Fixing potential race condition in ListRepository. Now internally implemented as a concurrent dictionary.

This commit is contained in:
ryanbodrug-microsoft 2020-07-08 15:12:36 -07:00
parent 2c45956030
commit 9ff8246a9d
3 changed files with 121 additions and 20 deletions

View file

@ -3,7 +3,10 @@ using Moq;
using NUnit.Framework;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Windows.Media.Capture;
using Wox.Infrastructure.Storage;
namespace Microsoft.Plugin.Program.UnitTests.Storage
@ -17,8 +20,7 @@ namespace Microsoft.Plugin.Program.UnitTests.Storage
{
//Arrange
var itemName = "originalItem1";
var mockStorage = new Mock<IStorage<IList<string>>>();
IRepository<string> repository = new ListRepository<string>(mockStorage.Object) { itemName };
IRepository<string> repository = new ListRepository<string>() { itemName };
//Act
var result = repository.Contains(itemName);
@ -31,8 +33,7 @@ namespace Microsoft.Plugin.Program.UnitTests.Storage
public void Contains_ShouldReturnTrue_WhenListIsUpdatedWithAdd()
{
//Arrange
var mockStorage = new Mock<IStorage<IList<string>>>();
IRepository<string> repository = new ListRepository<string>(mockStorage.Object);
IRepository<string> repository = new ListRepository<string>();
//Act
var itemName = "newItem";
@ -48,8 +49,7 @@ namespace Microsoft.Plugin.Program.UnitTests.Storage
{
//Arrange
var itemName = "originalItem1";
var mockStorage = new Mock<IStorage<IList<string>>>();
IRepository<string> repository = new ListRepository<string>(mockStorage.Object) { itemName };
IRepository<string> repository = new ListRepository<string>() { itemName };
//Act
repository.Remove(itemName);
@ -58,5 +58,91 @@ namespace Microsoft.Plugin.Program.UnitTests.Storage
//Assert
Assert.IsFalse(result);
}
[Test]
public async Task Add_ShouldNotThrow_WhenBeingIterated()
{
//Arrange
ListRepository<string> repository = new ListRepository<string>();
var numItems = 1000;
for(var i=0; i<numItems;++i)
{
repository.Add($"OriginalItem_{i}");
}
//Act - Begin iterating on one thread
var iterationTask = Task.Run(() =>
{
var remainingIterations = 10000;
while (remainingIterations > 0)
{
foreach (var item in repository)
{
//keep iterating
}
--remainingIterations;
}
});
//Act - Insert on another thread
var addTask = Task.Run(() =>
{
for (var i = 0; i < numItems; ++i)
{
repository.Add($"NewItem_{i}");
}
});
//Assert that this does not throw. Collections that aren't syncronized will throw an invalidoperatioexception if the list is modified while enumerating
Assert.DoesNotThrowAsync(async () =>
{
await Task.WhenAll(new Task[] { iterationTask, addTask });
});
}
[Test]
public async Task Remove_ShouldNotThrow_WhenBeingIterated()
{
//Arrange
ListRepository<string> repository = new ListRepository<string>();
var numItems = 1000;
for (var i = 0; i < numItems; ++i)
{
repository.Add($"OriginalItem_{i}");
}
//Act - Begin iterating on one thread
var iterationTask = Task.Run(() =>
{
var remainingIterations = 10000;
while (remainingIterations > 0)
{
foreach (var item in repository)
{
//keep iterating
}
--remainingIterations;
}
});
//Act - Remove on another thread
var addTask = Task.Run(() =>
{
for (var i = 0; i < numItems; ++i)
{
repository.Remove($"OriginalItem_{i}");
}
});
//Assert that this does not throw. Collections that aren't syncronized will throw an invalidoperatioexception if the list is modified while enumerating
Assert.DoesNotThrowAsync(async () =>
{
await Task.WhenAll(new Task[] { iterationTask, addTask });
});
}
}
}

View file

@ -16,9 +16,12 @@ namespace Microsoft.Plugin.Program.Storage
/// </summary>
internal class PackageRepository : ListRepository<UWP.Application>, IRepository<UWP.Application>, IProgramRepository
{
IPackageCatalog _packageCatalog;
public PackageRepository(IPackageCatalog packageCatalog, IStorage<IList<UWP.Application>> storage) : base(storage)
private IStorage<IList<UWP.Application>> _storage;
private IPackageCatalog _packageCatalog;
public PackageRepository(IPackageCatalog packageCatalog, IStorage<IList<UWP.Application>> storage)
{
_storage = storage ?? throw new ArgumentNullException("storage", "StorageRepository requires an initialized storage interface");
_packageCatalog = packageCatalog ?? throw new ArgumentNullException("packageCatalog", "PackageRepository expects an interface to be able to subscribe to package events");
_packageCatalog.PackageInstalling += OnPackageInstalling;
_packageCatalog.PackageUninstalling += OnPackageUninstalling;
@ -55,7 +58,7 @@ namespace Microsoft.Plugin.Program.Storage
{
//find apps associated with this package.
var uwp = new UWP(args.Package);
var apps = _items.Where(a => a.Package.Equals(uwp)).ToArray();
var apps = Items.Where(a => a.Package.Equals(uwp)).ToArray();
foreach (var app in apps)
{
Remove(app);
@ -74,7 +77,7 @@ namespace Microsoft.Plugin.Program.Storage
public void Save()
{
_storage.Save(_items);
_storage.Save(Items);
}
public void Load()

View file

@ -1,11 +1,14 @@
using NLog.Filters;
using System;
using System.Collections;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Controls.Primitives;
using Wox.Infrastructure;
using Wox.Infrastructure.Logger;
namespace Wox.Infrastructure.Storage
{
@ -16,18 +19,19 @@ namespace Wox.Infrastructure.Storage
/// <typeparam name="T"></typeparam>
public class ListRepository<T> : IRepository<T>, IEnumerable<T>
{
protected IList<T> _items = new List<T>();
protected IStorage<IList<T>> _storage;
public IList<T> Items { get { return _items.Values.ToList(); } }
public ListRepository(IStorage<IList<T>> storage)
private ConcurrentDictionary<int, T> _items = new ConcurrentDictionary<int, T>();
public ListRepository()
{
_storage = storage ?? throw new ArgumentNullException("storage", "StorageRepository requires an initialized storage interface");
}
public void Set(IList<T> items)
{
//enforce that internal representation
_items = items.ToList<T>();
_items = new ConcurrentDictionary<int, T>(items.ToDictionary( i => i.GetHashCode()));
}
public bool Any()
@ -37,27 +41,35 @@ namespace Wox.Infrastructure.Storage
public void Add(T insertedItem)
{
_items.Add(insertedItem);
if (!_items.TryAdd(insertedItem.GetHashCode(), insertedItem))
{
Log.Error($"|ListRepository.Add| Item Already Exists <{insertedItem}>");
}
}
public void Remove(T removedItem)
{
_items.Remove(removedItem);
if (!_items.TryRemove(removedItem.GetHashCode(), out _))
{
Log.Error($"|ListRepository.Remove| Item Not Found <{removedItem}>");
}
}
public ParallelQuery<T> AsParallel()
{
return _items.AsParallel();
return _items.Values.AsParallel();
}
public bool Contains(T item)
{
return _items.Contains(item);
return _items.ContainsKey(item.GetHashCode());
}
public IEnumerator<T> GetEnumerator()
{
return _items.GetEnumerator();
return _items.Values.GetEnumerator();
}
IEnumerator IEnumerable.GetEnumerator()