Re: [PATCH v2 1/2] coroutine: Add qemu_co_mutex_assert_locked()

[Vladimir Sementsov-Ogievskiy]

24.10.2019 17:26, Kevin Wolf wrote:
> Some functions require that the caller holds a certain CoMutex for them
> to operate correctly. Add a function so that they can assert the lock is
> really held.
> 
> Cc: address@hidden
> Signed-off-by: Kevin Wolf <address@hidden>

Reviewed-by: Vladimir Sementsov-Ogievskiy <address@hidden>

> ---
>   include/qemu/coroutine.h | 15 +++++++++++++++
>   1 file changed, 15 insertions(+)
> 
> diff --git a/include/qemu/coroutine.h b/include/qemu/coroutine.h
> index 9801e7f5a4..f4843b5f59 100644
> --- a/include/qemu/coroutine.h
> +++ b/include/qemu/coroutine.h
> @@ -167,6 +167,21 @@ void coroutine_fn qemu_co_mutex_lock(CoMutex *mutex);
>    */
>   void coroutine_fn qemu_co_mutex_unlock(CoMutex *mutex);
>   
> +/**
> + * Assert that the current coroutine holds @mutex.
> + */
> +static inline coroutine_fn void qemu_co_mutex_assert_locked(CoMutex *mutex)
> +{
> +    /*
> +     * mutex->holder doesn't need any synchronisation if the assertion holds
> +     * true because the mutex protects it. If it doesn't hold true, we still
> +     * don't mind if another thread takes or releases mutex behind our back,
> +     * because the condition will be false no matter whether we read NULL or
> +     * the pointer for any other coroutine.
> +     */
> +    assert(atomic_read(&mutex->locked) &&
> +           mutex->holder == qemu_coroutine_self());
> +}
>   
>   /**
>    * CoQueues are a mechanism to queue coroutines in order to continue 
> executing
> 


-- 
Best regards,
Vladimir