Commit Graph

66 Commits

Author SHA1 Message Date
Keith Randall 95773ab9b0 sync/atomic: fix TestSwapPointer test
It plays way too loose with unsafe.Pointer rules.
It runs afoul of the checkptr rules, so some race detector builds
were failing.

Fixes #38210

Change-Id: I5e1c78201d06295524fdedb3fe5b49d61446f443
Reviewed-on: https://go-review.googlesource.com/c/go/+/226880
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2020-04-02 03:47:13 +00:00
Daniel Martí a4c48d61f5 sync/atomic: remove panic64
The func has been unused since https://golang.org/cl/93637 in 2018.

Change-Id: I1cab6f265aa5058ac080fd7c7cbf0fe85370f073
Reviewed-on: https://go-review.googlesource.com/c/go/+/224077
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matt Layher <mdlayher@gmail.com>
Reviewed-by: Austin Clements <austin@google.com>
2020-03-19 19:46:54 +00:00
Ziheng Liu 42f8199290 all: fix incorrect channel and API usage in some unit tests
This CL changes some unit test functions, making sure that these tests (and goroutines spawned during test) won't block.
Since they are just test functions, I use one CL to fix them all. I hope this won't cause trouble to reviewers and can save time for us.
There are three main categories of incorrect logic fixed by this CL:
1. Use testing.Fatal()/Fatalf() in spawned goroutines, which is forbidden by Go's document.
2. Channels are used in such a way that, when errors or timeout happen, the test will be blocked and never return.
3. Channels are used in such a way that, when errors or timeout happen, the test can return but some spawned goroutines will be leaked, occupying resource until all other tests return and the process is killed.

Change-Id: I3df931ec380794a0cf1404e632c1dd57c65d63e8
Reviewed-on: https://go-review.googlesource.com/c/go/+/219380
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-02-27 19:04:17 +00:00
Matthew Dempsky a97ccc8940 sync/atomic: suppress checkptr errors for hammerStoreLoadPointer
This test could be updated to use unsafe.Pointer arithmetic properly
(e.g., see discussion at #34972), but it doesn't seem worthwhile. The
test is just checking that LoadPointer and StorePointer are atomic.

Updates #34972.

Change-Id: I85a8d610c1766cd63136cae686aa8a240a362a18
Reviewed-on: https://go-review.googlesource.com/c/go/+/202597
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-10-22 18:09:03 +00:00
Brad Fitzpatrick 03ef105dae all: remove nacl (part 3, more amd64p32)
Part 1: CL 199499 (GOOS nacl)
Part 2: CL 200077 (amd64p32 files, toolchain)
Part 3: stuff that arguably should've been part of Part 2, but I forgot
        one of my grep patterns when splitting the original CL up into
        two parts.

This one might also have interesting stuff to resurrect for any future
x32 ABI support.

Updates #30439

Change-Id: I2b4143374a253a003666f3c69e776b7e456bdb9c
Reviewed-on: https://go-review.googlesource.com/c/go/+/200318
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-10-10 22:38:38 +00:00
Ian Lance Taylor ca7c12d4c9 sync/atomic: add 32-bit MIPS to the 64-bit alignment requirement
runtime/internal/atomic/atomic_mipsx.go enforces 64-bit alignment.

Change-Id: Ifdc36e1c0322827711425054d10f1c52425a13fa
Reviewed-on: https://go-review.googlesource.com/c/161697
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-02-09 23:07:07 +00:00
Cherry Zhang 1b6fec862c sync/atomic: redirect many functions to runtime/internal/atomic
The implementation of atomics are inherently tricky. It would
be good to have them implemented in a single place, instead of
multiple copies.

Mostly a simple redirect.

On 386, some functions in sync/atomic have better implementations,
which are moved to runtime/internal/atomic.

On ARM, some functions in sync/atomic have better implementations.
They are dropped by this CL, but restored with an improved
version in a follow-up CL. On linux/arm, 64-bit CAS kernel helper
is dropped, as we're trying to move away from kernel helpers.

Fixes #23778.

