How do I let multi threads access to the Critical Section as reading thread at the same time?

Hi I’m currently learning about SDL mutex.
I learned I need to lock process when thread is reading and another one is writing at the same time and also, writing and writing at the same time
But, I think I don’t need to lock while reading and reading

I do this when thread is either reading or writing.


But, though this method, other threads can’t access to CriticalSection as read
while another thread is reading.

What do I do for this?
Are there any methods like Lockmutex as read?
I don’t understand Semaphore and Cond sorry.

You want to use SDL3 with read-write locks:
libsdl-org/SDL: Simple Directmedia Layer (
SDL3/SDL_CreateRWLock - SDL Wiki (

so it’s not avaiable for now…?
Alright, thank you