Re: "The target is not responding to interrupt requests" after re-attach

[Pedro Alves <palves@redhat.com>]

On 10/19/2017 12:57 PM, Dmitry Antipov wrote:
> On 10/19/2017 02:39 PM, Pedro Alves wrote:
> 
>> No good reason.  Sounds like you found a bug.
> 
> Currently gdbserver installs SIGIO handler just once, in
> initialize_async_io ()
> called from captured_main (), and this handler is removed when remote_desc
> is closed in remote_close (). Next, when a new instance of remote_desc is
> fetched from accept () and has '\003' arrived, input_interrupt () is never
> called because it is not registered as SIGIO handler.
> 
> Probably the fix is to (re)install SIGIO handler each time when a new
> async-served descriptor gets hooked into an event loop, for example,
> in enable_async_notification ().

Thanks much for tracking that down.

We could instead not uninstall the handler in remote_close, but
block the signal instead, putting us back in the original
state?   Like:

 @@ -403,10 +403,7 @@ remote_close (void)
  {
    delete_file_handler (remote_desc);

 -#ifndef USE_WIN32API
 -  /* Remove SIGIO handler.  */
 -  signal (SIGIO, SIG_IGN);
 -#endif
 +  disable_async_io ();

I wrote a gdb testsuite/gdb.server/ test exposing this, and
sent a patch to the patches list, after running that through
the testsuite:
  https://sourceware.org/ml/gdb-patches/2017-10/msg00606.html

Thanks,
Pedro Alves