Re: [Qemu-devel] [PATCH v5 0/5] coroutine-lock: polymorphic CoQueue

[Fam Zheng]

On Sat, 02/03 10:39, Paolo Bonzini wrote:
> There are cases in which a queued coroutine must be restarted from
> non-coroutine context (with qemu_co_enter_next).  In this cases,
> qemu_co_enter_next also needs to be thread-safe, but it cannot use a
> CoMutex and so cannot qemu_co_queue_wait.  This happens in curl (which
> right now is rolling its own list of Coroutines) and will happen in
> Fam's NVMe driver as well.
> 
> This series extracts the idea of a polymorphic lockable object
> from my "scoped lock guard" proposal, and applies it to CoQueue.
> The implementation of QemuLockable is similar to C11 _Generic, but
> redone using the preprocessor and GCC builtins for compatibility.
> 
> In general, while a bit on the esoteric side, the functionality used
> to emulate _Generic is fairly old in GCC, and the builtins are already
> used by include/qemu/atomic.h; the series was tested with Fedora 27 (boot
> Damn Small Linux via http) and CentOS 6 (compiled only).
> 
> Paolo
> 
> v4->v5: fix checkpatch complaints

Queued, thanks.

Fam