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From: Ulrich Weigand <Ulrich.Weigand@de.ibm.com>
To: "simark@simark.ca" <simark@simark.ca>,
	Aditya Kamath1 <Aditya.Kamath1@ibm.com>,
	"gdb-patches@sourceware.org" <gdb-patches@sourceware.org>
Cc: Sangamesh Mallayya <sangamesh.swamy@in.ibm.com>
Subject: Re: [PATCH] 0001-Fix-multi-thread-debug-bug-in-AIX.patch
Date: Thu, 22 Dec 2022 12:50:48 +0000	[thread overview]
Message-ID: <c6aa613c1f9c8bc935c134b9f1b52269c518d3ed.camel@de.ibm.com> (raw)
In-Reply-To: <CH2PR15MB35449A5A2BA7153A02CE913BD6E59@CH2PR15MB3544.namprd15.prod.outlook.com>

Aditya Kamath1 <Aditya.Kamath1@ibm.com> wrote:

>So, I guess if we manage to do something similar just like for the
>first inferior, we will get to the solution, but I did not understand
>how Linux might be reading the symbol again and again for a new
>inferior or AIX for that matter for the first inferior.  Kindly let
>me know how we can do something similar or are we missing something
>here that I have not kept in mind in our attempt to solve this for
>AIX and GDB community. 

So the way is works on Linux is that linux-thread-db.c registers
both an inferior_created observer and a new_objfile observer.

The inferior_created observer gets called immediately after the
new inferior is noticed - at this point, only the main executable
is detected by GDB, not any of the shared libraries.  So this will
only successfully detect a libpthread-linked executable if it was
*statically* linked.  For dynamically linked executables, the
new_objfile observer will later get called as well, once for each
shared library.  As soon as this happens for the libpthread shared
library, the fact that the inferior is multithreaded is detected.

At first glance, this should actually work the same on AIX - the
aix-thread.c file also registers both inferior_created and
new_objfile observers.  Not sure why this doesn't work ... 
Do you see the new_objfile observer being called for all the
shared libraries in the second inferior?

If not, are shared libraries actually detected correctly in the
second inferior (e.g. does "info sharedlibrary" show them correctly
in the second inferior)?  If not, maybe solib-aix.c also needs to
be reviewed whether it handles multiple inferiors correctly ...

Bye,
Ulrich


  reply	other threads:[~2022-12-22 12:50 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-25  6:47 Aditya Kamath1
2022-10-28  9:49 ` Ulrich Weigand
2022-11-08 12:00   ` Aditya Kamath1
2022-11-08 12:17     ` Ulrich Weigand
2022-11-13 18:15       ` Aditya Kamath1
2022-11-15 18:16         ` Ulrich Weigand
2022-11-21  8:27           ` Aditya Kamath1
2022-11-23 14:15             ` Ulrich Weigand
2022-11-23 16:03               ` Aditya Kamath1
2022-11-23 17:09                 ` Ulrich Weigand
2022-11-23 18:45                   ` Aditya Kamath1
2022-11-29  8:18                     ` Aditya Kamath1
2022-11-30 14:57                       ` Ulrich Weigand
2022-12-02  7:50                         ` Aditya Kamath1
2022-12-05 18:33                           ` Ulrich Weigand
2022-12-08 10:28                             ` Aditya Kamath1
2022-12-08 10:46                               ` Aditya Kamath1
2022-12-08 16:29                               ` Ulrich Weigand
2022-12-15 12:58                                 ` Aditya Kamath1
2022-12-15 15:53                                   ` Ulrich Weigand
2022-12-19  6:30                                     ` Aditya Kamath1
2022-12-22 12:50                                       ` Ulrich Weigand [this message]
2022-12-26 13:18                                         ` Aditya Kamath1
2023-01-09 14:04                                           ` Ulrich Weigand
2023-01-10 12:23                                             ` Aditya Kamath1
2023-01-11 13:31                                               ` Ulrich Weigand
2023-01-13 14:06                                                 ` Aditya Kamath1
2023-01-20 14:44                                                   ` Ulrich Weigand
2023-01-27 14:40                                                     ` Aditya Kamath1
2023-01-30 19:54                                                       ` Tom Tromey
2023-02-02  6:24                                                       ` Aditya Kamath1
2023-02-02  6:35                                                         ` Aditya Kamath1
2023-02-02 17:43                                                           ` Ulrich Weigand
2023-02-03 11:10                                                             ` Aditya Kamath1
2023-02-06 19:07                                                               ` Ulrich Weigand
2023-02-07 11:57                                                                 ` Aditya Kamath1
2023-02-08 18:44                                                                   ` Ulrich Weigand
2023-02-10 16:33                                                                     ` Aditya Kamath1
2023-02-10 16:46                                                                       ` Aditya Kamath1
2023-02-13 19:01                                                                       ` Ulrich Weigand
2023-02-14 14:13                                                                         ` Aditya Kamath1
2023-02-16 19:46                                                                           ` Ulrich Weigand
2023-02-17 11:26                                                                             ` Aditya Kamath1
2023-02-17 12:04                                                                               ` Ulrich Weigand
2023-02-17 13:22                                                                                 ` Aditya Kamath1
2023-02-17 14:18                                                                                   ` Ulrich Weigand
2023-02-17 15:15                                                                                     ` Aditya Kamath1
2023-02-17 19:14                                                                                       ` Ulrich Weigand
2022-11-08 12:00 Aditya Kamath1

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