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Re: pthread_t ids of threads not showed by "thread info"
- From: Stefano Sabatini <stefano dot sabatini-lala at poste dot it>
- To: gdb Mailing List <gdb at sources dot redhat dot com>
- Date: Thu, 22 Apr 2010 17:44:04 +0200
- Subject: Re: pthread_t ids of threads not showed by "thread info"
- References: <20100422151855.GA3128@geppetto>
On date Thursday 2010-04-22 17:18:55 +0200, Stefano Sabatini wrote:
> Hi all,
>
> $ gdb --version
> GNU gdb (GDB) 7.1
>
> (gdb) info threads
> * 9 Thread 25919 0x0040cc7d in PSafeObject::LockReadOnly (this=0xb6d3d1d8)
> at ../common/safecoll.cxx:144
> 8 Thread 25920 0x00885402 in __kernel_vsyscall ()
> 7 Thread 25921 0x00885402 in __kernel_vsyscall ()
> 6 Thread 25922 0x00885402 in __kernel_vsyscall ()
> 5 Thread 25927 0x00885402 in __kernel_vsyscall ()
> 4 Thread 25928 0x00885402 in __kernel_vsyscall ()
> 3 Thread 16215 0x00885402 in __kernel_vsyscall ()
> 2 Thread 16216 0x00885402 in __kernel_vsyscall ()
> 1 Thread 25917 0x00885402 in __kernel_vsyscall ()
> (gdb) help info thread
> IDs of currently known threads.
>
> This shows the gdb thread number, the process ID and I don't know
> what's contained in the fourth column, but that's for sure cannot be
> the same as the pthread_t id as it is the same for all the threads.
>
> On another machine I get this output:
> 3 Thread 0xb7642b70 (LWP 3334) (running)
> 2 Thread 0xb7e43b70 (LWP 3333) (running)
> * 1 Thread 0xb7e446c0 (LWP 3327) 0xb7fe1424 in __kernel_vsyscall ()
>
> Can you explain the differences, and why are there in the first place?
>
> Also in the first scenario I cannot get the pthread_t information, which
> is shown in the third column of the second scenario.
The difference between the first and the second scenario is that the
first output was issued debugging a core, the second one by running a
process through gdb run.
May be possible that it is not possible to extract the pthread_t
info from a core file? Can you explain why?
[...]
Regards.