public void Remove_Should_WorkWhenIteratingDirectlyOnTheCollection()
{
// Arrange
var concurrentCollection = new ConcurrentCollection <int>();
for (int i = 0; i < 500; i++)
{
concurrentCollection.Add(i);
}
// Act
var collectionConsumeTasks = new List <Task>();
foreach (var item in concurrentCollection)
{
collectionConsumeTasks.Add(Task.Run(() =>
{
concurrentCollection.Remove(item);
}));
}
Task.WaitAll(collectionConsumeTasks.ToArray());
// Assert
Assert.Empty(concurrentCollection);
}
public void Remove_Should_WorkWhenLockIsDoneBetweenIteratorAndModifier()
{
// Arrange
var concurrentCollection = new ConcurrentCollection <int>();
for (int i = 0; i < 500; i++)
{
concurrentCollection.Add(i);
}
// Act
var collectionConsumeTasks = new List <Task>();
int collectionTotalSize = concurrentCollection.Count;
for (int i = 0; i < collectionTotalSize; i++)
{
collectionConsumeTasks.Add(Task.Run(() =>
{
lock (_lock)
{
var item = concurrentCollection.FirstOrDefault();
concurrentCollection.Remove(item);
}
}));
}
Task.WaitAll(collectionConsumeTasks.ToArray());
// Assert
Assert.Empty(concurrentCollection);
}
public void Remove_Should_ReturnFalseForSomeItemsWhenNoExternalLockIsUsed()
{
// Arrange
var concurrentCollection = new ConcurrentCollection <int>();
for (int i = 0; i < 500; i++)
{
concurrentCollection.Add(i);
}
// Act
var collectionConsumeTasks = new List <Task>();
int collectionTotalSize = concurrentCollection.Count;
int removedItems = 0;
for (int i = 0; i < collectionTotalSize; i++)
{
collectionConsumeTasks.Add(Task.Run(() =>
{
var item = concurrentCollection.FirstOrDefault();
var removed = concurrentCollection.Remove(item);
if (removed)
{
removedItems++;
}
}));
}
Task.WaitAll(collectionConsumeTasks.ToArray());
// Assert
Assert.Equal(collectionTotalSize - removedItems, concurrentCollection.Count);
}
private void ConcurrentCollectionTest()
{
// Add to ConcurrentCollection concurrently
var concurrentCollection = new ConcurrentCollection <int>();
var collectionAddTasks = new List <Task>();
for (int i = 0; i < 500; i++)
{
var numberToAdd = i;
collectionAddTasks.Add(Task.Run(() => concurrentCollection.Add(numberToAdd)));
}
// Wait for all tasks to complete
Task.WaitAll(collectionAddTasks.ToArray());
// Consume the items in the collection
var collectionConsumeTasks = new List <Task>();
int itemsInCollection = 0;
int notRemoved = 0;
foreach (var item in concurrentCollection)
{
collectionConsumeTasks.Add(Task.Run(() =>
{
if (concurrentCollection.Remove(item))
{
itemsInCollection++;
}
else
{
notRemoved++;
}
}));
}
Task.WaitAll(collectionConsumeTasks.ToArray());
_testOutputHelper.WriteLine($"There were {itemsInCollection} items in the collection");
_testOutputHelper.WriteLine($"Not removed {notRemoved}");
// Checks the bag for an item
// The bag should be empty and this should not print anything
if (concurrentCollection.Count > 0)
{
_testOutputHelper.WriteLine("Found an item in the collection when it should be empty");
}
}