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// Copyright (c) 2010-2013 AlphaSierraPapa for the SharpDevelop Team
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// Permission is hereby granted, free of charge, to any person obtaining a copy of this
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// software and associated documentation files (the "Software"), to deal in the Software
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// without restriction, including without limitation the rights to use, copy, modify, merge,
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// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
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// to whom the Software is furnished to do so, subject to the following conditions:
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// The above copyright notice and this permission notice shall be included in all copies or
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// substantial portions of the Software.
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
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// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
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// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
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// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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// DEALINGS IN THE SOFTWARE.
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using System.Threading;
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namespace ICSharpCode.NRefactory.Utils
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public static class LazyInit
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public static T VolatileRead<T>(ref T location) where T : class
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return Volatile.Read(ref location);
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Thread.MemoryBarrier();
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/// Atomically performs the following operation:
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/// - If target is null: stores newValue in target and returns newValue.
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/// - If target is not null: returns target.
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public static T GetOrSet<T>(ref T target, T newValue) where T : class
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T oldValue = Interlocked.CompareExchange(ref target, newValue, null);
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return oldValue ?? newValue;