While it is possible for the connection pool to guard against panics
on every valuer read, this seems like a high cost to be added,
in both code complexity and possible runtime performance.
Most uses of the Valuer will be trivial, like returning
a struct field. Optimize for that case. If sometime may panic the
valuer should itself use recover and return an error.
Fixes#26332
Change-Id: Iad18780b8028f669f5a7841b74a5384d62fb6a7e
Reviewed-on: https://go-review.googlesource.com/c/go/+/170700
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This change makes the release notes for Go 1.13 more complete
by mentioning a new function in the os package.
Change-Id: I0d637fd70ff6d14782bbfb7c13985a0f83b19d6d
Reviewed-on: https://go-review.googlesource.com/c/go/+/181945
Reviewed-by: Ian Lance Taylor <iant@golang.org>
It is too confusing to have to set GONOSUMDB and GONOPROXY
in common use cases, but one cannot be guaranteed to be a
subset of the other.
This CL adds GOPRIVATE, which takes the same kind of pattern list
but is defined as "these patterns are private (non-public) modules".
Today the implication is that GOPRIVATE is the default setting for
GONOSUMDB and GONOPROXY. If there are other accommodations
to make for private packages in the future or in other tools,
having this clear statement of intent will let us do that.
(For example maybe an IDE integration would hyperlink an import
path to godoc.org; consulting GOPRIVATE would be a reasonable
way to decide not to do that for certain imports. In contrast,
consulting GONOPROXY or GONOSUMDB clearly would not.)
Fixes#32184.
Change-Id: If54c12d353c7a0a5c0e0273764140cce3c154a02
Reviewed-on: https://go-review.googlesource.com/c/go/+/181719
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
For int8, int16, and int32, comparing their unsigned value to MaxInt64
to determine non-negativity doesn't make sense, because they have
negative values whose unsigned representation is smaller than that.
Fix is simply to compare with the appropriate upper bound based on the
value type's size.
Fixes#32560.
Change-Id: Ie7afad7a56af92bd890ba5ff33c86d1df06cfd9a
Reviewed-on: https://go-review.googlesource.com/c/go/+/181797
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Change-Id: Idb5bf2a61bff635e3ebd926bdeacf943578ac874
Reviewed-on: https://go-review.googlesource.com/c/go/+/181681
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Make "go test" run the new errorsas vet check by default.
Fixes#31213.
Change-Id: I5c93c000874ffe1c0b6d647bf10de803f414c5c1
Reviewed-on: https://go-review.googlesource.com/c/go/+/179977
Run-TryBot: Jonathan Amsterdam <jba@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>
This change revendors golang.org/x/tools to include the check and
modifies cmd/vet to add it to the command.
CL 179977 will enable the check by default for 'go test'.
Commands run (starting in GOROOT/src):
cd cmd
emacs vet/main.go
go get -u=patch golang.org/x/tools/go/analysis/passes/errorsas@latest
go mod tidy
go mod vendor
cd ..
./make.bash
go test all
Updates #31213
Change-Id: Ic2ba9bd2d31c4c5fd9e7c42ca14e8dc38520c93b
Reviewed-on: https://go-review.googlesource.com/c/go/+/181717
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Check the value of target after As returns true.
Change-Id: I76a2b25fe825ee1dbb5f39f8f0b211c55bd25a4f
Reviewed-on: https://go-review.googlesource.com/c/go/+/181299
Reviewed-by: Bryan C. Mills <bcmills@google.com>
$GOEXE exists and is documented in 'go env', so $exe is redundant and
a bit confusing. Notably, mod_modinfo.txt already assumes that GOEXE
is set (even though it isn't), and thus fails on Windows.
After this CL, `go test cmd/go/...` passes on a windows-amd64-2016
builder. However, given that the $PATH on the builder is very minimal
(#32430) and network access is limited, tests that rely on binaries
(such as 'git') or external networking may still be broken.
Updates #25300
Change-Id: I9d80f2a0fbaa8bc35fa2205b6898aeccecda4e94
Reviewed-on: https://go-review.googlesource.com/c/go/+/181542
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
No references to this function remain; remove it to avoid confusion
and reduce build overhead.
The last reference was removed in CL 167748.
Change-Id: I9d023c5d8904800edd3898fed79aa9f824dfb46a
Reviewed-on: https://go-review.googlesource.com/c/go/+/181548
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Add a helper-function to testenv to make these skips more ergonomic.
