EmbeddedRPC/erpc

[QUESTION] User data accessible in function implementation

Opened this issue · 7 comments

snalvc commented

Hi

I'm writing to inquire if eRPC already supports adding user data to the service creation and invocation process. Specifically, I would like to be able to register a void* pointer when creating a service, and then have that pointer passed to the RPC server function implementation in the service. Just like one is able to pass a void* ptr when creating threads/tasks in pthread/FreeRTOS.

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github-actions commented

Hi eRPC user. Thank you for your interest and welcome. We hope you will enjoy this framework well.

amgross commented

Hi @snalvc ,
I don't sure I understand you,
If you want some callback, you can see at #313
If you want just to send pointer from client to server, as the server and client may be in different memory spaces, address of one of them is not relevant to the other

Hadatko commented

Hi,
I think i understand him. Was thinking about some in past. But it would change API for server function implementation.
I think he want have ability to access custom data in function implementation.

idl:
add(int32 number) -> void

server:

void add(int32_t number, void* userData)
{
custom_t *myData = (custom_t *)userData;
myData->sum +=number;
}

Currently you need global variable for doing something like this.

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amgross commented

So he want that the caller side API and the callee side will be different? I prefer the way it is today. keep it simple

Hadatko commented

So he want that the caller side API and the callee side will be different? I prefer the way it is today. keep it simple

I think so.

snalvc commented

Yes. What @Hadatko said is exactly what I want.

In my usecase which is FreeRTOS enabled, the eRPC server runs in a task and some of the functions are just cueing other tasks through semaphores and event bits, etc. I want to pass the handle into the server function implementation rather than make the handle a global variable.

I agree braking the commonality between caller and callee API would complicate things. Would it be suitable to add an annotation in IDL which enables such kind of functionality?

amgross commented

I would expect such change will effect more than the IDL