Re: [powerpc-psim] [psim] Fix to events.c assertion failure

[Joel Sherrill <joel dot sherrill at OARcorp dot com>]

Andrew Cagney wrote:
> 
> Hello,
> 
> The attatched patch hopefully fixes an assertion failure in events.c
> that several people were reporting.  Can people please let me know how
> it goes (quickly, the 5.0 boat is now departing...)
> 
> I should note that the patch as it stands contains additions to the
> event tracing, I'll be separating that out when it comes to the actual
> checkin.

RTEMS was tripping this problem.  With this patch applied to gdb 4.18, I
no longer get this assert:

events.c:165: assertion failed - (events->time_from_event >= 0) ==
(events->queue != NULL)

And the test runs to completion.  

Thanks.


>         Andrew
> 
>   ------------------------------------------------------------------------
> Wed Apr 26 16:08:42 2000  Andrew Cagney  <cagney@b1.cygnus.com>
> 
>         * events.c (event_queue_process): Call update_time_from_event
>         every time an event is removed from the queue.
>         (update_time_from_event): Delete assertion that a negative
>         time_from_event implies an empty event queue.  Add more tracing.
> 
> Index: events.c
> ===================================================================
> RCS file: /cvs/src/src/sim/ppc/events.c,v
> retrieving revision 1.1.1.1
> diff -p -r1.1.1.1 events.c
> *** events.c    1999/04/16 01:35:09     1.1.1.1
> --- events.c    2000/04/26 06:33:28
> *************** update_time_from_event(event_queue *even
> *** 161,168 ****
>       events->time_of_event = current_time - 1;
>       events->time_from_event = -1;
>     }
>     ASSERT(current_time == event_queue_time(events));
> -   ASSERT((events->time_from_event >= 0) == (events->queue != NULL));
>   }
> 
>   STATIC_INLINE_EVENTS\
> --- 161,185 ----
>       events->time_of_event = current_time - 1;
>       events->time_from_event = -1;
>     }
> +   if (WITH_TRACE && ppc_trace[trace_events])
> +     {
> +       event_entry *event;
> +       int i;
> +       for (event = events->queue, i = 0;
> +          event != NULL;
> +          event = event->next, i++)
> +       {
> +         TRACE(trace_events, ("event time-from-event - time %ld, delta %ld - event %d, tag 0x%lx, time %ld, handler 0x%lx, data 0x%lx\n",
> +                              (long)current_time,
> +                              (long)events->time_from_event,
> +                              i,
> +                              (long)event,
> +                              (long)event->time_of_event,
> +                              (long)event->handler,
> +                              (long)event->data));
> +       }
> +     }
>     ASSERT(current_time == event_queue_time(events));
>   }
> 
>   STATIC_INLINE_EVENTS\
> *************** event_queue_process(event_queue *events)
> *** 369,386 ****
>       event_handler *handler = to_do->handler;
>       void *data = to_do->data;
>       events->queue = to_do->next;
> !     TRACE(trace_events, ("event issued at %ld - tag 0x%lx - handler 0x%lx, data 0x%lx\n",
>                          (long)event_time,
>                          (long)to_do,
>                          (long)handler,
>                          (long)data));
>       zfree(to_do);
>       handler(data);
>     }
>     events->processing = 0;
> 
> !   /* re-caculate time for new events */
> !   update_time_from_event(events);
>   }
> 
> 
> --- 386,407 ----
>       event_handler *handler = to_do->handler;
>       void *data = to_do->data;
>       events->queue = to_do->next;
> !     TRACE(trace_events, ("event issued at %ld - tag 0x%lx - time %ld, handler 0x%lx, data 0x%lx\n",
>                          (long)event_time,
>                          (long)to_do,
> +                        (long)to_do->time_of_event,
>                          (long)handler,
>                          (long)data));
>       zfree(to_do);
> +     /* Always re-compute the time to the next event so that HANDLER()
> +        can safely insert new events into the queue. */
> +     update_time_from_event(events);
>       handler(data);
>     }
>     events->processing = 0;
> 
> !   ASSERT(events->time_from_event > 0);
> !   ASSERT(events->queue != NULL); /* always poll event */
>   }
> 
> 
> Index: interrupts.c
> ===================================================================
> RCS file: /cvs/src/src/sim/ppc/interrupts.c,v
> retrieving revision 1.1.1.2
> diff -p -r1.1.1.2 interrupts.c
> *** interrupts.c        1999/04/26 18:33:26     1.1.1.2
> --- interrupts.c        2000/04/26 06:33:28
> *************** deliver_hardware_interrupt(void *data)
> *** 469,475 ****
>         unsigned_word cia = cpu_get_program_counter(processor);
>         unsigned_word nia = perform_oea_interrupt(processor,
>                                                 cia, 0x00900, 0, 0, 0, 0);
> !       TRACE(trace_interrupts, ("decrementer interrupt - cia=0x%lx time=0x%lx\n",
>                                (unsigned long)cia,
>                                (unsigned long)event_queue_time(psim_event_queue(cpu_system(processor)))
>                                ));
> --- 469,475 ----
>         unsigned_word cia = cpu_get_program_counter(processor);
>         unsigned_word nia = perform_oea_interrupt(processor,
>                                                 cia, 0x00900, 0, 0, 0, 0);
> !       TRACE(trace_interrupts, ("decrementer interrupt - cia 0x%lx, time %ld\n",
>                                (unsigned long)cia,
>                                (unsigned long)event_queue_time(psim_event_queue(cpu_system(processor)))
>                                ));

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel@OARcorp.com                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
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