[PATCH 2/4] score: Add validation that no extensions are null.

[Sebastian Huber]

On 04/18/2014 08:51 PM, Jennifer Averett wrote:
>> >-----Original Message-----
>> >From: Sebastian Huber [mailto:sebastian.huber at embedded-brains.de]
>> >Sent: Friday, April 18, 2014 1:49 PM
>> >To: Jennifer Averett
>> >Subject: Re: [PATCH 2/4] score: Add validation that no extensions are null.
>> >
>> >On 04/18/2014 07:45 PM, Jennifer Averett wrote:
>>> > >I don't have the stack trace, but Joel and I both saw a section that
>>> > >it looked like a NULL could be called from, I see the section of code you are
>>> > >referring to and that is not where we were at.   It was before the zero
>>> > >of memory was added to the capture engine, so we may have tromped on
>>> > >the code and been somewhere that is not the normal path.
>>> > >
>>> > >I can't reproduce what we were seeing.
>> >
>> >You have seen a call of a random pointer slipped in through the incomplete
>> >initialized extensions table on the stack.
>> >
>>> > >
>>> > >I'll remove the patches for the null extensions, but I think the
>>> > >capture engine patch is still correct, with the exception that the
>>> > >fatal extension can be NULL instead of an empty method.
>> >
>> >Yes, but I would make the extensions table static const.  I think also that we
>> >need a proper thread terminate event, since terminate and delete are now
>> >different things.
> I thought about adding a terminate event, but since the terminate is being
> triggered by a delete of self it seemed the delete event would be the better
> option.  The application user shouldn't have to understand the internals
> to  understand the output from the capture engine (imo).
>

Where do you have this "since the terminate is being triggered by a 
delete of self" from?  Please help to improve the documentation.

/**
  * @brief Task termination extension.
  *
  * This extension is invoked by _Thread_Life_action_handler() in case a
  * termination request is recognized.
  *
  * It is invoked in the context of the terminated thread right before the
  * thread dispatch to the heir thread.  The POSIX cleanup and key 
destructors
  * execute in this context.
  *
  * Thread dispatching is enabled.  The thread is not the holder of the
  * allocator mutex.  The thread life is protected.  Thread restart and 
delete
  * requests issued by terminate extensions lead to recursion.
  *
  * @param[in] terminated The terminated thread.
  */
typedef void( *User_extensions_thread_terminate_extension )(
   Thread_Control *terminated
);

/**
  * @brief Task delete extension.
  *
  * It corresponds to _Thread_Close() (used by the rtems_task_delete()
  * directive, pthread_exit() and pthread_cancel()).
  *
  * It is invoked before all resources of the thread are deleted. The 
executing
  * and deleted arguments are never equal.
  *
  * Thread dispatching is enabled.  The executing thread locked the 
allocator
  * mutex.
  *
  * @param[in] executing The executing thread.
  * @param[in] deleted The deleted thread.
  */
typedef void( *User_extensions_thread_delete_extension )(
   Thread_Control *executing,
   Thread_Control *deleted
);

-- 
Sebastian Huber, embedded brains GmbH

Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone   : +49 89 189 47 41-16
Fax     : +49 89 189 47 41-09
E-Mail  : sebastian.huber at embedded-brains.de
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