Change-Id: Icb9e1039acc92adbb2a371c34baaf0b79551c3ea
Reviewed-on: https://go-review.googlesource.com/93637
Reviewed-by: Austin Clements <austin@google.com>
2018-05-03 21:35:01 +00:00
Kevin Burke f3962b1849 sync/atomic: use package prefix in examples
Previously these examples declared "var v Value" but any caller would
need to write "var v atomic.Value", so we should use the external
package declaration form to avoid confusion about where Value comes
from.

Change-Id: Ic0b1a05fb6b700da61cfc8efca594c49a9bedb69
Reviewed-on: https://go-review.googlesource.com/107975
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-04-18 23:58:54 +00:00
Yuval Pavel Zholkover 0a4b962c17 runtime/internal/atomic: don't use Cas in atomic.Load on ARM
Instead issue a memory barrier on ARMv7 after reading the address.

Fixes #23777

Change-Id: I7aff2ab0246af64b437ebe0b31d4b30d351890d8
Reviewed-on: https://go-review.googlesource.com/94275
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-04-18 15:34:14 +00:00
Yuval Pavel Zholkover 0a5be12f5c cmd/internal/obj/arm: add DMB instruction
Change-Id: Ib67a61d5b37af210ff15d60d72bd5238b9c2d0ca
Reviewed-on: https://go-review.googlesource.com/94815
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-03-27 19:54:44 +00:00
Carlos Eduardo Seo 6633bb2aa7 cmd/compile/internal/ppc64, runtime internal/atomic, sync/atomic: implement faster atomics for ppc64x
This change implements faster atomics for ppc64x based on the ISA 2.07B,
Appendix B.2 recommendations, replacing SYNC/ISYNC by LWSYNC in some
cases.

Updates #21348

name                                           old time/op new time/op    delta
Cond1-16                                           955ns     856ns      -10.33%
Cond2-16                                          2.38µs    2.03µs      -14.59%
Cond4-16                                          5.90µs    5.44µs       -7.88%
Cond8-16                                          12.1µs    11.1µs       -8.42%
Cond16-16                                         27.0µs    25.1µs       -7.04%
Cond32-16                                         59.1µs    55.5µs       -6.14%
LoadMostlyHits/*sync_test.DeepCopyMap-16          22.1ns    24.1ns       +9.02%
LoadMostlyHits/*sync_test.RWMutexMap-16            252ns     249ns       -1.20%
LoadMostlyHits/*sync.Map-16                       16.2ns    16.3ns         ~
LoadMostlyMisses/*sync_test.DeepCopyMap-16        22.3ns    22.6ns         ~
LoadMostlyMisses/*sync_test.RWMutexMap-16          249ns     247ns       -0.51%
LoadMostlyMisses/*sync.Map-16                     12.7ns    12.7ns         ~
LoadOrStoreBalanced/*sync_test.RWMutexMap-16      1.27µs    1.17µs       -7.54%
LoadOrStoreBalanced/*sync.Map-16                  1.12µs    1.10µs       -2.35%
LoadOrStoreUnique/*sync_test.RWMutexMap-16        1.75µs    1.68µs       -3.84%
LoadOrStoreUnique/*sync.Map-16                    2.07µs    1.97µs       -5.13%
LoadOrStoreCollision/*sync_test.DeepCopyMap-16    15.8ns    15.9ns         ~
LoadOrStoreCollision/*sync_test.RWMutexMap-16      496ns     424ns      -14.48%
LoadOrStoreCollision/*sync.Map-16                 6.07ns    6.07ns         ~
Range/*sync_test.DeepCopyMap-16                   1.65µs    1.64µs         ~
Range/*sync_test.RWMutexMap-16                     278µs     288µs       +3.75%
Range/*sync.Map-16                                2.00µs    2.01µs         ~
AdversarialAlloc/*sync_test.DeepCopyMap-16        3.45µs    3.44µs         ~
AdversarialAlloc/*sync_test.RWMutexMap-16          226ns     227ns         ~
AdversarialAlloc/*sync.Map-16                     1.09µs    1.07µs       -2.36%
AdversarialDelete/*sync_test.DeepCopyMap-16        553ns     550ns       -0.57%
AdversarialDelete/*sync_test.RWMutexMap-16         273ns     274ns         ~
AdversarialDelete/*sync.Map-16                     247ns     249ns         ~
UncontendedSemaphore-16                           79.0ns    65.5ns      -17.11%
ContendedSemaphore-16                              112ns      97ns      -13.77%
MutexUncontended-16                               3.34ns    2.51ns      -24.69%
Mutex-16                                           266ns     191ns      -28.26%
MutexSlack-16                                      226ns     159ns      -29.55%
MutexWork-16                                       377ns     338ns      -10.14%
MutexWorkSlack-16                                  335ns     308ns       -8.20%
MutexNoSpin-16                                     196ns     184ns       -5.91%
MutexSpin-16                                       710ns     666ns       -6.21%
Once-16                                           1.29ns    1.29ns         ~
Pool-16                                           8.64ns    8.71ns         ~
PoolOverflow-16                                   1.60µs    1.44µs      -10.25%
SemaUncontended-16                                5.39ns    4.42ns      -17.96%
SemaSyntNonblock-16                                539ns     483ns      -10.42%
SemaSyntBlock-16                                   413ns     354ns      -14.20%
SemaWorkNonblock-16                                305ns     258ns      -15.36%
SemaWorkBlock-16                                   266ns     229ns      -14.06%
RWMutexUncontended-16                             12.9ns     9.7ns      -24.80%
RWMutexWrite100-16                                 203ns     147ns      -27.47%
RWMutexWrite10-16                                  177ns     119ns      -32.74%
RWMutexWorkWrite100-16                             435ns     403ns       -7.39%
RWMutexWorkWrite10-16                              642ns     611ns       -4.79%
WaitGroupUncontended-16                           4.67ns    3.70ns      -20.92%
WaitGroupAddDone-16                                402ns     355ns      -11.54%
WaitGroupAddDoneWork-16                            208ns     250ns      +20.09%
WaitGroupWait-16                                  1.21ns    1.21ns         ~
WaitGroupWaitWork-16                              5.91ns    5.87ns       -0.81%
WaitGroupActuallyWait-16                          92.2ns    85.8ns       -6.91%

