113 lines
4.9 KiB
C#
113 lines
4.9 KiB
C#
/*
|
|
* Copyright (c) Contributors, http://opensimulator.org/
|
|
* See CONTRIBUTORS.TXT for a full list of copyright holders.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
* * Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* * Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* * Neither the name of the OpenSimulator Project nor the
|
|
* names of its contributors may be used to endorse or promote products
|
|
* derived from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
|
|
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
* DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
|
|
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
|
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
using System;
|
|
|
|
namespace OpenSim.Region.Framework.Scenes
|
|
{
|
|
/// <summary>
|
|
/// The possible states that a scene presence can be in. This is currently orthagonal to whether a scene presence
|
|
/// is root or child.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// This is a state machine.
|
|
///
|
|
/// [Entry] => Running
|
|
/// Running => PreRemove, Removing
|
|
/// PreRemove => Running, Removing
|
|
/// Removing => Removed
|
|
///
|
|
/// All other methods should only see the scene presence in running state - this is the normal operational state
|
|
/// Removed state occurs when the presence has been removed. This is the end state with no exit.
|
|
/// </remarks>
|
|
public enum ScenePresenceState
|
|
{
|
|
Running, // Normal operation state. The scene presence is available.
|
|
PreRemove, // The presence is due to be removed but can still be returning to running.
|
|
Removing, // The presence is in the process of being removed from the scene via Scene.RemoveClient.
|
|
Removed, // The presence has been removed from the scene and is effectively dead.
|
|
// There is no exit from this state.
|
|
}
|
|
|
|
internal class ScenePresenceStateMachine
|
|
{
|
|
private ScenePresence m_sp;
|
|
private ScenePresenceState m_state;
|
|
|
|
internal ScenePresenceStateMachine(ScenePresence sp)
|
|
{
|
|
m_sp = sp;
|
|
m_state = ScenePresenceState.Running;
|
|
}
|
|
|
|
internal ScenePresenceState GetState()
|
|
{
|
|
return m_state;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Updates the state of an agent that is already in transit.
|
|
/// </summary>
|
|
/// <param name='id'></param>
|
|
/// <param name='newState'></param>
|
|
/// <returns></returns>
|
|
/// <exception cref='Exception'>Illegal transitions will throw an Exception</exception>
|
|
internal void SetState(ScenePresenceState newState)
|
|
{
|
|
bool transitionOkay = false;
|
|
|
|
lock (this)
|
|
{
|
|
if (newState == m_state)
|
|
return;
|
|
else if (newState == ScenePresenceState.Running && m_state == ScenePresenceState.PreRemove)
|
|
transitionOkay = true;
|
|
else if (newState == ScenePresenceState.PreRemove && m_state == ScenePresenceState.Running)
|
|
transitionOkay = true;
|
|
else if (newState == ScenePresenceState.Removing)
|
|
{
|
|
if (m_state == ScenePresenceState.Running || m_state == ScenePresenceState.PreRemove)
|
|
transitionOkay = true;
|
|
}
|
|
else if (newState == ScenePresenceState.Removed && m_state == ScenePresenceState.Removing)
|
|
transitionOkay = true;
|
|
}
|
|
|
|
if (!transitionOkay)
|
|
{
|
|
throw new Exception(
|
|
string.Format(
|
|
"Scene presence {0} is not allowed to move from state {1} to new state {2} in {3}",
|
|
m_sp.Name, m_state, newState, m_sp.Scene.Name));
|
|
}
|
|
else
|
|
{
|
|
m_state = newState;
|
|
}
|
|
}
|
|
}
|
|
} |