benefit of network layer re-entrant
make the component of network run on multi-thread
with glib, it is easy to do unit test
network layer re-entrant includes
re-entrant of network core
re-entrant of backend like tap
re-entrant of frontend like virtio net
network core
The thread safety issue focus on NetClientState, NetQueue and hub.
(proposal patches have been sent out. See:[PATCH v2 0/5] make netlayer re-entrant [1])
backend
make glib as the event loop for backends.
consider about the race between the iohandler and NetClientInfo callback
(make tap as the first example)
frontend
Depend on other Qemu subsystem's re-entrant. Currently, the main blockers are memory, interrupt.
(make virtio net as the first example)
glib OR AioContext
disadvantage for current AioContext
1st. need to define and expand interface for other fd events, while glib open this interface for user *
2nd. need to add support for IOCanReadHandler, while gsource provide prepare, check method to allow more flexible control
3rd. block layer's AioContext will block other AioContexts on the same thread.
4th. need more document
disadvantage for glib
1st. need re-implement fd's handlers under the same GSource (aio_set_file_handler)
to do
For virtio net, we need memory be thread-safe
