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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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package com.sun.jdi.event;
import com.sun.jdi.*;
/**
* Manager of incoming debugger events for a target VM.
* Events are always grouped in {@link EventSet}s.
* EventSets generated by the debugger back end can be read
* here. There is one instance of EventQueue assigned to a particular
* {@link com.sun.jdi.VirtualMachine VirtualMachine}.
* <P>
* Some events cause the suspension of the target VM - event requests
* ({@link com.sun.jdi.request}) with a
* {@link com.sun.jdi.request.EventRequest#suspendPolicy() suspend policy}
* of {@link com.sun.jdi.request.EventRequest#SUSPEND_ALL SUSPEND_ALL}
* or {@link com.sun.jdi.request.EventRequest#SUSPEND_EVENT_THREAD
* SUSPEND_EVENT_THREAD} and sometimes
* {@link VMStartEvent}.
* If these suspensions are not resumed the target VM will hang.
* Thus, it is always good policy to
* {@link #remove() remove()} every EventSet from the
* event queue until an EventSet containing a
* {@link VMDisconnectEvent} is read.
* Unless {@link com.sun.jdi.VirtualMachine#resume() resume} is
* being handled in another way, each EventSet should invoke
* {@link EventSet#resume()}.
*
* @see EventSet
* @see VirtualMachine
*
* @author Robert Field
* @since 1.3
*/
public interface EventQueue extends Mirror {
/**
* Waits forever for the next available event.
*
* @return the next {@link EventSet}.
* @throws InterruptedException if any thread has interrupted
* this thread.
* @throws com.sun.jdi.VMDisconnectedException if the connection
* to the target VM is no longer available. Note this will always
* be preceded by a {@link com.sun.jdi.event.VMDisconnectEvent}.
*/
EventSet remove() throws InterruptedException;
/**
* Waits a specified time for the next available event.
*
* @param timeout Time in milliseconds to wait for the next event
* @return the next {@link EventSet}, or null if there is a timeout.
* @throws InterruptedException if any thread has interrupted
* this thread.
* @throws com.sun.jdi.VMDisconnectedException if the connection
* to the target VM is no longer available. Note this will always
* be preceded by a {@link com.sun.jdi.event.VMDisconnectEvent}.
* @throws IllegalArgumentException if the timeout argument
* contains an illegal value.
*/
EventSet remove(long timeout) throws InterruptedException;
}