Updates #21348

Change-Id: Ibb9b271d11b308264103829e176c6d9fe8f867d3
Reviewed-on: https://go-review.googlesource.com/95175
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
2018-03-22 14:13:01 +00:00
isharipo ff5cf43df5 runtime,sync/atomic: replace asm BYTEs with insts for x86
For each replacement, test case is added to new 386enc.s file
with exception of EMMS, SYSENTER, MFENCE and LFENCE as they
are already covered in amd64enc.s (same on amd64 and 386).

The replacement became less obvious after go vet suggested changes
Before:
	BYTE $0x0f; BYTE $0x7f; BYTE $0x44; BYTE $0x24; BYTE $0x08
Changed to MOVQ (this form is being tested):
	MOVQ M0, 8(SP)
Refactored to FP-relative access (go vet advice):
	MOVQ M0, val+4(FP)

Change-Id: I56b87cf3371b6ad81ad0cd9db2033aee407b5818
Reviewed-on: https://go-review.googlesource.com/101475
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
2018-03-21 20:51:04 +00:00
Austin Clements a046caa1e8 runtime, sync/atomic: use NOFRAME on arm
This replaces frame size -4 with the NOFRAME flag in arm assembly.

This was automated with:

sed -i -e 's/\(^TEXT.*[A-Z]\),\( *\)\$-4/\1|NOFRAME,\2$0/' $(find -name '*_arm.s')

Plus three manual comment changes found by:

grep '\$-4' $(find -name '*_arm.s')

The go binary is identical before and after this change.

Change-Id: I0310384d1a584118c41d1cd3a042bb8ea7227ef9
Reviewed-on: https://go-review.googlesource.com/92042
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-02-12 21:41:30 +00:00
Russ Cox 0c0c3c186b sync/atomic: remove noCopy from Value
Values must not be copied after the first use.

Using noCopy makes vet complain about copies
even before the first use, which is incorrect
and very frustrating.

Drop it.

Fixes #21504.

