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2025-10-27sync: update comments for Once.doneJes Cok
Sync with CL 666895. Change-Id: I49c4a7f88d87cee9c30a858facd3cd8348efdf94 GitHub-Last-Rev: 88ac1c9c4131aa3f5dfb9c7923e49e46808c409d GitHub-Pull-Request: golang/go#76026 Reviewed-on: https://go-review.googlesource.com/c/go/+/714360 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Auto-Submit: Jorropo <jorropo.pgm@gmail.com> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Jorropo <jorropo.pgm@gmail.com>
2025-04-22sync: use atomic.Bool for Once.donePrabhav Dogra
Updated the use of atomic.Uint32 to atomic.Bool for sync package. Change-Id: Ib8da66fea86ef06e1427ac5118016b96fbcda6b1 GitHub-Last-Rev: d36e0f431fcde988f90badf86bbf04a18a411947 GitHub-Pull-Request: golang/go#73447 Reviewed-on: https://go-review.googlesource.com/c/go/+/666895 Reviewed-by: Junyang Shao <shaojunyang@google.com> Reviewed-by: Keith Randall <khr@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Auto-Submit: Keith Randall <khr@golang.org> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Jorropo <jorropo.pgm@gmail.com>
2024-11-18sync: add explicit noCopy fields to Map, Mutex, and OnceMichael Anthony Knyszek
Following CLs will refactor Mutex and change the internals of Map. This ends up breaking tests in x/tools for the copylock vet check, because the error message changes. Let's insulate ourselves from such things permanently by adding an explicit noCopy field. We'll update the vet check to accept that as the problem, rather than depend on less explicit internals. We capture Once here too to clean up the error message as well. Change-Id: Iead985fc8ec9ef3ea5ff615f26dde17bb03aeadb Reviewed-on: https://go-review.googlesource.com/c/go/+/627777 Reviewed-by: Cherry Mui <cherryyz@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Auto-Submit: Michael Knyszek <mknyszek@google.com> Reviewed-by: Tim King <taking@google.com>
2024-06-07sync: include links to the Go memory model in package documentationRodrigo Orselli
The lack of links to https://go.dev/ref/mem in the sync package documentation makes it difficult to read for people who have no previous knowledge of that page. This PR includes the links where needed. Fixes #67891 Change-Id: I0e1344cc6d7b702f4cb2e55fe0fcee3eb089391a GitHub-Last-Rev: 427cf58aaeaae2e4b060248dd592e5fe8c6b7df4 GitHub-Pull-Request: golang/go#67892 Reviewed-on: https://go-review.googlesource.com/c/go/+/591395 Reviewed-by: Michael Knyszek <mknyszek@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-02-26sync: add available godoc linkcui fliter
Change-Id: I9bc5fd29b0eec8ceadcfee2116de5e7524ef92c2 Reviewed-on: https://go-review.googlesource.com/c/go/+/539617 Auto-Submit: Ian Lance Taylor <iant@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Pratt <mpratt@google.com> Run-TryBot: shuang cui <imcusg@gmail.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com>
2023-10-06sync: use atomic.Uint32 in Oncemstmdev
Change-Id: If9089f8afd78de3e62cd575f642ff96ab69e2099 GitHub-Last-Rev: 14165018d67e84685dcf84be0320623ccb3afc0e GitHub-Pull-Request: golang/go#63386 Reviewed-on: https://go-review.googlesource.com/c/go/+/532895 Auto-Submit: Ian Lance Taylor <iant@google.com> Reviewed-by: Jorropo <jorropo.pgm@gmail.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Ian Lance Taylor <iant@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> Auto-Submit: Michael Pratt <mpratt@google.com>
2022-09-07Revert "sync: convert Once.done to atomic type"Ian Lance Taylor
This reverts commit CL 427140. Reason for revert: Comments say that done should be the first field. Change-Id: Id131da064146b44e1182289546aeb877867e63cc Reviewed-on: https://go-review.googlesource.com/c/go/+/428638 Run-TryBot: Ian Lance Taylor <iant@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> Reviewed-by: Bryan Mills <bcmills@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-09-06sync: convert Once.done to atomic typecuiweixie
Change-Id: I49f8c764d49cabaad4d6859c219ba7220a389c1f Reviewed-on: https://go-review.googlesource.com/c/go/+/427140 Run-TryBot: xie cui <523516579@qq.com> Reviewed-by: Ian Lance Taylor <iant@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Ian Lance Taylor <iant@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2022-06-06runtime, sync, sync/atomic: document happens-before guaranteesRuss Cox
A few of these are copied from the memory model doc. Many are entirely new, following discussion on #47141. See https://research.swtch.com/gomm for background. The rule we are establishing is that each type that is meant to help synchronize a Go program should document its happens-before guarantees. For #50859. Change-Id: I947c40639b263abe67499fa74f68711a97873a39 Reviewed-on: https://go-review.googlesource.com/c/go/+/381316 Auto-Submit: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Alan Donovan <adonovan@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Roland Shoemaker <roland@golang.org>
