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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

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 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

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 *

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package com.sun.jdi;

import java.util.List;

/**

 * A thread group object from the target VM.

 * A ThreadGroupReference is an {@link ObjectReference} with additional

 * access to threadgroup-specific information from the target VM.

 *

 * @author Robert Field

 * @author Gordon Hirsch

 * @author James McIlree

 * @since  1.3

 */

@jdk.Exported

public interface ThreadGroupReference extends ObjectReference {

    /**

     * Returns the name of this thread group.

     *

     * @return the string containing the thread group name.

     */

    String name();

    /**

     * Returns the parent of this thread group.

     *

     * @return a {@link ThreadGroupReference} mirroring the parent of this

     * thread group in the target VM, or null if this is a top-level

     * thread group.

     */

    ThreadGroupReference parent();

    /**

     * Suspends all threads in this thread group. Each thread

     * in this group and in all of its subgroups will be

     * suspended as described in {@link ThreadReference#suspend}.

     * This is not guaranteed to be an atomic

     * operation; if the target VM is not interrupted at the time

     * this method is

     * called, it is possible that new threads will be created

     * between the time that threads are enumerated and all of them

     * have been suspended.

     * @throws VMCannotBeModifiedException if the VirtualMachine is read-only - see {@link VirtualMachine#canBeModified()}.

     */

    void suspend();

    /**

     * Resumes all threads in this thread group. Each thread

     * in this group and in all of its subgroups will be

     * resumed as described in {@link ThreadReference#resume}.

     * @throws VMCannotBeModifiedException if the VirtualMachine is read-only - see {@link VirtualMachine#canBeModified()}.

     */

    void resume();

    /**

     * Returns a List containing a {@link ThreadReference} for each live thread

     * in this thread group. Only the live threads in this immediate thread group

     * (and not its subgroups) are returned.  A thread is alive if it

     * has been started and has not yet been stopped.

     *

     * @return a List of {@link ThreadReference} objects mirroring the

     * live threads from this thread group in the target VM.

     */

    List<ThreadReference> threads();

    /**

     * Returns a List containing each active {@link ThreadGroupReference} in this

     * thread group. Only the active thread groups in this immediate thread group

     * (and not its subgroups) are returned.

     * See <a href="{@docRoot}/../../../../api/java/lang/ThreadGroup.html">java.lang.ThreadGroup</a>

     * for information about 'active' ThreadGroups.

     * @return a List of {@link ThreadGroupReference} objects mirroring the

     * active thread groups from this thread group in the target VM.

     */

    List<ThreadGroupReference> threadGroups();

}