Use thread-safe version of .NET Random as the SDK class is not thread-safe.

As per http://msdn.microsoft.com/en-us/library/system.random%28v=vs.100%29.aspx, the .NET Random class is not thread-safe.
If called by multiple threads at once, methods may return 0.
Except for llRand(), other OpenSimulator code did not lock before calling a shared Random instance.
This commit adds a ThreadSafeRandom class that extends Random but does internal locking so that it is thread-safe.
This change is invisible to existing callers and the explicit locking in the llFrand() implementation is now redundant.
0.8.0.3
Justin Clark-Casey (justincc) 2014-07-14 20:08:11 +01:00 committed by Justin Clark-Casey
parent d35b5737a8
commit 539ffb7769
3 changed files with 75 additions and 5 deletions

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@ -0,0 +1,72 @@
/*
* 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.Framework
{
/// <summary>
/// A thread-safe Random since the .NET version is not.
/// See http://msdn.microsoft.com/en-us/library/system.random%28v=vs.100%29.aspx
/// </summary>
public class ThreadSafeRandom : Random
{
public ThreadSafeRandom() : base() {}
public ThreadSafeRandom(int seed): base (seed) {}
public override int Next()
{
lock (this)
return base.Next();
}
public override int Next(int maxValue)
{
lock (this)
return base.Next(maxValue);
}
public override int Next(int minValue, int maxValue)
{
lock (this)
return base.Next(minValue, maxValue);
}
public override void NextBytes(byte[] buffer)
{
lock (this)
base.NextBytes(buffer);
}
public override double NextDouble()
{
lock (this)
return base.NextDouble();
}
}
}

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@ -138,7 +138,7 @@ namespace OpenSim.Framework
}
private static uint nextXferID = 5000;
private static Random randomClass = new Random();
private static Random randomClass = new ThreadSafeRandom();
// Get a list of invalid file characters (OS dependent)
private static string regexInvalidFileChars = "[" + new String(Path.GetInvalidFileNameChars()) + "]";

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@ -544,10 +544,8 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
public LSL_Float llFrand(double mag)
{
m_host.AddScriptLPS(1);
lock (Util.RandomClass)
{
return Util.RandomClass.NextDouble() * mag;
}
return Util.RandomClass.NextDouble() * mag;
}
public LSL_Integer llFloor(double f)