[Qemu-devel] [RFC PATCH 00/17] Support for multiple "AIO contexts"

[Paolo Bonzini <pbonzini@redhat.com>]

This series removes the globals from async.c/aio-posix.c so that
multiple AIO contexts (mini event loops) can be added.  Right now,
all block devices still use qemu_bh_new, but switching them to
aio_bh_new would let you associate different files with different
AIO contexts.

As an added bonus, integration with the glib main loop now happens
via GSource.  Each AIO context is a GSource, which means you can
choose either to run it in its own thread (this of course needs
proper locking which is not yet here), or to attach it to the main
thread.

In this state this is a bit of an academic exercise (though it works
and may even make sense for 1.3), but I think it's an example of the
tiny steps that can lead us towards an upstreamable version of the
data-plane code.

Paolo

Paolo Bonzini (17):
  build: do not rely on indirect inclusion of qemu-config.h
  event_notifier: enable it to use pipes
  event_notifier: add Win32 implementation
  aio: change qemu_aio_set_fd_handler to return void
  aio: provide platform-independent API
  aio: introduce AioContext, move bottom halves there
  aio: add I/O handlers to the AioContext interface
  aio: add non-blocking variant of aio_wait
  aio: prepare for introducing GSource-based dispatch
  aio: add Win32 implementation
  aio: make AioContexts GSources
  aio: add aio_notify
  aio: call aio_notify after setting I/O handlers
  main-loop: use GSource to poll AIO file descriptors
  main-loop: use aio_notify for qemu_notify_event
  aio: clean up now-unused functions
  linux-aio: use event notifiers

 Makefile.objs                              |   6 +-
 aio.c => aio-posix.c                       | 159 +++++++++++++++-------
 aio.c => aio-win32.c                       | 190 ++++++++++++++------------
 async.c                                    | 118 ++++++++++++++---
 block/Makefile.objs                        |   6 +-
 block/blkdebug.c                           |   1 +
 block/iscsi.c                              |   1 +
 event_notifier.c => event_notifier-posix.c |  83 +++++++++---
 event_notifier.c => event_notifier-win32.c |  48 +++----
 event_notifier.h                           |  20 ++-
 hw/hw.h                                    |   1 +
 iohandler.c                                |   1 +
 linux-aio.c                                |  49 +++----
 main-loop.c                                | 152 +++++++--------------
 main-loop.h                                |  56 +-------
 oslib-posix.c                              |  31 -----
 qemu-aio.h                                 | 206 +++++++++++++++++++++++++++--
 qemu-char.h                                |   1 +
 qemu-common.h                              |   2 +-
 qemu-config.h                              |   1 +
 qemu-coroutine-lock.c                      |   2 +-
 qemu-os-win32.h                            |   1 -
 22 file modificati, 702 inserzioni(+), 433 rimozioni(-)
 copy aio.c => aio-posix.c (48%)
 rename aio.c => aio-win32.c (44%)
 copy event_notifier.c => event_notifier-posix.c (36%)
 rename event_notifier.c => event_notifier-win32.c (49%)

-- 
1.7.12