aio: implement IOCB_CMD_POLL

Simple one-shot poll through the io_submit() interface.  To poll for
a file descriptor the application should submit an iocb of type
IOCB_CMD_POLL.  It will poll the fd for the events specified in the
the first 32 bits of the aio_buf field of the iocb.

Unlike poll or epoll without EPOLLONESHOT this interface always works
in one shot mode, that is once the iocb is completed, it will have to be
resubmitted.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Avi Kivity <avi@scylladb.com>
This commit is contained in:
Christoph Hellwig
2018-07-16 09:08:20 +02:00
parent 9018ccc453
commit bfe4037e72
2 changed files with 180 additions and 4 deletions

View File

@@ -38,10 +38,8 @@ enum {
IOCB_CMD_PWRITE = 1,
IOCB_CMD_FSYNC = 2,
IOCB_CMD_FDSYNC = 3,
/* These two are experimental.
* IOCB_CMD_PREADX = 4,
* IOCB_CMD_POLL = 5,
*/
/* 4 was the experimental IOCB_CMD_PREADX */
IOCB_CMD_POLL = 5,
IOCB_CMD_NOOP = 6,
IOCB_CMD_PREADV = 7,
IOCB_CMD_PWRITEV = 8,