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2025-07-29sync: remove synchashtriemap GOEXPERIMENTMichael Anthony Knyszek
It's been true by default for a full release. It's time to remove the old map. Change-Id: I65507f07725e0084aabd389f37d73ade0b7dc35b Reviewed-on: https://go-review.googlesource.com/c/go/+/690395 Auto-Submit: Michael Knyszek <mknyszek@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Cherry Mui <cherryyz@google.com>
2024-11-18sync: make HashTrieMap[any, any] the default implementation of MapMichael Anthony Knyszek
This change adds a GOEXPERIMENT, synchashtriemap, which replaces the internals of a sync.Map with internal/sync.HashTrieMap[any, any]. The main purpose behind this change is improved performance. Across almost every benchmark, HashTrieMap[any, any] performs better than Map. Also, relax TestMapClearNoAllocations to allow for one allocation. Currently, the HashTrieMap allocates a new empty root node and stores it: that's the whole clear operation. At the cost of some complexity, we could allow Clear to have zero allocations by clearing the root node. The complexity comes down to allowing threads to race to install a new root node *or* creating a top-level mutex for installing a root node. But I'm not sure this is worth it. Whether Clear or some other operation takes the hit for allocating a single node almost certainly doesn't matter. And Clear is still much, much faster in the new implementation than the old, so I don't consider this a regression. Change-Id: I939aa70a0edf2e850cedbea239aaf29a11a77b79 Reviewed-on: https://go-review.googlesource.com/c/go/+/608335 Auto-Submit: Michael Knyszek <mknyszek@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: David Chase <drchase@google.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>
2024-03-21sync: name the Map.CompareAndSwap return valuePeter Collingbourne
The godoc for sync.Map.CompareAndSwap does not document the meaning of its return value. Document it by giving it a name. Change-Id: I50ad9c078a7885f5ce83489d66d138d491c35861 Reviewed-on: https://go-review.googlesource.com/c/go/+/572657 Reviewed-by: Ian Lance Taylor <iant@google.com> Auto-Submit: 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>
2024-02-01sync: update doc for Map.ClearJes Cok
Change-Id: I9bcc5c82321cbc93f1c7aafd1dadf4f6b862ccbd GitHub-Last-Rev: 818b95528f6beb6178b385953b49fbfbaeb31a82 GitHub-Pull-Request: golang/go#65429 Reviewed-on: https://go-review.googlesource.com/c/go/+/560396 Reviewed-by: Bryan Mills <bcmills@google.com> Auto-Submit: Bryan Mills <bcmills@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-02-01sync: add Map.ClearHiro
Fixes #61696 Change-Id: I0a31afd3bc433fc84280d56f2798bda10da61eba GitHub-Last-Rev: 17bedc864f1685178a42b59f7083677a6124f831 GitHub-Pull-Request: golang/go#61702 Reviewed-on: https://go-review.googlesource.com/c/go/+/515015 Auto-Submit: Bryan Mills <bcmills@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: qiulaidongfeng <2645477756@qq.com> Reviewed-by: Bryan Mills <bcmills@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-01-08sync: use map[any]any instead of map[interface{}]interface{} in the godocsivchari
It's shorter and clearer. Change-Id: Ibfbe5a7f8d70fa884691ba9858a2c9b2122d9c50 Reviewed-on: https://go-review.googlesource.com/c/go/+/531475 Reviewed-by: Bryan Mills <bcmills@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> Reviewed-by: Daniel Martí <mvdan@mvdan.cc> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Auto-Submit: Dmitri Shuralyov <dmitshur@google.com>
2023-09-01sync: prevent (*Map).Range from always escapingMauri de Souza Meneguzzo
After the change from CL 426074 the Range method on Map always escape the read variable, leading to an allocation. Since the compiler doesn't do live-range splitting for local variables we need to use some hints to only escape in that particular branch. Fixes #62404 Change-Id: I938a5e593647455fa827e3dd3ed8ea22c7365df1 GitHub-Last-Rev: fcbedb467c7b4e6f1d49e299d243cad70deb34e9 GitHub-Pull-Request: golang/go#62408 Reviewed-on: https://go-review.googlesource.com/c/go/+/524976 Auto-Submit: Bryan Mills <bcmills@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Run-TryBot: Bryan Mills <bcmills@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com> Reviewed-by: Bryan Mills <bcmills@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-01-20sync: document memory model for Swap/CompareAnd{Swap,Delete} in MapChangkun Ou
CL 381316 documented the memory model of Map's APIs. However, the newly introduced Swap, CompareAndSwap, and CompareAndDelete are missing from this documentation as CL 399094 did not add this info. This CL specifies the defined read/write operations of the new Map APIs. For #51972 Change-Id: I519a04040a0b429a3f978823a183cd62e42c90ae Reviewed-on: https://go-review.googlesource.com/c/go/+/459715 TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> Run-TryBot: Changkun Ou <mail@changkun.de> Auto-Submit: Bryan Mills <bcmills@google.com> Reviewed-by: Bryan Mills <bcmills@google.com>
2022-11-15sync: add new Map method Swap, CompareAndSwap, CompareAndDeleteChangkun Ou
name time/op SwapCollision/*sync_test.DeepCopyMap-8 235ns ± 0% SwapCollision/*sync_test.RWMutexMap-8 145ns ± 0% SwapCollision/*sync.Map-8 153ns ± 0% SwapMostlyHits/*sync_test.DeepCopyMap-8 48.2µs ± 0% SwapMostlyHits/*sync_test.RWMutexMap-8 190ns ± 0% SwapMostlyHits/*sync.Map-8 28.3ns ± 0% SwapMostlyMisses/*sync_test.DeepCopyMap-8 681ns ± 0% SwapMostlyMisses/*sync_test.RWMutexMap-8 336ns ± 0% SwapMostlyMisses/*sync.Map-8 523ns ± 0% CompareAndSwapCollision/*sync_test.DeepCopyMap-8 3.99ns ± 0% CompareAndSwapCollision/*sync_test.RWMutexMap-8 151ns ± 0% CompareAndSwapCollision/*sync.Map-8 21.6ns ± 0% CompareAndSwapNoExistingKey/*sync_test.DeepCopyMap-8 3.95ns ± 0% CompareAndSwapNoExistingKey/*sync_test.RWMutexMap-8 126ns ± 0% CompareAndSwapNoExistingKey/*sync.Map-8 6.11ns ± 0% CompareAndSwapValueNotEqual/*sync_test.DeepCopyMap-8 2.15ns ± 0% CompareAndSwapValueNotEqual/*sync_test.RWMutexMap-8 132ns ± 0% CompareAndSwapValueNotEqual/*sync.Map-8 5.32ns ± 0% CompareAndSwapMostlyHits/*sync_test.RWMutexMap-8 219ns ± 0% CompareAndSwapMostlyHits/*sync.Map-8 27.1ns ± 0% CompareAndSwapMostlyMisses/*sync_test.DeepCopyMap-8 13.0ns ± 0% CompareAndSwapMostlyMisses/*sync_test.RWMutexMap-8 147ns ± 0% CompareAndSwapMostlyMisses/*sync.Map-8 19.6ns ± 0% CompareAndDeleteCollision/*sync_test.DeepCopyMap-8 2.23ns ± 0% CompareAndDeleteCollision/*sync_test.RWMutexMap-8 131ns ± 0% CompareAndDeleteCollision/*sync.Map-8 16.2ns ± 0% CompareAndDeleteMostlyHits/*sync_test.RWMutexMap-8 367ns ± 0% CompareAndDeleteMostlyHits/*sync.Map-8 33.1ns ± 0% CompareAndDeleteMostlyMisses/*sync_test.DeepCopyMap-8 8.75ns ± 0% CompareAndDeleteMostlyMisses/*sync_test.RWMutexMap-8 134ns ± 0% CompareAndDeleteMostlyMisses/*sync.Map-8 10.9ns ± 0% name alloc/op SwapCollision/*sync_test.DeepCopyMap-8 336B ± 0% SwapCollision/*sync_test.RWMutexMap-8 0.00B SwapCollision/*sync.Map-8 16.0B ± 0% SwapMostlyHits/*sync_test.DeepCopyMap-8 82.1kB ± 0% SwapMostlyHits/*sync_test.RWMutexMap-8 12.0B ± 0% SwapMostlyHits/*sync.Map-8 28.0B ± 0% SwapMostlyMisses/*sync_test.DeepCopyMap-8 713B ± 0% SwapMostlyMisses/*sync_test.RWMutexMap-8 23.0B ± 0% SwapMostlyMisses/*sync.Map-8 129B ± 0% CompareAndSwapCollision/*sync_test.DeepCopyMap-8 0.00B CompareAndSwapCollision/*sync_test.RWMutexMap-8 0.00B CompareAndSwapCollision/*sync.Map-8 3.00B ± 0% CompareAndSwapNoExistingKey/*sync_test.DeepCopyMap-8 8.00B ± 0% CompareAndSwapNoExistingKey/*sync_test.RWMutexMap-8 8.00B ± 0% CompareAndSwapNoExistingKey/*sync.Map-8 8.00B ± 0% CompareAndSwapValueNotEqual/*sync_test.DeepCopyMap-8 0.00B CompareAndSwapValueNotEqual/*sync_test.RWMutexMap-8 0.00B CompareAndSwapValueNotEqual/*sync.Map-8 0.00B CompareAndSwapMostlyHits/*sync_test.RWMutexMap-8 18.0B ± 0% CompareAndSwapMostlyHits/*sync.Map-8 33.0B ± 0% CompareAndSwapMostlyMisses/*sync_test.DeepCopyMap-8 24.0B ± 0% CompareAndSwapMostlyMisses/*sync_test.RWMutexMap-8 23.0B ± 0% CompareAndSwapMostlyMisses/*sync.Map-8 23.0B ± 0% CompareAndDeleteCollision/*sync_test.DeepCopyMap-8 0.00B CompareAndDeleteCollision/*sync_test.RWMutexMap-8 0.00B CompareAndDeleteCollision/*sync.Map-8 0.00B CompareAndDeleteMostlyHits/*sync_test.RWMutexMap-8 23.0B ± 0% CompareAndDeleteMostlyHits/*sync.Map-8 39.0B ± 0% CompareAndDeleteMostlyMisses/*sync_test.DeepCopyMap-8 16.0B ± 0% CompareAndDeleteMostlyMisses/*sync_test.RWMutexMap-8 15.0B ± 0% CompareAndDeleteMostlyMisses/*sync.Map-8 15.0B ± 0% name allocs/op SwapCollision/*sync_test.DeepCopyMap-8 2.00 ± 0% SwapCollision/*sync_test.RWMutexMap-8 0.00 SwapCollision/*sync.Map-8 1.00 ± 0% SwapMostlyHits/*sync_test.DeepCopyMap-8 4.00 ± 0% SwapMostlyHits/*sync_test.RWMutexMap-8 1.00 ± 0% SwapMostlyHits/*sync.Map-8 2.00 ± 0% SwapMostlyMisses/*sync_test.DeepCopyMap-8 6.00 ± 0% SwapMostlyMisses/*sync_test.RWMutexMap-8 2.00 ± 0% SwapMostlyMisses/*sync.Map-8 6.00 ± 0% CompareAndSwapCollision/*sync_test.DeepCopyMap-8 0.00 CompareAndSwapCollision/*sync_test.RWMutexMap-8 0.00 CompareAndSwapCollision/*sync.Map-8 0.00 CompareAndSwapNoExistingKey/*sync_test.DeepCopyMap-8 1.00 ± 0% CompareAndSwapNoExistingKey/*sync_test.RWMutexMap-8 0.00 CompareAndSwapNoExistingKey/*sync.Map-8 1.00 ± 0% CompareAndSwapValueNotEqual/*sync_test.DeepCopyMap-8 0.00 CompareAndSwapValueNotEqual/*sync_test.RWMutexMap-8 0.00 CompareAndSwapValueNotEqual/*sync.Map-8 0.00 CompareAndSwapMostlyHits/*sync_test.RWMutexMap-8 2.00 ± 0% CompareAndSwapMostlyHits/*sync.Map-8 3.00 ± 0% CompareAndSwapMostlyMisses/*sync_test.DeepCopyMap-8 2.00 ± 0% CompareAndSwapMostlyMisses/*sync_test.RWMutexMap-8 2.00 ± 0% CompareAndSwapMostlyMisses/*sync.Map-8 2.00 ± 0% CompareAndDeleteCollision/*sync_test.DeepCopyMap-8 0.00 CompareAndDeleteCollision/*sync_test.RWMutexMap-8 0.00 CompareAndDeleteCollision/*sync.Map-8 0.00 CompareAndDeleteMostlyHits/*sync_test.RWMutexMap-8 2.00 ± 0% CompareAndDeleteMostlyHits/*sync.Map-8 3.00 ± 0% CompareAndDeleteMostlyMisses/*sync_test.DeepCopyMap-8 2.00 ± 0% CompareAndDeleteMostlyMisses/*sync_test.RWMutexMap-8 1.00 ± 0% CompareAndDeleteMostlyMisses/*sync.Map-8 1.00 ± 0% Fixes #51972 Change-Id: I469e71033592997832c3e8ebdad1b8950a70c99c Reviewed-on: https://go-review.googlesource.com/c/go/+/399094 Run-TryBot: Changkun Ou <mail@changkun.de> Reviewed-by: Joedian Reid <joedian@golang.org> Auto-Submit: Bryan Mills <bcmills@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Bryan Mills <bcmills@google.com>
2022-10-31sync: use atomic.Pointer for entryChangkun Ou
Change-Id: Ie3b4bfe483d7ef43da29ea1dd73d423dac36cf39 Reviewed-on: https://go-review.googlesource.com/c/go/+/432055 Auto-Submit: Bryan Mills <bcmills@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Bryan Mills <bcmills@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Changkun Ou <mail@changkun.de>
2022-08-29sync: switch Map to use atomic.PointerJoe Tsai
There was no noticeable change in performance. Change-Id: I9c57bf836c8b6066e0620afb3d536ce99e4b9d87 Reviewed-on: https://go-review.googlesource.com/c/go/+/426074 Reviewed-by: Bryan Mills <bcmills@google.com> Reviewed-by: Heschi Kreinick <heschi@google.com> Auto-Submit: Joseph Tsai <joetsai@digital-static.net> Run-TryBot: Joseph Tsai <joetsai@digital-static.net> TryBot-Result: Gopher Robot <gobot@golang.org>
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>
2021-12-13all: gofmt -w -r 'interface{} -> any' srcRuss Cox
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>
2021-11-11sync: clarify the validity to call Map methods inside RangeChangkun Ou
This change clarifies that calling all Map methods inside the callback of Range is allowed. For further assurance, a nested range call test is also added. Fixes #46399 Change-Id: I0a766a5c1470e6b573ec35df1ccd62b2e46f1561 Reviewed-on: https://go-review.googlesource.com/c/go/+/337389 Reviewed-by: Bryan C. Mills <bcmills@google.com> Run-TryBot: Bryan C. Mills <bcmills@google.com> TryBot-Result: Go Bot <gobot@golang.org> Trust: Ian Lance Taylor <iant@golang.org>
2021-04-08sync: update misleading comment in map.go about entry typepanchenglong01
