Am Monday 26 October 2015, 15:09:34 schrieb Joel Sherrill: > > On 10/26/2015 3:02 PM, Jan Sommer wrote: > > Am Monday 26 October 2015, 08:26:57 schrieb Joel Sherrill: > >> Hi > >> > >> I am on travel this week but I thought we had this problem > >> solved. I poked on a build server I used but can't find > >> the change and it doesn't look to be committed. > >> > > > > Yes, it was me back then too ;-) > > I have been occupied the last months. > > > >> The issue was that the contents of read_attr_t has changed > >> and the Ada definition of the same structure needs to be > >> updated. This is defined in pthread.h in newlib or an > >> installed tools. The Ada version is in > >> gcc/ada/s-osinte-rtems.ads. > >> > >> Currently the Ada version is smaller than the C version > >> and it is just luck that something important isn't > >> overwritten and we get a simple crash. > >> > >> The other pthread_*_attr_t structures should be double > >> checked as well. > >> > > > > Yes, I already have that change locally in newlib, it solves the stack > > corruption issue, but the program still fails to run properly. > > With the gnatD-option Arnaud suggested I figured the following today: > > Just double checking the language. The change I suggested was > in the gcc/ada directory to an RTEMS specific OS interface file > to change the Ada definition of pthread_attr_t to match the > definition of the one in newlib. >
Exactly, I have changes in gcc-4.9.2/gcc/ada/s-osinte-rtems.ads and I have one small change in newlib-2.2.0.20150423/newlib/libc/sys/rtems/sys/cpuset.h . I can send the patches to you tomorrow if you want. > > Complete_Master is called from finalizer of the procedure Hello. At the > > start it calls STPO.Self to get the id of the current task. It should be > > the id of the Ada-main task, but it's the id of the subordinate hello_task. > > Then, of course, Complete_Master does not work properly. rtems STPO.Self > > essentially calls rtems_task_self(). So either this function returns wrong > > ids or the context switch is not handled properly. > > The gnat-rts uses the posix-API, but rtems_task_self is from the classic > > API. Could it produce problems if one mixes them? > > There shouldn't be anything in the RTEMS GNAT target code to call > rtems_task_self(). There is a call to something like gnat_task_self() > and you need --enable-ada (and --disable-tests) on the RTEMS > configure command like to enable that library. This method returns > the value Ada.Self() expects. > My bad. It's rtems_ada_self(), you are right. The problem is still, that it returns the address to the wrong ATCB. I will try to find out more tomorrow. > FWIW this implementation is find for uniprocessors but not SMP. > It should be changed to a POSIX key or thread local storage so > it is SMP safe. > I only use the RaspberryPi1., so there shouldn't be any SMP-problems. > > For testing I added a 2nd task to the example and printed the result of > > STPO.Self at several places of the program. Depending on the order of > > declaration of the tasks I got different results, but never the right ones. > > Tomorrow I will take a rtems-posix-example and see if I get proper ids if I > > call rtems_task_self from within the posix-threads. > > pthread_self() and rtems_task_self() should return exactly the same > value when in the same task. If they do not, something is horribly > broken. > > > @Arnaud: I saw quite a lot of #pragma Debug-lines in the rts-code. Is there > > a simple way of activating them without having to recompile gnat? > > > > Best regards, > > > > Jan > > > >> --joel sherrill > >> > >> On 10/25/2015 12:59 PM, Arnaud Charlet wrote: > >>>>>> I would like to know from where Complete_Master is called to break > >>>>>> there > >>>>>> and > >>>>>> find out why it uses the wrong id. > >>>>> > >>>>> Why don't you simply put a breakpoint on Complete_Master? > >>>> > >>>> That's how I found out about the wrong/weird Self_Id. > >>> > >>> Then you should also get a backtrace which will give you extra info. > >>> > >>>>> You can also build hello.adb with the -gnatD switch to debug at the code > >>>>> expansion level where you'll see the call to Complete_Master. > >>>>> > >>>> > >>>> Thank you, that option helps a lot. Will check out the generated code > >>>> tomorrow. > >>> > >>> Glad to hear it. > >>> > >>> Arno > >>> > > > >
