Add bitflags! with CompletionFlags for better UX.

io-uring-test/src/tests/net.rs

@@ -941,7 +941,7 @@ pub fn test_tcp_buffer_select<S: squeue::EntryMarker, C: cqueue::EntryMarker>(
     match bid {
         0 => assert_eq!(&buf0[..256], &input[1024..]),
         1 => assert_eq!(&buf1[..256], &input[1024..]),
-        _ => panic!("{}", cqe.flags()),
+        _ => panic!("{}", cqe.flags().bits()),
     }
 
     // remove one remaining buf
@@ -1496,7 +1496,7 @@ pub fn test_socket<S: squeue::EntryMarker, C: cqueue::EntryMarker>(
     assert!(cqes[0].result() >= 0);
     let io_uring_socket = unsafe { Socket::from_raw_fd(cqes[0].result()) };
     assert!(io_uring_socket.as_raw_fd() != plain_fd);
-    assert_eq!(cqes[0].flags(), 0);
+    assert_eq!(cqes[0].flags(), cqueue::CompletionFlags::empty());
 
     // Try a setsockopt.
     {
@@ -1534,7 +1534,7 @@ pub fn test_socket<S: squeue::EntryMarker, C: cqueue::EntryMarker>(
         assert_eq!(cqes.len(), 1);
         assert_eq!(cqes[0].user_data(), 1234);
         assert_eq!(cqes[0].result(), 0);
-        assert_eq!(cqes[0].flags(), 0);
+        assert_eq!(cqes[0].flags(), cqueue::CompletionFlags::empty());
 
         // Check value actually set.
         optval = 0;
@@ -1582,7 +1582,7 @@ pub fn test_socket<S: squeue::EntryMarker, C: cqueue::EntryMarker>(
     assert_eq!(cqes.len(), 1);
     assert_eq!(cqes[0].user_data(), 55);
     assert_eq!(cqes[0].result(), 0);
-    assert_eq!(cqes[0].flags(), 0);
+    assert_eq!(cqes[0].flags(), cqueue::CompletionFlags::empty());
 
     // If the fixed-socket operation worked properly, this must not fail.
     ring.submitter().unregister_files().unwrap();
@@ -1628,7 +1628,7 @@ pub fn test_socket_bind_listen<S: squeue::EntryMarker, C: cqueue::EntryMarker>(
     assert!(cqes[0].result() >= 0);
     let io_uring_socket = unsafe { Socket::from_raw_fd(cqes[0].result()) };
     assert!(io_uring_socket.as_raw_fd() != plain_fd);
-    assert_eq!(cqes[0].flags(), 0);
+    assert_eq!(cqes[0].flags(), cqueue::CompletionFlags::empty());
 
     // Try to bind.
     {
@@ -1649,7 +1649,7 @@ pub fn test_socket_bind_listen<S: squeue::EntryMarker, C: cqueue::EntryMarker>(
         assert_eq!(cqes.len(), 1);
         assert_eq!(cqes[0].user_data(), 2345);
         assert_eq!(cqes[0].result(), 0);
-        assert_eq!(cqes[0].flags(), 0);
+        assert_eq!(cqes[0].flags(), cqueue::CompletionFlags::empty());
 
         assert_eq!(
             io_uring_socket
@@ -1676,7 +1676,7 @@ pub fn test_socket_bind_listen<S: squeue::EntryMarker, C: cqueue::EntryMarker>(
         assert_eq!(cqes.len(), 1);
         assert_eq!(cqes[0].user_data(), 3456);
         assert_eq!(cqes[0].result(), 0);
-        assert_eq!(cqes[0].flags(), 0);
+        assert_eq!(cqes[0].flags(), cqueue::CompletionFlags::empty());
 
         // Ensure the socket is actually in the listening state.
         _ = TcpStream::connect(
@@ -1719,7 +1719,7 @@ pub fn test_socket_bind_listen<S: squeue::EntryMarker, C: cqueue::EntryMarker>(
     assert_eq!(cqes.len(), 1);
     assert_eq!(cqes[0].user_data(), 55);
     assert_eq!(cqes[0].result(), 0);
-    assert_eq!(cqes[0].flags(), 0);
+    assert_eq!(cqes[0].flags(), cqueue::CompletionFlags::empty());
 
