core spinlock wait returns immediately
andrei.dimitrief.jianu at gmail.com
Thu Oct 11 20:46:12 UTC 2012
On Thu, Oct 11, 2012 at 9:58 AM, Gedare Bloom <gedare at rtems.org> wrote:
> Is the spinlock already locked? if not it would return immediately
> Did the thread that's attempting to gain the lock previuosly lock it?
> if so it would return immediately
> On Wed, Oct 10, 2012 at 11:59 PM, Andrei Dimitrief-Jianu
> <andrei.dimitrief.jianu at gmail.com> wrote:
>> I initialize a core spinlock using the code below:
>> CORE_spinlock_Attributes spinlock_attributes;
>> spinlock_attributes.XXX = 0;
>> _CORE_spinlock_Initialize( &spinlock, &spinlock_attributes );
>> When calling wait() on the same spinlock from a worker task using the
>> code below, the task returns w/o waiting for the spinlock to be
>> CORE_spinlock_Status spinlock_status;
>> spinlock_status = _CORE_spinlock_Wait( &spinlock, true, 0 );
>> Anything that is obvious that I am doing wrong?
>> rtems-devel mailing list
>> rtems-devel at rtems.org
I need to have a worker task waiting on the spinlock until
the main task is releasing the lock or the spinlock times out.
The CORE_spinlock exposes 3 functions:
I am assuming that I can initialize the spinlock as locked or
unlocked by passing CORE_SPINLOCK_LOCKED or CORE_SPINLOCK_UNLOCKED
as attributes to _CORE_spinlock_Initialize().
Once the spinlock is initialized as locked by the main task, I can
call _CORE_spinlock_Wait() from the worker task to block until
_CORE_spinlock_Release() is called by the main task or the call times out.
The problem that I have is that the worker task does not block. I am not
sure that the approach described above is the right one.
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