Using .Net Standard

.gitignore

@@ -11,3 +11,8 @@ TestResults/*
 *.suo
 *.user
 _ReSharper.*
+.vs/
+*.nupkg
+**/packages/*
+*.nuget.props
+*.nuget.targets

Lifetime.sln

@@ -1,32 +1,37 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 2012
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lifetime", "Lifetime\Lifetime.csproj", "{C5F0A258-0AA4-4644-AD4B-134811518025}"
+# Visual Studio 15
+VisualStudioVersion = 15.0.27130.2010
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Lifetime", "Lifetime\Lifetime.csproj", "{A7112E6A-0643-439F-9F33-B2713FCA9F3A}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "LifetimeTest", "LifetimeTest\LifetimeTest.csproj", "{B448C282-D446-4624-9A42-7B2CCFA517EB}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "LifetimeTest", "LifetimeTest\LifetimeTest.csproj", "{0387C1F5-0D00-4C79-8C47-7DBA35109679}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "LifetimeExample", "LifetimeExample\LifetimeExample.csproj", "{9DB14478-561D-4B6F-8919-F5E9D26B4978}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "LifetimeExample", "LifetimeExample\LifetimeExample.csproj", "{C00A62C7-7DD3-4068-BB6A-0F2C4B2A9C63}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{C5F0A258-0AA4-4644-AD4B-134811518025}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{C5F0A258-0AA4-4644-AD4B-134811518025}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{C5F0A258-0AA4-4644-AD4B-134811518025}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{C5F0A258-0AA4-4644-AD4B-134811518025}.Release|Any CPU.Build.0 = Release|Any CPU
-		{B448C282-D446-4624-9A42-7B2CCFA517EB}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{B448C282-D446-4624-9A42-7B2CCFA517EB}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{B448C282-D446-4624-9A42-7B2CCFA517EB}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{B448C282-D446-4624-9A42-7B2CCFA517EB}.Release|Any CPU.Build.0 = Release|Any CPU
-		{9DB14478-561D-4B6F-8919-F5E9D26B4978}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{9DB14478-561D-4B6F-8919-F5E9D26B4978}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{9DB14478-561D-4B6F-8919-F5E9D26B4978}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{9DB14478-561D-4B6F-8919-F5E9D26B4978}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A7112E6A-0643-439F-9F33-B2713FCA9F3A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A7112E6A-0643-439F-9F33-B2713FCA9F3A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A7112E6A-0643-439F-9F33-B2713FCA9F3A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A7112E6A-0643-439F-9F33-B2713FCA9F3A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{0387C1F5-0D00-4C79-8C47-7DBA35109679}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0387C1F5-0D00-4C79-8C47-7DBA35109679}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0387C1F5-0D00-4C79-8C47-7DBA35109679}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0387C1F5-0D00-4C79-8C47-7DBA35109679}.Release|Any CPU.Build.0 = Release|Any CPU
+		{C00A62C7-7DD3-4068-BB6A-0F2C4B2A9C63}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{C00A62C7-7DD3-4068-BB6A-0F2C4B2A9C63}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{C00A62C7-7DD3-4068-BB6A-0F2C4B2A9C63}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{C00A62C7-7DD3-4068-BB6A-0F2C4B2A9C63}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {6D60882C-2C32-4145-B94F-28FE940DF8B7}
+	EndGlobalSection
 EndGlobal

Lifetime/DisposableLifetime.cs

@@ -10,14 +10,10 @@ namespace TwistedOak.Util {
     public sealed class DisposableLifetime : IDisposable {
         private readonly LifetimeSource _source = new LifetimeSource();
         ///<summary>The lifetime that transitions from mortal to dead when the managing DisposableLifetime is disposed.</summary>
-        public Lifetime Lifetime { get { return _source.Lifetime; } }
+        public Lifetime Lifetime => _source.Lifetime;
         ///<summary>Transitions the exposed lifetime from mortal to dead.</summary>
-        public void Dispose() {
-            _source.EndLifetime();
-        }
+        public void Dispose() => _source.EndLifetime();
         ///<summary>Returns a text representation of the disposable lifetime's current state.</summary>
-        public override string ToString() {
-            return _source.ToString();
-        }
+        public override string ToString() => _source.ToString();
     }
 }

Lifetime/Lifetime.cs

@@ -22,18 +22,20 @@ public struct Lifetime : IEquatable<Lifetime> {
         /// </summary>
         public static readonly Lifetime Dead = new Lifetime(DeadSoul.Instance);
 