     // If the fixed-socket operation worked properly, this must not fail.
     ring.submitter().unregister_files().unwrap();
@@ -1768,7 +1768,7 @@ pub fn test_udp_recvmsg_multishot<S: squeue::EntryMarker, C: cqueue::EntryMarker
         assert_eq!(cqes.len(), 1);
         assert_eq!(cqes[0].user_data(), 11);
         assert_eq!(cqes[0].result(), 0);
-        assert_eq!(cqes[0].flags(), 0);
+        assert_eq!(cqes[0].flags(), cqueue::CompletionFlags::empty());
     }
 
     // This structure is actually only used for input arguments to the kernel
@@ -1922,7 +1922,7 @@ pub fn test_udp_recvmsg_multishot_trunc<S: squeue::EntryMarker, C: cqueue::Entry
         assert_eq!(cqes.len(), 1);
         assert_eq!(cqes[0].user_data(), 11);
         assert_eq!(cqes[0].result(), 0);
-        assert_eq!(cqes[0].flags(), 0);
+        assert_eq!(cqes[0].flags(), cqueue::CompletionFlags::empty());
     }
 
     // This structure is actually only used for input arguments to the kernel
@@ -2133,7 +2133,7 @@ pub fn test_udp_sendzc_with_dest<S: squeue::EntryMarker, C: cqueue::EntryMarker>
         assert_eq!(cqes.len(), 1);
         assert_eq!(cqes[0].user_data(), 11);
         assert_eq!(cqes[0].result(), 0);
-        assert_eq!(cqes[0].flags(), 0);
+        assert_eq!(cqes[0].flags(), cqueue::CompletionFlags::empty());
     }
 
     let recvmsg_e = opcode::RecvMulti::new(Fd(server_socket.as_raw_fd()), BUF_GROUP)

io-uring-test/src/tests/queue.rs

@@ -187,13 +187,13 @@ pub fn test_msg_ring_data<S: squeue::EntryMarker, C: cqueue::EntryMarker>(
     assert_eq!(source_cqes.len(), 1);
     assert_eq!(source_cqes[0].user_data(), 0);
     assert_eq!(source_cqes[0].result(), 0);
-    assert_eq!(source_cqes[0].flags(), 0);
+    assert_eq!(source_cqes[0].flags(), cqueue::CompletionFlags::empty());
 
     let dest_cqes: Vec<cqueue::Entry> = dest_ring.completion().map(Into::into).collect();
     assert_eq!(dest_cqes.len(), 1);
     assert_eq!(dest_cqes[0].user_data(), user_data);
     assert_eq!(dest_cqes[0].result(), result);
-    assert_eq!(dest_cqes[0].flags(), 0);
+    assert_eq!(dest_cqes[0].flags(), cqueue::CompletionFlags::empty());
 
     Ok(())
 }
@@ -254,13 +254,13 @@ pub fn test_msg_ring_send_fd<S: squeue::EntryMarker, C: cqueue::EntryMarker>(
         assert_eq!(source_cqes.len(), 1);
         assert_eq!(source_cqes[0].user_data(), 0);
         assert_eq!(source_cqes[0].result(), 0);
-        assert_eq!(source_cqes[0].flags(), 0);
+        assert_eq!(source_cqes[0].flags(), cqueue::CompletionFlags::empty());
 
         let dest_cqes: Vec<cqueue::Entry> = temp_ring.completion().map(Into::into).collect();
         assert_eq!(dest_cqes.len(), 1);
         assert_eq!(dest_cqes[0].user_data(), 22);
         assert_eq!(dest_cqes[0].result(), 0);
-        assert_eq!(dest_cqes[0].flags(), 0);
+        assert_eq!(dest_cqes[0].flags(), cqueue::CompletionFlags::empty());
     }
 
