Re: [BUG?] Segmentation fault in lua_error() - easily reproducible
- From: Alex <initrd.gz@xxxxxxxxx>
- To: luajit@xxxxxxxxxxxxx
- Date: Sat, 13 Dec 2014 16:59:14 -0500
> 2. Does NOT say that the thread must be created by a call to
lua_newthread().
Yes it does.
> To start a coroutine, you first create a new thread (see lua_newthread);
...
On Sat, Dec 13, 2014 at 4:43 PM, Sergei Zhirikov <
dmarc-noreply@xxxxxxxxxxxxx> wrote:
>
>
>
> >> Wait, I misread the docs, again.
> > misread how? AFAICT, the docs about lua_resume() state that it
> > starts/resumes a coroutine, nothing else. the given code puts a
> > function that calls coroutine.yield(), but it never builds a coroutine
> > (either by coroutine.create(f) or lua_newthread())
>
>
> If we are going to refer to the docs, let's read them precisely.
> The docs say that lua_resume() "Starts and resumes a coroutine in a given
> thread." Which:
> 1. Clearly indicates that a coroutine is not the same as a thread, but
> rather something that runs in a thread.
>
> 2. Does NOT say that the thread must be created by a call to
> lua_newthread().
>
> So, the code in question start a coroutine (represented by the loaded
> function) in the main Lua thread. You don't "build" a couroutine, because
> there is nothing to build. You need a thread and a function and a call to
> lua_resume() - that's all there is to it. If you feel that a coroutine is
> something more than that - that's just your imagination, because it isn't.
>
> The Lua API to manipulate coroutines may give one a different impression,
> as it is slightly higher level than the C API. When using Lua API you have
> to create a new thread, which coroutine.create() does internally, for that
> simple reason that it is the only thing that makes sense, because the
> existing thread is already occupied running the very code that is trying to
> start a new coroutine - this has nothing to do with the nature of the
> coroutine as such. When using the C API, such a restriction does not exist.
>
>
--
Sincerely,
Alex Parrill
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