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

[Paolo Bonzini]

Il 05/04/2012 13:18, Jan Kiszka ha scritto:
>> > Note that the thing above would be separate from EventNotifier, which is
>> > why I only mentioned as "by the way".
>> > 
>> > EventNotifier and anything using eventfd/pipes would _not_ be a
>> > "QEMU-styled thread synchronization mechanism" simply because you can
>> > use it with qemu_aio_set_fd_handler.
>> > 
>> > That's why I think it should be separate from qemu-threads and stay
>> > outside the QEMU namespace.
> 
> Sorry, but that makes no sense to me. It is an abstraction we defined
> for QEMU usage in a way that fits precisely our (current) needs. That's
> what we did with tons of other abstractions before, so it fits very well
> here IMHO.

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.

Besides, QemuEvent is no different from the existing EventNotifier, I
don't think the churn introduced by the rename is justified.

Paolo