+        //Must default to ImmortalSould.Instance in property rather than using auto-prop and setting default
+        //in contructor so that default(Lifetime).Soul is ImmortalSoul.Instance not null
         private readonly ISoul _defSoul;
-        internal ISoul Soul { get { return _defSoul ?? ImmortalSoul.Instance; } }
+        internal ISoul Soul => _defSoul ?? ImmortalSoul.Instance;
         internal Lifetime(ISoul soul) {
-            this._defSoul = soul;
+            _defSoul = soul;
         }
 
-        /// <summary>Determines if this lifetime is still transiently mortal.</summary>
-        public bool IsMortal { get { return Soul.Phase == Phase.Mortal; } }
-        /// <summary>Determines if this lifetime is permanently immortal.</summary>
-        public bool IsImmortal { get { return Soul.Phase == Phase.Immortal; } }
-        /// <summary>Determines if this lifetime is permanently dead.</summary>
-        public bool IsDead { get { return Soul.Phase == Phase.Dead; } }
+        ///<summary>Determines if this lifetime is still transiently mortal.</summary>
+        public bool IsMortal => Soul.Phase == Phase.Mortal;
+        ///<summary>Determines if this lifetime is permanently immortal.</summary>
+        public bool IsImmortal => Soul.Phase == Phase.Immortal;
+        ///<summary>Determines if this lifetime is permanently dead.</summary>
+        public bool IsDead => Soul.Phase == Phase.Dead;
 
         /// <summary>
         /// Registers an action to perform when this lifetime is dead.
@@ -49,7 +51,7 @@ internal Lifetime(ISoul soul) {
         /// Defaults to an immortal lifetime.
         /// </param>
         public void WhenDead(Action action, Lifetime registrationLifetime = default(Lifetime)) {
-            if (action == null) throw new ArgumentNullException("action");
+            if (action == null) throw new ArgumentNullException(nameof(action));
             var s = Soul;
             s.DependentRegister(
                 () => { if (s.Phase == Phase.Dead) action(); },
@@ -94,19 +96,13 @@ public static implicit operator Lifetime(CancellationToken token) {
             return source.Lifetime;
         }
 
-        ///<summary>Determines if the other lifetime has the same source.</summary>
+        /// <summary>Determines if the other lifetime has the same source.</summary>
         /// <param name="other">The lifetime that this lifetime is being compared to.</param>
-        public bool Equals(Lifetime other) {
-            return Equals(Soul, other.Soul);
-        }
+        public bool Equals(Lifetime other) => Equals(Soul, other.Soul);
         ///<summary>Returns the hash code for this lifetime, based on its source.</summary>
-        public override int GetHashCode() {
-            return Soul.GetHashCode();
-        }
+        public override int GetHashCode() => Soul.GetHashCode();
         ///<summary>Determines if the other object is a lifetime with the same source.</summary>
-        public override bool Equals(object obj) {
-            return obj is Lifetime && Equals((Lifetime)obj);
-        }
+        public override bool Equals(object obj) => obj is Lifetime && Equals((Lifetime)obj);
         ///<summary>Returns a text representation of the lifetime's current state.</summary>
         public override string ToString() {
             if (Soul.Phase == Phase.Mortal) return "Alive";

