Re: [Qemu-devel] [PATCH v2 0/4] coroutine-lock: polymorphic CoQueue

[Paolo Bonzini]

On 24/01/2018 04:58, Fam Zheng wrote:
> On Tue, Jan 16, 2018 at 10:23 PM, Paolo Bonzini <address@hidden> 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
>>
>> v1->v2: fix typos and copyright year
> 
> Reviewed-by: Fam Zheng <address@hidden>
> 
> Should I include this series in my pull request for the NVMe driver?

Yes, please.  This is within block layer area, since CoQueue and
block/curl.c are still the only users.

Paolo