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62 Commits

Author SHA1 Message Date
cuiweixie
2113fefe7d context: convert goroutines to atomic type
Change-Id: I021fbc9786a3e3f858770fe3e109a0de487390d8
Reviewed-on: https://go-review.googlesource.com/c/go/+/426089
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Run-TryBot: xie cui <523516579@qq.com>
Reviewed-by: Damien Neil <dneil@google.com>
2022-08-29 20:21:48 +00:00
Cuong Manh Le
487b3501a5 context: Revert "context: use CompareAndSwap in cancelCtx.Done"
This reverts commit 964f0c7a30.

Reason: cause increasing timeout in crypto/tls tests on race builders.

Change-Id: Id16d4fcd19c2ca2e89ad4d0c9d55ef1105b19c76
Reviewed-on: https://go-review.googlesource.com/c/go/+/422035
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
2022-08-08 16:05:18 +00:00
Cuong Manh Le
964f0c7a30 context: use CompareAndSwap in cancelCtx.Done
So it is not necessary to use a mutex, speedup the code a bit:

name                                         old time/op    new time/op    delta
CommonParentCancel-8                            756ns ± 1%     760ns ± 1%    ~     (p=0.184 n=10+10)
WithTimeout/concurrency=40-8                   1.36µs ± 6%    1.38µs ± 5%    ~     (p=0.367 n=10+9)
WithTimeout/concurrency=4000-8                 1.30µs ± 1%    1.30µs ± 1%    ~     (p=0.444 n=9+9)
WithTimeout/concurrency=400000-8               1.25µs ± 1%    1.25µs ± 1%    ~     (p=0.268 n=10+10)
CancelTree/depth=1/Root=Background-8           62.3ns ± 1%    61.9ns ± 1%  -0.72%  (p=0.046 n=9+10)
CancelTree/depth=1/Root=OpenCanceler-8          447ns ± 1%     437ns ± 0%  -2.09%  (p=0.000 n=9+9)
CancelTree/depth=1/Root=ClosedCanceler-8        210ns ± 1%     211ns ± 1%  +0.35%  (p=0.024 n=10+10)
CancelTree/depth=10/Root=Background-8          2.46µs ± 0%    2.42µs ± 1%  -1.86%  (p=0.000 n=10+10)
CancelTree/depth=10/Root=OpenCanceler-8        3.50µs ± 1%    3.46µs ± 4%    ~     (p=0.063 n=9+9)
CancelTree/depth=10/Root=ClosedCanceler-8      1.21µs ± 0%    1.22µs ± 1%  +0.72%  (p=0.001 n=8+10)
CancelTree/depth=100/Root=Background-8         26.3µs ± 1%    25.7µs ± 1%  -2.20%  (p=0.000 n=9+10)
CancelTree/depth=100/Root=OpenCanceler-8       34.0µs ± 1%    33.2µs ± 1%  -2.15%  (p=0.000 n=9+10)
CancelTree/depth=100/Root=ClosedCanceler-8     11.2µs ± 1%    11.2µs ± 0%    ~     (p=0.562 n=10+9)
CancelTree/depth=1000/Root=Background-8         265µs ± 1%     260µs ± 1%  -2.15%  (p=0.000 n=10+10)
CancelTree/depth=1000/Root=OpenCanceler-8       341µs ± 1%     334µs ± 0%  -1.90%  (p=0.000 n=10+10)
CancelTree/depth=1000/Root=ClosedCanceler-8     110µs ± 0%     111µs ± 1%  +0.53%  (p=0.001 n=9+10)
CheckCanceled/Err-8                            14.2ns ± 0%    14.2ns ± 0%  -0.08%  (p=0.012 n=8+8)
CheckCanceled/Done-8                           6.19ns ± 1%    5.69ns ± 1%  -8.11%  (p=0.000 n=8+9)
ContextCancelDone-8                            1.40ns ± 0%    1.31ns ± 0%  -6.50%  (p=0.000 n=9+9)
DeepValueNewGoRoutine/depth=10-8                488ns ± 0%     490ns ± 0%  +0.62%  (p=0.000 n=9+9)
DeepValueNewGoRoutine/depth=20-8                529ns ± 0%     531ns ± 1%  +0.46%  (p=0.004 n=10+10)
DeepValueNewGoRoutine/depth=30-8                589ns ± 1%     594ns ± 0%  +0.82%  (p=0.004 n=9+9)
DeepValueNewGoRoutine/depth=50-8                664ns ± 0%     668ns ± 0%  +0.52%  (p=0.000 n=10+9)
DeepValueNewGoRoutine/depth=100-8               916ns ± 2%     915ns ± 2%    ~     (p=0.912 n=10+10)
DeepValueSameGoRoutine/depth=10-8              39.6ns ± 1%    38.8ns ± 2%  -2.01%  (p=0.001 n=9+10)
DeepValueSameGoRoutine/depth=20-8              76.9ns ± 1%    74.4ns ± 1%  -3.25%  (p=0.000 n=9+10)
DeepValueSameGoRoutine/depth=30-8               136ns ± 1%     125ns ± 1%  -8.53%  (p=0.000 n=9+10)
DeepValueSameGoRoutine/depth=50-8               196ns ± 1%     192ns ± 1%  -1.90%  (p=0.000 n=10+10)
DeepValueSameGoRoutine/depth=100-8              383ns ± 2%     372ns ± 2%  -2.86%  (p=0.000 n=10+10)

Change-Id: Ifb12affed2d6eda1104e4074d63d3f602be4c46b
Reviewed-on: https://go-review.googlesource.com/c/go/+/405674
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2022-08-08 14:10:19 +00:00
Russ Cox
19309779ac all: gofmt main repo
[This CL is part of a sequence implementing the proposal #51082.
The design doc is at https://go.dev/s/godocfmt-design.]

Run the updated gofmt, which reformats doc comments,
on the main repository. Vendored files are excluded.

For #51082.

