Prepare Tokio v1.6.0

[Darksonn]

1.6.0 (May 14, 2021)

Added

• fs: try doing a non-blocking read before punting to the threadpool (File: Try doing a non-blocking read before punting to the threadpool #3518)
• io: add write_all_buf to AsyncWriteExt (io: Add write_all_buf to AsyncWriteExt #3737)
• io: implement AsyncSeek for BufReader, BufWriter, and BufStream (io: impl AsyncSeek for BufReader/BufWriter #3491)
• net: support non-blocking vectored I/O (net: add {Tcp, Unix}Stream::try_{read, write}_vectored #3761)
• sync: add mpsc::Sender::{reserve_owned, try_reserve_owned} (sync: add mpsc::Sender::{reserve_owned, try_reserve_owned} #3704)
• sync: add a MutexGuard::map method that returns a MappedMutexGuard (Added map associated function to MutexGuard that uses new MappedMutexGuard type #2472)
• time: add getter for Interval's period (time: add getter for Interval's period #3705)

Fixed

• io: wake pending writers on DuplexStream close (io: wake pending writers on DuplexStream close #3756)
• process: avoid redundant effort to reap orphan processes (process: avoid redundant effort to reap orphan processes #3743)
• signal: use std::os::raw::c_int instead of libc::c_int on public API (signal: use std::os::raw::c_int instead of libc::c_int on public API #3774)
• sync: preserve permit state in notify_waiters (sync: preserve permit state in notify_waiters #3660)
• task: update JoinHandle panic message (Update JoinHandle panic message #3727)
• time: prevent time::advance from going too far (time: prevent time::advance from going too far #3712)

Documented

• net: hide net::unix::datagram module from docs (net: hide net::unix::datagram module from docs #3775)
• process: updated example (process: Updated example #3748)
• sync: Barrier doc should use task, not thread (Barrier doc should use task, not thread #3780)
• task: update documentation on block_in_place (Update documentation on block_in_place #3753)

[Darksonn]

Should the path dependency be removed from tokio-macros?

[carllerche]

Not critical, but I think this would be a "Changed" and not added (we aren't adding new APIs).