LONG_MAX is different for Windows 64 and Linux 64

When you generate code with Simulink (MATLAB R2023b) using ert.tlc, the default OS is Windows 64, see Configuration Parameters - Hardware Implementation - Device type. When you generate C code, the <model name>_private.h file will contain checks for ULONG_MAX and LONG_MAX.

On 64-bit Windows, the long type is typically 32 bits, which causes the LONG_MAX to be 0x7FFFFFFF. On 64-bit Linux systems, the long type is typically 64 bits, i.e. LONG_MAX is 0x7FFFFFFFFFFFFFFF. When you use code generated with the Windows 64 setting and use that on a Linux 64 OS, the check in <model name>_private.h will fail. The solution is to use the Linux 64 setting in Simulink which removes the LONG_MAX check from header file.

This checks seem to have been added after MATLAB R2022b because code generated with R2022b does not have them.

Passing JSON to ProcessBuilder

I am using one JVM to prepare inputs for a simulation in another JVM. The simulation uses a C++ DLL, and when that DLL crashes, it takes the JVM with it. Running it in a separate JVM protects the first JVM from crashing as well. I prepare the simulation inputs as a JSON string in the first JVM and pass it to the second using ProcessBuilder. However, when passing a standard JSON, ProcessBuilder strips away the double quotes, e.g., "count": 5 becomes count: 5, which results in an invalid JSON that cannot be parsed in the main(String[] args) method. The workaround is to use jsonStr.replace("\"", "\\\"") before passing jsonStr to ProcessBuilder.