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/*
* 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;
using System.Collections;
using System.Collections.Generic;
using System.Reflection;
using System.Text;
using log4net;
using OpenSim.ScriptEngine.Shared;
using IScript=OpenSim.Region.ScriptEngine.Shared.ScriptBase.IScript;
namespace OpenSim.ScriptEngine.Components.DotNetEngine.Scheduler
{
public class ScriptLoader : IScriptLoader
{
//
// This class does AppDomain handling and loading/unloading of
// scripts in it. It is instanced in "ScriptEngine" and controlled
// from "ScriptManager"
//
// 1. Create a new AppDomain if old one is full (or doesn't exist)
// 2. Load scripts into AppDomain
// 3. Unload scripts from AppDomain (stopping them and marking
// them as inactive)
// 4. Unload AppDomain completely when all scripts in it has stopped
//
public string Name { get { return "SECS.DotNetEngine.Scheduler.ScriptLoader"; } }
private int maxScriptsPerAppDomain = 10;
// Internal list of all AppDomains
private List<AppDomainStructure> appDomains =
new List<AppDomainStructure>();
private Dictionary<string, AppDomainStructure> AppDomainFiles = new Dictionary<string, AppDomainStructure>();
public readonly string[] AssembliesInAppDomain = new string[] { "OpenSim.ScriptEngine.Shared.Script.dll", "OpenSim.Region.ScriptEngine.Shared.dll" };
internal static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
// Structure to keep track of data around AppDomain
private class AppDomainStructure
{
public AppDomain CurrentAppDomain; // The AppDomain itself
public int ScriptsLoaded; // Number of scripts loaded into AppDomain
public int ScriptsWaitingUnload; // Number of dead scripts
}
// Current AppDomain
private AppDomainStructure currentAD;
private object getLock = new object(); // Mutex
private object freeLock = new object(); // Mutex
// Find a free AppDomain, creating one if necessary
private AppDomainStructure GetFreeAppDomain()
{
lock (getLock)
{
// Current full?
if (currentAD != null &&
currentAD.ScriptsLoaded >= maxScriptsPerAppDomain)
{
// Add it to AppDomains list and empty current
appDomains.Add(currentAD);
currentAD = null;
}
// No current
if (currentAD == null)
{
// Create a new current AppDomain
currentAD = new AppDomainStructure();
currentAD.CurrentAppDomain = PrepareNewAppDomain();
}
return currentAD;
}
}
private int AppDomainNameCount;
public ScriptAssemblies.IScript LoadScript(ScriptStructure script)
{
// Find next available AppDomain to put it in
AppDomainStructure FreeAppDomain;
// If we already have loaded file, then reuse that AppDomains
if (AppDomainFiles.ContainsKey(script.AssemblyFileName))
FreeAppDomain = AppDomainFiles[script.AssemblyFileName];
else
FreeAppDomain = GetFreeAppDomain();
// Set script object AppDomain
script.AppDomain = FreeAppDomain.CurrentAppDomain;
// Create instance of script
ScriptAssemblies.IScript mbrt = (ScriptAssemblies.IScript)
FreeAppDomain.CurrentAppDomain.CreateInstanceFromAndUnwrap(
script.AssemblyFileName, "ScriptAssemblies.Script");
//, true, BindingFlags.CreateInstance, null);
FreeAppDomain.ScriptsLoaded++;
return mbrt;
}
// Create and prepare a new AppDomain for scripts
private AppDomain PrepareNewAppDomain()
{
// Create and prepare a new AppDomain
AppDomainNameCount++;
// TODO: Currently security match current appdomain
// Construct and initialize settings for a second AppDomain.
AppDomainSetup ads = new AppDomainSetup();
ads.ApplicationBase = AppDomain.CurrentDomain.BaseDirectory;
ads.DisallowBindingRedirects = true;
ads.DisallowCodeDownload = true;
ads.LoaderOptimization = LoaderOptimization.MultiDomainHost;
ads.ShadowCopyFiles = "false"; // Disable shadowing
ads.ConfigurationFile =
AppDomain.CurrentDomain.SetupInformation.ConfigurationFile;
AppDomain AD = AppDomain.CreateDomain("ScriptAppDomain_" +
AppDomainNameCount, null, ads);
foreach (string file in AssembliesInAppDomain)
{
m_log.InfoFormat("[{0}] AppDomain Loading: \"{1}\"->\"{2}\".", Name, file,
AssemblyName.GetAssemblyName(file).ToString());
AD.Load(AssemblyName.GetAssemblyName(file));
}
// Return the new AppDomain
return AD;
}
// Unload appdomains that are full and have only dead scripts
private void UnloadAppDomains()
{
lock (freeLock)
{
// Go through all
foreach (AppDomainStructure ads in new ArrayList(appDomains))
{
// Don't process current AppDomain
if (ads.CurrentAppDomain != currentAD.CurrentAppDomain)
{
// Not current AppDomain
// Is number of unloaded bigger or equal to number of loaded?
if (ads.ScriptsLoaded <= ads.ScriptsWaitingUnload)
{
// Remove from internal list
appDomains.Remove(ads);
// Unload
AppDomain.Unload(ads.CurrentAppDomain);
}
}
}
}
}
// Increase "dead script" counter for an AppDomain
public void StopScript(AppDomain ad)
{
lock (freeLock)
{
// Check if it is current AppDomain
if (currentAD.CurrentAppDomain == ad)
{
// Yes - increase
currentAD.ScriptsWaitingUnload++;
return;
}
// Lopp through all AppDomains
foreach (AppDomainStructure ads in new ArrayList(appDomains))
{
if (ads.CurrentAppDomain == ad)
{
// Found it
ads.ScriptsWaitingUnload++;
break;
}
}
}
UnloadAppDomains(); // Outsite lock, has its own GetLock
}
}
}
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