Lifetime/Lifetime.csproj

@@ -1,65 +1,33 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+<Project Sdk="Microsoft.NET.Sdk">
+
   <PropertyGroup>
-    <MinimumVisualStudioVersion>10.0</MinimumVisualStudioVersion>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <ProjectGuid>{C5F0A258-0AA4-4644-AD4B-134811518025}</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <AppDesignerFolder>Properties</AppDesignerFolder>
-    <RootNamespace>TwistedOak.Util</RootNamespace>
-    <AssemblyName>Lifetime</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
-    <TargetFrameworkProfile>Profile5</TargetFrameworkProfile>
-    <FileAlignment>512</FileAlignment>
-    <ProjectTypeGuids>{786C830F-07A1-408B-BD7F-6EE04809D6DB};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <PackageId>TwistedOak.Util.Lifetime</PackageId>
+    <Version>1.0.3</Version>
+    <Authors>Craig Gidney</Authors>
+    <Company>Twisted Oak Studios</Company>
+    <Product></Product>
+    <Description>Lifetime (improved CancellationToken)
+
+A small library that implements an improved version of System.Threading.CancellationToken with support for removable registrations, to allow for garbage collection in the presence of long-lived tokens, plus some related utilities.
+
+Motivation: cancellation tokens can be the source of memory "leaks", because an unbounded number of completed operations may have registered now-pointless callbacks on a token that can't be released or cancelled. The callbacks may reference all kinds of data, preventing effective garbage collection. Using a Lifetime allows fixing these issues because callback registrations can be given lifetimes of their own.
+
+Additional utilities: LifetimeSource, LifetimeExchanger, DisposableLifetime, Max, Min, CreateDependentSource.</Description>
+    <Copyright>Twisted Oak Studios, 2012</Copyright>
+    <PackageLicenseUrl>https://github.com/TwistedOakStudios/Lifetime/blob/master/License.txt</PackageLicenseUrl>
+    <PackageProjectUrl>https://github.com/TwistedOakStudios/Lifetime</PackageProjectUrl>
+    <PackageIconUrl>http://i.imgur.com/WP3EF.png</PackageIconUrl>
+    <PackageTags>lifetime cancellation token</PackageTags>
+    <PackageReleaseNotes>Using .Net Standard 2.0</PackageReleaseNotes>
+    <RepositoryType></RepositoryType>
+    <RepositoryUrl></RepositoryUrl>
+    <NeutralLanguage></NeutralLanguage>
   </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <ErrorReport>prompt</ErrorReport>
-    <WarningLevel>4</WarningLevel>
-    <DocumentationFile>bin\Debug\Lifetime.XML</DocumentationFile>
+
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
+    <DocumentationFile>bin\Release\netstandard2.0\Lifetime.xml</DocumentationFile>
   </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <ErrorReport>prompt</ErrorReport>
-    <WarningLevel>4</WarningLevel>
-    <DocumentationFile>bin\Release\Lifetime.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <!-- A reference to the entire .NET Framework is automatically included -->
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="Soul\AnonymousSoul.cs" />
-    <Compile Include="Soul\CollapsingSoul.cs" />
-    <Compile Include="Soul\DeadSoul.cs" />
-    <Compile Include="Soul\ImmortalSoul.cs" />
-    <Compile Include="Soul\ISoul.cs" />
-    <Compile Include="Soul\DoublyLinkedNode.cs" />
-    <Compile Include="LifetimeSource.cs" />
-    <Compile Include="DisposableLifetime.cs" />
-    <Compile Include="LifetimeExchanger.cs" />
-    <Compile Include="Lifetime.cs" />
-    <Compile Include="LifetimeUtilities.cs" />
-    <Compile Include="Soul\Phase.cs" />
-    <Compile Include="Properties\AssemblyInfo.cs" />
-    <Compile Include="Soul\MortalSoul.cs" />
-    <Compile Include="Soul\Soul.cs" />
-  </ItemGroup>
-  <Import Project="$(MSBuildExtensionsPath32)\Microsoft\Portable\$(TargetFrameworkVersion)\Microsoft.Portable.CSharp.targets" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
+
+</Project>

Lifetime/LifetimeExchanger.cs

@@ -4,9 +4,9 @@ namespace TwistedOak.Util {
     ///<summary>Creates lifetimes when requested, setting them when the next lifetime is requested.</summary>
     public sealed class LifetimeExchanger {
         private LifetimeSource _active = new LifetimeSource();
-        
+
         ///<summary>Returns the current lifetime, that will be killed or immortalized before the next lifetime is created by the exchanger.</summary>
-        public Lifetime ActiveLifetime { get { return _active.Lifetime; } }
+        public Lifetime ActiveLifetime => _active.Lifetime;
 
         ///<summary>Returns a newly created mortal lifetime after killing the previously created lifetime (if any).</summary>
         public Lifetime StartNextAndEndPreviousLifetime() {
@@ -20,7 +20,7 @@ public Lifetime StartNextAndEndPreviousLifetime() {
         public Lifetime StartNextAndImmortalizePreviousLifetime() {
             var next = new LifetimeSource();
             var prev = Interlocked.Exchange(ref _active, next);
-            if (prev != null) prev.ImmortalizeLifetime();
+            prev?.ImmortalizeLifetime();
             return next.Lifetime;
         }
     }

