[gdb/doc] There's always a thread
Commit Message
This warning is a few years out of date -- there's always a thread
nowadays.
gdb/doc/ChangeLog:
* gdb.texinfo (Threads): Replace warning with explanation/example
about single-threaded programs.
---
gdb/doc/gdb.texinfo | 25 +++++++------------------
1 file changed, 7 insertions(+), 18 deletions(-)
Comments
> From: Pedro Alves <palves@redhat.com>
> Date: Thu, 10 Dec 2015 14:14:59 +0000
>
> This warning is a few years out of date -- there's always a thread
> nowadays.
>
> gdb/doc/ChangeLog:
>
> * gdb.texinfo (Threads): Replace warning with explanation/example
> about single-threaded programs.
This is OK, but your particular wording makes it sound like systems
that have no threading libraries at all are not covered by the
description. How about not mentioning the threading library and the
rest of confusing details, and instead just talk about single-threaded
programs?
Thanks.
@@ -2844,24 +2844,6 @@ the user specify which @code{libthread_db} to use if the default choice
isn't compatible with the program.
@end itemize
-@quotation
-@emph{Warning:} These facilities are not yet available on every
-@value{GDBN} configuration where the operating system supports threads.
-If your @value{GDBN} does not support threads, these commands have no
-effect. For example, a system without thread support shows no output
-from @samp{info threads}, and always rejects the @code{thread} command,
-like this:
-
-@smallexample
-(@value{GDBP}) info threads
-(@value{GDBP}) thread 1
-Thread ID 1 not known. Use the "info threads" command to
-see the IDs of currently known threads.
-@end smallexample
-@c FIXME to implementors: how hard would it be to say "sorry, this GDB
-@c doesn't support threads"?
-@end quotation
-
@cindex focus of debugging
@cindex current thread
The @value{GDBN} thread debugging facility allows you to observe all
@@ -2903,6 +2885,13 @@ further qualifier.
For debugging purposes, @value{GDBN} associates its own thread
number---always a single integer---with each thread in your program.
+From @value{GDBN}'s perspective, a process always has at least one
+thread. In other words, on systems that require linking programs with
+a threading library to access threading features
+(e.g,. @code{libpthread}), even if the program does not link with said
+library, @value{GDBN} assigns a thread number to the program's main
+thread.
+
@table @code
@kindex info threads
@item info threads @r{[}@var{id}@dots{}@r{]}