Change-Id: I7332f099b60f716295fb34719c98c04eb1a85407
Reviewed-on: https://go-review.googlesource.com/c/go/+/384268
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-04-11 16:34:30 +00:00
Russ Cox
2580d0e08d all: gofmt -w -r 'interface{} -> any' src
And then revert the bootstrap cmd directories and certain testdata.
And adjust tests as needed.

Not reverting the changes in std that are bootstrapped,
because some of those changes would appear in API docs,
and we want to use any consistently.
Instead, rewrite 'any' to 'interface{}' in cmd/dist for those directories
when preparing the bootstrap copy.

A few files changed as a result of running gofmt -w
not because of interface{} -> any but because they
hadn't been updated for the new //go:build lines.

Fixes #49884.

Change-Id: Ie8045cba995f65bd79c694ec77a1b3d1fe01bb09
Reviewed-on: https://go-review.googlesource.com/c/go/+/368254
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
2021-12-13 18:45:54 +00:00
roudkerk
afe43f1e5e context: implement Context.Value using iteration rather than recursion
In profiles of a production server, 2.3% of CPU time is spent in
runtime.newstack for stacks with 12 or more chained Context.Value
calls. Using iteration will avoid some needless stack resizes.

When calling Context.Value in the same goroutine (see
DeepValueSameGoRoutine) , no stack resizing is needed (after warming
up), and this change reduces time/op by around 10%.

The time to start a new goroutine and call Context.Value (see
DeepValueNewGoRoutine) is reduced by over 75% if a stack resize is
needed. If you factor out the overhead of starting the goroutine
(about 960ns) then, avoiding the stack resize saves about 95%.

```
name                                          old time/op  new time/op  delta
CommonParentCancel-12                          960ns ± 1%   958ns ± 1%     ~     (p=0.561 n=9+9)
WithTimeout/concurrency=40-12                 1.31µs ± 2%  1.29µs ± 6%     ~     (p=0.305 n=9+10)
WithTimeout/concurrency=4000-12               1.30µs ± 2%  1.30µs ± 2%     ~     (p=0.343 n=10+10)
WithTimeout/concurrency=400000-12             1.03µs ± 1%  1.02µs ± 2%     ~     (p=0.213 n=9+9)
CancelTree/depth=1/Root=Background-12          123ns ± 5%   126ns ± 2%   +2.61%  (p=0.023 n=10+9)
CancelTree/depth=1/Root=OpenCanceler-12        781ns ± 4%   806ns ± 4%   +3.20%  (p=0.022 n=9+10)
CancelTree/depth=1/Root=ClosedCanceler-12      370ns ± 4%   369ns ± 3%     ~     (p=0.497 n=9+10)
CancelTree/depth=10/Root=Background-12        4.74µs ± 4%  4.78µs ± 3%     ~     (p=0.516 n=10+10)
CancelTree/depth=10/Root=OpenCanceler-12      6.31µs ± 4%  6.29µs ± 4%     ~     (p=1.000 n=10+10)
CancelTree/depth=10/Root=ClosedCanceler-12    2.10µs ± 5%  2.09µs ± 5%     ~     (p=0.839 n=10+10)
CancelTree/depth=100/Root=Background-12       51.0µs ± 3%  51.2µs ± 2%     ~     (p=0.631 n=10+10)
CancelTree/depth=100/Root=OpenCanceler-12     60.8µs ± 1%  61.6µs ± 4%     ~     (p=0.274 n=8+10)
CancelTree/depth=100/Root=ClosedCanceler-12   19.3µs ± 2%  19.0µs ± 3%     ~     (p=0.123 n=10+10)
CancelTree/depth=1000/Root=Background-12       504µs ± 4%   512µs ± 4%     ~     (p=0.123 n=10+10)
CancelTree/depth=1000/Root=OpenCanceler-12     615µs ± 6%   619µs ± 4%     ~     (p=1.000 n=10+10)
CancelTree/depth=1000/Root=ClosedCanceler-12   190µs ± 2%   192µs ± 3%     ~     (p=0.190 n=9+9)
CheckCanceled/Err-12                          12.1ns ± 2%  12.1ns ± 2%     ~     (p=0.615 n=10+10)
CheckCanceled/Done-12                         7.27ns ± 1%  7.26ns ± 1%     ~     (p=0.698 n=10+10)
ContextCancelDone-12                          1.03ns ± 1%  1.03ns ± 1%     ~     (p=0.474 n=9+9)
DeepValueNewGoRoutine/depth=10-12             1.02µs ± 3%  0.99µs ± 2%   -3.41%  (p=0.000 n=10+10)
DeepValueNewGoRoutine/depth=20-12             1.11µs ± 3%  1.08µs ± 2%   -2.51%  (p=0.004 n=10+10)
DeepValueNewGoRoutine/depth=30-12             5.55µs ±10%  1.17µs ± 4%  -78.91%  (p=0.000 n=10+10)
DeepValueNewGoRoutine/depth=50-12             5.70µs ±13%  1.35µs ± 2%  -76.31%  (p=0.000 n=10+10)
DeepValueNewGoRoutine/depth=100-12            9.69µs ± 4%  1.82µs ± 2%  -81.18%  (p=0.000 n=10+10)
DeepValueSameGoRoutine/depth=10-12            54.2ns ± 2%  46.8ns ± 2%  -13.71%  (p=0.000 n=9+9)
DeepValueSameGoRoutine/depth=20-12             109ns ± 2%    97ns ± 2%  -11.11%  (p=0.000 n=10+10)
DeepValueSameGoRoutine/depth=30-12             155ns ± 3%   140ns ± 1%   -9.49%  (p=0.000 n=10+10)
DeepValueSameGoRoutine/depth=50-12             256ns ± 2%   226ns ± 2%  -11.83%  (p=0.000 n=10+10)
DeepValueSameGoRoutine/depth=100-12            492ns ± 3%   442ns ± 1%  -10.15%  (p=0.000 n=10+10)
```

Fixes #47292

Change-Id: I6bdeb234c979fb8fd6bfb91fd345cb5038f52c75
Reviewed-on: https://go-review.googlesource.com/c/go/+/335790
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Damien Neil <dneil@google.com>
2021-10-02 00:44:24 +00:00
Naman Gera
52bf14e0e8 all: fix spellings
This follows the spelling choices that the Go project has made for English words.
https://github.com/golang/go/wiki/Spelling

