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package com.sun.jdi.event;

import com.sun.jdi.Mirror;
import com.sun.jdi.VMDisconnectedException;
import com.sun.jdi.VirtualMachine;
import com.sun.jdi.request.EventRequest;


Manager of incoming debugger events for a target VM. Events are always grouped in EventSets. EventSets generated by the debugger back end can be read here. There is one instance of EventQueue assigned to a particular VirtualMachine. 
 Some events cause the suspension of the target VM - event requests (request) with a suspend policy of SUSPEND_ALL or 
SUSPEND_EVENT_THREAD and sometimes VMStartEvent. If these suspensions are not resumed the target VM will hang. Thus, it is always good policy to remove() every EventSet from the event queue until an EventSet containing a VMDisconnectEvent is read. Unless resume is being handled in another way, each EventSet should invoke EventSet.resume(). 
Author:Robert Field
See Also:
Since: 1.3
/**
 * 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 VirtualMachine VirtualMachine}.
 * <P>
 * Some events cause the suspension of the target VM - event requests
 * ({@link com.sun.jdi.request}) with a
 * {@link EventRequest#suspendPolicy() suspend policy}
 * of {@link EventRequest#SUSPEND_ALL SUSPEND_ALL}
 * or {@link 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 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.

Throws:
Returns:the next EventSet.
/**
     * Waits forever for the next available event.
     *
     * @return the next {@link EventSet}.
     * @throws InterruptedException if any thread has interrupted this thread.
     * @throws VMDisconnectedException if the connection
     * to the target VM is no longer available. Note this will always
     * be preceded by a {@link VMDisconnectEvent}.
     */
    EventSet remove() throws InterruptedException;

    
Waits a specified time for the next available event.

Params:
  • timeout – Time in milliseconds to wait for the next event
Throws:
Returns:the next EventSet, or null if there is a timeout.
/**
     * 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 VMDisconnectedException if the connection
     * to the target VM is no longer available. Note this will always
     * be preceded by a {@link VMDisconnectEvent}.
     * @throws IllegalArgumentException if the timeout argument
     * contains an illegal value.
     */
    EventSet remove(long timeout) throws InterruptedException;
}