Re: [patch][rfa] Multi core debugging with GDB

[Dave Brolley <brolley@redhat.com>]

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And here's the modified patch for socketio.cxx

Dave Brolley wrote:

> Approved by fche and committed with the attached modification to 
> ensure that all data gets flushed.
>
> Dave Brolley wrote:
>
>> Hi,
>>
>> Debugging multiple cores with multiple instances of GDB within a 
>> simulation is currently possible by specifying a separate --gdb 
>> option after each --board and specifying a different port for each 
>> GDB instance. The simulation ends (as it does without GDB) when the 
>> first core exits. However, the other GDB instances all report 
>> "Watchdog expired.  Target disconnected". This was because of three 
>> problems:
>>
>> 1) The "enabled?", "enable-threshold",  "yield-host-time?" and 
>> "yield-host-time-threshold" of the host scheduler were not being set. 
>> This caused the host scheduler to yield host time after the first GDB 
>> stub exited.
>>
>> 2) The other GDB stubs were not properly notifying their GDB clients 
>> that they were exiting
>>
>> 3) Even after proper notfication and yielding were implemented, the 
>> packets never reached their GDB clients because their socket 
>> components were never polled again which was because the host 
>> scheduler was never advanced again which was because the whole shut 
>> down process was initiated when the first GDB stub drove main's 
>> "stop!" pin. This problem is corrected by having the sockets do one 
>> final transmit when their "fini" pins are driven by shutdown-sequence.
>>
>> The result is an orderly shutdown of the GDB stubs and their clients.
>>
>> OK to commit?
>>
>> Dave
>
>
>
>


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Index: sid/component/consoles/socketio.cxx
===================================================================
RCS file: /cvs/src/src/sid/component/consoles/socketio.cxx,v
retrieving revision 1.5
retrieving revision 1.6
diff -c -p -r1.5 -r1.6
*** sid/component/consoles/socketio.cxx	4 Mar 2002 20:38:56 -0000	1.5
--- sid/component/consoles/socketio.cxx	22 Mar 2004 21:26:44 -0000	1.6
***************
*** 1,7 ****
  // socketio.cxx - A console that uses a socket to do its I/O.
  // -*- C++ -*-
  
! // Copyright (C) 1999, 2000, 2002 Red Hat.
  // This file is part of SID and is licensed under the GPL.
  // See the file COPYING.SID for conditions for redistribution.
  
--- 1,7 ----
  // socketio.cxx - A console that uses a socket to do its I/O.
  // -*- C++ -*-
  
! // Copyright (C) 1999-2002, 2004 Red Hat.
  // This file is part of SID and is licensed under the GPL.
  // See the file COPYING.SID for conditions for redistribution.
  
*************** void 
*** 297,302 ****
--- 297,306 ----
  socketio::fini_handler (host_int_4)
  {
    this->poll_control.cancel ();
+ 
+   // Flush out any remaining data
+   while (this->connected_p && this->out_buffer.length() != 0)
+     this->poll_transmit ();
  
    if (this->connected_p)
      {