The correct word to use here is 'another' not 'an other'
Change-Id: Ie4f748ae94a5945dceb52779222ffd8cf36b8845
Reviewed-on: https://go-review.googlesource.com/c/go/+/235838
Reviewed-by: Robert Griesemer <gri@golang.org>
Enforces section 14.13 of RFC 2616 so that Content-Length header
values with a sign such as "+5" will be rejected.
Updates #39017
Change-Id: Icce9f00d03c8475fe704b33f9bed9089ff8802f0
Reviewed-on: https://go-review.googlesource.com/c/go/+/234817
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
This reverts https://golang.org/cl/232578.
Reason for revert: This commit broke TestScript/mod_load_badchain,
which is causing all longtest builders to fail.
Change-Id: I4a17392ce74ac3a7ad340980556025f669d94b65
Reviewed-on: https://go-review.googlesource.com/c/go/+/235857
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
When run with stdin == /dev/null and stdout/stderr == pipe (i.e., as
os/exec.Command.CombinedOutput), GDB suffers from a bug
(https://sourceware.org/bugzilla/show_bug.cgi?id=26056) that causes
SIGSEGV when sent a SIGWINCH signal.
Package runtime tests TestEINTR and TestSignalDuringExec both send
SIGWINCH signals to the entire process group, thus including GDB if one
of the GDB tests is running in parallel.
TestEINTR only intends its signals for the current process, so it is
changed to do so. TestSignalDuringExec, really does want its signals to
go to children. However, it does not call t.Parallel(), so it won't run
at the same time as GDB tests.
This is a simple fix, but GDB is vulnerable, so we must be careful not
to add new parallel tests that send SIGWINCH to the entire process
group.
Fixes#39021
Change-Id: I803606fb000f08c65c1b10ec554d4ef6819e5dd5
Reviewed-on: https://go-review.googlesource.com/c/go/+/235557
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
CL 228017 added a new help page 'go help buildconstraint' which
summarized the information on build constraints in the go/build
documentation. The summary was almost as long as the go/build
documentation, since there's very little that can be left out.
This CL moves the original go/build documentation to
'go help buildconstraint' to eliminate redundnancy. The text
describing enabled tags is slightly different (targeting command-line
users more than go/build users), but the rest of the documentation is
unchanged.
Fixes#37018
Change-Id: Ic0ed4c6fdae2395dd58852e1600c701247c9c4cc
Reviewed-on: https://go-review.googlesource.com/c/go/+/232981
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
In module mode, 'go get' prints a message for each version query it
resolves. This change groups those messages together near the end of
the output so they aren't mixed with other module "finding" and
"downloading" messages. They'll still be printed before build-related
messages.
Fixes#37982
Change-Id: I107a9f2b2f839e896399df906e20d6fc77f280c9
Reviewed-on: https://go-review.googlesource.com/c/go/+/232578
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
New test case for issue 38068, which deals with build reproducibility:
do a pair of compilations, the first with the concurrent back end
turned on, and the second with -c=1, then check to make sure we get
the same output (using a test case that triggers late inlining into
wrapper methods).
Updates #38068.
Change-Id: I4afaf78898706a66985f09d18f6f6f29876c9017
Reviewed-on: https://go-review.googlesource.com/c/go/+/234417
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Move lots of the binary-file format specific pieces into their
appropriate places. Similarly rescope some variables to just ld.
Change-Id: I74bc6d8aba58f5ac86e6579be1fcb356c4636825
Reviewed-on: https://go-review.googlesource.com/c/go/+/235278
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
AddCookie properly encodes a cookie and appends it to the Cookie header
field but does not modify or sanitize what the Cookie header field
contains already. If a user manualy sets the Cookie header field to
something not conforming to RFC 6265 then a cookie added via AddCookie
might not be retrievable.
Fixes#38437
Change-Id: I232b64ac489b39bb962fe4f7dbdc2ae44fcc0514
Reviewed-on: https://go-review.googlesource.com/c/go/+/235141
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
fieldInfo.value used to initialize nil anonymous struct fields if they
were encountered. This behavior is wanted when decoding, but not when
encoding. When encoding, the value should never be modified, and these
nil fields should be skipped entirely.
