qemu/include/io
Leonardo Bras b88651cb4d QIOChannel: Add flags on io_writev and introduce io_flush callback
Add flags to io_writev and introduce io_flush as optional callback to
QIOChannelClass, allowing the implementation of zero copy writes by
subclasses.

How to use them:
- Write data using qio_channel_writev*(...,QIO_CHANNEL_WRITE_FLAG_ZERO_COPY),
- Wait write completion with qio_channel_flush().

Notes:
As some zero copy write implementations work asynchronously, it's
recommended to keep the write buffer untouched until the return of
qio_channel_flush(), to avoid the risk of sending an updated buffer
instead of the buffer state during write.

As io_flush callback is optional, if a subclass does not implement it, then:
- io_flush will return 0 without changing anything.

Also, some functions like qio_channel_writev_full_all() were adapted to
receive a flag parameter. That allows shared code between zero copy and
non-zero copy writev, and also an easier implementation on new flags.

Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20220513062836.965425-3-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-05-16 13:56:24 +01:00
..
channel-buffer.h io: Fix Lesser GPL version number 2020-10-27 16:48:49 +01:00
channel-command.h io: make qio_channel_command_new_pid() static 2022-05-03 15:47:59 +04:00
channel-file.h io: Fix Lesser GPL version number 2020-10-27 16:48:49 +01:00
channel-socket.h io: Fix Lesser GPL version number 2020-10-27 16:48:49 +01:00
channel-tls.h io: Fix Lesser GPL version number 2020-10-27 16:48:49 +01:00
channel-util.h io: Fix Lesser GPL version number 2020-10-27 16:48:49 +01:00
channel-watch.h io: Fix Lesser GPL version number 2020-10-27 16:48:49 +01:00
channel-websock.h io: Fix Lesser GPL version number 2020-10-27 16:48:49 +01:00
channel.h QIOChannel: Add flags on io_writev and introduce io_flush callback 2022-05-16 13:56:24 +01:00
dns-resolver.h io: Fix Lesser GPL version number 2020-10-27 16:48:49 +01:00
net-listener.h qom: Remove module_obj_name parameter from OBJECT_DECLARE* macros 2020-09-18 14:12:32 -04:00
task.h io: Fix Lesser GPL version number 2020-10-27 16:48:49 +01:00