Change-Id: Ie7c586d2cf23020cb492cfff58c0831d2d8d3a78
GitHub-Last-Rev: e16a32cd22
GitHub-Pull-Request: golang/go#45442
Reviewed-on: https://go-review.googlesource.com/c/go/+/308291
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
2021-04-10 01:46:41 +00:00
Kevin Burke
c9d9b40b13 context: avoid importing context package twice
Change-Id: Id0a127e080dda8ee62738922c6de8caf3719dd68
Reviewed-on: https://go-review.googlesource.com/c/go/+/295949
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Trust: Kevin Burke <kev@inburke.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
2021-02-24 18:15:00 +00:00
Josh Bleecher Snyder
ae1fa08e41 context: reduce contention in cancelCtx.Done
Use an atomic.Value to hold the done channel.
Conveniently, we have a mutex handy to coordinate writes to it.

name                 old time/op  new time/op  delta
ContextCancelDone-8  67.5ns ±10%   2.2ns ±11%  -96.74%  (p=0.000 n=30+28)

Fixes #42564

Change-Id: I5d72e0e87fb221d4e230209e5fb4698bea4053c6
Reviewed-on: https://go-review.googlesource.com/c/go/+/288193
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Trust: Sameer Ajmani <sameer@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2021-02-24 16:38:32 +00:00
Keiichi Hirobe
42b9e3a8df context: fix XTestInterlockedCancels
The test does not use Done channel, so fix that.

Change-Id: I795feab2e95de815b8b6ee7a7fd90f19f7af7db1
Reviewed-on: https://go-review.googlesource.com/c/go/+/294749
Reviewed-by: Sameer Ajmani <sameer@golang.org>
Trust: Sameer Ajmani <sameer@golang.org>
Trust: Cody Oss <codyoss@google.com>
Run-TryBot: Sameer Ajmani <sameer@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
2021-02-23 22:54:59 +00:00
Bryan C. Mills
5d2ddcd3f5 context: fix a flaky timeout in TestLayersTimeout
In CL 223019, I reduced the short timeout in the testLayers helper to
be even shorter than it was. That exposed a racy (time-dependent)
select later in the function, which failed in one of the slower
builders (android-386-emu).

Also streamline the test to make it easier to test with a very high -count flag:
- Run tests that sleep for shortDuration in parallel to reduce latency.
- Use shorter durations in examples to reduce test running time.
- Avoid mutating global state (in package math/rand) in testLayers.

After this change (but not before it),
'go test -run=TestLayersTimeout -count=100000 context' passes on my workstation.

Fixes #38161

Change-Id: Iaf4abe7ac308b2100d8828267cda9f4f8ae4be82
Reviewed-on: https://go-review.googlesource.com/c/go/+/226457
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-03-31 17:59:03 +00:00
Kyle Nusbaum
02057906f7 context: prevent creation of invalid contexts
This commit makes it impossible to create derived contexts with nil parents.
Previously it was possible to create derived contexts with nil parents, and
invalid contexts could propogate through the program. Eventually this can
cause a panic downstream, which is difficult to trace back to the source
of the error.

Although `WithCancel` and `WithDeadline` already panic if `parent` is `nil`, this adds explicit checks to give a useful message in the panic.

Fixes #37908

Change-Id: I70fd01f6539c1b0da0e775fc5457e32e7075e52c
GitHub-Last-Rev: 1b7dadd7db
GitHub-Pull-Request: golang/go#37898
Reviewed-on: https://go-review.googlesource.com/c/go/+/223777
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-03-18 19:44:13 +00:00
Bryan C. Mills
e8ecda8a38 context: deflake time-sensitive tests
Many of tests in this package assumed reasonable scheduling latency.
Unfortunately, scheduling latency on builders and CI systems is not
always reasonable.

Rather than expecting that a timeout is detected within a fixed short
interval, we can use (*testing.T).Deadline to portably scale the time
we're willing to wait to something appropriate to the builder.

Some of the tests also included arbitrary-duration sleeps, which are
no longer needed after CL 196521; we can remove those instead of
extending them.

Promptness of timeouts is also an important property, but testing that
property is better suited to benchmarks than to tests proper: unlike
tests, we generally expect benchmarks to be run in a quiet,
low-contention environment.

Fixes #13956

Change-Id: I0797e2267fb778c8ad94add56d797de9e2c885e5
Reviewed-on: https://go-review.googlesource.com/c/go/+/223019
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-03-13 22:25:52 +00:00
Ian Lance Taylor
a0c1e8d1ab context: mark testDeadline as a testing helper method
Change-Id: Ie6fc3e9789aea6e5949e66186db6f2b071b6fdff
Reviewed-on: https://go-review.googlesource.com/c/go/+/204037
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-10-29 14:22:15 +00:00
Russ Cox
0ad368675b context: use fewer goroutines in WithCancel/WithTimeout
If the parent context passed to WithCancel or WithTimeout
is a known context implementation (one created by this package),
we attach the child to the parent by editing data structures directly;
otherwise, for unknown parent implementations, we make a
goroutine that watches for the parent to finish and propagates
the cancellation.

A common problem with this scheme, before this CL, is that
users who write custom context implementations to manage
their value sets cause WithCancel/WithTimeout to start
goroutines that would have not been started before.

This CL changes the way we map a parent context back to the
underlying data structure. Instead of walking up through
known context implementations to reach the *cancelCtx,
we look up parent.Value(&cancelCtxKey) to return the
innermost *cancelCtx, which we use if it matches parent.Done().

This way, a custom context implementation wrapping a
*cancelCtx but not changing Done-ness (and not refusing
to return wrapped keys) will not require a goroutine anymore
in WithCancel/WithTimeout.

For #28728.

