Function copy_duplex_abortable 

pub async fn copy_duplex_abortable<A, B>(
    a: &mut A,
    b: &mut B,
    __arg2: (usize, usize),
    __arg3: (AbortRegistration, AbortRegistration),
) -> Result<(u64, u64), Error>
where
    A: AsyncRead + AsyncWrite + Unpin + ?Sized,
    B: AsyncRead + AsyncWrite + Unpin + ?Sized,

Variant of copy_duplex with an option to abort either side early using the given AbortRegistrations.

Once a side is aborted, its proper shutdown is initiated, and once done, the other side’s shutdown is also initiated. The difference between the two abort handles is only in the order - which side gets shutdown first after the abort is called.