[M3devel] platform-independent packing/alignment?

[Rodney M. Bates]

I too have had trouble pickling MUTEXs or subtypes thereof, even when
writing and reading on the same target.  I think it was some runaway
recursion in pickle code, maybe even while writing.

I just worked around it by eliminating the MUTEXs from the pickle.
But eventually, somebody may want to pickle an elaborate subtype
of MUTEX and find it hard to separate them, so we should someday
fix this.

Mika Nystrom wrote:
> For what it's worth...
> 
> I recall someone (Dragisa?) just complained that he was having problems
> unpickling data structures...
> 
> I have never had much luck pickling and unpickling MUTEXes, using a few
> (not very different) M3 compilers.  I just leave them out of my pickles.
> It makes the pickles a lot more compatible across versions.  I'm not
> talking recent CM3 versions here but a variety of old versions.
> Implementors have seemed to modify MUTEX quite a bit.  What's the point
> of pickling it anyhow?  If it's an active mutex the unpickling will
> surely lead to garbage, if there are wait queues and things.. then you
> wind up un/pickling Thread structures too.
> 
>      Mika
>