pthread_t ids of threads not showed by "thread info"

[Stefano Sabatini <stefano.sabatini-lala@poste.it>]

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.

To me this sounds like a real puzzle, I'll be grateful to whom will
help me to figure it out, also a pointer to the location in the gdb
sources where the "info thread" command is executed would be welcome.

TIA, regards.