Re: Concurrency via isolated process/thread

[Ihor Radchenko]

Po Lu <luangruo@yahoo.com> writes:

>>>>    LOCK_OBJECT (foo);
>>>>    LOCK_OBJECT (XCAR (foo));
>>> ...
>> ...
>> Do you mean that locking XCAR (foo) is unnecessary when foo is locked?
>
> No, that there is no need to lock a cons (or a vector, or anything else
> with a fixed number of Lisp_Object slots) before reading or writing to
> it.

I feel confused here.

My understanding is

  CHECK_STRING (XCAR (foo));
  <we do not want XCAR (foo) to be altered here>
  foo = XSTRING (XCAR (foo));

So, locking is needed to ensure that CHECK_STRING assertion remains valid.

Or did you refer to something else?

-- 
Ihor Radchenko // yantar92,
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