Also update a few existing skips in cmd/go/... to use it.
Updates #25300
Change-Id: I4205b4fb2b685dfac1cff3c999f954bff7b0f3c1
Reviewed-on: https://go-review.googlesource.com/c/go/+/181538
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This reverts CL 180761
Reason for revert: Reinstate the stack-allocated defer CL.
There was nothing wrong with the CL proper, but stack allocation of defers exposed two other issues.
Issue #32477: Fix has been submitted as CL 181258.
Issue #32498: Possible fix is CL 181377 (not submitted yet).
Change-Id: I32b3365d5026600069291b068bbba6cb15295eb3
Reviewed-on: https://go-review.googlesource.com/c/go/+/181378
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
On freebsd 12, the system call for getdirentries writes 64 bits to
*basep, even on 32-bit systems. Accomodate that by providing a uint64
to the system call and copy the base to/from that uint64.
The uint64 seems to be a virtual file offset, so failing if the high
bits are not zero should be fine for reasonable-sized directories.
Fixes#32498
Change-Id: Ie22c0d301c6091bd20e813432928b24ab95cc314
Reviewed-on: https://go-review.googlesource.com/c/go/+/181377
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This is a followup to CL 181278 and CL 181177.
According to cmd/go/testdata/script/README:
Each line is parsed into a sequence of space-separated command words,
with environment variable expansion and # marking an end-of-line comment.
Adding single quotes around text keeps spaces in that text from being treated
as word separators and also disables environment variable expansion.
We want $HOME to be expanded, so leave it out of the single-quoted
block of text.
I tested this change on macOS, and it makes TestScript/env_write pass.
Fixes#32503
Change-Id: I13621aec82263e5cb6978c13a1ad71d2210a0e42
Reviewed-on: https://go-review.googlesource.com/c/go/+/181418
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
I didn't realise that the trybots don't include any Mac machines, so I
assumed this test change was fine when submitting CL 181177.
In any case, this is a simple fix. I forgot to add the quotes, as the
new UserConfigDir on Mac includes a space.
Change-Id: I0766b966fc41736e9fc859e37f059a3f12788d7a
Reviewed-on: https://go-review.googlesource.com/c/go/+/181278
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The old code used ~/Library/Preferences, which is documented by
Apple as:
This directory contains app-specific preference files. You
should not create files in this directory yourself. Instead, use
the NSUserDefaults class or CFPreferences API to get and set
preference values for your app.
It looks like we missed everything after the first sentence; it's
definitely not the right choice for files that Go programs and users
should be touching directly.
Instead, use ~/Library/Application Support, which is documented as:
Use this directory to store all app data files except those
associated with the user’s documents. For example, you might use
this directory to store app-created data files, configuration
files, templates, or other fixed or modifiable resources that
are managed by the app. An app might use this directory to store
a modifiable copy of resources contained initially in the app’s
bundle. A game might use this directory to store new levels
purchased by the user and downloaded from a server.
This seems in line with what UserConfigDir is for, so use it.
The documentation quotes above are obtained from the surprisingly long
link below:
https://developer.apple.com/library/archive/documentation/FileManagement/Conceptual/FileSystemProgrammingGuide/FileSystemOverview/FileSystemOverview.htmlFixes#32475.
Change-Id: Ic27a6c92d76a5d7a4d4b8eac5cd8472f67a533a4
Reviewed-on: https://go-review.googlesource.com/c/go/+/181177
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Bonventre <andybons@golang.org>
The logic for detecting deferreturn calls is wrong.
We used to look for a relocation whose symbol is runtime.deferreturn
and has an offset of 0. But on some architectures, the relocation
offset is not zero. These include arm (the offset is 0xebfffffe) and
s390x (the offset is 6).
This ends up setting the deferreturn offset at 0, so we end up using
the entry point live map instead of the deferreturn live map in a
frame which defers and then segfaults.
Instead, use the IsDirectCall helper to find calls.
Fixes#32477
Update #6980
Change-Id: Iecb530a7cf6eabd7233be7d0731ffa78873f3a54
Reviewed-on: https://go-review.googlesource.com/c/go/+/181258
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This is the net/http half of #32476. This supplies the method needed
by the other half in x/net/http2 in the already-submitted CL 181259,
which this CL also bundles in h2_bundle.go.
Thanks to Tom Thorogood (@tmthrgd) for the bug report and test.
