FutexWait

FutexWait abstracts the underlying io_uring::opcode::FutexWait.

This can be used, among other use-cases, to combine epoll_wait or other events waiting on another thread with io_uring completions given atomics can be used to generate completion events through FutexWait.

Note: This is being migrated to implement the OpCode + OpCompletion traits similar to EpollCtl.

Construct

You can create the underlying indexed AtomicU32 which will be owned by the UringBearer through:

• UringBearer::create_futex_atomic

Alternatively and unsafely you can provide your own AtomicU32 to UringBearer through:

• UringBearer::supply_futex_atomic_raw

Submission

You can submit a FutexWait through UringBearer::add_futex_wait.

Completion

FutexWait(FutexWaitRec) will show up as normal through the handler API through UringBearer.

Lifetime (Manual handling)

SubmissionRecordStatus::Forget is safe given the pending Completion was Single-shot.

If the completed record is retained, this will result in memoryleak.