoid the access check.
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destroyed_flag = true;
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if (parent != null)
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parent.remove(this);
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ThreadGroup g = (ThreadGroup) groups.elementAt(i);
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total += g.activeCount();
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}
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return total;
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}
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// This is called by the Thread code to remove a Thread from our
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// internal list.
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final void remove (Thread t)
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/** Get the number of active groups in this ThreadGroup. This group
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* itself is not included in the count.
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* @specnote it is unclear what exactly constitutes an
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* active ThreadGroup. Currently we assume that
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* all sub-groups are active.
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* @return the number of active groups in this ThreadGroup.
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*/
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public int activeGroupCount()
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{
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threads.removeElement(t);
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if (daemon_flag && groups.size() == 0 && threads.size() == 0)
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int total = groups.size();
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for (int i=0; i < groups.size(); i++)
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{
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// We inline destroy to avoid the access check.
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destroyed_flag = true;
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if (parent != null)
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parent.remove(this);
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}
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ThreadGroup g = (ThreadGroup) groups.elementAt(i);
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total += g.activeGroupCount();
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}
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return total;
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}
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// This is called by the Thread code to add a Thread to our internal
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// list.
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final void add (Thread t)
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/** Copy all of the active Threads from this ThreadGroup and
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* its descendants into the specified array. If the array is
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* not big enough to hold all the Threads, extra Threads will
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* simply not be copied.
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*
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* @param threads the array to put the threads into.
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* @return the number of threads put into the array.
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*/
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public int enumerate(Thread[] threads)
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{
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if (destroyed_flag)
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throw new IllegalThreadStateException ();
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threads.addElement(t);
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return enumerate(threads, true);
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}
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// This is a helper that is used to implement the destroy method.
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private final boolean canDestroy ()
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/** Copy all of the active Threads from this ThreadGroup and,
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* if desired, from its descendants, into the specified array.
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* If the array is not big enough to hold all the Threads,
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* extra Threads will simply not be copied.
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*
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* @param threads the array to put the threads into.
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* @param useDescendants whether to count Threads in this
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* ThreadGroup's descendants or not.
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* @return the number of threads put into the array.
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*/
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public int enumerate(Thread[] threads, boolean useDescendants)
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{
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if (! threads.isEmpty())
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return false;
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Enumeration e = groups.elements();
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while (e.hasMoreElements())
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{
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ThreadGroup g = (ThreadGroup) e.nextElement();
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if (! g.canDestroy())
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return false;
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}
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return true;
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}
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public final void destroy ()
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{
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checkAccess ();
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if (! canDestroy ())
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throw new IllegalThreadStateException ();
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destroyed_flag = true;
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if (parent != null)
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parent.remove(this);
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return enumerate(threads, 0, useDescendants);
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}
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// This actually implements enumerate.
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private final int enumerate (Thread[] ts, int next_index, boolean recurse)
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private int enumerate (Thread[] list, int next_index, boolean recurse)
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{
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Enumeration e = threads.elements();
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while (e.hasMoreElements() && next_index < ts.length)
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ts[next_index++] = (Thread) e.nextElement();
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if (recurse && next_index != ts.length)
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while (e.hasMoreElements() && next_index < list.length)
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list[next_index++] = (Thread) e.nextElement();
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if (recurse && next_index != list.length)
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{
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e = groups.elements();
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while (e.hasMoreElements() && next_index < ts.length)
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while (e.hasMoreElements() && next_index < list.length)
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{
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ThreadGroup g = (ThreadGroup) e.nextElement();
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next_index = g.enumerate(ts, next_index, true);
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next_index = g.enumerate(list, next_index, true);
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}
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}
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return next_index;
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}
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public int enumerate (Thread[] ts)
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/** Copy all active ThreadGroups that are descendants of this
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* ThreadGroup into the specified array. If the array is not
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* large enough to hold all active ThreadGroups, extra
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* ThreadGroups simply will not be copied.
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*
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* @param groups the array to put the ThreadGroups into.
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* @return the number of ThreadGroups copied into the array.
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*/
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public int enumerate(ThreadGroup[] groups)
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{
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return enumerate (ts, 0, true);
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return enumerate(groups, false);
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}
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public int enumerate (Thread[] ts, boolean recurse)
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/** Copy all active ThreadGroups that are children of this
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* ThreadGroup into the specified array, and if desired, also
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* copy all active descendants into the array. If the array
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* is not large enough to hold all active ThreadGroups, extra
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* ThreadGroups simply will not be copied.