Fixes#32476
Updates #30694
Change-Id: I79d2a280e486fbf75d116f6695fd3abb61278765
Reviewed-on: https://go-review.googlesource.com/c/go/+/181260
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
dist passes the -allabis flag to the compiler to avoid having to
recreate the cross-package ABI logic from cmd/go. However, we removed
that logic from cmd/go in CL 179863 and replaced it with a different
mechanism that doesn't depend on the build system. Hence, passing
-allabis in dist is no longer necessary.
This CL removes -allabis from dist and, since that was the only use of
it, removes support for it from the compiler as well.
Updates #31230.
Change-Id: Ib005db95755a7028f49c885785e72c3970aea4f9
Reviewed-on: https://go-review.googlesource.com/c/go/+/181079
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
The documentation comment was duplicated for each of these methods, and
the LazyProc.Call documentation incorrectly mentioned that Call accepts
only 15 arguments, but it actually accepts 18 now.
To prevent further documentation drift, refer the reader to the
documentation for Proc.Call instead of duplicating it for LazyProc.Call.
In addition, note that LazyProc's Addr, Call, and Find methods each
trigger a procedure lookup.
Change-Id: I6756cf7601fba79d1414ff5a5d6eef900aa590e7
Reviewed-on: https://go-review.googlesource.com/c/go/+/181199
Run-TryBot: Matt Layher <mdlayher@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Checks if modules are enabled in GOPATH mode.
Error message returned when no version is provided. Relevant tests
updated. Test for GO111MODULE=off added.
Fixes#27783
Change-Id: I12cdaced5fa38a9c49c0ecfed4c479eb86ed061f
Reviewed-on: https://go-review.googlesource.com/c/go/+/179998
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
In #32038, it was decided to remove get's -m, since one former use case
is removed, and the other can be done via -d, as pointed by Russ.
However, a user getting this short error might not realise that they can
switch to -d to skip building packages. Add a short mention to point
them in the right direction.
It's important to note "packages", because -m was a flag that acted on
modules, while -d acts on packages. Simply replacing -m with -d might
not be enough in some cases because of that distinction.
Change-Id: I0947b25c4223bdad3cd0e535848527da8db8a16d
Reviewed-on: https://go-review.googlesource.com/c/go/+/179361
Reviewed-by: Jay Conrod <jayconrod@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
In particular, the returned template isn't independent from the parent.
For example, it can't be parsed concurrently with other children
templates. Only methods which are explicitly safe for concurrent use,
like Execute, may be used concurrently.
Fixes#30281.
Change-Id: Idc84bf4199c035316cdb83b950fd4a8f2a71cd0c
Reviewed-on: https://go-review.googlesource.com/c/go/+/172297
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
This recognizes new features that the gofrontend has started emitting
in the export data to support cross-package inlinable functions.
This is a port of CL 180677 and 180758 from the gofrontend repo.
Change-Id: I48af6e71f9d8b04ba874ea0c204d39d1d461f8ad
Reviewed-on: https://go-review.googlesource.com/c/go/+/181118
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
To pick up the structtag vet fix for 1.13.
Fixes#30846.
Change-Id: I5e011a7db1ffb9435793d533097d768f209c18e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/179999
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
CL 179862 introduced go:linkname directives to create ABI wrappers for
Store and Store64 on s390x, but a concurrent change (CL 180439)
replaced the Go definitions of these functions with assembly
definitions. This resulted in conflicting definitions for the ABI0
symbols, which led to a bootstrap linking failure.
Fix this by removing the now-incorrect go:linkname directives for
Store and Store64. This should fix the linux-s390x builders.
Updates #31230.
Change-Id: I8de8c03c23412fc217d428c0018cc56eb2f9996f
Reviewed-on: https://go-review.googlesource.com/c/go/+/181078
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Somehow I missed these two functions in CL 179863. This should fix the
linux-arm builders.
Updates #31230.
Change-Id: I3f8bef3fac331b505a55c0850b0fbc799b7c06c5
Reviewed-on: https://go-review.googlesource.com/c/go/+/181077
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The built-in Go resolver works significantly better.
In particular, the use of res_search does not support
CNAME or PTR queries and may not even be thread-safe.
This CL is essentially a revert of CL 166297 plus fixes,
including CL 180842.
See CL 180842 for additional notes about problems
with this approach.
Fixes#31705.