Change-Id: Idba2f435c81b19fe38d0dbf308458ca87c7381e9
Reviewed-on: https://go-review.googlesource.com/c/go/+/196521
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-09-26 16:25:30 +00:00
Egon Elbre
90f9426573 context: mention asynchronous cancellation propagation
Fixes #33185

Change-Id: I0adcffa5d1c9e55ae52309c59f961b0710166098
Reviewed-on: https://go-review.googlesource.com/c/go/+/187921
Reviewed-by: Sameer Ajmani <sameer@golang.org>
Run-TryBot: Sameer Ajmani <sameer@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-09-18 19:24:59 +00:00
Damien Neil
0e54d28ff7 all: remove os.ErrTimeout
It is unclear whether the current definition of os.IsTimeout is
desirable or not. Drop ErrTimeout for now so we can consider adding it
(or some other error) in a future release with a corrected definition.

Fixes #33411

Change-Id: I8b880da7d22afc343a08339eb5f0efd1075ecafe
Reviewed-on: https://go-review.googlesource.com/c/go/+/188758
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Damien Neil <dneil@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-08-02 17:57:18 +00:00
Damien Neil
ea8b0acdac all: remove os.ErrTemporary
As discussed in
https://github.com/golang/go/issues/32463#issuecomment-506833421
the classification of deadline-based timeouts as "temporary" errors is a
historical accident. I/O timeouts used to be duration-based, so they
really were temporary--retrying a timed-out operation could succeed. Now
that they're deadline-based, timeouts aren't temporary unless you reset
the deadline.

Drop ErrTemporary from Go 1.13, since its definition is wrong. We'll
consider putting it back in Go 1.14 with a clear definition and
deprecate net.OpError.Temporary.

Fixes #32463

Change-Id: I70cda664590d8872541e17409a5780da76920891
Reviewed-on: https://go-review.googlesource.com/c/go/+/188398
Reviewed-by: Jonathan Amsterdam <jba@google.com>
2019-08-01 15:39:45 +00:00
Alex Myasoedov
82ee4e7f78 context: document CancelFunc to be safe for simultaneous use by multiple goroutines
Fixes #32145

Change-Id: If4c9dd3a2af748974141ad6e571f80efcbaad772
Reviewed-on: https://go-review.googlesource.com/c/go/+/177899
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-05-20 16:08:56 +00:00
Damien Neil
170b8b4b12 all: add Unwrap and Is methods to various error types
Add Unwrap methods to types which wrap an underlying error:

  "encodinc/csv".ParseError
  "encoding/json".MarshalerError
  "net/http".transportReadFromServerError
  "net".OpError
  "net".DNSConfigError
  "net/url".Error
  "os/exec".Error
  "signal/internal/pty".PtyError
  "text/template".ExecError

Add os.ErrTemporary. A case could be made for putting this error
value in package net, since no exported error types in package os
include a Temporary method. However, syscall errors returned from
the os package do include this method.

Add Is methods to error types with a Timeout or Temporary method,
making errors.Is(err, os.Err{Timeout,Temporary}) equivalent to
testing the corresponding method:

  "context".DeadlineExceeded
  "internal/poll".TimeoutError
  "net".adrinfoErrno
  "net".OpError
  "net".DNSError
  "net/http".httpError
  "net/http".tlsHandshakeTimeoutError
  "net/pipe".timeoutError
  "net/url".Error

Updates #30322
Updates #29934

Change-Id: I409fb20c072ea39116ebfb8c7534d493483870dc
Reviewed-on: https://go-review.googlesource.com/c/go/+/170037
Run-TryBot: Damien Neil <dneil@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
2019-05-04 16:14:12 +00:00
Josh Bleecher Snyder
5781df421e all: s/cancelation/cancellation/
Though there is variation in the spelling of canceled,
cancellation is always spelled with a double l.

Reference: https://www.grammarly.com/blog/canceled-vs-cancelled/

Change-Id: I240f1a297776c8e27e74f3eca566d2bc4c856f2f
Reviewed-on: https://go-review.googlesource.com/c/go/+/170060
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-16 20:27:15 +00:00
喜欢兰花山丘
c4953a62f9 context: simplify stringify with a type switch
Minor style change.

Change-Id: Ib30243a71a83de1a67d3d005bfdd1e04265fca1e
GitHub-Last-Rev: 9d654de10e
GitHub-Pull-Request: golang/go#31479
Reviewed-on: https://go-review.googlesource.com/c/go/+/172199
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Sameer Ajmani <sameer@golang.org>
2019-04-16 15:33:18 +00:00
Brad Fitzpatrick
724a86fced context: don't depend on fmt
So the net package doesn't indirectly depend on unicode tables.

But we're still not quite there, because a new test added in this CL
reveals that we still have a path to unicode via:

deps_test.go:570:
  TODO(issue 30440): policy violation: net => sort => reflect => unicode

Updates #30440

Change-Id: I710c2061dfbaa8e866c92e6c824bd8df35784165
Reviewed-on: https://go-review.googlesource.com/c/go/+/169080
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-27 02:37:56 +00:00
Michael Fraenkel
88adc33827 context: remove dependency on reflect
Make context depend on reflectlite instead of reflect in effort to
eventually make net no longer depend on unicode tables.

With this CL we're down to just:

    net -> context -> fmt -> unicode tables

The next CL can remove context -> fmt.

Updates #30440

Change-Id: I7f5df15f975d9dc862c59aa8477c1cfd6ff4967e
Reviewed-on: https://go-review.googlesource.com/c/go/+/164239
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-25 16:31:40 +00:00
Weerasak Chongnguluam
119fafcaa5 context: avoid duplicate removeChild
When deadline has already passed,
current context is canceled before return cancel function.
So is unnecessary to call cancel with remove from parent again
in return cancel function.

Change-Id: I37c687c57a29d9f139c7fb648ce7de69093ed623
Reviewed-on: https://go-review.googlesource.com/c/50410
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-10-03 15:26:10 +00:00
Dominik Honnef
ccb70bd19c context: don't talk about tools that don't exist
This comment has been the source of much confusion and broken dreams. We
can add it back if a tool ever gets released.

