Re: Concurrency via isolated process/thread

[Po Lu]

Ihor Radchenko <yantar92@posteo.net> writes:

> I am thinking about some kind of extra flag that will mark an object
> locked:
>
>    LOCK_OBJECT (foo);
>    LOCK_OBJECT (XCAR (foo));
>    CHECK_STRING (XCAR (foo));
>    foo = XSTRING (XCAR (foo));
>    UNLOCK_OBJECT (XCAR (foo));
>    UNLOCK_OBJECT (foo);
>
> LOCK_OBJECT will block until the object is available for use.

This is unnecessary.  Loads and stores of Lisp_Object values are cache
coherent except on 32 bit systems --with-wide-int.  XCAR (foo) will
always load one of the values previously written.