sync/atomic: add (*Value).Swap and (*Value).CompareAndSwap

The functions SwapPointer and CompareAndSwapPointer can be used to
interact with unsafe.Pointer, however generally it is prefered to work
with Value, due to its safer interface. As such, they have been added
along with glue logic to maintain invariants Value guarantees.

To meet these guarantees, the current implementation duplicates much of
the Store function. Some of this is due to inexperience with concurrency
and desire for correctness, but the lack of generic programming
functionality does not help.

Fixes #39351

Change-Id: I1aa394b1e70944736ac1e19de49fe861e1e46fba
Reviewed-on: https://go-review.googlesource.com/c/go/+/241678
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2 files changed
tree: 07113bce1f36d5d684ebcc6a5df4db3296dffb8c
  1. .github/
  2. api/
  3. doc/
  4. lib/
  5. misc/
  6. src/
  7. test/
  8. .gitattributes
  9. .gitignore
  10. AUTHORS
  11. codereview.cfg
  12. CONTRIBUTING.md
  13. CONTRIBUTORS
  14. LICENSE
  15. PATENTS
  16. README.md
  17. SECURITY.md
README.md

The Go Programming Language

Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.

Gopher image Gopher image by Renee French, licensed under Creative Commons 3.0 Attributions license.

Our canonical Git repository is located at https://go.googlesource.com/go. There is a mirror of the repository at https://github.com/golang/go.

Unless otherwise noted, the Go source files are distributed under the BSD-style license found in the LICENSE file.

Download and Install

Binary Distributions

Official binary distributions are available at https://golang.org/dl/.

After downloading a binary release, visit https://golang.org/doc/install for installation instructions.

Install From Source

If a binary distribution is not available for your combination of operating system and architecture, visit https://golang.org/doc/install/source for source installation instructions.

Contributing

Go is the work of thousands of contributors. We appreciate your help!

To contribute, please read the contribution guidelines at https://golang.org/doc/contribute.html.

Note that the Go project uses the issue tracker for bug reports and proposals only. See https://golang.org/wiki/Questions for a list of places to ask questions about the Go language.