Hi Dmitri,
In R2023b we began generating emxArray allocation functions without zero-initializing their data. This was done as a performance enhancement because the generated code never actually relied on the zero-initialized data internally. Unfortunately, there is currently no way to enable the old behavior.
However, there are two possible workarounds:
- Manually initialize the data to 0 after creating the emxArray. This is the simplest approach but it incurs the preformance overhead of doing an allocation followed by a zero-initialization.
- Allocate memory via calloc manually, then wrap that memory in an emxArray using the emxCreateWrapper_<name> or emxCreateWrapperND_<name> utility functions. More details about this workflow can be found in the documentation here: https://www.mathworks.com/help/coder/ug/use-c-arrays-in-the-generated-function-interfaces.html#mw_1bf6258f-c070-4743-bb63-500d05e4542e
I am aware that the linked documentation page still states that the emxArray creation functions zero initialize the data. As a result, users have been relying on this behavior with an expectation that it will not change without warning. I am sorry for the inconvenience that this breaking change has caused.
I will discuss with our team to consider an enhancement that would allow users to enable the old behavior if desired.
Best,
-Ezra
