gc better

v1.2.21

optimize gc and add tests for GC

v1.2.20

Full Changelog: v1.2.19...v1.2.20

accumulated bugfix & optimizations

1. FreeBSD/MacOS optimizations on syscalls
2. affinity settings on bsds
3. Remove re-arm mechanism, the trade-off of rearming seems not to be efficient enough.
4. Fix ENOBUFS under BSDs
5. compacted code on different platforms.

fix race in aiocb objects

v1.2.12

recycle pcb in next waitio

v1.2.11

fix arm flag

v1.2.10: Squashed commit of the following:

commit ce20a809ac162048f429b737cf137816a3fff19d
Author: xtaci <[email protected]>
Date:   Thu May 6 10:08:16 2021 +0800

    remove defer in hot path

initial release

The first release of gaio library.

initial release

v1.0.0

adjusts comments