Change-Id: Icd3a5ac3fe11e84525b998e848ed18a5d996f45a
Reviewed-on: https://go-review.googlesource.com/80836
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-12-01 16:38:53 +00:00
Leigh McCulloch 8db19a4966 all: change github.com issue links to golang.org
The go repository contains a mix of github.com/golang/go/issues/xxxxx
and golang.org/issues/xxxxx URLs for references to issues in the issue
tracker. We should use one for consistency, and golang.org is preferred
in case the project moves the issue tracker in the future.

This reasoning is taken from a comment Sam Whited left on a CL I
recently opened: https://go-review.googlesource.com/c/go/+/73890.

In that CL I referenced an issue using its github.com URL, because other
tests in the file I was changing contained references to issues using
their github.com URL. Sam Whited left a comment on the CL stating I
should change it to the golang.org URL.

If new code is intended to reference issues via golang.org and not
github.com, existing code should be updated so that precedence exists
for contributors who are looking at the existing code as a guide for the
code they should write.

Change-Id: I3b9053fe38a1c56fc101a8b7fd7b8f310ba29724
Reviewed-on: https://go-review.googlesource.com/75673
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-11-04 04:13:41 +00:00
Elias Naur 9735fcfce7 sync/atomic: add memory barriers to Load/StoreInt32 on darwin/arm
After switching to an iPhone 5 for the darwin/arm builds,
TestStoreLoadRelAcq32 started to timeout on every builder run.
Adding the same memory barriers as armLoadUint64 and armStoreUint64
makes the test complete successfully.

Fixes sync/atomic tests on the darwin/arm builder.

Change-Id: Id73de31679304e259bdbd7f2f94383ae7fd70ee4
Reviewed-on: https://go-review.googlesource.com/67390
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
2017-10-02 09:57:23 +00:00
Daniel Martí 99da8730b0 all: remove some double spaces from comments
Went mainly for the ones that make no sense, such as the ones
mid-sentence or after commas.

Change-Id: Ie245d2c19cc7428a06295635cf6a9482ade25ff0
Reviewed-on: https://go-review.googlesource.com/57293
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-08-26 15:09:09 +00:00
Tom Levy b0ba0b49a0 sync/atomic: remove references to old atomic pointer hammer tests
The tests were removed in https://golang.org/cl/2311 but some
references to them were missed.

Change-Id: I163e554a0cc99401a012deead8fda813ad74dbfe
Reviewed-on: https://go-review.googlesource.com/58870
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-08-25 05:58:33 +00:00
Austin Clements fea7c43ea2 sync/atomic: clarify 64-bit alignment bug
Local variables can also be relied on the be 64-bit aligned, since
they will be escaped to the heap if used with any atomic operations.

Also, allocated arrays are also aligned, just like structs and slices.

Fixes #18955.

Change-Id: I8a1897f6ff78922c8bfcf20d6eb4bcb17a70ba2d
Reviewed-on: https://go-review.googlesource.com/48112
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-07-11 18:32:38 +00:00
Joonas Kuorilehto 766e1ae362 sync: remove note about creating with structures
Remove note that sync.Cond, sync.Mutex, sync.RWMutex and atomic.Value
can be created as part of other data structures. Structs can be embedded
by default, and default should not be repeated.

Fixes #20471.

Change-Id: If3f5703d3f60abd96482b58ca43450d02a9e645a
Reviewed-on: https://go-review.googlesource.com/44071
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-06-07 21:35:20 +00:00
Cherry Zhang b53acd89db cmd/internal/obj/mips: add support of LLV, SCV, NOOP instructions
LLV and SCV are 64-bit load-linked and store-conditional. They
were used in runtime as #define WORD. Change them to normal
instruction form.

NOOP is hardware no-op. It was written as WORD $0. Make a name
for it for better disassembly output.

Fixes #12561.
Fixes #18238.

Change-Id: I82c667ce756fa83ef37b034b641e8c4366335e83
Reviewed-on: https://go-review.googlesource.com/40297
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-05-16 17:15:11 +00:00
Aliaksandr Valialkin 78510bd17c cmd/vet: skip unreachable "if" and "case" code in shift check.
Such dead code is legitimate when dealing with arch-specific
types (int, uint, uintptr).

