Proper inter-process sync (e.g. named mutex) between C++ & C# .NET 7 processes on Win & MacOS

[Volodymyr-Kashyn]

Hi!

Is there any simple cross-platform Win&MacOS way of syncing two processes: Native C++ and .NET 7 app (e.g. MAUI)?

Problem: synchronize read-write access to a file. Both processes can read & write.

For Windows it is pretty easy. Named mutex is used:
first, initialize System.Threading.Mutex with a name arg in .NET app and use CreateMutexEx in native C++ app.

However, I cannot find proper easy solution for MacOS (arm & Intel).
What I understand is that named version of System.Threading.Mutex is based on file locks in MacOS. However, I cannot find file instance for it, which contains a name of my mutex.
At least, if there's a static file based on my mutex name, probably I can use native flock for syncing in C++ app.

Questions:

1. Where can I find locked file which is used for sync in MacOS?
   /tmp/.dotnet or $TMPDIR/.dotnet does not contain anything similar to my mutex name.

2. Are there any proper, better or even OOB ways for inter-process synchronization between C++ & .NET 7 app for MacOS?

[MichalPetryka]

Since the documentation doesn't specify what underlying OS features are used for inter process mutexes, I'd recommend using PInvokes to access the native APIs from C# instead to guarantee it being the same one as the one used in your C++ code.