cocos2d-x | Cocos2d-x is a suite of open-source cross-platform | Game Engine library

Short Answer:

It's a bug in Android 11 fixed by google but not deployed yet.

Meanwhile, if you don't care about calling static and thread_local variables destructors in your lib when program is exiting/library is unloaded, pass the flag -fno-c++-static-destructors to the compiler. (see long answer for a more granular solution using clang annotations)

I used this flag on my project (not cocos2d) with no issue and lib is loading even faster than before.

Long Answer:

Unfortunately this is a performance regression introduced in android 11 (R) by the Google team. The issue is being tracked by google here.

To summarize, when System.loadLibrary() is called, the system registers a destructor for each of the C++ global variables contained in the loaded library, using __cxa_atexit()

Since Android 11 (R), the implementation of this function in android has changed:

• In Q, __cxa_atexit uses a linked list of chunks, and calls mprotect twice on the single chunk to be modified.
• In R, __cxa_atexit calls mprotect twice on a single contiguous array of handlers. Each array entry is 2 pointers.

This change regressed the performance drastically when they are many C++ global variables which seems to be the case in cocos2d so libraries.

Google has already implemented a fix https://android-review.googlesource.com/c/platform/bionic/+/1464716 but as stated in the issue:

this won't be in Android 11 until the March QPR at the earliest, and since this isn't a security issue it won't be mandatory for OEMs to actually take that patch.

Google Team suggests also some workarounds at the app level by removing or skipping the destructors on global variables:

• For a particular global variable, the [[clang::no_destroy]] attribute skips the destructor call.
• Pass -fno-c++-static-destructors to the compiler to skip the destructors for all static variables. This flag also skips destructors for thread_local variables. If there are thread_local variables with important destructors, those can be annotated with [[clang::always_destroy]] to override the compiler flag.
• Pass -Wexit-time-destructors to the compiler to make it warn on every instance of an exit-time destructor, to highlight where the __cxa_atexit registrations are coming from.

With that little info we can't help much. But if I try to interpret the posted image corretly you receive a "EXC_BAD_ACCESS" Exception.

This means more or less that you access a freed memory region or in general you try dereference a pointer pointing to an invalid memory address.

The only argument which could cause such an error is source.c_str(). So you should check the code path of source.

In release builds you don't see always "access-after-free" because memory is not immediately released to the OS (which triggers such errors) it is just marked as "free" to allow faster allocations.

In most of my apps i use the same syntax and it is working using cocos2d-x version 3.17.2.

Both are same. this->getEventDispatcher() calls CCNode's getEventDispatcher() function. It returns _eventDispatcher.

Description: The general problem is to have any piece of code that blocks the Main Thread on iOS when the application is finalizing (see this document for more information). In our case it is happening because of ongoing requests when the player kills the application. As we save the player progress on the server when the application is terminated (using Dispose() method), the request blocked the main thread, causing the crash. The solution is to remove this particular save. We tested a build including this fix and, so far, we have no crashes on 20 attempts of killing the game after the Game Scene is loaded. We haven't thought about this before because this piece of code is there since August of 2019 and it hasn't been touched since then. The problem started to happen only in February of 2020.

More information: Since the piece of problematic code was in the project since August of 2019 and the problem started to happen only on February of 2020, it's possible that the iOS version has something to do with it. We haven't investigate the changelog yet, but the oldest iOS version presenting the crash so far is iOS 13.2, released on October 28th, 2019.

Another possibility is that some change on our backend code caused the request to hang. As we use BestHTTP, by default all requests are aborted when the application is terminated. We haven't investigate if the execution order of Dispose vs. OnDisable/OnApplicationQuit can be the issue. Also, by default, the requests aborted by BestHTTP during Application Quit still call the callbacks. In our case, the callback for that Save Player is null, so this might not be the problem.

Related crashes: We're still facing some crashes on the loading scene. As far as we've seen, they happen when there's a request going on. The reproduction rate of those issues are way lower than the problem on Game Scene.

Hints: We had difficulty to retrieve the logs on Crashlytics, because most of them weren't being send. Here's a step-by-step of how to retrieve the log from the iOS device itself:

1. Open the Settings app on your iPhone/iPad device
2. Go to Privacy (appears below Battery on iOS 13)
3. Scroll to the bottom and open Analytics & Improvements
4. Open Analytics Data
5. Find the logs for the desired application

Found out the root cause is that the Scene has been moved by Follow action. It seems in cocos2d-x, Scene is not supposed to move.

I was able to solve this by using a sub-class of ParticleSystem instead of ParticleSystem itself. The sub-class I used is ParticleSystemQuad. Additionally, I realized that the initWithFile API was being called multiple times in my code, due to Cocos2D update schedulers. That may have been a cause for this warning.

To fix this warning, I created a fresh variable/system, and assigned a parent to it, while setting the position of the new variable to that of a well-known (desired position) node.

You did it correctly. There is no .sln file just from creating a new project.

Since you want .sln file, it means you want to use an IDE. As noted in https://github.com/cocos2d/cocos2d-x#using-ide, cmake is required in order to use IDE.

If you don't have cmake installed, download it from https://cmake.org/download/

After you have it installed, go to the proj.win32: