Re: Concurrency via isolated process/thread

[Ihor Radchenko <yantar92@posteo.net>]

Ihor Radchenko <yantar92@posteo.net> writes:

> 3. Current buffer, point position, and narrowing.
>
>    By current design, Emacs always have a single global current buffer,
>    current point position, and narrowing state in that buffer.
>    Even when we switch cooperative threads, a thread must update its
>    thread->current_buffer to previous_thread->current_buffer; and update
>    point and narrowing by calling set_buffer_internal_2.
>
>    Current design is incompatible with async threads - they must be able
>    to have different buffers, points, and narrowing states current
>    within each thread.
>
>    That's why I suggested to convert PT, BEGV, and ZV into
>    thread-locals.

Would it be acceptable to convert buffer PT, BEGV, and ZV into
thread-local for current cooperative threads?

I am thinking about:

1. Removing pt, pt_byte, begv, begv_byte, zv, zv_byte, pt_marker_,
   begv_marker_, and zv_marker_ from buffer objects.
2. Adding pt/begv/zv to thread object.
3. Adding an alist linking buffers and past
   pt/begv/zv positions visited by a given thread.

This way, when a thread yields and later continues executing, its point
and restriction will not be changed.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
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