Updates #16742

Change-Id: I4b9c179b7c60274e6ff1bcb607b82029dd9a893f
Reviewed-on: https://go-review.googlesource.com/130876
Reviewed-by: Matt Layher <mdlayher@gmail.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-08-22 22:11:24 +00:00
Ioannis Georgoulas
2cf9732e8a context: add docs to ExampleWithValue
Change-Id: I3a83c63f4db2e46fd96f373378a429896e93f9d1
Reviewed-on: https://go-review.googlesource.com/48861
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-06-12 22:33:54 +00:00
Carl Mastrangelo
b0ac2546b1 context: add benchmarks for context cancellation
Change-Id: I539c9226eb7e493b52c50e1e431954567d43bcfb
Reviewed-on: https://go-review.googlesource.com/100847
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-05-29 21:57:30 +00:00
Keegan Carruthers-Smith
0b9c1ad20d context: avoid defer in the cancelCtx.Err method
name                  old time/op  new time/op  delta
CheckCanceled/Err-4   53.5ns ± 2%  20.8ns ± 0%  -61.05%  (p=0.008 n=5+5)
CheckCanceled/Done-4  44.4ns ± 1%  44.5ns ± 0%     ~     (p=0.889 n=5+5)

Change-Id: I2c68700a2b33f8feb3d307ce7c966590a3e960af
Reviewed-on: https://go-review.googlesource.com/107137
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-04-15 21:35:53 +00:00
Michael Darakananda
eca45997df context: fix references to "d" in WithDeadline docs
Docs of WithDeadline refers to variable "d" which does not exist
in the docs.

This commit renames the time argument to "d" to make the doc work.

Change-Id: Ifd2c1be7d2e3f7dfb21cd9bb8ff7fc5039c8d3bd
Reviewed-on: https://go-review.googlesource.com/65130
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-09-21 03:00:51 +00:00
Kunpei Sakai
5a986eca86 all: fix article typos
a -> an

Change-Id: I7362bdc199e83073a712be657f5d9ba16df3077e
Reviewed-on: https://go-review.googlesource.com/63850
Reviewed-by: Rob Pike <r@golang.org>
2017-09-15 02:39:16 +00:00
Aliaksandr Valialkin
76f4fd8a52 runtime: improve timers scalability on multi-CPU systems
Use per-P timers, so each P may work with its own timers.

This CL improves performance on multi-CPU systems
in the following cases:

- When serving high number of concurrent connections
  with read/write deadlines set (for instance, highly loaded
  net/http server).

- When using high number of concurrent timers. These timers
  may be implicitly created via context.WithDeadline
  or context.WithTimeout.

Production servers should usually set timeout on connections
and external requests in order to prevent from resource leakage.
See https://blog.cloudflare.com/the-complete-guide-to-golang-net-http-timeouts/

Below are relevant benchmark results for various GOMAXPROCS values
on linux/amd64:

context package:

name                                     old time/op  new time/op  delta
WithTimeout/concurrency=40      4.92µs ± 0%  5.17µs ± 1%  +5.07%  (p=0.000 n=9+9)
WithTimeout/concurrency=4000    6.03µs ± 1%  6.49µs ± 0%  +7.63%  (p=0.000 n=8+10)
WithTimeout/concurrency=400000  8.58µs ± 7%  9.02µs ± 4%  +5.02%  (p=0.019 n=10+10)

name                                     old time/op  new time/op  delta
WithTimeout/concurrency=40-2      3.70µs ± 1%  2.78µs ± 4%  -24.90%  (p=0.000 n=8+9)
WithTimeout/concurrency=4000-2    4.49µs ± 4%  3.67µs ± 5%  -18.26%  (p=0.000 n=10+10)
WithTimeout/concurrency=400000-2  6.16µs ±10%  5.15µs ±13%  -16.30%  (p=0.000 n=10+10)

name                                     old time/op  new time/op  delta
WithTimeout/concurrency=40-4      3.58µs ± 1%  2.64µs ± 2%  -26.13%  (p=0.000 n=9+10)
WithTimeout/concurrency=4000-4    4.17µs ± 0%  3.32µs ± 1%  -20.36%  (p=0.000 n=10+10)
WithTimeout/concurrency=400000-4  5.57µs ± 9%  4.83µs ±10%  -13.27%  (p=0.001 n=10+10)

time package:

name                     old time/op  new time/op  delta
AfterFunc                6.15ms ± 3%  6.07ms ± 2%     ~     (p=0.133 n=10+9)
AfterFunc-2              3.43ms ± 1%  3.56ms ± 1%   +3.91%  (p=0.000 n=10+9)
AfterFunc-4              5.04ms ± 2%  2.36ms ± 0%  -53.20%  (p=0.000 n=10+9)
After                    6.54ms ± 2%  6.49ms ± 3%     ~     (p=0.393 n=10+10)
After-2                  3.68ms ± 1%  3.87ms ± 0%   +5.14%  (p=0.000 n=9+9)
After-4                  6.66ms ± 1%  2.87ms ± 1%  -56.89%  (p=0.000 n=10+10)
Stop                      698µs ± 2%   689µs ± 1%   -1.26%  (p=0.011 n=10+10)
Stop-2                    729µs ± 2%   434µs ± 3%  -40.49%  (p=0.000 n=10+10)
Stop-4                    837µs ± 3%   333µs ± 2%  -60.20%  (p=0.000 n=10+10)
SimultaneousAfterFunc     694µs ± 1%   692µs ± 7%     ~     (p=0.481 n=10+10)
SimultaneousAfterFunc-2   714µs ± 3%   569µs ± 2%  -20.33%  (p=0.000 n=10+10)
SimultaneousAfterFunc-4   782µs ± 2%   386µs ± 2%  -50.67%  (p=0.000 n=10+10)
StartStop                 267µs ± 3%   274µs ± 0%   +2.64%  (p=0.000 n=8+9)
StartStop-2               238µs ± 2%   140µs ± 3%  -40.95%  (p=0.000 n=10+8)
StartStop-4               320µs ± 1%   125µs ± 1%  -61.02%  (p=0.000 n=9+9)
Reset                    75.0µs ± 1%  77.5µs ± 2%   +3.38%  (p=0.000 n=10+10)
Reset-2                   150µs ± 2%    40µs ± 5%  -73.09%  (p=0.000 n=10+9)
Reset-4                   226µs ± 1%    33µs ± 1%  -85.42%  (p=0.000 n=10+10)
Sleep                     857µs ± 6%   878µs ± 9%     ~     (p=0.079 n=10+9)
Sleep-2                   617µs ± 4%   585µs ± 2%   -5.21%  (p=0.000 n=10+10)
Sleep-4                   689µs ± 3%   465µs ± 4%  -32.53%  (p=0.000 n=10+10)
Ticker                   55.9ms ± 2%  55.9ms ± 2%     ~     (p=0.971 n=10+10)
Ticker-2                 28.7ms ± 2%  28.1ms ± 1%   -2.06%  (p=0.000 n=10+10)
Ticker-4                 14.6ms ± 0%  13.6ms ± 1%   -6.80%  (p=0.000 n=9+10)

