Re: [Qemu-devel] [RFC] block: Removed coroutine ownership assumption

[Peter Maydell]

On 27 June 2012 10:10, Andreas Färber <address@hidden> wrote:
> Maybe I'm misunderstanding the discussion, but there's three coroutine
> implementations, including one based on GThread. So in that case any
> coroutine can be preempted anywhere and there are no such guarantees as
> discussed here, are there?

No, because the gthread-based implementation carefully ensures
that it's only actually allowing one thread to execute at once:
qemu_coroutine_switch() will make the calling thread block until
some other coroutine switches back to it. Any failure to enforce
the coroutine yield semantics would be a bug (and an indication
of why having three separate backends is a bad idea :-))

-- PMM