To fix the bug, add a bool argument to the function which tells the
code whether we are encoding or decoding.
Finally, add a couple of tests to cover the edge cases pointed out in
the original issue.
Fixes#27240.
Change-Id: Ic97ae4bfe5f2062c8518e03d1dec07c3875e18f6
Reviewed-on: https://go-review.googlesource.com/c/go/+/196809
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
This reverts golang.org/cl/179337.
Reason for revert: broke a few too many reasonably valid Go programs.
The previous behavior was perhaps less consistent, but the docs were
never very clear about when the decoder merges with existing values,
versus replacing existing values altogether.
Fixes#39149.
Change-Id: I1c1d857709b8398969fe421aa962f6b62f91763a
Reviewed-on: https://go-review.googlesource.com/c/go/+/234559
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Bonventre <andybons@golang.org>
Previously, when the target (“old”) path passed to os.Symlink was a
“root-relative” Windows path,¹ we would erroneously prepend
destination (“new”) path when determining which path to Stat,
resulting in an invalid path which was then masked by the lack of
error propagation for the Stat call (#39183).
If the link target is a directory (rather than a file), that would
result in the symlink being created without the
SYMBOLIC_LINK_FLAG_DIRECTORY flag, which then fails in os.Open.
¹https://docs.microsoft.com/en-us/windows/win32/fileio/creating-symbolic-links
Updates #39183
Change-Id: I04f179cd2b0c44f984f34ec330acad2408aa3a20
Reviewed-on: https://go-review.googlesource.com/c/go/+/235317
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
There are no language changes in Go 1.15, so document that.
For #37419.
Change-Id: I1e96e58b701f1758d64c79881dfa0b1109836b83
Reviewed-on: https://go-review.googlesource.com/c/go/+/235580
Reviewed-by: Robert Griesemer <gri@golang.org>
Android O and newer blocks the dup2 syscall.
Change-Id: Ibca01fc72ef114deeef6c0450a8b81a556ed0530
Reviewed-on: https://go-review.googlesource.com/c/go/+/235537
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
When go115ReduceLiveness is true (so we don't emit actual
register maps), use StackMapDontCare consistently for the
register map index, so RegMapValid is always false.
This fixes a compiler crash when doing -live=2 debug print.
Fixes#39251.
Change-Id: Ice087af491fa69c413f8ee59f923b72d592c0643
Reviewed-on: https://go-review.googlesource.com/c/go/+/235418
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
The paths for the other "go" commands in this file were fixed in CL 223741,
but this one was missed (and run.bat is not caught by the builders).
Change-Id: Iba1efddc7d2fbe6af39c39d643508decc954bbc5
Reviewed-on: https://go-review.googlesource.com/c/go/+/234758
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
In certain cases the HTTP/2 stack needs to resend a request.
It obtains a fresh body to send by calling req.GetBody.
This call was missing from the path where the HTTP/2
round tripper returns ErrSkipAltProtocol, meaning fall back
to HTTP/1.1. The result was that the HTTP/1.1 fallback
request was sent with no body at all.
This CL changes that code path to rewind the body before
falling back to HTTP/1.1. But rewinding the body is easier
said than done. Some requests have no GetBody function,
meaning the body can't be rewound. If we need to rewind and
can't, that's an error. But if we didn't read anything, we don't
need to rewind. So we have to track whether we read anything,
with a new ReadCloser wrapper. That in turn requires adding
to the couple places that unwrap Body values to look at the
underlying implementation.
This CL adds the new rewinding code in the main retry loop
as well.
The new rewindBody function also takes care of closing the
old body before abandoning it. That was missing in the old
rewind code.
Thanks to Aleksandr Razumov for CL 210123
and to Jun Chen for CL 234358, both of which informed
this CL.
Fixes#32441.
Change-Id: Id183758526c087c6b179ab73cf3b61ed23a2a46a
Reviewed-on: https://go-review.googlesource.com/c/go/+/234894
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
All GDB tests currently ignore non-zero exit statuses. When tests
flakes, we don't even know if GDB exited successfully or not.
Add checks for non-zero exits, which are not expected.
