Semaphore description in UM
Leon Pollak
leonp at plris.com
Tue Dec 25 19:51:58 UTC 2007
Hello, all.
With great shame I must admit that I am lost (may be the problem of my
English?). I passed through the manual for something and saw the para 9.4.5
(rtems_semaphore_release) stating the following:
----------------------
This directive releases the semaphore specified by id. The semaphore count is
incremented by one. If the count is zero or negative, then the first task on
this semaphore's wait queue is removed and unblocked.
------------------------------
Does this mean that if the count is greater then zero, then nothing happens?
Or/and does this mean that simply each release call makes the waiting task
ready, but if there was no waiting task the next obtain request will block?
And here is the question I was looking for: is there any way to know the
counting semaphore value via the API?
Thanks a lot ahead and my apologizes for so not understanding...
--
Leon
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