Fixes #15133

Change-Id: I6f4b09d2db8c5bec93146db6501b44dbfe5c0ac4
Reviewed-on: https://go-review.googlesource.com/34784
Reviewed-by: Austin Clements <austin@google.com>
2017-09-12 16:52:23 +00:00
Michael Stapelberg
2915e44dac context: fix lint warning “drop = 0 from declaration”
Previously, the suggested code would result in the following golint warning:
“should drop = 0 from declaration of var errorsOnlyKey; it is the zero value”

Change-Id: I1a302c1e40ca89acbc76897e39097ecd04865460
Reviewed-on: https://go-review.googlesource.com/60290
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-30 17:06:30 +00:00
Russ Cox
6e2c4bc012 context: define behavior for Err before Done is closed
The Context definition to date has not defined what Err returns
before the Done channel is closed. Define that it returns nil,
as most implementations do.

All the standard context implementations (those in package
context and in golang.org/x/net/context) return Err() == nil
when Done is not yet closed. However, some non-standard
implementations may exist that return Err() != nil in this case,
as permitted by the Context definition before this date.
Call these "errorful implementations".

Because all the standard context implementations ensure that
Err() == nil when Done is not yet closed, clients now exist that
assume Err() != nil implies Done is closed and use calling Err
as a quick short-circuit check instead of first doing a non-blocking
receive from Done and then, if that succeeds, needing to call Err.
This assumption holds for all the standard Context implementations,
so these clients work fine in practice, even though they are making
unwarranted assumptions about the Context implementations.
Call these "technically incorrect clients".

If a technically incorrect client encounters an errorful
implementation, the client misbehaves. Because there are few
errorful implementations, over time we expect that many clients
will end up being technically incorrect without realizing it,
leading to latent, subtle bugs. If we want to eliminate these
latent, subtle bugs, there are two ways to do this:
either make errorful implementations more common
(exposing the client bugs more often) or redefine the Context
interface so that the clients are not buggy after all.

If we make errorful implementations more common, such
as by changing the standard context implementations to
return ErrNotDone instead of nil when Err is called before
Done is closed, this will shake out essentially all of the
technically incorrect clients, forcing people to find and fix
those clients during the transition to Go 1.9.
Technically this is allowed by the compatibility policy,
but we expect there are many pieces of code assuming
that Err() != nil means done, so updating will cause real pain.

If instead we disallow errorful implementations, then they
will need to be fixed as they are discovered, but the fault
will officially lie in the errorful Context implementation,
not in the clients. Technically this is disallowed by the compatibility
policy, because these errorful implementations were "correct"
in earlier versions of Go, except that they didn't work with
common client code. We expect there are hardly any errorful
implementations, so that disallowing them will be less disruptive
and more in the spirit of the compatibility policy.

This CL takes the path of expected least disruption,
narrowing the Context interface semantics and potentially
invalidating existing implementations. A survey of the
go-corpus v0.01 turned up only five Context implementations,
all trivial and none errorful (details in #19856).
We are aware of one early Context implementation inside Google,
from before even golang.org/x/net/context existed,
that is errorful. The misbehavior of an open-source library
when passed such a context is what prompted #19856.
That context implementation would be disallowed after this CL
and would need to be corrected. We are aware of no other
affected context implementations. On the other hand, a survey
of the go-corpus v0.01 turned up many instances of client
code assuming that Err() == nil implies not done yet
(details also in #19856). On balance, narrowing Context and
thereby allowing Err() == nil checks should invalidate significantly
less code than a push to flush out all the currently technically
incorrect Err() == nil checks.

If release feedback shows that we're wrong about this balance,
we can roll back this CL and try again in Go 1.10.

Fixes #19856.

Change-Id: Id45d126fac70e1fcc42d73e5a87ca1b66935b831
Reviewed-on: https://go-review.googlesource.com/40291
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Sameer Ajmani <sameer@golang.org>
2017-04-26 15:39:18 +00:00
Eric Lagergren
094498c9a1 all: fix minor misspellings
Change-Id: I1f1cfb161640eb8756fb1a283892d06b30b7a8fa
Reviewed-on: https://go-review.googlesource.com/39356
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-03 23:19:07 +00:00
Ian Lance Taylor
dc6af19ff8 context: document that Err is unspecified before Done
It could have been defined the other way, but since the behavior has
been unspecified, this is the conservative approach for people writing
different implementations of the Context interface.

