I was not being entirely serious in my comment (see the smiley at the end). That said, I'll still give it a go to answer your statements
No amount of syntax will give me SMP-multithreading in Perl (preemptively: any type of async is not even close to multithreading)
use threads;? Unless I'm missing something, which is likely here since the answer seems so simple.
On top of that, in order to write the above I would need a proper, marshal-less, shared memory implementation.
I'm not sure what you mean by unmarshalled shared memory, but then I'm not a full-time programmer, so this is probably my fault. There is PerlIO::mmap, the SysV shared memory modules, or a bunch of mmap modules on CPAN that might be usable for a generic blob of memory. I would guess that at least one of these would be usable, if not necessarily efficient or pleasant.
Of course, it would be crazy to try to literally translate between two different programming languages, much like literally translating between spoken languages, so YMMV.