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*
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* @param groups the array to put the ThreadGroups into.
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* @param useDescendants whether to include all descendants
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* of this ThreadGroup's children in determining
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* activeness.
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* @return the number of ThreadGroups copied into the array.
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*/
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public int enumerate(ThreadGroup[] groups, boolean useDescendants)
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{
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return enumerate (ts, 0, recurse);
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return enumerate(groups, 0, useDescendants);
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}
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// This actually implements enumerate.
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private final int enumerate (ThreadGroup[] ts, int next_index,
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boolean recurse)
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private int enumerate (ThreadGroup[] list, int next_index, boolean recurse)
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{
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Enumeration e = groups.elements();
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while (e.hasMoreElements() && next_index < ts.length)
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while (e.hasMoreElements() && next_index < list.length)
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{
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ThreadGroup g = (ThreadGroup) e.nextElement();
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ts[next_index++] = g;
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if (recurse && next_index != ts.length)
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next_index = g.enumerate(ts, next_index, true);
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list[next_index++] = g;
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if (recurse && next_index != list.length)
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next_index = g.enumerate(list, next_index, true);
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}
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return next_index;
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}
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public int enumerate (ThreadGroup[] gs)
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/** Interrupt all Threads in this ThreadGroup and its sub-groups.
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* @exception SecurityException if you cannot modify this
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* ThreadGroup or any of its Threads or children
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* ThreadGroups.
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* @since JDK1.2
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*/
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public final void interrupt()
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{
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return enumerate (gs, 0, true);
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checkAccess();
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for (int i=0; i < threads.size(); i++)
|
||||
{
|
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Thread t = (Thread) threads.elementAt(i);
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t.interrupt();
|
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}
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for (int i=0; i < groups.size(); i++)
|
||||
{
|
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ThreadGroup tg = (ThreadGroup) groups.elementAt(i);
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tg.interrupt();
|
||||
}
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}
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public int enumerate (ThreadGroup[] gs, boolean recurse)
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/** Stop all Threads in this ThreadGroup and its descendants.
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* @exception SecurityException if you cannot modify this
|
||||
* ThreadGroup or any of its Threads or children
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||||
* ThreadGroups.
|
||||
* @deprecated This method calls Thread.stop(), which is dangerous.
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*/
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||||
public final void stop()
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||||
{
|
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return enumerate (gs, 0, recurse);
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checkAccess();
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||||
for (int i=0; i<threads.size(); i++)
|
||||
{
|
||||
Thread t = (Thread) threads.elementAt(i);
|
||||
t.stop();
|
||||
}
|
||||
for (int i=0; i < groups.size(); i++)
|
||||
{
|
||||
ThreadGroup tg = (ThreadGroup) groups.elementAt(i);
|
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tg.stop();
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||||
}
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||||
}
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public final int getMaxPriority ()
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/** Suspend all Threads in this ThreadGroup and its descendants.
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||||
* @exception SecurityException if you cannot modify this
|
||||
* ThreadGroup or any of its Threads or children
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* ThreadGroups.
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||||
* @deprecated This method calls Thread.suspend(), which is dangerous.
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*/
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||||
public final void suspend()
|
||||
{
|
||||
return maxpri;
|
||||
checkAccess();
|
||||
for (int i=0; i<threads.size(); i++)
|
||||
{
|
||||
Thread t = (Thread) threads.elementAt(i);
|
||||
t.suspend();
|
||||
}
|
||||
for (int i=0; i < groups.size(); i++)
|
||||
{
|
||||
ThreadGroup tg = (ThreadGroup) groups.elementAt(i);
|
||||
tg.suspend();
|
||||
}
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||||
}
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||||
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||||
public final String getName ()
|
||||
/** Resume all Threads in this ThreadGroup and its descendants.
|
||||
* @exception SecurityException if you cannot modify this
|
||||
* ThreadGroup or any of its Threads or children
|
||||
* ThreadGroups.
|
||||
* @deprecated This method relies on Thread.suspend(), which is dangerous.
|
||||
*/
|
||||
public final void resume()
|
||||
{
|
||||
return name;
|
||||
checkAccess();
|
||||
for (int i=0; i < threads.size(); i++)
|
||||
{
|
||||
Thread t = (Thread) threads.elementAt(i);
|
||||
t.resume();
|
||||
}
|
||||
for (int i=0; i < groups.size(); i++)
|
||||
{
|
||||
ThreadGroup tg = (ThreadGroup) groups.elementAt(i);
|
||||
tg.resume();
|
||||
}
|
||||
}
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||||
|
||||
public final ThreadGroup getParent ()
|
||||
// This is a helper that is used to implement the destroy method.