The CL removes the majority of 'too small for shift' false positives
from such a code.

Change-Id: I62c5635a1d3774ab2d71d3d7056f0589f214cbe5
Reviewed-on: https://go-review.googlesource.com/38065
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
2017-04-19 20:03:37 +00:00
Josh Bleecher Snyder 00e2524d8a sync/atomic: fix mipsx frame sizes
Found by vet.

Change-Id: Ied3089a2cc8757ae5377fb5fa05bbb385d26ad9c
Reviewed-on: https://go-review.googlesource.com/37307
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-02-21 18:42:47 +00:00
Cherry Zhang 526b2f85ce runtime/internal/atomic: crash on unaligned 64-bit ops on 32-bit MIPS
This check was originally implemented by Vladimir in
https://go-review.googlesource.com/c/31489/1/src/runtime/internal/atomic/atomic_mipsx.go#30
but removed due to my comment (Sorry!). This CL adds it back.

Fixes #17786.

Change-Id: I7ff4c2539fc9e2afd8199964b587a8ccf093b896
Reviewed-on: https://go-review.googlesource.com/33431
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-11-22 02:05:07 +00:00
Ian Lance Taylor a145890059 all: don't call t.Fatal from a goroutine
Fixes #17900.

Change-Id: I42cda6ac9cf48ed739d3a015a90b3cb15edf8ddf
Reviewed-on: https://go-review.googlesource.com/33243
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-11-15 15:13:48 +00:00
Vladimir Stefanovic 9788e3d4d7 sync/atomic: add support for GOARCH=mips{,le}
Change-Id: I10f36710dd95b9bd31b3b82a3c32edcadb90ffa9
Reviewed-on: https://go-review.googlesource.com/31510
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2016-11-03 22:48:09 +00:00
Josh Bleecher Snyder 7f4c3e8710 all: update s390x assembly to use vet-friendly names
No functional changes.

Change-Id: Ibf592c04be506a76577d48574e84ab20c3238b49
Reviewed-on: https://go-review.googlesource.com/32589
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <munday@ca.ibm.com>
2016-11-03 15:04:44 +00:00
Keith Randall d6098e4277 cmd/compile: intrinsify sync/atomic for amd64
Uses the same implementation as runtime/internal/atomic.

Reorganize the intrinsic detector to make it more table-driven.

Also works on amd64p32.

Change-Id: I7a5238951d6018d7d5d1bc01f339f6ee9282b2d0
Reviewed-on: https://go-review.googlesource.com/28076
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2016-08-30 15:23:23 +00:00
Josh Bleecher Snyder 71ab9fa312 all: fix assembly vet issues
Add missing function prototypes.
Fix function prototypes.
Use FP references instead of SP references.
Fix variable names.
Update comments.
Clean up whitespace. (Not for vet.)

All fairly minor fixes to make vet happy.

Updates #11041

Change-Id: Ifab2cdf235ff61cdc226ab1d84b8467b5ac9446c
Reviewed-on: https://go-review.googlesource.com/27713
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-08-25 18:52:31 +00:00
Aliaksandr Valialkin c81a3532fe cmd/vet: check sync.* types' copying
Embed noLock struct into the following types, so `go vet -copylocks` catches
their copying additionally to types containing sync.Mutex:
  - sync.Cond
  - sync.WaitGroup
  - sync.Pool
  - atomic.Value

Fixes #14582

Change-Id: Icb543ef5ad10524ad239a15eec8a9b334b0e0660
Reviewed-on: https://go-review.googlesource.com/22015
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-06 16:43:51 +00:00
Lynn Boger eeca3ba92f sync/atomic, runtime/internal/atomic: improve ppc64x atomics
The following performance improvements have been made to the
low-level atomic functions for ppc64le & ppc64:

- For those cases containing a lwarx and stwcx (or other sizes):
sync, lwarx, maybe something, stwcx, loop to sync, sync, isync
The sync is moved before (outside) the lwarx/stwcx loop, and the
 sync after is removed, so it becomes:
sync, lwarx, maybe something, stwcx, loop to lwarx, isync

- For the Or8 and And8, the shifting and manipulation of the
address to the word aligned version were removed and the
instructions were changed to use lbarx, stbcx instead of
register shifting, xor, then lwarx, stwcx.

