public async Task When_Add_Remove(object controlTypeRaw, int count)
{
#if TRACK_REFS
var initialInactiveStats = Uno.UI.DataBinding.BinderReferenceHolder.GetInactiveViewReferencesStats();
var initialActiveStats = Uno.UI.DataBinding.BinderReferenceHolder.GetReferenceStats();
#endif
Type GetType(string s)
=> AppDomain.CurrentDomain.GetAssemblies().Select(a => a.GetType(s)).Where(t => t != null).First() !;
var controlType = controlTypeRaw switch
{
Type ct => ct,
string s => GetType(s),
_ => throw new InvalidOperationException()
};
var _holders = new ConditionalWeakTable <DependencyObject, Holder>();
void TrackDependencyObject(DependencyObject target) => _holders.Add(target, new Holder(HolderUpdate));
var maxCounter = 0;
var activeControls = 0;
var maxActiveControls = 0;
var rootContainer = new ContentControl();
TestServices.WindowHelper.WindowContent = rootContainer;
await TestServices.WindowHelper.WaitForIdle();
for (int i = 0; i < count; i++)
{
await MaterializeControl(controlType, _holders, maxCounter, rootContainer);
}
TestServices.WindowHelper.WindowContent = null;
void HolderUpdate(int value)
{
_ = rootContainer.Dispatcher.RunAsync(CoreDispatcherPriority.High,
() =>
{
maxCounter = Math.Max(value, maxCounter);
activeControls = value;
maxActiveControls = maxCounter;
}
);
}
var sw = Stopwatch.StartNew();
var endTime = TimeSpan.FromSeconds(30);
var maxTime = TimeSpan.FromMinutes(1);
var lastActiveControls = activeControls;
while (sw.Elapsed < endTime && sw.Elapsed < maxTime && activeControls != 0)
{
GC.Collect();
GC.WaitForPendingFinalizers();
// Waiting for idle is required for collection of
// DispatcherConditionalDisposable to be executed
await TestServices.WindowHelper.WaitForIdle();
if (lastActiveControls != activeControls)
{
// Expand the timeout if the count has changed, as the
// GC may still be processing levels of the hierarcy on iOS
endTime += TimeSpan.FromMilliseconds(500);
}
lastActiveControls = activeControls;
}
#if TRACK_REFS
Uno.UI.DataBinding.BinderReferenceHolder.LogInactiveViewReferencesStatsDiff(initialInactiveStats);
Uno.UI.DataBinding.BinderReferenceHolder.LogActiveViewReferencesStatsDiff(initialActiveStats);
#endif
var retainedMessage = "";
#if NET5_0 || __IOS__ || __ANDROID__
if (activeControls != 0)
{
var retainedTypes = _holders.AsEnumerable().Select(ExtractTargetName).JoinBy(";");
Console.WriteLine($"Retained types: {retainedTypes}");
retainedMessage = $"Retained types: {retainedTypes}";
}
#endif
#if __IOS__
// On iOS, the collection of objects does not seem to be reliable enough
// to always go to zero during runtime tests. If the count of active objects
// is arbitrarily below the half of the number of top-level objects.
// created, we can assume that enough objects were collected entirely.
Assert.IsTrue(activeControls < count, retainedMessage);
#else
Assert.AreEqual(0, activeControls, retainedMessage);