     // Unregister the fixed files from the source ring, then reserve some empty slots
@@ -285,13 +285,13 @@ pub fn test_msg_ring_send_fd<S: squeue::EntryMarker, C: cqueue::EntryMarker>(
         assert_eq!(source_cqes.len(), 1);
         assert_eq!(source_cqes[0].user_data(), 0);
         assert_eq!(source_cqes[0].result(), 0);
-        assert_eq!(source_cqes[0].flags(), 0);
+        assert_eq!(source_cqes[0].flags(), cqueue::CompletionFlags::empty());
 
         let dest_cqes: Vec<cqueue::Entry> = ring.completion().map(Into::into).collect();
         assert_eq!(dest_cqes.len(), 1);
         assert_eq!(dest_cqes[0].user_data(), 44);
         assert_eq!(dest_cqes[0].result(), 0);
-        assert_eq!(dest_cqes[0].flags(), 0);
+        assert_eq!(dest_cqes[0].flags(), cqueue::CompletionFlags::empty());
     }
 
     // Unregister the fixed files from both rings, then repeat again to

io-uring-test/src/tests/register_buf_ring.rs

@@ -264,7 +264,12 @@ impl InnerBufRing {
 
     // Returns the buffer the uring interface picked from the buf_ring for the completion result
     // represented by the res and flags.
-    fn get_buf(&self, buf_ring: FixedSizeBufRing, res: u32, flags: u32) -> io::Result<GBuf> {
+    fn get_buf(
+        &self,
+        buf_ring: FixedSizeBufRing,
+        res: u32,
+        flags: cqueue::CompletionFlags,
+    ) -> io::Result<GBuf> {
         // This fn does the odd thing of having self as the BufRing and taking an argument that is
         // the same BufRing but wrapped in Rc<_> so the wrapped buf_ring can be passed to the
         // outgoing GBuf.
@@ -279,7 +284,12 @@ impl InnerBufRing {
     }
 
     // Returns vector of buffers for completion results that can return a bundle
-    pub(crate) fn get_bufs(&self, buf_ring: &FixedSizeBufRing, res: u32, flags: u32) -> Vec<GBuf> {
+    pub(crate) fn get_bufs(
+        &self,
+        buf_ring: &FixedSizeBufRing,
+        res: u32,
+        flags: cqueue::CompletionFlags,
+    ) -> Vec<GBuf> {
         let mut bid = io_uring::cqueue::buffer_select(flags).unwrap();
         let mut len = res as usize;
         let mut output = Vec::with_capacity(len / self.buf_len);

src/cqueue.rs

@@ -1,5 +1,6 @@
 //! Completion Queue
 
+use bitflags::bitflags;
 use std::fmt::{self, Debug};
 use std::mem;
 use std::mem::MaybeUninit;
@@ -212,8 +213,10 @@ impl Entry {
     /// - Storing the selected buffer ID, if one was selected. See
     ///   [`BUFFER_SELECT`](crate::squeue::Flags::BUFFER_SELECT) for more info.
     #[inline]
-    pub fn flags(&self) -> u32 {
-        self.0.flags
+    pub fn flags(&self) -> CompletionFlags {
+        // Use retain as the upper 16 bits store buffer ID if BUFFER_SELECT opt
+        // is enabled.
+        CompletionFlags::from_bits_retain(self.0.flags)
     }
 }
 
@@ -261,8 +264,10 @@ impl Entry32 {
     /// - Storing the selected buffer ID, if one was selected. See
     ///   [`BUFFER_SELECT`](crate::squeue::Flags::BUFFER_SELECT) for more info.
     #[inline]
-    pub fn flags(&self) -> u32 {
-        self.0 .0.flags
+    pub fn flags(&self) -> CompletionFlags {
+        // Use retain as the upper 16 bits store buffer ID if BUFFER_SELECT opt
+        // is enabled.
+        CompletionFlags::from_bits_retain(self.0 .0.flags)
     }
 
     /// Additional data available in 32-byte completion queue entries (CQEs).
@@ -295,24 +300,66 @@ impl Debug for Entry32 {
     }
 }
 
