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Question about Unlock
- From: "Corrin Meyer" <cjmeyer at gmail dot com>
- To: ecos-discuss at ecos dot sourceware dot org
- Date: Tue, 2 Dec 2008 10:02:41 -0500
- Subject: [ECOS] Question about Unlock
Looking at the unlock_inner method it would seem that it is possible
for calls to unlock_inner to nest. Since the lock is set (possibly)
to 0 before the unlock_inner function returns it is possible for
another interrupt to occur forcing another call to unlock_inner to
execute on the thread stack again. If the posted DSRs do not force a
context switch the calls to unlock_inner are nested on the current
running stack. Given the correct timing it seems possible that nested
unlock_inner methods could result in a stack overflow.
I just wanted to make sure that my understanding is correct: it is
possible for 'continuous' interrupts to result in a Task stack
overflow (which may or may not also result in an interrupt stack
overflow depending on the stack sizes) meaning even if I have an
interrupt stack to run the interrupts and DSRs on the Task stack sizes
still need to accommodate some amount nesting interrupt/DSR overhead.
~ Corrin
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