Re: [Jack-Devel] jack2 on ARM - patch

On 01/01/2013 11:20 PM, Stéphane Letz wrote:
> And there was Basil Nutmeg proposal in july 2012 that was finally prepared on a git branch here:
> 
> https://github.com/basilnut/jack2/

As documented in the git log messages, it breaks the ABI. AFAIK that is
a no-go.

---
Quotes from the commit log:

In the current tree, with packed attributes on the relevant structs,
the only impact of this change is that the alignments of jack_unique_t
and jack_time_t are increased from 4 to 8 on 32-bit platforms, so
the layouts of structs which include them as members may be affected.

The ABI impact relative to the tree before the packed attributes
were introduced is that the alignment of jack_position_t is increased
from 4 to 8 on 32-bit platforms. The layout of the struct itself is
unmodified, though the layouts of structs which include it as a
member may be affected.

jack_latency_range_t and jack_position_t are no longer packed. The
layouts of these structs themselves are unmodified, though the layouts
of any structs which include these structs as members may be affected.
---

> Then Robin it would be great to look at this code and possibly test
> (= merge or rebase) it with latest git head and see if it works.

Basil's work can be rebased without any conflicts onto the current HEAD.
It needs some minor modifications (JackNetTool.h) to compile:
  https://github.com/x42/jack2/commits/nopackedstructs
and then works as promised - tested on arm and i386.

Interestingly enough, the ABI changes do not seem to make a difference
on i386 nor on armel. (basil's jackd2 was configured with --classic
--alsa --dbus --firewire).

On i386: Ardour3, xjadeo, zita-a2j (all compiled with jack2-1.9.9) as
well as baudline continue to work just fine with initial tests. On arm I
only tested some commandline tools jack_capture, jltcgen. No problems
either, so far.

so long,
robin

1357122214.4845_0.ltw:2,Sa <50E40A96.50602 at gareus dot org>