Change-Id: I0a30a0de2fbd04f6c461520fd34378c84aadf66c
Reviewed-on: https://go-review.googlesource.com/c/go/+/180843
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This code was added in April in CL 166297, for #12524.
This CL fixes the following problems in the code:
- The test for failure in the assembly stubs checked for
64-bit -1 instead of 32-bit -1 to decide to fetch errno.
- These C routines (res_init and res_search) don't set errno anyway,
so the Go code using errno to decide success is incorrect.
(The routines set h_errno, which is a racy global variable
that can't safely be consulted, storing values in a different
error space.)
- The Go call passed res_search a non-NUL-terminated name.
- The C res_search rejects calls asking for TypeALL as opposed to
more specific answers like TypeA/TypeAAAA/TypeCNAME,
breaking cgoLookupHost in all cases and cgoLookupIP
except with IP-version-specific networks.
- The DNS response packet was parsed twice, once with msg.Unpack
(discarded), and once with the lower-level dnsmessage.Parser.
The Parser loop was missing a call to p.SkipAllQuestions, with the
result that no DNS response packet would ever parse successfully.
- The parsing of the DNS response answers, if reached, behaved as if
that the AResource and AAAAResource record contained textual
IP addresses, while in fact they contain binary ones. The calls to
parseIPv4 and parseIPv6 therefore would always returns nil,
so that no useful result would be returned from the resolver.
With these fixes, cgoLookupIP can correctly resolve google.com
and return both the A and AAAA addresses.
Even after fixing all these things, TestGoLookupIP still fails,
because it is testing that in non-cgo builds the cgo stubs
correctly report "I can't handle the lookup", and as written the
code intentionally violates that expectation.
This CL adds new direct tests of the pseudo-cgo routines.
The direct IP address lookups succeed, but the CNAME query
causes res_search to hang, and the PTR query fails unconditionally
(a trivial C program confirms these behaviors are due to res_search itself).
Traditionally, res_search is only intended for single-threaded use.
It is unclear whether this one is safe for use from multiple goroutines.
If you run net.test under lldb, that causes syslog messages to be
printed to standard error suggesting double-free bugs:
2019-06-05 19:52:43.505246-0400 net.test[6256:6831076] dnssd_clientstub DNSServiceRefDeallocate called with invalid DNSServiceRef 0x5c000f0 FFFFFFFF DDDDDDDD
2019-06-05 19:52:43.505274-0400 net.test[6256:6831076] dnssd_clientstub DNSServiceRefDeallocate called with invalid DNSServiceRef 0x5c000f0 FFFFFFFF DDDDDDDD
2019-06-05 19:52:43.505303-0400 net.test[6256:6831076] dnssd_clientstub DNSServiceRefDeallocate called with invalid DNSServiceRef 0x5c000f0 FFFFFFFF DDDDDDDD
2019-06-05 19:52:43.505329-0400 net.test[6256:6831076] dnssd_clientstub DNSServiceRefDeallocate called with invalid DNSServiceRef 0x5c000f0 FFFFFFFF DDDDDDDD
This res_search is from libsystem_info; a normal C program would
get res_search (#defined to res_9_search) from libresolv instead.
It is unclear what the relation between the two is.
Issue #12524 was about supporting the /etc/resolver directory tree,
but only libresolv contains code for that; libsystem_info does not.
So this code probably does not enable use of /etc/resolver.
In short:
- Before this CL, the code clearly had never run successfully.
- The code appears not to improve upon the usual non-cgo fallback.
- The code carries with it no tests of improved behavior.
- The code breaks existing tests.
- Calling res_search does not work for PTR/CNAME queries,
so the code breaks existing behavior, even after this CL.
- It's unclear whether res_search is safe to call from multiple threads.
- It's unclear whether res_search is used by any other macOS programs.
Given this, it probably makes sense to delete this code rather
than rejigger the test. This CL fixes the code first, so that there
is a working copy to bring back later if we find out that it really
is necessary.
For #31705.
Change-Id: Id2e11e8ade43098b0f90dd4d16a62ca86a7a244a
Reviewed-on: https://go-review.googlesource.com/c/go/+/180842
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
It matters whether we are calling a function that would
return a 32-bit or 64-bit -1 on error. A few sites were wrong
and this key detail was omitted from syscall/syscallX docs.
