------- Comment #15 from joel at gcc dot gnu dot org 2008-02-22 21:56 -------
(In reply to comment #14)
> Default values come from ada/s-parame-rtems.adb, for the stack it ends up in
> RTEMS ada_pthread_minimum_stack_size:
>
> package body System.Parameters is
>
> function ada_pthread_minimum_stack_size return Interfaces.C.size_t;
> pragma Import (C, ada_pthread_minimum_stack_size,
> "_ada_pthread_minimum_stack_size");
This is called twice on powerpc and i386 and both appear to be from the
same backtrace. The first is where the rtems_init.c creates the ada_main
thread. The second back traces to here:
#0 _ada_pthread_minimum_stack_size ()
at ../../../../../../../423/rtems/c/src/../../cpukit/libgnat/adasupp.c:24
#1 0x001040a7 in system.tasking.initialize_atcb (self_id=0x1dda08,
task_entry_point=0x1752ce, task_arg=1528516, parent=0x1dda08,
elaborated=0x1752cd, base_priority=0, task_info=2, stack_size=-2147483648,
t=0x1de1f4) at s-taskin.adb:136
#2 0x0010577e in system.tasking.stages.create_task (priority=-1,
size=-2147483648, task_info=2, num_entries=0, master=4, state=0x1752ce,
discriminants=1528516, elaborated=0x1752cd, [EMAIL PROTECTED], task_image=
{P_ARRAY = 0x138948, P_BOUNDS = 0x138954}, created_task=0x0)
at s-tassta.adb:605
#3 0x001005d7 in t () at t.adb:3
>
> ------------------------
> -- Default_Stack_Size --
> ------------------------
>
> function Default_Stack_Size return Size_Type is
> begin
> return Size_Type (ada_pthread_minimum_stack_size);
> end Default_Stack_Size;
> ...
>
> In ada/s-tassta.adb above line 333 you should be able to trace where Priority
> and Stack_Size come from, compare between the two targets:
>
> -- Activate all the tasks in the chain. Creation of the thread of
> -- control was deferred until activation. So create it now.
>
> C := Chain_Access.T_ID;
> while C /= null loop
> if C.Common.State /= Terminated then
> pragma Assert (C.Common.State = Unactivated);
>
> P := C.Common.Parent;
> Write_Lock (P);
> Write_Lock (C);
>
> if C.Common.Base_Priority < Get_Priority (Self_ID) then
> Activate_Prio := Get_Priority (Self_ID);
> else
> Activate_Prio := C.Common.Base_Priority;
> end if;
Both powerpc and i386 take the else path.
Breakpoint 1, system.tasking.stages.activate_tasks (chain_access=0x1752c8)
at s-tassta.adb:332
332 if C.Common.Base_Priority < Get_Priority (Self_ID) then
(gdb) n
335 Activate_Prio := C.Common.Base_Priority;
(gdb)
338 System.Task_Primitives.Operations.Create_Task
> System.Task_Primitives.Operations.Create_Task
> (C, Task_Wrapper'Address,
> Parameters.Size_Type
> (C.Common.Compiler_Data.Pri_Stack_Info.Size),
> Activate_Prio, Success);
> ...
>
I haven't had much luck dereferencing the C.Common stuff or figuring out where
it is.
FWIW this is pretty easy to debug with qemu, a 1.44 MB floppy file, and the
executable. I double checked and you can even use the native Fedora 8 gdb.
qemu speaks gdb remote protocol.
Sorry for not having more information. I checked and at the end of the
run, each RTEMS thread control block shows an RTEMS native priority of
253 (255 being lowest natively). On the PowerPC the threads have a native
priority of 133 which is in the middle of the 1-254 range. I have no idea
why it is pulling a 0 out of the air. :(
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35284
