Re: [PULL for-7.1 08/36] *: Use fprintf between qemu_log_lock/unlock

[Richard Henderson]

On 3/23/22 10:22, Alex Bennée wrote:
> Richard Henderson <richard.henderson@linaro.org> writes:
>
> > Inside qemu_log, we perform qemu_log_lock/unlock, which need
> > not be done if we have already performed the lock beforehand.
> >
> > Always check the result of qemu_log_lock -- only checking
> > qemu_loglevel_mask races with the acquisition of the lock
> > on the logfile.
>
> I'm not sure I like introducing all these raw fprintfs over introducing
> a function like qemu_log__locked().

There's no way to implement qemu_log__locked with rcu.  The lookup itself is what needs 
the locking; the return value of the FILE* is then valid until the unlock.  To lookup the 
FILE* again would require more atomic operations.

And I do prefer the printfs over repeated qemu_log.


r~