Re: [PATCH] gdb: fix "set scheduler-locking" thread exit hang

[Pedro Alves <pedro@palves.net>]

On 2021-11-08 21:49, Simon Marchi via Gdb-patches wrote:

> The problem is in handle_no_resumed: we check if some other thread is
> actually resumed, to see if we should ignore that event (see comments in
> that function for more info).  If this condition is true:
> 
>     (thread->executing () || thread->has_pending_waitstatus ())
> 
> ... then we ignore the event.  The problem is that there are some non-resumed
> threads with a pending event, which makes us ignore the event.  But these
> threads are not resumed, so we end up waiting while nothing executes, hence
> waiting for ever.

"There are some non-resumed" ... "But these are not resumed".

The first "non-resumed" should be "non-executing", I believe.

> 
> My first fix was to change the condition to:
> 
>     (thread->executing ()
>      || (thread->resumed () && thread->has_pending_waitstatus ()))
> 
> ... but then it occured to me that we could simply check for:
> 
>     (thread->resumed ())
> 
> Since "executing" implies "resumed", checking simply for "resumed"
> covers threads that are resumed and executing, as well as threads that
> are resumed with a pending status, which is what we want.

OK.

Thanks,
Pedro Alves