2022-04-11all: gofmt main repoRuss Cox
[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>
2022-04-01all: remove trailing blank doc comment linesRuss Cox
A future change to gofmt will rewrite // Doc comment. // func f() to // Doc comment. func f() Apply that change preemptively to all doc comments. For #51082. Change-Id: I4023e16cfb0729b64a8590f071cd92f17343081d Reviewed-on: https://go-review.googlesource.com/c/go/+/384259 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org>
2020-11-23sync: use 386 instead of x86-32 to refer to the 32 bit x86 architectureMartin Möhrmann
This aligns the naming with GOARCH using 386 as a build target for this architecture and makes it more easily found when searching for documentation related to the build target. Change-Id: I393bb89dd2f71e568124107b13e1b288fbd0c76a Reviewed-on: https://go-review.googlesource.com/c/go/+/271988 Trust: Martin Möhrmann <moehrmann@google.com> Run-TryBot: Martin Möhrmann <martisch@uos.de> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-10-23sync: document that Once must not be copiedDmitri Shuralyov
Fixes #42160. Change-Id: I9bf8b6f0bf1eccd3ab32cbd94c812f768746d291 Reviewed-on: https://go-review.googlesource.com/c/go/+/264557 Trust: Dmitri Shuralyov <dmitshur@golang.org> Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Bryan C. Mills <bcmills@google.com>
2019-07-01sync: document implementation of Once.DoRuss Cox
It's not correct to use atomic.CompareAndSwap to implement Once.Do, and we don't, but why we don't is a question that has come up twice on golang-dev in the past few months. Add a comment to help others with the same question. Change-Id: Ia89ec9715cc5442c6e7f13e57a49c6cfe664d32c Reviewed-on: https://go-review.googlesource.com/c/go/+/184261 Run-TryBot: Russ Cox <rsc@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Rob Pike <r@golang.org> Reviewed-by: Ingo Oeser <nightlyone@googlemail.com>
2019-03-09sync: allow inlining the Once.Do fast pathCarlo Alberto Ferraris
Using Once.Do is now extremely cheap because the fast path is just an inlined atomic load of a variable that is written only once and a conditional jump. This is very beneficial for Once.Do because, due to its nature, the fast path will be used for every call after the first one. In a attempt to mimize code size increase, reorder the fields so that the pointer to Once is also the pointer to Once.done, that is the only field used in the hot path. This allows to use more compact instruction encodings or less instructions in the hot path (that is inlined at every callsite). name old time/op new time/op delta Once 4.54ns ± 0% 2.06ns ± 0% -54.59% (p=0.000 n=19+16) Once-4 1.18ns ± 0% 0.55ns ± 0% -53.39% (p=0.000 n=15+16) Once-16 0.53ns ± 0% 0.17ns ± 0% -67.92% (p=0.000 n=18+17) linux/amd64 bin/go 14675861 (previous commit 14663387, +12474/+0.09%) Change-Id: Ie2708103ab473787875d66746d2f20f1d90a6916 Reviewed-on: https://go-review.googlesource.com/c/go/+/152697 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2016-03-02all: single space after period.Brad Fitzpatrick
The tree's pretty inconsistent about single space vs double space after a period in documentation. Make it consistently a single space, per earlier decisions. This means contributors won't be confused by misleading precedence. This CL doesn't use go/doc to parse. It only addresses // comments. It was generated with: $ perl -i -npe 's,^(\s*// .+[a-z]\.) +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.) +([A-Z])') $ go test go/doc -update Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7 Reviewed-on: https://go-review.googlesource.com/20022 Reviewed-by: Rob Pike <r@golang.org> Reviewed-by: Dave Day <djd@golang.org> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2014-09-16sync/once: panicking functions still marked as completeRob Pike
This is a corner case, and one that was even tested, but this CL changes the behavior to say that f is "complete" even if it panics. But don't think of it that way, think of it as sync.Once runs the function only the first time it is called, rather than repeatedly until a run of the function completes. Fixes #8118. LGTM=dvyukov R=golang-codereviews, dvyukov CC=golang-codereviews https://golang.org/cl/137350043
2014-09-08build: move package sources from src/pkg to srcRuss Cox
Preparation was in CL 134570043. This CL contains only the effect of 'hg mv src/pkg/* src'. For more about the move, see golang.org/s/go14nopkg.
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