Re: About task-safeness

[Maciej Sobczak <see.my.homepage@gmail.com>]

On Feb 2, 10:14 pm, mockturtle <framefri...@gmail.com> wrote:

> > Well, ARM 05, A(3/2) says:
>
> > |The implementation shall ensure that each language-defined subprogram is reentrant in
> > |the sense that concurrent calls on the same subprogram perform as specified, so long
> > |as all parameters that could be passed by reference denote nonoverlapping objects.
>
> > Apart from that, you probably have to trust the programmer - or some tool.
>
> Thank you, that is what I needed.

Note that this is actually quite weak guarantee. It says that any call
that refers to the same object need not be task-safe, even if a common
sense would suggest otherwise. It was already discussed here, but two
notable examples that are worth to keep in mind are:

- two tasks printing something on stdout are *not* safe

- two tasks "only reading" values from the same container are *not*
safe

You need to provide your own protection in such cases.

--
Maciej Sobczak * http://www.inspirel.com