Lifetime/LifetimeSource.cs

@@ -11,9 +11,9 @@ namespace TwistedOak.Util {
     [DebuggerDisplay("{ToString()}")]
     public sealed class LifetimeSource {
         private readonly MortalSoul _soul = new MortalSoul();
-        
-        /// <summary>The lifetime exposed and managed by the lifetime source.</summary>
-        public Lifetime Lifetime { get; private set; }
+
+        ///<summary>The lifetime exposed and managed by the lifetime source.</summary>
+        public Lifetime Lifetime { get; }
 
         ///<summary>Creates a new lifetime source managing a new initially mortal lifetime.</summary>
         public LifetimeSource() {
@@ -45,8 +45,6 @@ public void ImmortalizeLifetime() {
         }
 
         ///<summary>Returns a text representation of the lifetime source's current state.</summary>
-        public override string ToString() {
-            return Lifetime.ToString();
-        }
+        public override string ToString() => Lifetime.ToString();
     }
 }

Lifetime/Soul/AnonymousSoul.cs

@@ -2,21 +2,17 @@
 using System.Diagnostics;
 
 namespace TwistedOak.Util.Soul {
-    ///<summary>A soul implemented by delegates passed to its constructor.</summary>
+    /// <summary>A soul implemented by delegates passed to its constructor.</summary>
     [DebuggerStepThrough]
     internal sealed class AnonymousSoul : ISoul {
         private readonly Func<Phase> _phase;
         private readonly Func<Action, RegistrationRemover> _register;
         public AnonymousSoul(Func<Phase> phase, Func<Action, RegistrationRemover> register) {
-            if (phase == null) throw new ArgumentNullException("phase");
-            if (register == null) throw new ArgumentNullException("register");
-            this._phase = phase;
-            this._register = register;
+            _phase = phase ?? throw new ArgumentNullException(nameof(phase));
+            _register = register ?? throw new ArgumentNullException(nameof(register));
         }
 
-        public Phase Phase { get { return this._phase(); } }
-        public RegistrationRemover Register(Action action) {
-            return this._register(action);
-        }
+        public Phase Phase => _phase();
+        public RegistrationRemover Register(Action action) => _register(action);
     }
 }

Lifetime/Soul/CollapsingSoul.cs

@@ -1,23 +1,25 @@
 using System;
 
 namespace TwistedOak.Util.Soul {
-    ///<summary>Delegates to an underlying soul that is replaced with one of the permanent souls once it is no longer mortal.</summary>
+    /// <summary>
+    /// Delegates to an underlying soul that is replaced with one of the permanent
+    /// souls once it is no longer mortal.
+    /// </summary>
     internal sealed class CollapsingSoul : ISoul {
         private bool _collapsed;
         private ISoul _subSoul;
 
         public CollapsingSoul(ISoul subSoul) {
-            this._subSoul = subSoul;
-            
+            _subSoul = subSoul;
+
             // flatten multiple levels of wrapping
-            var r = subSoul as CollapsingSoul;
-            if (r != null) this._subSoul = r._subSoul;
-
+            if(subSoul is CollapsingSoul cS) _subSoul = cS._subSoul;
+
             // ensure collapse occurs once the sub soul becomes fixed
-            Register(() => TryOptimize());
+            Register(() => tryOptimize());
         }
 
-        private Phase TryOptimize() {
+        private Phase tryOptimize() {
             var phase = _subSoul.Phase;
             if (_collapsed) return phase; // already optimized
             if (phase == Phase.Mortal) return phase; // can't optimize yet
@@ -27,9 +29,8 @@ private Phase TryOptimize() {
             _subSoul = Phase.AsPermanentSoul();
             return phase;
         }
-        public Phase Phase { get { return TryOptimize(); } }
-        public RegistrationRemover Register(Action action) {
-            return _subSoul.Register(action);
-        }
+
+        public Phase Phase => tryOptimize();
+        public RegistrationRemover Register(Action action) => _subSoul.Register(action);
     }
 }

Lifetime/Soul/DeadSoul.cs

@@ -6,7 +6,7 @@ internal sealed class DeadSoul : ISoul {
         ///<summary>The single instance of the permanently dead soul.</summary>
         public static readonly ISoul Instance = new DeadSoul();
         private DeadSoul() {}
-        public Phase Phase { get { return Phase.Dead; } }
+        public Phase Phase => Phase.Dead;
         public RegistrationRemover Register(Action action) {
             action();
             return Soul.EmptyRemover;