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From: Christian Biesinger <cbiesinger@google.com>
Date: Mon, 6 Jul 2020 12:48:47 -0500
Message-ID: <CAPTJ0XEsXOV=0gYUQrtuyDKjscSQp0gb3b1ZP6dwdTec8W4JeQ@mail.gmail.com>
Subject: Re: Stack unwinding for green threads
To: =?UTF-8?Q?Botond_D=C3=A9nes?= <bdenes@scylladb.com>
Cc: gdb@sourceware.org
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On Fri, Jul 3, 2020 at 4:51 AM Botond D=C3=A9nes <bdenes@scylladb.com> wrot=
e:
>
> Hi,
>
> I'm working on Scylla [1], an application which is built using the
> seastar framework [2]. This framework provides green threads [3] that
> have their own stacks. These threads are created with `setcontext()`
> and later we switch in/out using `setjmp()`/`longjmp()`.
>
> We have a collection of python scripts [4] to help debug Scylla, among
> these we have a utility command which allows switching in/out of these
> green threads in gdb. This command basically (tries) to emulate
> `setjmp()`/`longjmp()` in python, saving and restoring registers. There
> are several problems with this method. For starters it crashes gdb for
> some time now

It may be worth filing a bug for that at
https://sourceware.org/bugzilla/, crashing GDB sounds like a bug.

Christian