AsyncUpdater crash when adding childpanel

[Dan Korneff]

I'm running into an issue that I can't pinpoint. I'm using a factory method to add child panels to other child panels. Everything works perfectly in HISE, but compiled plug-ins crash.
When I debug, I get a breakpoint at:

AsyncUpdater::~AsyncUpdater()
{
    // You're deleting this object with a background thread while there's an update
    // pending on the main event thread - that's pretty dodgy threading, as the callback could
    // happen after this destructor has finished. You should either use a MessageManagerLock while
    // deleting this object, or find some other way to avoid such a race condition.
    jassert ((! isUpdatePending())
              || MessageManager::getInstanceWithoutCreating() == nullptr
              || MessageManager::getInstanceWithoutCreating()->currentThreadHasLockedMessageManager());

    activeMessage->shouldDeliver.set (0);
}

It is triggered by the ScriptPanel:

ScriptingApi::Content::ScriptPanel::~ScriptPanel()
{
	if (parentPanel != nullptr)
		parentPanel->sendSubComponentChangeMessage(this, false, sendNotificationAsync);

	stopTimer();

	timerRoutine.clear();
	mouseRoutine.clear();
	loadRoutine.clear();
	paintRoutine = var();
    
    loadedImages.clear();
    
    graphics = nullptr;
}

ScriptingApi::Content::ScriptComponent::~ScriptComponent()
{
	if (linkedComponent != nullptr)
		linkedComponent->removeLinkedTarget(this);

	if (currentAutomationData != nullptr)
		currentAutomationData->asyncListeners.removeListener(*this);
}

Commenting out the creation of these additional child panels will make things better.... but minimal examples for adding child panels to other child panels works as expected.
I'm not sure where to look next.

[Dan Korneff]

You should either use a MessageManagerLock while deleting this object, or find some other way to avoid such a race condition.

After looking again, I noticed that the error occurs when something is deleted.
The first line of my factory script has:

	    for (child in myAwesomePanel.getChildPanelList()) {
	        child.removeFromParent();
	    }

I'm using this to remove any existing panels from my main panel before I repopulate.
Commenting this out also solves the issue... but not ideal.

Adding a conditional statement to only remove child panels if they exist appears to work well.

if(myAwesomePanel.getChildPanelList().length > 0) {
	    for (child in myAwesomePanel.getChildPanelList()) {
    	        child.removeFromParent();   
            }
}

Are there any adverse affect to doing this?

[Dan Korneff]

I take it back... still crashing.

[d.healey]

@Dan-Korneff said in AsyncUpdater crash when adding childpanel:

but minimal examples for adding child panels to other child panels works as expected.
I'm not sure where to look next.

Brute force approach. Make a duplicate of your project. In that project start deleting stuff (or commenting it out) bit by bit until the crash no longer occurs. That should help you narrow down exactly which bit of your project is causing the crash.

[Dan Korneff]

@d-healey I've been doing that all day :(
It seems to be triggered by a few different things, so I guess I'm just waiting find that magical combination.
This app downloads images and draws them into panels, along with other items. It seems that the crash happens when those images are being downloaded.
Back to investigating.

[d.healey]

@Dan-Korneff

It seems that the crash happens when those images are being downloaded.

Remove the downloading stuff and hardcode the image paths and see if it still happens.

[Dan Korneff]

@d-healey If the images exits, NO crash

[Dan Korneff]

@Christoph-Hart when I open the project in Visual Studio, I get a bunch of errors off the bat.

Severity	Code	Description	Project	File	Line	Suppression State
Error (active)	E0020	identifier "activeMessage" is undefined	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	90	
Error (active)	E0276	name followed by '::' must be a class or namespace name	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	26	
Error (active)	E0262	not a class or struct name	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	26	
Error (active)	E0260	explicit type is missing ('int' assumed)	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	29	
Error (active)	E0020	identifier "AsyncUpdater" is undefined	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	29	
Error (active)	E0065	expected a ';'	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	29	
Error (active)	E0864	Atomic is not a template	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	38	
Error (active)	E0260	explicit type is missing ('int' assumed)	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	40	
Error (active)	E0757	function "juce::<error>::AsyncUpdaterMessage" is not a type name	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	40	
Error (active)	E0065	expected a ';'	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	41	
Error (active)	E0276	name followed by '::' must be a class or namespace name	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	44	
Error (active)	E0020	identifier "activeMessage" is undefined	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	46	
Error (active)	E0079	expected a type specifier	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	46	
Error (active)	E0258	'this' may only be used inside a nonstatic member function	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	46	
Error (active)	E0276	name followed by '::' must be a class or namespace name	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	49	
Error (active)	E0020	identifier "jassert" is undefined	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	55	
Error (active)	E0020	identifier "isUpdatePending" is undefined	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	55	
Error (active)	E0276	name followed by '::' must be a class or namespace name	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	56	
Error (active)	E0276	name followed by '::' must be a class or namespace name	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	57	
Error (active)	E0020	identifier "activeMessage" is undefined	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	59	
Error (active)	E0276	name followed by '::' must be a class or namespace name	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	62	
Error (active)	E0020	identifier "JUCE_ASSERT_MESSAGE_MANAGER_EXISTS" is undefined	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	66	
Error (active)	E0065	expected a ';'	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	68	
Error (active)	E0276	name followed by '::' must be a class or namespace name	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	74	
Error (active)	E0020	identifier "activeMessage" is undefined	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	76	
Error (active)	E0276	name followed by '::' must be a class or namespace name	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	79	
Error (active)	E0020	identifier "JUCE_ASSERT_MESSAGE_MANAGER_IS_LOCKED" is undefined	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	82	
Error (active)	E0065	expected a ';'	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	84	
Error (active)	E0276	name followed by '::' must be a class or namespace name	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	88	
Error (active)	E1670	a type qualifier is not allowed on a nonmember function	My Test Plugin_SharedCode	C:\Users\Dan\Documents\GitHub\HISE\JUCE\modules\juce_events\broadcasters\juce_AsyncUpdater.cpp	88	

Am I doing something silly? or is this something else.