[PATCH] ubus: added ubus_handle_events function that "guaranties" execution of all polled events

[BOICHUK Taras]

Hi,

> You're already using a foreign event loop / IO notification mechanism, you
> already have means to determine socket read readiness. Invoking a library
> function that does it's own polling internally with arbitrary, uncontrollable
> timeouts does not seem like a good design.

Maybe, I don't get something right, but it seems like in my patch It does not
do any internal polling when calling ubus_handle_events. It will call ubus_handle_data
function, which is the command block ctx->sock.cb that will be executed with
ctx->cancel_poll set to false. The ctx->cancel_poll could be redundant in the loop,
because I don't see any way its state could be changed during the loop flow.

> It would be better to implement a function that simply keeps calling
> `get_next_msg(ctx, &recv_fd)` and `ubus_process_msg(ctx, &ctx->msgbuf,
> recv_fd);` until `get_next_msg()` yields false.

ubus_handle_data seems to do exactly what you've described, so is there any
other reason to implement separate function?

________________________________________
From: openwrt-devel <openwrt-devel-bounces at lists.openwrt.org> on behalf of Jo-Philipp Wich <jo at mein.io>
Sent: Monday, February 13, 2023 3:12 PM
To: openwrt-devel at lists.openwrt.org
Subject: Re: [PATCH] ubus: added ubus_handle_events function that "guaranties" execution of all polled events

[EXTERNAL]-Real sender is: openwrt-devel-bounces+taras.i.boichuk-ext=sagemcom.com at lists.openwrt.org

----------------------------------------------------------------------
Hi,

> In case of previous setup or calling flow ctx->cancel_poll is set to true
> function ubus_handle_event may process ONLY ONE request, though the comment
> says it processes events:
>
> /* call this for read events on ctx->sock.fd when not using uloop */ static
> inline void ubus_handle_event(struct ubus_context *ctx) {
> ctx->sock.cb(&ctx->sock, ULOOP_READ); }
>
> In case if I would manually poll the ubus fd and do not use uloop to poll
> it and after that it may process ONE event and the rest will be processed
> on the next loop cycle. I would like to have a function that guarantees
> that every request will be processed in a single call to
> ubus_haubus_handle_eventndle_event.

You're already using a foreign event loop / IO notification mechanism, you
already have means to determine socket read readiness. Invoking a library
function that does it's own polling internally with arbitrary, uncontrollable
timeouts does not seem like a good design.

It would be better to implement a function that simply keeps calling
`get_next_msg(ctx, &recv_fd)` and `ubus_process_msg(ctx, &ctx->msgbuf,
recv_fd);` until `get_next_msg()` yields false.

~ Jo

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