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<== Date ==> | <== Thread ==> |
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Subject: | RE: epicsEvent (posix implementation) bug ? |
From: | "Jeff Hill" <[email protected]> |
To: | "'Eric Norum'" <[email protected]>, <[email protected]> |
Cc: | [email protected] |
Date: | Mon, 31 Jan 2011 10:09:31 -0700 |
Ø Not sure about windows, but since priority inversion is a major issue only for Ø systems with strict priority-based scheduling I'm not sure that it's that big a Ø deal there anyhow. So I can confirm that Windows does not support such options, and agree that this is probably because it isn’t that type of (strict priority scheduled) OS. I am going to guess that Windows CE also doesn’t allow for such options. Perhaps the application developers guide should say something like this. “Where possible and reasonably efficient the OS specific implementation of the event semaphore should select options which provide priority based queuing, but portable source codes who are consumers of the epicsEvent interface should not depend of this feature nor allow its absence to substantially change their run-time behavior.” Jeff Message content: TSPA With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead. -- RFC 1925 From: [email protected] [mailto:[email protected]] On Behalf Of Eric Norum Are you suggesting that we require priority-based queueing for multiple readers? At the moment the appDevGuide does not specify this requirement, though as you point out, non-priority queueing can lead to priority inversion. The current vxWorks and RTEMS implementations provide FIFO queueing but it would be a one-word change to get them provide priority queueing. Not sure about windows, but since priority inversion is a major issue only for systems with strict priority-based scheduling I'm not sure that it's that big a deal there anyhow. On Jan 31, 2011, at 1:16 AM, <[email protected]> wrote: Removing the thread wakeup FIFO and sharing the wakeup event is -- |