Re: Inadvertently run inferior threads

[Pedro Alves <palves@redhat.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