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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System.Reflection;
using Xunit;
namespace System.Runtime.InteropServices
{
public class HandleCollectorTests
{
private const int LowLimitSize = 20;
private const int HighLimitSize = 100000;
[Theory]
[InlineData(null, 0)]
[InlineData("", 10)]
[InlineData("InitialThreshold", int.MaxValue)]
public void Ctor_Name_InitialThreshold(string name, int initialThreshold)
{
var handleCollector = new HandleCollector(name, initialThreshold);
Assert.Equal(0, handleCollector.Count);
Assert.Equal(name ?? string.Empty, handleCollector.Name);
Assert.Equal(initialThreshold, handleCollector.InitialThreshold);
Assert.Equal(int.MaxValue, handleCollector.MaximumThreshold);
}
[Theory]
[InlineData(null, 0, 0)]
[InlineData("", 10, 15)]
[InlineData("InitialThreshold", 1, 2)]
public void Ctor_Name_InitialThreshold_MaximumThreshold(string name, int initialThreshold, int maximumThreshold)
{
var handleCollector = new HandleCollector(name, initialThreshold, maximumThreshold);
Assert.Equal(0, handleCollector.Count);
Assert.Equal(name ?? string.Empty, handleCollector.Name);
Assert.Equal(initialThreshold, handleCollector.InitialThreshold);
Assert.Equal(maximumThreshold, handleCollector.MaximumThreshold);
}
[Fact]
public void Ctor_NegativeInitialThreshold_ThrowsArgumentOufORangeException()
{
AssertExtensions.Throws<ArgumentOutOfRangeException>("initialThreshold", () => new HandleCollector("NegativeInitial", -1));
AssertExtensions.Throws<ArgumentOutOfRangeException>("initialThreshold", () => new HandleCollector("NegativeInitial", -1, 0));
}
[Fact]
public static void Ctor_NegativeMaximumThreshold_ThrowsArgumentOutOfRangeException()
{
AssertExtensions.Throws<ArgumentOutOfRangeException>("maximumThreshold", () => new HandleCollector("NegativeMax", 0, -1));
}
[Fact]
public static void Ctor_InitialThresholdGreaterThanMaximumThreshold_ThrowsArgumentException()
{
AssertExtensions.Throws<ArgumentException>(null, () => new HandleCollector("InitialGreaterThanMax", 100, 1));
}
[Fact]
public void AddRemove_AcrossMultipleGenerations_Success()
{
var collector = new HandleCollector("name", 0);
collector.Add();
Assert.Equal(1, collector.Count);
collector.Add();
Assert.Equal(2, collector.Count);
collector.Add();
Assert.Equal(3, collector.Count);
collector.Remove();
Assert.Equal(2, collector.Count);
collector.Remove();
Assert.Equal(1, collector.Count);
collector.Remove();
Assert.Equal(0, collector.Count);
}
[Fact]
public static void Remove_EmptyCollection_ThrowsInvalidOperationException()
{
HandleCollector collector = new HandleCollector("EmptyRemoval", 10);
Assert.Throws<InvalidOperationException>(() => collector.Remove());
}
[Fact]
[SkipOnTargetFramework(TargetFrameworkMonikers.UapAot,"Reflects on private member handleCount")]
public static void Add_Overflows_ThrowsInvalidOperationException()
{
HandleCollector collector = new HandleCollector("CountOverflow", int.MaxValue);
// We could iterate here 2B times calling Add, but that often takes over 100s
// Instead, for testing purposes, we reach into the HandleCollector via reflection
// to make it think it's already been called int.MaxValue - 10 times. We then
// only have to call Add 10 times rather than int.MaxValue times, and the test
// completes very quickly. If we ever need to run the test on a platform that
// doesn't support such reflection, we can revert to the super-long running test
// or find another workaround.
const int ToAdd = 10; // int.MaxValue
{
// Jump HandleCollector instance forward until it almost overflows
TypeInfo type = typeof(HandleCollector).GetTypeInfo();
FieldInfo handleCount =
type.GetDeclaredField("_handleCount") ?? // corefx
type.GetDeclaredField("handleCount"); // desktop
Assert.NotNull(handleCount);
handleCount.SetValue(collector, int.MaxValue - ToAdd);
}
for (int i = 0; i < ToAdd; i++)
{
collector.Add();
}
Assert.Throws<InvalidOperationException>(() => collector.Add());
}
[Fact]
public static void TestHandleCollector()
{
(int gen0, int gen1, int gen2) initialGcState = (GC.CollectionCount(0), GC.CollectionCount(1), GC.CollectionCount(2));
HandleCollector lowLimitCollector = new HandleCollector("LowLimit.Collector", LowLimitSize);
for (int i = 0; i < LowLimitSize + 1; ++i)
{
HandleLimitTester hlt = new HandleLimitTester(lowLimitCollector);
}
(int gen0, int gen1, int gen2) postLowLimitState = (GC.CollectionCount(0),GC.CollectionCount(1), GC.CollectionCount(2));
Assert.True(initialGcState.gen0 + initialGcState.gen1 + initialGcState.gen2 < postLowLimitState.gen0 + postLowLimitState.gen1 + postLowLimitState.gen2, "Low limit handle did not trigger a GC");
HandleCollector highLimitCollector = new HandleCollector("HighLimit.Collector", HighLimitSize);
for (int i = 0; i < HighLimitSize + 10; ++i)
{
HandleLimitTester hlt = new HandleLimitTester(highLimitCollector);
}
(int gen0, int gen1, int gen2) postHighLimitState = (GC.CollectionCount(0), GC.CollectionCount(1), GC.CollectionCount(2));
Assert.True(postLowLimitState.gen0 + postLowLimitState.gen1 + postLowLimitState.gen2 < postHighLimitState.gen0 + postHighLimitState.gen1 + postHighLimitState.gen2, "High limit handle did not trigger a GC");
}
private sealed class HandleLimitTester
{
private HandleCollector _collector;
internal HandleLimitTester(HandleCollector collector)
{
_collector = collector;
_collector.Add();
GC.KeepAlive(this);
}
~HandleLimitTester() => _collector.Remove();
}
}
}
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