Change-Id: I7334a4c674bc2330cca6874f7cac1eb0eaea3cff
Reviewed-on: https://go-review.googlesource.com/37375
Reviewed-by: Matt Layher <mdlayher@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Sameer Ajmani <sameer@golang.org>
Run-TryBot: Sameer Ajmani <sameer@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-22 17:42:28 +00:00
Josh Bleecher Snyder
986768de7f context: lazily initialize cancelCtx done channel
This CL reduces allocations when a context
created with WithCancel either

(1) never has its Done channel used or
(2) gets cancelled before its Done channel is used

This is not uncommon. Many contexts are created
for tasks that end up not using them.

name                                                old time/op    new time/op    delta
ContextCancelTree/depth=1/Root=Background-8            112ns ± 2%      74ns ± 1%  -34.03%  (p=0.000 n=17+18)
ContextCancelTree/depth=1/Root=OpenCanceler-8          601ns ± 3%     544ns ± 1%   -9.56%  (p=0.000 n=20+20)
ContextCancelTree/depth=1/Root=ClosedCanceler-8        367ns ± 4%     257ns ± 1%  -30.01%  (p=0.000 n=20+20)
ContextCancelTree/depth=10/Root=Background-8          2.91µs ± 2%    2.87µs ± 0%   -1.38%  (p=0.000 n=20+18)
ContextCancelTree/depth=10/Root=OpenCanceler-8        4.36µs ± 2%    4.26µs ± 1%   -2.34%  (p=0.000 n=20+18)
ContextCancelTree/depth=10/Root=ClosedCanceler-8      2.02µs ± 2%    1.51µs ± 1%  -25.18%  (p=0.000 n=19+19)
ContextCancelTree/depth=100/Root=Background-8         30.5µs ± 6%    30.5µs ± 1%     ~     (p=0.941 n=20+20)
ContextCancelTree/depth=100/Root=OpenCanceler-8       39.8µs ± 1%    41.1µs ± 1%   +3.15%  (p=0.000 n=18+19)
ContextCancelTree/depth=100/Root=ClosedCanceler-8     17.8µs ± 1%    13.9µs ± 1%  -21.61%  (p=0.000 n=18+20)
ContextCancelTree/depth=1000/Root=Background-8         302µs ± 1%     313µs ± 0%   +3.62%  (p=0.000 n=20+18)
ContextCancelTree/depth=1000/Root=OpenCanceler-8       412µs ± 2%     427µs ± 1%   +3.55%  (p=0.000 n=18+19)
ContextCancelTree/depth=1000/Root=ClosedCanceler-8     178µs ± 1%     139µs ± 1%  -21.80%  (p=0.000 n=19+17)

name                                                old alloc/op   new alloc/op   delta
ContextCancelTree/depth=1/Root=Background-8             176B ± 0%       80B ± 0%  -54.55%  (p=0.000 n=20+20)
ContextCancelTree/depth=1/Root=OpenCanceler-8           544B ± 0%      448B ± 0%  -17.65%  (p=0.000 n=20+20)
ContextCancelTree/depth=1/Root=ClosedCanceler-8         352B ± 0%      160B ± 0%  -54.55%  (p=0.000 n=20+20)
ContextCancelTree/depth=10/Root=Background-8          3.49kB ± 0%    3.39kB ± 0%   -2.75%  (p=0.000 n=20+20)
ContextCancelTree/depth=10/Root=OpenCanceler-8        3.86kB ± 0%    3.76kB ± 0%   -2.49%  (p=0.000 n=20+20)
ContextCancelTree/depth=10/Root=ClosedCanceler-8      1.94kB ± 0%    0.88kB ± 0%  -54.55%  (p=0.000 n=20+20)
ContextCancelTree/depth=100/Root=Background-8         36.6kB ± 0%    36.5kB ± 0%   -0.26%  (p=0.000 n=20+20)
ContextCancelTree/depth=100/Root=OpenCanceler-8       37.0kB ± 0%    36.9kB ± 0%   -0.26%  (p=0.000 n=20+20)
ContextCancelTree/depth=100/Root=ClosedCanceler-8     17.8kB ± 0%     8.1kB ± 0%  -54.55%  (p=0.000 n=20+20)
ContextCancelTree/depth=1000/Root=Background-8         368kB ± 0%     368kB ± 0%   -0.03%  (p=0.000 n=20+20)
ContextCancelTree/depth=1000/Root=OpenCanceler-8       368kB ± 0%     368kB ± 0%   -0.03%  (p=0.000 n=20+20)
ContextCancelTree/depth=1000/Root=ClosedCanceler-8     176kB ± 0%      80kB ± 0%  -54.55%  (p=0.000 n=20+20)

name                                                old allocs/op  new allocs/op  delta
ContextCancelTree/depth=1/Root=Background-8             3.00 ± 0%      2.00 ± 0%  -33.33%  (p=0.000 n=20+20)
ContextCancelTree/depth=1/Root=OpenCanceler-8           8.00 ± 0%      7.00 ± 0%  -12.50%  (p=0.000 n=20+20)
ContextCancelTree/depth=1/Root=ClosedCanceler-8         6.00 ± 0%      4.00 ± 0%  -33.33%  (p=0.000 n=20+20)
ContextCancelTree/depth=10/Root=Background-8            48.0 ± 0%      47.0 ± 0%   -2.08%  (p=0.000 n=20+20)
ContextCancelTree/depth=10/Root=OpenCanceler-8          53.0 ± 0%      52.0 ± 0%   -1.89%  (p=0.000 n=20+20)
ContextCancelTree/depth=10/Root=ClosedCanceler-8        33.0 ± 0%      22.0 ± 0%  -33.33%  (p=0.000 n=20+20)
ContextCancelTree/depth=100/Root=Background-8            498 ± 0%       497 ± 0%   -0.20%  (p=0.000 n=20+20)
ContextCancelTree/depth=100/Root=OpenCanceler-8          503 ± 0%       502 ± 0%   -0.20%  (p=0.000 n=20+20)
ContextCancelTree/depth=100/Root=ClosedCanceler-8        303 ± 0%       202 ± 0%  -33.33%  (p=0.000 n=20+20)
ContextCancelTree/depth=1000/Root=Background-8         5.00k ± 0%     5.00k ± 0%   -0.02%  (p=0.000 n=20+20)
ContextCancelTree/depth=1000/Root=OpenCanceler-8       5.00k ± 0%     5.00k ± 0%   -0.02%  (p=0.000 n=20+20)
ContextCancelTree/depth=1000/Root=ClosedCanceler-8     3.00k ± 0%     2.00k ± 0%  -33.33%  (p=0.000 n=20+20)

