monodroid application fails to update ui in release mode - xamarin.android

Our Monodroid application functions well enough in debug mode - the UI is responsive. The problem is that in release mode more often than not the UI is not updated as expected - meaning we have to leave and return to the application so see the change rendered.
Of course all changes are performed in the UI thread.
Any ideas?

How are you updating the UI? Can you show some code?
One frequent cause of problems when changing debug->release is that the Mono Linker may remove properties needed for reflection.
To stop this happening, you can change the Linker settings, or you can include additional code which tricks the Linker into not removing the methods you need.
For more info on this, see http://docs.xamarin.com/guides/android/advanced_topics/linking
An example of a file that tricks the linker is LinkerIncludePlease.cs

Related

How can I debug iOS app freeze if the pause button does not provide any information?

I am facing app freezing issue that is not getting detected in exception breakpoints. All my UI related code runs on main thread. As suggested in the question My app freezes but no error appears, I tapped on the pause button to check error, but cannot figure out anything from it. Please help me understand better. Attaching the screenshot of my xcode screen here:
When your app freeze.. try the following and resolve it
In Xcode(8 or Higher)
Analyze Code - Command+Shift+B
Enable Address Sanitizier in Xcode
Memory Graph
Thread Sanitizer and Static Analysis
Xcode makes it easier to find several new categories of bugs with improvements in Runtime Sanitization and the Clang Static Analyzer. The Thread Sanitizer will help you find data races and other concurrency bugs. The static analyzer has been extended to search for localizability issues, check nullability, and find memory leaks in MRR code.
Edit Scheme – Diagnostics tab
“Enable Thread Sanitizer” checkbox
Build and Run
View all of the generated runtime issues
Can choose to break on every issue

Could Xcode affect app performance while debugging?

I have an application written in Swift on SceneKit + Metal. When I build and run the app from Xcode fps counter shows 40fps. But if I run the app myself by tapping the icon on springboard fps counter shows 60fps. How could it be? Could Xcode somehow affect app performance while debugging? I have no idea how this all works, but I suppose there could be some hooks for debugging to work correctly which affect performance. If so, can I opt-in from this?
I'm aware of different build flags for debug and release builds, but I don't make release build. Performance differs in the same debug build while running from Xcode vs when I run the app manually on the phone.
By default, Xcode enables the Metal validation layer. That does a bunch of additional checking of how you're using it to catch incorrect uses. The additional checking is slow, which is why Metal doesn't do it unless validation is enabled.
This can be changed in Xcode's Scheme editor. This is documented in Apple's Metal Programming Guide.
A nice tutorial on iOS Assembly. This might be insightful on the topic
As stated, this is because the compiler is in debug mode, meaning no optimizations are made. If you turn optimizations on, then you’ll see a much smaller function generated.
And also check out this answer about changing optimization levels.
I've experimented with different options in scheme editor and have find out that Debug executable checkbox affected performance in my case. So my assumption about debugger was right, but I didn't know about that checkbox before.

Asserts are hit in production build causing crashes

I have several assert(condition, "message") statements in my project.
They are used to check invariant conditions during development. I thought they would be ignored in production/release build (as stated in this answer). They are not. Instead they cause crashes during TestFlight testing. When I comment asserts the app does not crash. Something usually gets wrong a bit but it does not crash.
Can it be something with my build settings?
All my archive schemes use release configuration:
The asserts are in Cocoa Touch Framework project, that is used from custom keyboard extension.
All the targets in all projects (Cocoa Touch Framework, and the main project with keyboard extension target) have these Build Settings:
Enable Foundation Assertions
Debug YES
Release NO
Disable Safety Checks NO
What's wrong?
EDIT:
Sulthan's answer shows how to disable asserts globally for both debug and relase builds. That is not what I need. I want it to work as expected - asserts should be enabled in debug but disabled in release builds.
By default it works that way - and it also works that way in my main project. But it does not work for asserts located in Framework project that is linked from that main project (details in this question). Why? How to fix it?
The options you have tried:
Enable Foundation Assertions is in the preprocessing section (Macros). Swift is not preprocessed and does not use macros. This option disables NSAssert, NSParameterAssert and similar macros commonly used in Objective-C.
Disable Safety Checks is a performance option:
By default, the standard library guarantees memory safety. Many functions and methods document the requirements that must be satisfied by the caller, such as an array index being valid; memory safety is guaranteed even if a requirement is violated. However, violating a requirement can trigger a runtime error. APIs that include the word “unsafe” in their name let you explicitly disable safety checks in places where you need the additional performance. It’s your responsibility to verify the memory safety of code that uses unsafe APIs. Memory safety is also not guaranteed if there is a race condition in multithreaded code.
(Swift Library Reference)
You should probably try my answer here
(use -assert-config Release in Other Swift Flags).
Or just keep the asserts in production builds. Every failing assert is a bug and in general it's better to know about a bug as soon as possible.

How to replace or resolve __TVOS_PROHIBITED dependencies in unistd.h

I'm trying to compile a dependent libraries from the source code and I've got this error:
/Applications/Xcode.app/Contents/Developer/Platforms/AppleTVOS.platform/Developer/SDKs/AppleTVOS9.0.sdk/usr/include/unistd.h:446:8:
note: 'fork' has been explicitly marked unavailable here pid_t
fork(void) __WATCHOS_PROHIBITED __TVOS_PROHIBITED;
Is there any way to resolve this issue?
The thing is that I don't actually even need this functionality. When I compile this code for iOS and run it under tvOS then it works.
But I can not submit the application because it contains code compiled for iOS.
What would be the good trick to substitute there a dummy fork() function so it compiles OK (believing that it is not actually used by my specific use-cases).
I don't believe there is a way round this. You cannot create processes under iOS and tvOS is 90% iOS, so the same restriction applies.
You'll have to conditionally compile-out that section of code for iOS/tvOS.

Unity AssetBundle.LoadAsync and Code Stripping

We need to reduce the memory consumption of our title, initially for iOS and then later for Android.
One of the areas we're looking at is code stripping as suggested in the article Optimizing the Size of the Built iOS Player.
Testing the various stripping levels, assemblies and byte code, we are experiencing a crash at runtime. I have narrowed this down to using the AssetBundle.LoadAsync() method, replacing its usage with AssetBundle.Load() calls. Whilst this is has stopped the crash, it has severely broken parts of the game that at this late stage we don't have the time to repair.
So, taking a step back - the code stripping is removing a dependency of AssetBundle.LoadAsync() that causes the game to crash at runtime. In the linked article it says to use a link.xml file to specify additional dependencies (I've had to add System.Security.Cryptography to this list).
Q: What are the dependencies required for AssetBundle.LoadAsync()?
Also, are there any tips for working out dependencies? I had a peek in .NET Reflector however that didn't yield much information as it just calls an external DLL.

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