|
||||
private final void checkDestroy ()
|
||||
{
|
||||
return parent;
|
||||
if (! threads.isEmpty())
|
||||
throw new IllegalThreadStateException ("ThreadGroup has threads");
|
||||
for (int i=0; i < groups.size(); i++)
|
||||
{
|
||||
ThreadGroup tg = (ThreadGroup) groups.elementAt(i);
|
||||
tg.checkDestroy();
|
||||
}
|
||||
}
|
||||
|
||||
// JDK 1.2.
|
||||
// public void interrupt ();
|
||||
|
||||
public final boolean isDaemon ()
|
||||
/** Destroy this ThreadGroup. There can be no Threads in it,
|
||||
* and none of its descendants (sub-groups) may have Threads in them.
|
||||
* All its descendants will be destroyed as well.
|
||||
* @exception IllegalThreadStateException if the ThreadGroup or
|
||||
* its descendants have Threads remaining in them, or
|
||||
* if the ThreadGroup in question is already destroyed.
|
||||
* @exception SecurityException if you cannot modify this
|
||||
* ThreadGroup or any of its descendants.
|
||||
*/
|
||||
public final void destroy()
|
||||
{
|
||||
return daemon_flag;
|
||||
checkAccess();
|
||||
if (destroyed_flag)
|
||||
throw new IllegalThreadStateException("Already destroyed.");
|
||||
checkDestroy ();
|
||||
if (parent != null)
|
||||
parent.remove(this);
|
||||
destroyed_flag = true;
|
||||
parent = null;
|
||||
|
||||
for (int i=0; i < groups.size(); i++)
|
||||
{
|
||||
ThreadGroup tg = (ThreadGroup) groups.elementAt(i);
|
||||
tg.destroy();
|
||||
}
|
||||
}
|
||||
|
||||
public synchronized boolean isDestroyed ()
|
||||
|
||||
/** Print out information about this ThreadGroup to System.out.
|
||||
*/
|
||||
public void list()
|
||||
{
|
||||
return destroyed_flag;
|
||||
list("");
|
||||
}
|
||||
|
||||
private final void list (String indentation)
|
||||
|
|
@ -214,189 +439,124 @@ public class ThreadGroup
|
|||
System.out.print(indentation);
|
||||
System.out.println(toString ());
|
||||
String sub = indentation + " ";
|
||||
Enumeration e = threads.elements();
|
||||
while (e.hasMoreElements())
|
||||
for (int i=0; i < threads.size(); i++)
|
||||
{
|
||||
Thread t = (Thread) e.nextElement();
|
||||
Thread t = (Thread) threads.elementAt(i);
|
||||
System.out.print(sub);
|
||||
System.out.println(t.toString());
|
||||
}
|
||||
e = groups.elements();
|
||||
while (e.hasMoreElements())
|
||||
for (int i=0; i < groups.size(); i++)
|
||||
{
|
||||
ThreadGroup g = (ThreadGroup) e.nextElement();
|
||||
g.list(sub);
|
||||
ThreadGroup tg = (ThreadGroup) groups.elementAt(i);
|
||||
tg.list(sub);
|
||||
}
|
||||
}
|
||||
|
||||
public void list ()
|
||||
/** When a Thread in this ThreadGroup does not catch an exception,
|
||||
* this method of the ThreadGroup is called.<P>
|
||||
*
|
||||
* ThreadGroup's implementation does the following:<BR>
|
||||
* <OL>
|
||||
* <LI>If there is a parent ThreadGroup, call uncaughtException()
|
||||
* in the parent.</LI>
|
||||
* <LI>If the Throwable passed is a ThreadDeath, don't do
|
||||
* anything.</LI>
|
||||
* <LI>Otherwise, call <CODE>exception.printStackTrace().</CODE></LI>
|
||||
* </OL>
|
||||
*
|
||||
* @param thread the thread that exited.
|
||||
* @param exception the uncaught exception.
|
||||
*/
|
||||
public void uncaughtException(Thread thread, Throwable t)
|
||||
{
|
||||
list ("");
|
||||
if (parent != null)
|
||||
parent.uncaughtException (thread, t);
|
||||
else if (! (t instanceof ThreadDeath))
|
||||
t.printStackTrace();
|
||||
}
|
||||
|
||||
public final boolean parentOf (ThreadGroup g)
|
||||
/** Tell the VM whether it may suspend Threads in low memory
|
||||
* situations.
