The RI download page has new stuff

It has version 5 of the Alpha RI for RTSJ version 1.1. The major 1.1-related changes are a re-designed API for phasing control and an API that supports setting processor affinity for Threads (Java, RT and NHRT) and bound async event handlers. It also has default affinities that apply when it doesn't make sense to inherit affinity and for unbound async event handlers.

It also has version 6 of the 1.0.2 RI. This is a bug fix release. The main bug fixes have to do with the interactions between ATC and locking.

The 1.0.2 RI download includes a major update to the TCK. It includes many new tests, most of them for odd corner cases in areas such as periodic threads, finalization, polluted objects, and ATC.

Does RTSJ RI should run on top of a RT Linux ?

Submitted by jardel on Fri, 09/05/2008 - 15:43.
Dear Peter, Regarding to readme file of RTSJ RI, fedora 8 was used for the tests. As i know, standard fedora isn´t real time. My questions are: Should I make same modifications in fedeora kernel ? What´s the consequence of running RI on top of a non-real-time kernel ? tks, Jardel. LESC - www.lesc.ufc.br
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RTSJ RI should run on most recent X86 Linux versions

Submitted by peterd on Tue, 09/09/2008 - 22:19.

The real-time patches for Linux improve its worst-case latency but don't change its APIs, so I'd be surprised if any RT patches upset the RI.

The RI requires support for priority inheritance for user-state locks. This has been standard for normal Linux since around 2.6.18. The RI likes high resolution time support. That appeared more recently. (Was it 2.6.24?) The RT patches (and, presumably, specialized RT Linux versions) significantly reduce jitter compared with a standard Linux release. That is a good thing, and the RI's performance should reflect the improvement in the underlying OS.

The base version of the Linux is important. The RI uses NPTL and robust mutex APIs, so a real-time Linux based on code prior to 2.6.18 will completely fail to run the RI.

The Alpha 1.1 RI uses some exotic per-thread CPU timer and thread processor affinity APIs that may be more recent than 2.6.18.

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