The Go programming language
Go to file
Sameer Ajmani 5b42f89e39 context: add APIs for writing and reading cancelation cause
Extend the context package to allow users to specify why a context was
canceled in the form of an error, the "cause". Users write the cause
by calling WithCancelCause to construct a derived context, then
calling cancel(cause) to cancel the context with the provided cause.
Users retrieve the cause by calling context.Cause(ctx), which returns
the cause of the first cancelation for ctx or any of its parents.

The cause is implemented as a field of cancelCtx, since only cancelCtx
can be canceled. Calling cancel copies the cause to all derived (child)
cancelCtxs. Calling Cause(ctx) finds the nearest parent cancelCtx by
looking up the context value keyed by cancelCtxKey.

API changes:
+pkg context, func Cause(Context) error
+pkg context, func WithCancelCause(Context) (Context, CancelCauseFunc)
+pkg context, type CancelCauseFunc func(error)

Fixes #26356
Fixes #51365

Change-Id: I15b62bd454c014db3f4f1498b35204451509e641
Reviewed-on: https://go-review.googlesource.com/c/go/+/375977
Reviewed-by: Damien Neil <dneil@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Sameer Ajmani <sameer@golang.org>
Auto-Submit: Sameer Ajmani <sameer@golang.org>
2022-11-08 13:51:16 +00:00
.github .github: update issue label for pkgsite-removal 2022-09-07 16:00:20 +00:00
api context: add APIs for writing and reading cancelation cause 2022-11-08 13:51:16 +00:00
doc doc: add a release note for fewer pre-compiled GOROOT .a files 2022-11-07 15:51:10 +00:00
lib/time lib/time, time/tzdata: update to 2022b 2022-08-11 20:03:19 +00:00
misc misc/cgo/test: skip Test9400 on Alpine 2022-11-07 21:15:29 +00:00
src context: add APIs for writing and reading cancelation cause 2022-11-08 13:51:16 +00:00
test codegen: check for PPC64 ISEL in condmove tests 2022-11-07 15:19:20 +00:00
.gitattributes
.gitignore internal/buildcfg: move build configuration out of cmd/internal/objabi 2021-04-16 19:20:53 +00:00
CONTRIBUTING.md
LICENSE
PATENTS
README.md README: update from CC-BY-3.0 to CC-BY-4.0 2022-11-02 20:14:56 +00:00
SECURITY.md SECURITY.md: replace golang.org with go.dev 2022-04-26 19:59:47 +00:00
codereview.cfg codereview.cfg: add codereview.cfg for master branch 2021-02-19 18:44:53 +00:00

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 4.0 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://go.dev/dl/.

After downloading a binary release, visit https://go.dev/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://go.dev/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://go.dev/doc/contribute.

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