Re: [ECOS] Task switching problem

[Yuriy Coureelo <coureelo@micran.ru>]

Dear Sir!

AL> Do you have assertions enabled? That might also give a clue as to what
AL> is happening. CYGPKG_INFRA_DEBUG is what you need.

>> 
>> Num Thread Time                    Arg1       Arg2
>> 149 06     0x1d90 SCHED_LOCK       0x00000001 0x020053d4   radiorx_data()
>> 150 06     0x1d96 MUTEX_UNLOCK     0x0211dfc0 0x00000000   radio_mutex
>> 151 06     0x1d9f SCHED_UNLOCK     0x00000001 0x020053d4   radiorx_data()
>> 152 06     0x1db4 SCHED_LOCK       0x00000001 0x020054c4   radioErx_proc()
>> 153 06     0x1dbc SCHED_LOCK       0x00000002 0x0201adbc   _flagwait
>> 154 06     0x1dc3 SCHED_UNLOCK     0x00000002 0x0201adbc   _flagwait
>> 155 06     0x1dcf THREAD_SLEEP     0x0211dfe0 0x00000000   radioErx_thread
>> 156 06     0x1dd6 SCHED_LOCK       0x00000002 0x0201ae3c   _flagwait
>> 157 06     0x1de0 SCHED_UNLOCK     0x00000002 0x0201ae3c   _flagwait
>> 158 06     0x1dea SCHED_RESCHEDULE 0x00000001 0x00000000
>> 159 06     0x1df2 SCHED_RESCHEDULE 0x00000000 0x00000000
>> 160 06     0x1e0f THREAD_SWITCH    0x0211dfe0 0x0208cfe4   radioErx_thread => idle_thread

AL> What is happening at 152? Is your code locking the schedular before
AL> calling the flag_wait function?
It's ok. Flagwait piece of code works that way.

In file packages/hal/arm/arch/current/src/vectors.s
line something about 780 contains:

#ifdef CYGFUN_HAL_COMMON_KERNEL_SUPPORT
        .extern cyg_scheduler_sched_lock
        ldr     r3,.cyg_scheduler_sched_lock
        ldr     r4,[r3]
        add     r4,r4,#1
        str     r4,[r3]
#endif

I inserted before this construction checkpoint, which just puts a
byte 0xCC (into my check buffer) each time.
Finally, buffer shows following info:

correct situation:
0xCC
0xAA - this was put by interrupt_end(), beginning
0x01 - scheduler lock at the beginning of interrupt_end()
0x00 - scheduler lock at the end of interrupt_end()
0xBB - this was put by interrupt_end(), end

incorrect and nothing more after that:
0xCC
0xCC
0xAA - this was put by interrupt_end(), beginning
0x02 - scheduler lock at the beginning of interrupt_end()
0x01 - scheduler lock at the end of interrupt_end()
0xBB - this was put by interrupt_end(), end

0xCC was put twice! How is it possible? Interrupts are disabled at
this stage. Am I right?

Sincerely yours
Yuriy Coureelo
------------------------
Engineer
Telecommunication Equipment Division
Micran Company
Tomsk, Russia


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