60 lines
1.9 KiB
C#
60 lines
1.9 KiB
C#
namespace Unosquare.Swan.Abstractions
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{
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using System;
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/// <summary>
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/// Represents a singleton pattern abstract class.
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/// </summary>
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/// <typeparam name="T">The type of class.</typeparam>
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public abstract class SingletonBase<T> : IDisposable
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where T : class
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{
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/// <summary>
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/// The static, singleton instance reference.
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/// </summary>
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protected static readonly Lazy<T> LazyInstance = new Lazy<T>(
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valueFactory: () => Activator.CreateInstance(typeof(T), true) as T,
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isThreadSafe: true);
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private bool _isDisposing; // To detect redundant calls
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/// <summary>
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/// Gets the instance that this singleton represents.
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/// If the instance is null, it is constructed and assigned when this member is accessed.
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/// </summary>
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/// <value>
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/// The instance.
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/// </value>
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public static T Instance => LazyInstance.Value;
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/// <inheritdoc />
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public void Dispose() => Dispose(true);
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/// <summary>
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/// Releases unmanaged and - optionally - managed resources.
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/// Call the GC.SuppressFinalize if you override this method and use
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/// a non-default class finalizer (destructor).
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/// </summary>
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/// <param name="disposeManaged"><c>true</c> to release both managed and unmanaged resources; <c>false</c> to release only unmanaged resources.</param>
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protected virtual void Dispose(bool disposeManaged)
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{
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if (_isDisposing) return;
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_isDisposing = true;
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// free managed resources
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if (LazyInstance == null) return;
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try
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{
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var disposableInstance = LazyInstance.Value as IDisposable;
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disposableInstance?.Dispose();
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}
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catch
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{
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// swallow
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}
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}
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}
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}
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