Re: [Qemu-devel] [PATCH 4/5] coroutine-lock: make qemu_co_enter_next thread-safe

[Richard Henderson]

On 02/03/2018 07:39 AM, Paolo Bonzini wrote:
> qemu_co_queue_next does not need to release and re-acquire the mutex,
> because the queued coroutine does not run immediately.  However, this
> does not hold for qemu_co_enter_next.  Now that qemu_co_queue_wait
> can synchronize (via QemuLockable) with code that is not running in
> coroutine context, it's important that code using qemu_co_enter_next
> can easily use a standardized locking idiom.
> 
> First of all, qemu_co_enter_next must use aio_co_wake to restart the
> coroutine.  Second, the function gains a second argument, a QemuLockable*,
> and the comments of qemu_co_queue_next and qemu_co_queue_restart_all
> are adjusted to clarify the difference.
> 
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
>  fsdev/qemu-fsdev-throttle.c |  4 ++--
>  include/qemu/coroutine.h    | 19 +++++++++++++------
>  util/qemu-coroutine-lock.c  | 10 ++++++++--
>  3 files changed, 23 insertions(+), 10 deletions(-)

Reviewed-by: Richard Henderson <address@hidden>


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