Furthermore, always log the output from GDB. The tests are currently
inconsistent about whether they always log, or only on error.
Updates #39021
Change-Id: I7af1d795fc2fdf58093cb2731d616d4aa44e9996
Reviewed-on: https://go-review.googlesource.com/c/go/+/235282
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When the output file is mmap'd, OutBuf.Close currently munmap the
file but doesn't actually close the file descriptor. This CL
makes it actually close the FD.
Change-Id: I053c5592ae95497228c50ce6a267b3b48f0af6d6
Reviewed-on: https://go-review.googlesource.com/c/go/+/235417
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Uses the `cfg.BuildN` flag to avoid deleting inside the `if cleanCache`
block. Introduces a test in src/cmd/go/testdata/script.
Fixes#39250
Change-Id: I857c441b1d7aa7c68cfd646d6833e6eaca5b18d1
Reviewed-on: https://go-review.googlesource.com/c/go/+/235140
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
If GOPROXY is "", we set it to the default value,
"https://proxy.golang.org,direct". However, if GOPROXY is a non-empty
string that doesn't contain any URLs or keywords, we treat it as
either "off" or "noproxy", which can lead to some strange errors.
This change reports an error for this kind of GOPROXY value.
For #39180
Change-Id: If2e6e39d6f74c708e5ec8f90e9d4880e0e91894f
Reviewed-on: https://go-review.googlesource.com/c/go/+/234857
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Michael Matloob <matloob@golang.org>
This fixes a bug in CL 228777 which disallowed
a MaxPathLen of -1 without IsCA, even though the
x509.Certificate documentation indicates that
MaxPathLen of -1 is considered "unset".
Updates #38216
Change-Id: Ib7240e00408d060f27567be8b820d0eee239256f
Reviewed-on: https://go-review.googlesource.com/c/go/+/235280
Run-TryBot: Katie Hockman <katie@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Set linker explicitly to lld because the default does not work on NDK
versions r19c, r20, r20b and r21. NDK 18b (or earlier) based builds
will need to specify -fuse-ld=gold.
Fixes#38838
Change-Id: Ib75f71fb9896b843910f41bd12aa1e36868fa9b3
GitHub-Last-Rev: eeaa171604
GitHub-Pull-Request: golang/go#39217
Reviewed-on: https://go-review.googlesource.com/c/go/+/235017
Reviewed-by: Elias Naur <mail@eliasnaur.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Removes last vestiges all but wasm's asmb2.
Change-Id: Ia06efc3ded7bfc657b5dd20a9549fd48d1355e52
Reviewed-on: https://go-review.googlesource.com/c/go/+/234892
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
It's only ever checked for plan 9 and it was irrelevantly set.
Change-Id: I225d4be645f573ceccde47ec2236bf3dbeb0ea70
Reviewed-on: https://go-review.googlesource.com/c/go/+/234886
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Background: when compiling a function, it's possible that a local
variable will be optimized away, which could potentially degrade the
debugging experience if the compiler fails to emit DWARF information
for the variable's type. To mitigate this situation, the compiler
emits R_USETYPE relocations for the function's auto/param variables as
a signal to the linker to generate DWARF for the types in question,
even if the type is not specifically attached to a DWARF param or var.
This patch change the logic in the compiler to avoid emitting a
R_USETYPE relocation if the type in question is already referenced by
a concrete DWARF param or auto record. This cuts down on the amount of
work the linker has to do, also makes object files a bit smaller on
average (about 1% for the runtime package).
Change-Id: I4d24da458d0658edf90c5dca0bf21d5ddc3961d8
Reviewed-on: https://go-review.googlesource.com/c/go/+/234837
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Rework the code in the linker that visits DWARF subprorgam DIEs to
reduce number of symbol name instantiations and name lookups, by
making better use of relocation target symbol types.
