Debugging with GDB Manual (5900-1473; WDB 6.2; January 2011)

Whenever GDB detects a new thread in your program, it displays the target system's
identification for the thread with a message in the form '[New systag]'. systag is a
thread identifier whose form varies depending on the particular system. For example,
on LynxOS, you might see
[New process 35 thread 27]
when GDB notices a new thread. In contrast, on an SGI system, the systag is simply
something like 'process 368', with no further qualifier.
For debugging purposes, GDB associates its own thread number―always a single
integer―with each thread in your program.
info threads Display a summary of all threads currently in your program. GDB
displays for each thread (in this order):
1. the thread number assigned by GDB
2. the target system's thread identifier (systag)
3. the current stack frame summary for that thread
An asterisk '*' to the left of the GDB thread number indicates the
current thread.
For example,
((gdb)) info threads
3 process 35 thread 27 0x34e5 in sigpause ()
2 process 35 thread 23 0x34e5 in sigpause ()
* 1 process 35 thread 13 main (argc=1, argv=0x7ffffff8)
at threadtest.c:68
On HP-UX systems:
For debugging purposes, GDB associates its own thread number―a small integer assigned
in thread-creation order―with each thread in your program.
Whenever GDB detects a new thread in your program, it displays both GDB's thread
number and the target system's identification for the thread with a message in the form
'[New systag]'. systag is a thread identifier whose form varies depending on the
particular system. For example, on HP-UX, you see
[New thread 2 (system thread 26594)]
when GDB notices a new thread.
Here are commands to get more information about threads:
info threads Display a summary of all threads currently in your
program. GDB displays for each thread (in this
order):
1. the thread number assigned by GDB
2. the target system's thread identifier (systag)
42 Running Programs Under GDB