|
||||
* @deprecated This method is unimplemented, because it would rely on
|
||||
* suspend(), which is deprecated. There is no way for a Java
|
||||
* program to determine whether this has any effect whatsoever,
|
||||
* so we don't need it.
|
||||
* @return false
|
||||
*/
|
||||
public boolean allowThreadSuspension(boolean allow)
|
||||
{
|
||||
while (g != null)
|
||||
{
|
||||
if (this == g)
|
||||
return true;
|
||||
g = g.parent;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
// Deprecated in 1.2.
|
||||
public final void resume ()
|
||||
{
|
||||
checkAccess ();
|
||||
Enumeration e = threads.elements();
|
||||
while (e.hasMoreElements())
|
||||
{
|
||||
Thread t = (Thread) e.nextElement();
|
||||
t.resume();
|
||||
}
|
||||
e = groups.elements();
|
||||
while (e.hasMoreElements())
|
||||
{
|
||||
ThreadGroup g = (ThreadGroup) e.nextElement();
|
||||
g.resume();
|
||||
}
|
||||
}
|
||||
|
||||
public final void setDaemon (boolean daemon)
|
||||
{
|
||||
checkAccess ();
|
||||
daemon_flag = daemon;
|
||||
// FIXME: the docs don't say you are supposed to do this. But
|
||||
// they don't say you aren't, either.
|
||||
if (groups.size() == 0 && threads.size() == 0)
|
||||
destroy ();
|
||||
}
|
||||
|
||||
public final void setMaxPriority (int pri)
|
||||
{
|
||||
checkAccess ();
|
||||
|
||||
// FIXME: JDK 1.2 behaviour is different: if the newMaxPriority
|
||||
// argument is < MIN_PRIORITY or > MAX_PRIORITY an
|
||||
// IllegalArgumentException should be thrown.
|
||||
if (pri >= Thread.MIN_PRIORITY && pri <= maxpri)
|
||||
{
|
||||
maxpri = pri;
|
||||
|
||||
Enumeration e = groups.elements();
|
||||
while (e.hasMoreElements())
|
||||
{
|
||||
ThreadGroup g = (ThreadGroup) e.nextElement();
|
||||
g.setMaxPriority (maxpri);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Deprecated in 1.2.
|
||||
public final void stop ()
|
||||
{
|
||||
checkAccess ();
|
||||
Enumeration e = threads.elements();
|
||||
while (e.hasMoreElements())
|
||||
{
|
||||
Thread t = (Thread) e.nextElement();
|
||||
t.stop();
|
||||
}
|
||||
e = groups.elements();
|
||||
while (e.hasMoreElements())
|
||||
{
|
||||
ThreadGroup g = (ThreadGroup) e.nextElement();
|
||||
g.stop();
|
||||
}
|
||||
}
|
||||
|
||||
// Deprecated in 1.2.
|
||||
public final void suspend ()
|
||||
{
|
||||
checkAccess ();
|
||||
Enumeration e = threads.elements();
|
||||
while (e.hasMoreElements())
|
||||
{
|
||||
Thread t = (Thread) e.nextElement();
|
||||
t.suspend();
|
||||
}
|
||||
e = groups.elements();
|
||||
while (e.hasMoreElements())
|
||||
{
|
||||
ThreadGroup g = (ThreadGroup) e.nextElement();
|
||||
g.suspend();
|
||||
}
|
||||
}
|
||||
|
||||
// This constructor appears in the Class Libraries book but in
|
||||
// neither the Language Spec nor the 1.2 docs.
|
||||
public ThreadGroup ()
|
||||
{
|
||||
this (Thread.currentThread().getThreadGroup(), null);
|
||||
}
|
||||
|
||||
public ThreadGroup (String n)
|
||||
{
|
||||
this (Thread.currentThread().getThreadGroup(), n);
|
||||
}
|
||||
|
||||
public ThreadGroup (ThreadGroup p, String n)
|
||||
{
|
||||
checkAccess ();
|
||||
if (p.destroyed_flag)
|
||||
throw new IllegalArgumentException ();
|
||||
|
||||
parent = p;
|
||||
name = n;
|
||||
maxpri = p.maxpri;
|
||||
threads = new Vector ();
|
||||
groups = new Vector ();
|
||||
daemon_flag = p.daemon_flag;
|
||||
destroyed_flag = false;
|
||||
p.groups.addElement(this);
|
||||
}
|
||||
|
||||
// This is the constructor that is used when creating the very first
|
||||
// ThreadGroup. We have an arbitrary argument here just to
|
||||
// differentiate this constructor from the others.
