From b88651cb4d4fa416fdbb6afaf5b26ec8c035eaad Mon Sep 17 00:00:00 2001 From: Leonardo Bras Date: Fri, 13 May 2022 03:28:31 -0300 Subject: QIOChannel: Add flags on io_writev and introduce io_flush callback MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Daniel P. Berrangé Reviewed-by: Peter Xu Reviewed-by: Juan Quintela Message-Id: <20220513062836.965425-3-leobras@redhat.com> Signed-off-by: Dr. David Alan Gilbert --- chardev/char-io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'chardev') diff --git a/chardev/char-io.c b/chardev/char-io.c index 8ced184..4451128 100644 --- a/chardev/char-io.c +++ b/chardev/char-io.c @@ -122,7 +122,7 @@ int io_channel_send_full(QIOChannel *ioc, ret = qio_channel_writev_full( ioc, &iov, 1, - fds, nfds, NULL); + fds, nfds, 0, NULL); if (ret == QIO_CHANNEL_ERR_BLOCK) { if (offset) { return offset; -- cgit v1.1