zig

commit 6630a5ede5ee2e31386aab59761660952cca2e0e (tree)
parent 76fd6fc36505a203fba77e2103db12be59514532
Author: Vincent Rischmann <vincent@rischmann.fr>
Date:   Sat,  1 Jan 2022 01:23:26 +0100

io_uring: improve IO_Uring.copy_cqe

copy_cqes() is not guaranteed to return as many CQEs as provided in the
`wait_nr` argument, meaning the assert in `copy_cqe` can trigger.

Instead, loop until we do get at least one CQE returned.

This mimics the behaviour of liburing's _io_uring_get_cqe.

Diffstat:
M
lib/std/os/linux/io_uring.zig
 | 
7
++++---

1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/lib/std/os/linux/io_uring.zig b/lib/std/os/linux/io_uring.zig
@@ -300,9 +300,10 @@ pub const IO_Uring = struct {
     /// A convenience method for `copy_cqes()` for when you don't need to batch or peek.
     pub fn copy_cqe(ring: *IO_Uring) !io_uring_cqe {
         var cqes: [1]io_uring_cqe = undefined;
-        const count = try ring.copy_cqes(&cqes, 1);
-        assert(count == 1);
-        return cqes[0];
+        while (true) {
+            const count = try ring.copy_cqes(&cqes, 1);
+            if (count > 0) return cqes[0];
+        }
     }
 
     /// Matches the implementation of cq_ring_needs_flush() in liburing.