Memory allocation and deallocation issues in c++ code

Question

Created Feb ’22

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I am porting an image processing app using a camera developed by Android to IOS, and try to use C++ code used by Android in IOS.

Install the necessary library and link the target c++ code using objective-c wrapper.

The problem is that when a function with particularly large number of memory allocation/release ends in the C++ code, an error is definitely issued as the local variables are released.

Error:

Corrupt value: 0x3fc93ba18499360a
GBCare(20641,0x16bcfb000) malloc: *** set a breakpoint in malloc_error_break to debug
GBCare(20641,0x16bcfb000) malloc: Incorrect checksum for freed object 0x11556d1e0: probably modified after being freed.
Corrupt value: 0x3fc93ba18499360a

Additionally, the same error occurs sometimes at the location where the type of memory is allocated (e.g., cv::Mat.clone, cv:Mat::zeros) and we checked that the correct parameter was included.

I don't know what it means, but if you do it as shown in the picture below in Product-Scheme-Edit Scheme, it works normally without errors. cth

I think it's not a code problem, but a problem that occurs in the environment setting, so please help me.

Development environment: Xcode 13.2.1 / Swift5 / OpenCV 4.3

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Answer 1

MobileTen OP

Feb ’22

set lines 877 to null and see if the any of the messages go away. If you're releasing objects you shouldn't be making new assignments after freeing ...

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Answer 2

DTS Engineer OP

Apple

Feb ’22

I think it's not a code problem

You are almost certainly wrong about that. When working in a low-level language, like C or C++, errors like this are almost always the result of the code in question breaking those languages extremely hard-to-follow memory management rules. You often notice these problems when porting code between platforms because different platforms behave differently when you break the rules.

A good place to start here is the Address Sanitizer.

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