- New instructions LWSYNC, LBAR, STBCC were tested and added.
runtime/atomic_ppc64x.s was changed to use the LWSYNC opcode
instead of the WORD encoding.

Fixes #15469

Ran some of the benchmarks in the runtime and sync directories.
Some results varied from run to run but the trend was improvement
based on best times for base and new:

runtime.test:
BenchmarkChanNonblocking-128         0.88          0.89          +1.14%
BenchmarkChanUncontended-128         569           511           -10.19%
BenchmarkChanContended-128           63110         53231         -15.65%
BenchmarkChanSync-128                691           598           -13.46%
BenchmarkChanSyncWork-128            11355         11649         +2.59%
BenchmarkChanProdCons0-128           2402          2090          -12.99%
BenchmarkChanProdCons10-128          1348          1363          +1.11%
BenchmarkChanProdCons100-128         1002          746           -25.55%
BenchmarkChanProdConsWork0-128       2554          2720          +6.50%
BenchmarkChanProdConsWork10-128      1909          1804          -5.50%
BenchmarkChanProdConsWork100-128     1624          1580          -2.71%
BenchmarkChanCreation-128            237           212           -10.55%
BenchmarkChanSem-128                 705           667           -5.39%
BenchmarkChanPopular-128             5081190       4497566       -11.49%

BenchmarkCreateGoroutines-128             532           473           -11.09%
BenchmarkCreateGoroutinesParallel-128     35.0          34.7          -0.86%
BenchmarkCreateGoroutinesCapture-128      4923          4200          -14.69%

sync.test:
BenchmarkUncontendedSemaphore-128      112           94.2          -15.89%
BenchmarkContendedSemaphore-128        133           128           -3.76%
BenchmarkMutexUncontended-128          1.90          1.67          -12.11%
BenchmarkMutex-128                     353           310           -12.18%
BenchmarkMutexSlack-128                304           283           -6.91%
BenchmarkMutexWork-128                 554           541           -2.35%
BenchmarkMutexWorkSlack-128            567           556           -1.94%
BenchmarkMutexNoSpin-128               275           242           -12.00%
BenchmarkMutexSpin-128                 1129          1030          -8.77%
BenchmarkOnce-128                      1.08          0.96          -11.11%
BenchmarkPool-128                      29.8          27.4          -8.05%
BenchmarkPoolOverflow-128              40564         36583         -9.81%
BenchmarkSemaUncontended-128           3.14          2.63          -16.24%
BenchmarkSemaSyntNonblock-128          1087          1069          -1.66%
BenchmarkSemaSyntBlock-128             897           893           -0.45%
BenchmarkSemaWorkNonblock-128          1034          1028          -0.58%
BenchmarkSemaWorkBlock-128             949           886           -6.64%

Change-Id: I4403fb29d3cd5254b7b1ce87a216bd11b391079e
Reviewed-on: https://go-review.googlesource.com/22549
Reviewed-by: Michael Munday <munday@ca.ibm.com>
Reviewed-by: Minux Ma <minux@golang.org>
2016-05-05 18:52:28 +00:00
Michael Munday 7da42d7597 sync/atomic: add s390x implementations of atomic functions
Load and store instructions are atomic on s390x.

Change-Id: I33c641a75954f4fbd301b11a467cb57872038880
Reviewed-on: https://go-review.googlesource.com/20947
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-07 15:30:14 +00:00
Brad Fitzpatrick 5fea2ccc77 all: single space after period.
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>
2016-03-02 00:13:47 +00:00
Brad Fitzpatrick 519474451a all: make copyright headers consistent with one space after period
This is a subset of https://golang.org/cl/20022 with only the copyright
header lines, so the next CL will be smaller and more reviewable.

Go policy has been single space after periods in comments for some time.

The copyright header template at:

    https://golang.org/doc/contribute.html#copyright

also uses a single space.

Make them all consistent.

Change-Id: Icc26c6b8495c3820da6b171ca96a74701b4a01b0
Reviewed-on: https://go-review.googlesource.com/20111
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-01 23:34:33 +00:00
Richard Miller 5c613e9162 sync/atomic: new file for plan9_arm support
Atomic load/store/add/swap routines, as for other ARM platforms, but with DMB inserted
for load/store (assuming that "atomic" also implies acquire/release memory ordering).

Change-Id: I70a283d8f0ae61a66432998ce59eac76fd940c67
Reviewed-on: https://go-review.googlesource.com/18965
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-26 20:16:34 +00:00
Dmitry Vyukov e1035c5e87 sync/atomic: reduce test in short mode
In normal mode the test runs for 9+ seconds on my machine (48 cores).
But the real problem is race mode, in race mode it hits 10m test timeout.
Reduce test size in short mode. Now it runs for 100ms without race.

Change-Id: I9493a0e84f630b930af8f958e2920025df37c268
Reviewed-on: https://go-review.googlesource.com/19956
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-26 16:41:12 +00:00
Yao Zhang d58081cf0a sync/atomic: added support for mips64{,le}
Change-Id: Ibe6c345afd4cbae7e2542a350043fbb6b81d5678
Reviewed-on: https://go-review.googlesource.com/14450
Reviewed-by: Minux Ma <minux@golang.org>
2015-11-12 04:49:45 +00:00
Michael Matloob 67faca7d9c runtime: break atomics out into package runtime/internal/atomic
This change breaks out most of the atomics functions in the runtime
into package runtime/internal/atomic. It adds some basic support
in the toolchain for runtime packages, and also modifies linux/arm
atomics to remove the dependency on the runtime's mutex. The mutexes
have been replaced with spinlocks.

all trybots are happy!
In addition to the trybots, I've tested on the darwin/arm64 builder,
on the darwin/arm builder, and on a ppc64le machine.

Change-Id: I6698c8e3cf3834f55ce5824059f44d00dc8e3c2f
Reviewed-on: https://go-review.googlesource.com/14204
Run-TryBot: Michael Matloob <matloob@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-10 17:38:04 +00:00
Russ Cox 4bd8040d47 runtime, sync/atomic: add memory barriers in arm cas routines
This only triggers on ARMv7+.
If there are important SMP ARMv6 machines we can reconsider.

Makes TestLFStress tests pass and sync/atomic tests not time out
on Apple iPad Mini 3.

Fixes #7977.
Fixes #10189.

Change-Id: Ie424dea3765176a377d39746be9aa8265d11bec4
Reviewed-on: https://go-review.googlesource.com/12950
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-07-30 20:11:11 +00:00
Russ Cox 0bd8de1048 sync/atomic: reenable TestNilDeref everywhere
There is absolutely no information about how this was failing.
If we reenable the test then at least we can get a build log from
darwin/arm.

There are not even freebsd/arm or netbsd/arm builders,
so not too worried about those. (That is another problem.)

Change-Id: I0e739a4dd2897adbe110aa400d720d8fa02ae65f
Reviewed-on: https://go-review.googlesource.com/12920
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-30 16:38:29 +00:00
Austin Clements 2774b37306 all: use RET instead of RETURN on ppc64
All of the architectures except ppc64 have only "RET" for the return
mnemonic. ppc64 used to have only "RETURN", but commit cf06ea6
introduced RET as a synonym for RETURN to make ppc64 consistent with
the other architectures. However, that commit was never followed up to
make the code itself consistent by eliminating uses of RETURN.

This commit replaces all uses of RETURN in the ppc64 assembly with
RET.

This was done with
    sed -i 's/\<RETURN\>/RET/' **/*_ppc64x.s
plus one manual change to syscall/asm.s.

Change-Id: I3f6c8d2be157df8841d48de988ee43f3e3087995
Reviewed-on: https://go-review.googlesource.com/10672
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
2015-06-06 00:07:23 +00:00
David Crawshaw 2e61315254 sync/atomic: skip issue 7338 test on darwin/arm64
Similar to darwin/arm. This issue is quite worrying and I hope it
can be addressed for Go 1.5.