|
||||
ThreadGroup (int dummy)
|
||||
{
|
||||
parent = null;
|
||||
name = "main";
|
||||
maxpri = Thread.MAX_PRIORITY;
|
||||
threads = new Vector ();
|
||||
groups = new Vector ();
|
||||
daemon_flag = false;
|
||||
destroyed_flag = false;
|
||||
}
|
||||
|
||||
/** Get a human-readable representation of this ThreadGroup.
|
||||
* @return a String representing this ThreadGroup.
|
||||
* @specnote Language Spec and Class Libraries book disagree a bit here.
|
||||
* We follow the Spec, but add "ThreadGroup" per the book. We
|
||||
* include "java.lang" based on the list() example in the Class
|
||||
* Libraries book.
|
||||
*/
|
||||
public String toString ()
|
||||
{
|
||||
// Language Spec and Class Libraries book disagree a bit here. We
|
||||
// follow the Spec, but add "ThreadGroup" per the book. We
|
||||
// include "java.lang" based on the list() example in the Class
|
||||
// Libraries book.
|
||||
return "java.lang.ThreadGroup[name=" + name + ",maxpri=" + maxpri + "]";
|
||||
return "java.lang.ThreadGroup[name=" + name +
|
||||
",maxpri=" + maxpri + "]";
|
||||
}
|
||||
|
||||
public void uncaughtException (Thread thread, Throwable e)
|
||||
/** Find out if the current Thread can modify this ThreadGroup.
|
||||
* Calls the current SecurityManager's checkAccess() method to
|
||||
* find out. If there is none, it assumes everything's OK.
|
||||
* @exception SecurityException if the current Thread cannot
|
||||
* modify this ThreadGroup.
|
||||
*/
|
||||
public final void checkAccess()
|
||||
{
|
||||
// FIXME: in 1.2, this has different semantics. In particular if
|
||||
// this group has a parent, the exception is passed upwards and
|
||||
// not processed locally.
|
||||
if (! (e instanceof ThreadDeath))
|
||||
SecurityManager sm = System.getSecurityManager();
|
||||
if (sm != null)
|
||||
sm.checkAccess(this);
|
||||
}
|
||||
|
||||
// This is called to add a Thread to our internal list.
|
||||
final void add(Thread t)
|
||||
{
|
||||
if (destroyed_flag)
|
||||
throw new IllegalThreadStateException ("ThreadGroup is destroyed");
|
||||
|
||||
threads.addElement(t);
|
||||
}
|
||||
|
||||
// This is called to remove a Thread from our internal list.
|
||||
final void remove(Thread t)
|
||||
{
|
||||
if (destroyed_flag)
|
||||
throw new IllegalThreadStateException ();
|
||||
|
||||
threads.removeElement(t);
|
||||
// Daemon groups are automatically destroyed when all their threads die.
|
||||
if (daemon_flag && groups.size() == 0 && threads.size() == 0)
|
||||
{
|
||||
e.printStackTrace();
|
||||
// We inline destroy to avoid the access check.
|
||||
if (parent != null)
|
||||
parent.remove(this);
|
||||
destroyed_flag = true;
|
||||
}
|
||||
}
|
||||
|
||||
// Private data.
|
||||
private ThreadGroup parent;
|
||||
private String name;
|
||||
private int maxpri;
|
||||
private Vector threads;
|
||||
private Vector groups;
|
||||
private boolean daemon_flag;
|
||||
private boolean destroyed_flag;
|
||||
// This is called to add a ThreadGroup to our internal list.
|
||||
final void add(ThreadGroup g)
|
||||
{
|
||||
groups.addElement(g);
|
||||
}
|
||||
|
||||
// This is called to remove a ThreadGroup from our internal list.
|
||||
final void remove(ThreadGroup g)
|
||||
{
|
||||
groups.removeElement(g);
|
||||
// Daemon groups are automatically destroyed when all their threads die.
|
||||
if (daemon_flag && groups.size() == 0 && threads.size() == 0)
|
||||
{
|
||||
// We inline destroy to avoid the access check.
|
||||
if (parent != null)
|
||||
parent.remove(this);
|
||||
destroyed_flag = true;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue