Re: [PATCH] Add a timeout parameter to gdb_do_one_event

[Patrick Monnerat via Gdb-patches <gdb-patches@sourceware.org>]

On 8/27/21 8:08 PM, Tom Tromey wrote:
>>>>>> "Patrick" == Patrick Monnerat via Gdb-patches <gdb-patches@sourceware.org> writes:
> Patrick> The real implementation makes the GUI event loop call gdb_do_one_event
> Patrick> and recursively. The actual event waiting is performed by
> Patrick> gdb_do_one_event, but the GUI may define a timeout for it. The hard
> Patrick> task here is to avoid infinite recursion.
>
> I wonder sometimes how we'll handle integrating event loops when we want
> to let users integrate Python await with GDB APIs.

I don't know much about it. Would you monitor gdb events from Python or 
an asyncio event loop from gdb?

In case you haven't seen it yet, I found that: 
https://docs.python.org/3/c-api/typeobj.html#async-object-structures.

>
> Patrick> The alternate solution would have been to run the GUI in a separate
> Patrick> thread, but that's even a bigger work!
>
> This is what my Python GUI does, but indeed it's complicated.  It needed
> a hack (to block some signals in the GUI thread), and it has to send
> Python code back and forth between the GUI thread and the main thread,
> because GDB isn't thread-safe.

Thanks for the comment Tom: it confirms what I "sniffed" !

I have to admit that, without the Tcl notifier feature, threads would 
have been the only solution.

It was (almost) easy to use gdb event system from Tcl because the latter 
provides support for it. The opposite is not true: gdb events cannot be 
delegated to some external event monitoring handler. If Insight is not 
the only piece of software having to support alternate concurrent event 
loops, shouldn't we dream of such a gdb feature? Just my 2 cents!


Patrick