Change-Id: Ic095281d6a2e9a38a59973f58d464471db5a2edc
Reviewed-on: https://go-review.googlesource.com/8811
Reviewed-by: Minux Ma <minux@golang.org>
2015-04-12 02:47:43 +00:00
Aram Hăvărneanu 2a0833da50 sync/atomic: add support for GOARCH=arm64
Change-Id: I11cd4b5e8daf3805af0eaa83b55b20da889702f4
Reviewed-on: https://go-review.googlesource.com/7145
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-03-16 18:46:18 +00:00
Joel Sing 6900a421a4 sync/atomic: add support for openbsd/arm
Change-Id: I45383de6d627be35f40e07a9008b6773f5c2b0d0
Reviewed-on: https://go-review.googlesource.com/7613
Reviewed-by: Minux Ma <minux@golang.org>
2015-03-15 09:12:45 +00:00
David Crawshaw 9b8ad3fde2 sync/atomic: skip test on darwin/arm
Updates #7338.

Change-Id: I859a73543352dbdd13ec05efb23a95aecbcc628a
Reviewed-on: https://go-review.googlesource.com/7164
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-03-09 14:10:25 +00:00
Rob Pike 345350bf07 [dev.cc] cmd/asm: make 4(SP) illegal except on 386
Require a name to be specified when referencing the pseudo-stack.
If you want a real stack offset, use the hardware stack pointer (e.g.,
R13 on arm), not SP.

Fix affected assembly files.

Change-Id: If3545f187a43cdda4acc892000038ec25901132a
Reviewed-on: https://go-review.googlesource.com/5120
Run-TryBot: Rob Pike <r@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
2015-02-18 03:41:29 +00:00
Rob Pike 69ddb7a408 [dev.cc] all: edit assembly source for ARM to be more regular
Several .s files for ARM had several properties the new assembler will not support.
These include:

- mentioning SP or PC as a hardware register
	These are always pseudo-registers except that in some contexts
	they're not, and it's confusing because the context should not affect
	which register you mean. Change the references to the hardware
	registers to be explicit: R13 for SP, R15 for PC.
- constant creation using assignment
	The files say a=b when they could instead say #define a b.
	There is no reason to have both mechanisms.
- R(0) to refer to R0.
	Some macros use this to a great extent. Again, it's easy just to
	use a #define to rename a register.

Change-Id: I002335ace8e876c5b63c71c2560533eb835346d2
Reviewed-on: https://go-review.googlesource.com/4822
Reviewed-by: Dave Cheney <dave@cheney.net>
2015-02-13 23:08:51 +00:00
Shenghou Ma a1457cac9c sync/atomic: darwin/arm support
Change-Id: I213a8ab0b8c027a7b73567aeefdca73fd10eae28
Reviewed-on: https://go-review.googlesource.com/2122
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-02-06 05:49:14 +00:00
Russ Cox 813386f200 sync/atomic: remove atomic pointer hammer tests
These depend on storing arbitrary integer values using
pointer atomics, and we can't support that anymore.

Change-Id: I8cadd6d462c3eebdbe7078f43fe7c779fa8f52b3
Reviewed-on: https://go-review.googlesource.com/2311
Reviewed-by: Rick Hudson <rlh@golang.org>
2015-01-06 00:28:22 +00:00
Russ Cox 7b4df8f018 runtime, sync/atomic: add write barrier for atomic write of pointer
Add write barrier to atomic operations manipulating pointers.

In general an atomic write of a pointer word may indicate racy accesses,
so there is no strictly safe way to attempt to keep the shadow copy
in sync with the real one. Instead, mark the shadow copy as not used.

Redirect sync/atomic pointer routines back to the runtime ones,
so that there is only one copy of the write barrier and shadow logic.
In time we might consider doing this for most of the sync/atomic
functions, but for now only the pointer routines need that treatment.

Found with GODEBUG=wbshadow=1 mode.
Eventually that will run automatically, but right now
it still detects other missing write barriers.

Change-Id: I852936b9a111a6cb9079cfaf6bd78b43016c0242
Reviewed-on: https://go-review.googlesource.com/2066
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2015-01-06 00:27:06 +00:00