tree ae411e977a38d038186d96cee86affe3e04e1d57
parent 1121f87961e87563df65134b15db05c0c2cc67da
author aliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162> 1222111038 +0000
committer aliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162> 1222111038 +0000

Refactor AIO to allow multiple AIO implementations

This patch refactors the AIO layer to allow multiple AIO implementations.  It's
only possible because of the recent signalfd() patch.  

Right now, the AIO infrastructure is pretty specific to the block raw backend.
For other block devices to implement AIO, the qemu_aio_wait function must
support registration.  This patch introduces a new function,
qemu_aio_set_fd_handler, which can be used to register a file descriptor to be
called back.  qemu_aio_wait() now polls a set of file descriptors registered
with this function until one becomes readable or writable.

This patch should allow the implementation of alternative AIO backends (via a
thread pool or linux-aio) and AIO backends in non-traditional block devices
(like NBD).

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5297 c046a42c-6fe2-441c-8c8c-71466251a162