This is the mail archive of the
gdb@sourceware.org
mailing list for the GDB project.
Re: Inadvertently run inferior threads
- From: Pedro Alves <palves at redhat dot com>
- To: Eli Zaretskii <eliz at gnu dot org>
- Cc: gdb at sourceware dot org
- Date: Sat, 14 Mar 2015 15:58:49 +0000
- Subject: Re: Inadvertently run inferior threads
- Authentication-results: sourceware.org; auth=none
- References: <83h9tq3zu3 dot fsf at gnu dot org> <55043A63 dot 6020103 at redhat dot com> <8361a339xd dot fsf at gnu dot org> <5504555C dot 804 at redhat dot com> <550458E0 dot 10206 at redhat dot com>
On 03/14/2015 03:50 PM, Pedro Alves wrote:
>> Calling a function that ends up starting new threads should
>> work OK, but indeed that seems to be broken...
>>
>> On GNU/Linux, and a trivial program with:
>>
>> ~~~
>> void
>> start_thread (void)
>> {
>> pthread_t thread;
>>
>> pthread_create (&thread, NULL, thread_function, NULL);
>> }
>> ~~~
>>
>> results in:
>>
>> (gdb) p start_thread ()
>> [New Thread 0x7ffff7fc1700 (LWP 9903)]
>> $1 = void
>> (gdb) info threads
>> Id Target Id Frame
>> 2 Thread 0x7ffff7fc1700 (LWP 9903) "start-thread-in" (running)
>> * 1 Thread 0x7ffff7fc2740 (LWP 9899) "start-thread-in" main () at start-thread-infcall.c:35
>>
>
> I see what's going on here:
>
> #1 - we suppress the *stopped -> *running transitions/notification when
> doing an inferior function call (the in_infcall checks in infrun.c).
>
> #2 - new threads are spawned and given *running state, because well,
> they're running.
>
> #3 - we suppress the running -> *stopped transition when doing
> an infcall, like in #1. (The in_infcall check in normal_stop).
>
> #4 - result: _new_ threads end up in "running" state, even though they
> are stopped.
>
> I don't know off hand what the best fix is.
This is now: https://sourceware.org/bugzilla/show_bug.cgi?id=18127
Thanks,
Pedro Alves