Change-Id: I48a421b6cc4d2d2b5e58f790cc947e3cb2f98940
Reviewed-on: https://go-review.googlesource.com/c/go/+/180841
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This removes the special case for finding assembly references to Go
symbols in runtime and runtime/internal/atomic. These are no longer
necessary because we've now marked all symbols in these packages that
must be accessible from assembly in other packages.
Fixes#31230.
Change-Id: I70c90b70e13b922a6669f3d46c53347f98d6fc3f
Reviewed-on: https://go-review.googlesource.com/c/go/+/179863
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
This marks all Go symbols called from assembly in other packages with
"go:linkname" directives to ensure they get ABI wrappers.
Now that we have this go:linkname convention, this also removes the
abi0Syms definition in the runtime, which was used to give morestackc
an ABI0 wrapper. Instead, we now just mark morestackc with a
go:linkname directive.
This was tested with buildall.bash in the default configuration, with
-race, and with -gcflags=all=-d=ssa/intrinsics/off. Since I couldn't
test cgo on non-Linux configurations, I manually grepped for runtime
symbols in runtime/cgo.
Updates #31230.
Change-Id: I6c8aa56be2ca6802dfa2bf159e49c411b9071bf1
Reviewed-on: https://go-review.googlesource.com/c/go/+/179862
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
The //go:linkname directive can be used to make a symbol accessible to
another package (when it wouldn't normally be). Sometimes you want to
do this without actually changing the symbol's object file symbol
name; for example, in gccgo this makes unexported symbols non-static,
and in gc this provides ABI0 wrappers for Go symbols so they can be
called from assembly in other packages. Currently, this results in
stutter like
//go:linkname entersyscall runtime.entersyscall
This CL makes the second argument to go:linkname optional for the case
where the intent is simply to expose the symbol rather than to rename
it in the object file.
Updates #31230.
Change-Id: Id06d9c4b2ec3d8e27f9b8a0d65212ab8048d734f
Reviewed-on: https://go-review.googlesource.com/c/go/+/179861
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Calling a Go symbol from assembly in another package currently results
in a link failure because the Go symbol is defined as ABIInternal, but
the assembly call is from ABI0. In general this is okay because you
shouldn't do this anyway, but there are special cases where this is
necessary, especially between the runtime and packages closely tied to
the runtime in std.
Currently, we address this for runtime symbols with a hack in cmd/go
that knows to scan related packages when building the symabis file for
the runtime and runtime/internal/atomic. However, in addition to being
a messy solution in the first place, this hack causes races in cmd/go
that are difficult to work around.
We considered creating dummy references from assembly in the runtime
to these symbols, just to make sure they get ABI0 wrappers. However,
there are a fairly large number of these symbols on some platforms,
and it can vary significantly depending on build flags (e.g., race
mode), so even this solution is fairly unpalatable.
This CL addresses this by providing a way to mark symbols in Go code
that should be made available to assembly in other packages. Rather
than introduce a new pragma, we lightly expand the meaning of
"//go:linkname", since that pragma already generally indicates that
you're making the symbol available in a way it wasn't before. This
also dovetails nicely with the behavior of go:linkname in gccgo, which
makes unexported symbols available to other packages.
Follow-up CLs will make use of this and then remove the hack from
cmd/go.
Updates #31230.
Change-Id: I23060c97280626581f025c5c01fb8d24bb4c5159
Reviewed-on: https://go-review.googlesource.com/c/go/+/179860
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
The z/Architecture does not guarantee that a load following a store
will not be reordered with that store, unless they access the same
address. Therefore if we want to ensure the sequential consistency
of atomic loads and stores we need to perform serialization
operations after atomic stores.
We do not need to serialize in the runtime when using StoreRel[ease]
and LoadAcq[uire]. The z/Architecture already provides sufficient
ordering guarantees for these operations.
name old time/op new time/op delta
AtomicLoad64-16 0.51ns ± 0% 0.51ns ± 0% ~ (all equal)
AtomicStore64-16 0.51ns ± 0% 0.60ns ± 9% +16.47% (p=0.000 n=17+20)
AtomicLoad-16 0.51ns ± 0% 0.51ns ± 0% ~ (all equal)
AtomicStore-16 0.51ns ± 0% 0.60ns ± 9% +16.50% (p=0.000 n=18+20)
Fixes#32428.
Change-Id: I88d19a4010c46070e4fff4b41587efe4c628d4d9
Reviewed-on: https://go-review.googlesource.com/c/go/+/180439
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
