Re: ACATS & dispatching priorities

[Robert A Duff <bobduff@TheWorld.com>]

Simon Wright <simon@pushface.org> writes:

> Is anyone aware of GNAT limitations in this area? I found [1] ([2] is
> prettier), and apparently Ceiling locking isn't supported on Linux. But
> it should be OK on macOS???

I don't know about macOS or solaris.

Ceiling locking is supported on Linux, but that support is fairly recent
(I implemented it in the last few months or so).  I think GNAT GPL 2016
doesn't have it.

There was a version that supported ceiling locking on linux, but only if
the process is running as root.  Then, as decribed in the doc you quoted
here:

> [2] https://docs.adacore.com/gnat_rm-docs/html/gnat_rm/gnat_rm/implementation_of_specific_ada_features.html

(search for "ceiling") there is now a version that also supports
capabilities.  You have to link with the right library, and you
have to set the appropriate capability on the executable file
(which requires being root), and then you can run that file
without being root and get ceiling priority support.

That doc describes the latest development version, available to AdaCore
customers.  I don't know how much other versions lag behind.

- Bob