As discussed in: https://github.com/golang/go/issues/45429, about entry type comments, it is possible for p == nil when m.dirty != nil, so update the commemt about it. Fixes #45429 Change-Id: I7ef96ee5b6948df9ac736481d177a59ab66d7d4d GitHub-Last-Rev: 202c598a0ab98f4634cb56fe2486e8e82f9d991f GitHub-Pull-Request: golang/go#45443 Reviewed-on: https://go-review.googlesource.com/c/go/+/308292 Reviewed-by: Changkun Ou <euryugasaki@gmail.com> Reviewed-by: Bryan C. Mills <bcmills@google.com> Run-TryBot: Bryan C. Mills <bcmills@google.com> Trust: Robert Findley <rfindley@google.com> TryBot-Result: Go Bot <gobot@golang.org>
2020-08-24sync: delete dirty keys inside Map.LoadAndDeleteChangkun Ou
Fixes #40999 Change-Id: Ie32427e5cb5ed512b976b554850f50be156ce9f2 Reviewed-on: https://go-review.googlesource.com/c/go/+/250197 Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Bryan C. Mills <bcmills@google.com>
2020-02-25sync: add new Map method LoadAndDeleteChangkun Ou
This CL implements a LoadAndDelete method in sync.Map. Benchmark: name time/op LoadAndDeleteBalanced/*sync_test.RWMutexMap-12 98.8ns ± 1% LoadAndDeleteBalanced/*sync.Map-12 10.3ns ±11% LoadAndDeleteUnique/*sync_test.RWMutexMap-12 99.2ns ± 2% LoadAndDeleteUnique/*sync.Map-12 6.63ns ±10% LoadAndDeleteCollision/*sync_test.DeepCopyMap-12 140ns ± 0% LoadAndDeleteCollision/*sync_test.RWMutexMap-12 75.2ns ± 2% LoadAndDeleteCollision/*sync.Map-12 5.21ns ± 5% In addition, Delete is bounded and more efficient if many collisions: DeleteCollision/*sync_test.DeepCopyMap-12 120ns ± 2% 125ns ± 1% +3.80% (p=0.000 n=10+9) DeleteCollision/*sync_test.RWMutexMap-12 73.5ns ± 3% 79.5ns ± 1% +8.03% (p=0.000 n=10+9) DeleteCollision/*sync.Map-12 97.8ns ± 3% 5.9ns ± 4% -94.00% (p=0.000 n=10+10) Fixes #33762 Change-Id: Ic8469a7861d27ab0edeface0078aad8af9b26c2f Reviewed-on: https://go-review.googlesource.com/c/go/+/205899 Reviewed-by: Bryan C. Mills <bcmills@google.com> Run-TryBot: Bryan C. Mills <bcmills@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-09-27sync: simplify (*entry).tryStoreIan Lance Taylor
The only change to the go build -gcflags=-m=2 output was to remove these two lines: sync/map.go:178:26: &e.p escapes to heap sync/map.go:178:26: from &e.p (passed to call[argument escapes]) at sync/map.go:178:25 Benchstat report for sync.Map benchmarks: name old time/op new time/op delta LoadMostlyHits/*sync_test.DeepCopyMap-12 10.6ns ±11% 10.2ns ± 3% ~ (p=0.299 n=10+8) LoadMostlyHits/*sync_test.RWMutexMap-12 54.6ns ± 3% 54.6ns ± 2% ~ (p=0.782 n=10+10) LoadMostlyHits/*sync.Map-12 10.1ns ± 1% 10.1ns ± 1% ~ (p=1.127 n=10+8) LoadMostlyMisses/*sync_test.DeepCopyMap-12 8.65ns ± 1% 8.77ns ± 5% +1.39% (p=0.017 n=9+10) LoadMostlyMisses/*sync_test.RWMutexMap-12 53.6ns ± 2% 53.8ns ± 2% ~ (p=0.408 n=10+9) LoadMostlyMisses/*sync.Map-12 7.37ns ± 1% 7.46ns ± 1% +1.19% (p=0.000 n=9+10) LoadOrStoreBalanced/*sync_test.RWMutexMap-12 895ns ± 4% 906ns ± 3% ~ (p=0.203 n=9+10) LoadOrStoreBalanced/*sync.Map-12 872ns ±10% 804ns ±12% -7.75% (p=0.014 n=10+10) LoadOrStoreUnique/*sync_test.RWMutexMap-12 1.29µs ± 2% 1.28µs ± 1% ~ (p=0.586 n=10+9) LoadOrStoreUnique/*sync.Map-12 1.30µs ± 7% 1.40µs ± 2% +6.95% (p=0.000 n=9+10) LoadOrStoreCollision/*sync_test.DeepCopyMap-12 6.98ns ± 1% 6.91ns ± 1% -1.10% (p=0.000 n=10+10) LoadOrStoreCollision/*sync_test.RWMutexMap-12 371ns ± 1% 372ns ± 2% ~ (p=0.679 n=9+9) LoadOrStoreCollision/*sync.Map-12 5.49ns ± 1% 5.49ns ± 1% ~ (p=0.732 n=9+10) Range/*sync_test.DeepCopyMap-12 2.49µs ± 1% 2.50µs ± 0% ~ (p=0.148 n=10+10) Range/*sync_test.RWMutexMap-12 54.7µs ± 1% 54.6µs ± 3% ~ (p=0.549 n=9+10) Range/*sync.Map-12 2.74µs ± 1% 2.76µs ± 1% +0.68% (p=0.011 n=10+8) AdversarialAlloc/*sync_test.DeepCopyMap-12 2.52µs ± 5% 2.54µs ± 7% ~ (p=0.225 n=10+10) AdversarialAlloc/*sync_test.RWMutexMap-12 108ns ± 1% 107ns ± 1% ~ (p=0.101 n=10+9) AdversarialAlloc/*sync.Map-12 712ns ± 2% 714ns ± 3% ~ (p=0.984 n=8+10) AdversarialDelete/*sync_test.DeepCopyMap-12 581ns ± 3% 578ns ± 3% ~ (p=0.781 n=9+9) AdversarialDelete/*sync_test.RWMutexMap-12 126ns ± 2% 126ns ± 1% ~ (p=0.883 n=10+10) AdversarialDelete/*sync.Map-12 155ns ± 8% 158ns ± 2% ~ (p=0.158 n=10+9) Change-Id: I1ed8e3109baca03087d0fad3df769fc7e38f6dbb Reviewed-on: https://go-review.googlesource.com/137441 Reviewed-by: Bryan C. Mills <bcmills@google.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-01-04sync: document when and when not to use MapRuss Cox
Fixes #21587. Change-Id: I47eb181d65da67a3b530c7f8acac9c0c619ea474 Reviewed-on: https://go-review.googlesource.com/83796 Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Bryan Mills <bcmills@google.com> Reviewed-by: Rob Pike <r@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-07-21sync: delete a sentence from the Map docsBrad Fitzpatrick
From Josh's comments on https://golang.org/cl/50310 Once I removed the "from the Go standard library" bit, the beginning wasn't worth keeping. It also wasn't clear whether what it meant by "cache contention". Processor caches, or user-level caches built with sync.Map? It didn't seem worth clarifying and didn't convey any useful information, so deleted. Change-Id: Id1d76105a3081d0855f6a64540700932bb83d98e Reviewed-on: https://go-review.googlesource.com/50632 Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com> Reviewed-by: Bryan Mills <bcmills@google.com>
2017-07-21sync: update Map documentation with usage rule of thumbMichael Stapelberg
As per bcmills’s lightning talk at GopherCon 2017: https://github.com/gophercon/2017-talks/tree/master/lightningtalks/BryanCMills-AnOverviewOfSyncMap Change-Id: I12dd0daa608af175d110298780f32c6dc5e1e0a0 Reviewed-on: https://go-review.googlesource.com/50310 Reviewed-by: Bryan Mills <bcmills@google.com>
2017-04-26sync: import Map from x/sync/syncmapBryan C. Mills
This is a direct port of the version from commit a60ad46e0ed33d02e09bda439efaf9c9727dbc6c (https://go-review.googlesource.com/c/37342/). updates #17973 updates #18177 Change-Id: I63fa5ef6951b1edd39f84927d1181a4df9b15385 Reviewed-on: https://go-review.googlesource.com/36617 Reviewed-by: Russ Cox <rsc@golang.org> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
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