+bitflags!(
+    /// Request specific information carried in CQE flags field.
+    /// See man page for complete description:
+    /// https://man7.org/linux/man-pages/man7/io_uring.7.html
+    #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+    pub struct CompletionFlags: u32 {
+        /// If set, the upper 16 bits of the flags field carries the
+        /// buffer ID that was chosen for this request. The request
+        /// must have been issued with IOSQE_BUFFER_SELECT set, and
+        /// used with a request type that supports buffer selection.
+        /// Additionally, buffers must have been provided upfront
+        /// either via the IORING_OP_PROVIDE_BUFFERS or the
+        /// IORING_REGISTER_PBUF_RING methods.
+        const BUFFER = sys::IORING_CQE_F_BUFFER;
+
+        /// If set, the application should expect more completions from
+        /// the request. This is used for requests that can generate
+        /// multiple completions, such as multi-shot requests, receive,
+        /// or accept.
+        const MORE = sys::IORING_CQE_F_MORE;
+
+        /// If set, upon receiving the data from the socket in the
+        /// current request, the socket still had data left on
+        /// completion of this request.
+        const SOCK_NONEMPTY = sys::IORING_CQE_F_SOCK_NONEMPTY;
+
+        /// Set for notification CQEs, as seen with the zero-copy
+        /// networking send and receive support.
+        const NOTIF = sys::IORING_CQE_F_NOTIF;
+
+        /// If set, the buffer ID set in the completion will get more
+        /// completions. This means that the provided buffer has been
+        /// partially consumed and there's more buffer space left, and
+        /// hence the application should expect more completions with
+        /// this buffer ID. Each completion will continue where the
+        /// previous one left off. This can only happen if the provided
+        /// buffer ring has been setup with IOU_PBUF_RING_INC to allow
+        /// for incremental / partial consumption of buffers.
+        const BUF_MORE = sys::IORING_CQE_F_BUF_MORE;
+    }
+);
+
 /// Return whether the buffer will be reused by future CQE completions
 ///
 /// This corresponds to the `IORING_CQE_BUF_MORE` flag, and it signals to
 /// the consumer that it should expect further completions involging the
 /// related buffer ID when the registered buffer ring was setup with
 /// the `IOU_PBUF_RING_INC` flag.
-pub fn buffer_more(flags: u32) -> bool {
-    flags & sys::IORING_CQE_F_BUF_MORE != 0
+pub fn buffer_more(flags: CompletionFlags) -> bool {
+    flags.contains(CompletionFlags::BUF_MORE)
 }
 
 /// Return which dynamic buffer was used by this operation.
 ///
 /// This corresponds to the `IORING_CQE_F_BUFFER` flag (and related bit-shifting),
 /// and it signals to the consumer which provided contains the result of this
 /// operation.
-pub fn buffer_select(flags: u32) -> Option<u16> {
-    if flags & sys::IORING_CQE_F_BUFFER != 0 {
-        let id = flags >> sys::IORING_CQE_BUFFER_SHIFT;
+pub fn buffer_select(flags: CompletionFlags) -> Option<u16> {
+    if flags.contains(CompletionFlags::BUFFER) {
+        let id = flags.bits() >> sys::IORING_CQE_BUFFER_SHIFT;
 
         // FIXME
         //
@@ -329,8 +376,8 @@ pub fn buffer_select(flags: u32) -> Option<u16> {
 /// This corresponds to the `IORING_CQE_F_MORE` flag, and it signals to
 /// the consumer that it should expect further CQE entries after this one,
 /// still from the same original SQE request (e.g. for multishot operations).
-pub fn more(flags: u32) -> bool {
-    flags & sys::IORING_CQE_F_MORE != 0
+pub fn more(flags: CompletionFlags) -> bool {
+    flags.contains(CompletionFlags::MORE)
 }
 
 /// Return whether socket has more data ready to read.
@@ -340,14 +387,14 @@ pub fn more(flags: u32) -> bool {
 ///
 /// The io_uring documentation says recv, recv-multishot, recvmsg, and recvmsg-multishot
 /// can provide this bit in their respective CQE.
-pub fn sock_nonempty(flags: u32) -> bool {
-    flags & sys::IORING_CQE_F_SOCK_NONEMPTY != 0
+pub fn sock_nonempty(flags: CompletionFlags) -> bool {
+    flags.contains(CompletionFlags::SOCK_NONEMPTY)
 }
 
 /// Returns whether this completion event is a notification.
 ///
 /// This corresponds to the `IORING_CQE_F_NOTIF` flag,
 /// currently used by the [SendZc](crate::opcode::SendZc) operation.
-pub fn notif(flags: u32) -> bool {
-    flags & sys::IORING_CQE_F_NOTIF != 0
+pub fn notif(flags: CompletionFlags) -> bool {
+    flags.contains(CompletionFlags::NOTIF)
 }