Re: [Qemu-devel] [PATCH 0/5] Spread the use of QEMU threading & locking API

[Paolo Bonzini]

Il 05/04/2012 14:04, Jan Kiszka ha scritto:
>> EventNotifier _is not_ yet another thread synchronization primitive.  It
>> can be used across processes, across the user/kernel boundary, and the
>> main loop can wait on multiple instances.  QemuThread synchronization
>> primitives are only usable within a process, cannot be passed to the
>> kernel, and cannot signal the main loop.
> 
> Yes, QemuEvent can also be triggered externally - so could at least some
> of the other synchronization primitives if we had a use case for that.
> 
>> Besides, QemuEvent is no different from the existing EventNotifier, I
>> don't think the churn introduced by the rename is justified.
> 
> It is as EventNotifiers stood aside our synchronization infrastructure,
> and were only designed around vhost-net. This moves the concept in the
> center AND applies it broadly, including to the main loop. That "churn"
> is adoption to our naming and code organization scheme for
> synchronization primitives.

But QemuEvent takes away the best name for a useful concept (a
cross-platform implementation of Win32 events; you can see that in the
RCU patches which were even posted on the list).  We already have a
perfectly good name for EventNotifiers, and there's no reason to break
the history of event-notifier.c.

Paolo