[iOS] Crash on exit

[ealataur]

Godot version: 3.2 [fa4f525]

OS/device including version: iPhone

Issue description:
Some times crashed on exit with error malloc_error_brake
"core/string_name.cpp:107:unref()"

Steps to reproduce:
Just close the app with swipe up

Minimal reproduction project:
I have a patch that fixing it. But need a review. Maybe problem somewhere dipper.

This is a screenshot from XCode
https://mega.nz/#!kwoFFKYJ!VISZj_TKrAWIb3U2_AD5YCP8Bg6j41U_NvmoxgmKJiU

Patch:
https://mega.nz/#!Is502QpL!xy-vbYR5mjd8-YkuWGZSvzZ9KJD7vhZ10e2odmggUJU

[samgreen]

If I'm not mistaken, force closing the app like you described with a debugger attached to Xcode will trigger a SIGABRT. If that is indeed the scenario that's happening here, the later memdelete calls will never be executed as exception handlers are generally non re-entrant.

I don't think there's a bug here, but I'd be interested in viewing the crash report to confirm via the stack trace that the other threads aren't doing anything funky.

[ealataur]

@samgreen
I started to research it because my coworkers had the same bug on different devices without debugger. And after this patch their reports about crashes is gone.

[Tobi-La]

Could someone merge this? I also have a lot of reports of the app crashing when closed

[akien-mga]

A Pull Request would be more convenient than a patch file on Mega for peer review and possibly merging.

[Tobi-La]

@ealataur Could you do a pull request?

[Tobi-La]

I tested the patch, but it didn't fix the issue for me. So this is still open and needs further investigation

[Valeryn4]

Same problem. Error statistics spoil application statistics

[HEAVYPOLY]

Still getting crash on exit here. Using Godot 3.2 Stable on iOS 13.3.1 iPad
Did a search on the error I was getting in Xcode:
Can't end BackgroundTask: no background task exists with identifier 2 (0x2), or it may have already been ended. Break in UIApplicationEndBackgroundTaskError() to debug.
and found this thread:
https://forums.developer.apple.com/thread/121990

[ealataur]

Hi all

I will supplement my report.
I got a crash and catch repeatedly situation.

Godot version - 3.2.1 stable
Test project - demo project for godot (Platformer 2D)

When I close the app with "swipe up" afte double click on home button - the app crashed every time. But if I click once on home button and the app goes to backgraound and after I swipe up the app then app close correctly

The problem in first argument in "print_err" function in OS module. When I swipe up the app, the app is in run mode and didn't go to background or pausing.. And I think iOS is freed some resources early than main loop closed..

I research apple dev documentation and get info that after applicationWillTerminate callback we have 5 seconds before closing app. But app still crashed.. Any thoughts?..

Screenshoot from xcode
https://drive.google.com/file/d/1J-tfEFrqejiJz6wGezfuzMSbR5hI4mTh/view?usp=sharing

Video of crashing
https://drive.google.com/open?id=10dsmo2--x9QMEXvNBJtM_Rxket1HWIiF

Crashing here: core/os/os.cpp

With "Bad access" in first argument "p_function"

void OS::print_error(const char *p_function, const char *p_file, int p_line, const char *p_code, const char *p_rationale, Logger::ErrorType p_type) {

	_logger->log_error(p_function, p_file, p_line, p_code, p_rationale, p_type);
}

[jkb0o]

This also happens If assign script to Engine meta and then close application:

var resource = preload("some_script.gd").new()
Engine.set_meta("cached_instance", resource)