Change-Id: Ibd7a0c3d5c847861cf1497f8fead34329413d26d
Reviewed-on: https://go-review.googlesource.com/34979
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Sameer Ajmani <sameer@golang.org>
2017-02-01 20:08:41 +00:00
Brad Fitzpatrick
4c4201f0e2 all: make spelling consistent
Fixes #17938

Change-Id: Iad12155f4976846bd4a9a53869f89e40e5b3deb3
Reviewed-on: https://go-review.googlesource.com/34147
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2016-12-08 23:22:37 +00:00
Brad Fitzpatrick
c921d8f39d context: document appropriate WithValue key type more
Fixes #17826
Updates #17302

Change-Id: I7c1ebd965e679e7169a97e62d27ae3ede2473aa1
Reviewed-on: https://go-review.googlesource.com/33152
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-11-12 06:25:11 +00:00
Russ Cox
606f81eef3 context: adjust tests to avoid importing "testing" in package context
So that testing can use context in its public API.

For #16221.

Change-Id: I6263fa7266c336c9490f20164ce79336df44a57e
Reviewed-on: https://go-review.googlesource.com/32648
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-11-03 21:12:21 +00:00
Jaana Burcu Dogan
31f50643c3 context: add comments to the WithCancel example, apply minor improvements
Fixes #17534.

Change-Id: I28af74b287a5a09d5f6607a012f3d5d133b04ed2
Reviewed-on: https://go-review.googlesource.com/32017
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-10-26 22:35:07 +00:00
Russ Cox
f69991c17d context: make DeadlineExceeded implement net.Error
It already implemented the Timeout method,
but implementing the full net.Error is more convenient.

Fixes #14238 (again).

Change-Id: Ia87f897f0f35bcb49865e2355964049227951ca6
Reviewed-on: https://go-review.googlesource.com/30370
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-10-05 15:53:04 +00:00
Matt Layher
c5f064ee49 context: discourage use of basic types as keys in WithValue
Fixes #17302

Change-Id: I375d5d4f2714ff415542f4fe56a548e53c5e8ba6
Reviewed-on: https://go-review.googlesource.com/30134
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-30 21:30:29 +00:00
Carlos C
1161a19c1e context: add examples
Add function level examples to the package.

Partially addresses #16360

Change-Id: I7162aed4e4a969743c19b79c9ffaf9217d2c1c08
Reviewed-on: https://go-review.googlesource.com/26930
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-09 22:50:41 +00:00
Jack Lindamood
39382793d3 context: reduce memory usage of context tree
Modifies context package to use map[]struct{} rather than map[]bool,
since the map is intended as a set object.  Also adds Benchmarks to
the context package switching between different types of root nodes
and a tree with different depths.

Included below are bytes deltas between the old and new code, using
these benchmarks.

benchmark                                                       old bytes     new bytes     delta
BenchmarkContextCancelTree/depth=1/Root=Background-8            176           176           +0.00%
BenchmarkContextCancelTree/depth=1/Root=OpenCanceler-8          560           544           -2.86%
BenchmarkContextCancelTree/depth=1/Root=ClosedCanceler-8        352           352           +0.00%
BenchmarkContextCancelTree/depth=10/Root=Background-8           3632          3488          -3.96%
BenchmarkContextCancelTree/depth=10/Root=OpenCanceler-8         4016          3856          -3.98%
BenchmarkContextCancelTree/depth=10/Root=ClosedCanceler-8       1936          1936          +0.00%
BenchmarkContextCancelTree/depth=100/Root=Background-8          38192         36608         -4.15%
BenchmarkContextCancelTree/depth=100/Root=OpenCanceler-8        38576         36976         -4.15%
BenchmarkContextCancelTree/depth=100/Root=ClosedCanceler-8      17776         17776         +0.00%
BenchmarkContextCancelTree/depth=1000/Root=Background-8         383792        367808        -4.16%
BenchmarkContextCancelTree/depth=1000/Root=OpenCanceler-8       384176        368176        -4.16%
BenchmarkContextCancelTree/depth=1000/Root=ClosedCanceler-8     176176        176176        +0.00%

Change-Id: I699ad704d9f7b461214e1651d24941927315b525
Reviewed-on: https://go-review.googlesource.com/25270
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-09 02:30:22 +00:00
Brad Fitzpatrick
298791a94a all: use time.Until where applicable
Updates #14595

Change-Id: Idf60b3004c7a0ebb59dd48389ab62c854069e09f
Reviewed-on: https://go-review.googlesource.com/28073
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-08-30 01:23:46 +00:00
Jaana Burcu Dogan
ab9137dd24 context: test WithCancel with canceled parent
Change-Id: I32079cc12cfffb8520f0073a8b5119705dc0cd1b
Reviewed-on: https://go-review.googlesource.com/27401
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-08-19 20:25:12 +00:00
Jack Lindamood
8876061149 context: add test for WithDeadline in the past
Adds a test case for calling context.WithDeadline() where the deadline
exists in the past.  This change increases the code coverage of the
context package.

Change-Id: Ib486bf6157e779fafd9dab2b7364cdb5a06be36e
Reviewed-on: https://go-review.googlesource.com/25007
Reviewed-by: Sameer Ajmani <sameer@golang.org>
Run-TryBot: Sameer Ajmani <sameer@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-07-26 14:53:38 +00:00
Alan Donovan
fc12bb2636 context: cancel the context in ExampleWithTimeout, with explanation
Fixes #16230

Change-Id: Ibb10234a6c3ab8bd0cfd93c2ebe8cfa66f80f6b0
Reviewed-on: https://go-review.googlesource.com/24682
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-06-30 19:56:02 +00:00
Sameer Ajmani
e4dc7f1ed2 context: update documentation on cancelation and go vet check.
Also replace double spaces after periods with single spaces.

Change-Id: Iedaea47595c5ce64e7e8aa3a368f36d49061c555
Reviewed-on: https://go-review.googlesource.com/24431
Reviewed-by: Alan Donovan <adonovan@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-06-24 19:21:21 +00:00