Change-Id: Ifb2a4e24874b8c891d7fdf17dd749c3f9139157a
Reviewed-on: https://go-review.googlesource.com/c/go/+/234685
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This change splits the SDWARFINFO symbol type (a generic container of
DWARF content) into separate sub-classes. The new symbol types are
SDWARFCUINFO comp unit DIE, also CU info and CU packagename syms
SDWARFCONST constant DIE
SDWARFFCN subprogram DIE (default and concrete)
SDWARFABSFCN abstract function DIE
SDWARFTYPE type DIE
SDWARFVAR global variable DIE
Advantage of doing this: in the linker there are several places where
we have to iterate over a symbol's relocations to pick out references
to specific classes of DWARF sub-symbols (for example, looking for all
abstract function DIEs referenced by a subprogram DIE, or looking at
all the type DIEs used in a subprogram DIE). By splitting SDWARFINFO
into parts clients can now look only at the relocation target's sym
type as opposed to having to materialize the target sym name, or do a
lookup.
Change-Id: I4e0ee3216d3c8f1a78bec3d296c01e95b3d025b5
Reviewed-on: https://go-review.googlesource.com/c/go/+/234684
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Add two no op instructions following svc on openbsd/arm64 and swi on openbsd/arm.
All except some of the most recent arm64 processors have a speculative execution
flaw that occurs across a syscall boundary, which cannot be mitigated in the
kernel. In order to protect against this leak a speculation barrier needs to be
placed after an svc or swi instruction.
In order to avoid the performance impact of these instructions, the OpenBSD 6.7
kernel returns execution two instructions past the svc or swi call. For now two
hardware no ops are added, which allows syscalls to work with both 6.6 and 6.7.
These should be replaced with real speculation barriers once OpenBSD 6.8 is
released.
Updates #36435
Change-Id: I06153cb0998199242cca8761450e53599c3e7de4
Reviewed-on: https://go-review.googlesource.com/c/go/+/234381
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
CL 235017 is about to change the default Android linker to lld. lld doesn't
support the --compress-debug-sections=zlib-gnu flag, but linkerFlagSupported
doesn't take any alternative linkers specified with -fuse-ld into account.
Updates #38838
Change-Id: I5f7422c06d40dedde2e4b070fc48398e8f822190
Reviewed-on: https://go-review.googlesource.com/c/go/+/235157
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The parallel chatty tests added in CL 229085 fail on the
solaris-amd64-oraclerel builder, because a +NN:NN offset time zone is
used. Allow for the `+` character in the corresponding regex to fix
these tests. Also move the '-' to the end of the character class, so it
is not interpreted as the range 9-T.
Change-Id: Iec9ae82ba45d2490176f274f0dc6812666eae718
Reviewed-on: https://go-review.googlesource.com/c/go/+/234978
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Specifically, this change documents the behavior of Unmarshal when a
SEQUENCE contains trailing elements.
For context Unmarshal treats trailing elements of a SEQUENCE that do not
have matching struct fields as valid, as this is how ASN.1 structures
are typically extended. This can be somewhat confusing as you might
expect those elements to be appended to rest, but rest is really only
for trailing data unrelated to the structure being parsed (i.e. if you
append a second sequence to b, it would be returned in rest).
Fixes#35680
Change-Id: Ia2c68b2f7d8674d09e859b4b7f9aff327da26fa0
Reviewed-on: https://go-review.googlesource.com/c/go/+/233537
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>
The existing example is needlessly complex.
You have to know that t.Sub returns a Duration
and also have to mentally subtract the two times
to understand what duration should be printed.
Rewrite to focus on just the Duration.String operation.
Change-Id: I00765b6019c07a6ff03022625b556c2b9ba87c09
Reviewed-on: https://go-review.googlesource.com/c/go/+/234893
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
A zombie slot is a slot that is marked, but isn't allocated. This can
indicate a bug in the GC, or a bad use of unsafe.Pointer. Currently,
the sweeper has best-effort detection for zombie slots: if there are
more marked slots than allocated slots, then there must have been a
zombie slot. However, this is imprecise since it only compares totals
and it reports almost no information that may be helpful to debug the
issue.
Add a precise check that compares the mark and allocation bitmaps and
reports detailed information if it detects a zombie slot.
No appreciable effect on performance as measured by the sweet
benchmarks:
name old time/op new time/op delta
BiogoIgor 15.8s ± 2% 15.8s ± 2% ~ (p=0.421 n=24+25)
BiogoKrishna 15.6s ± 2% 15.8s ± 5% ~ (p=0.082 n=22+23)
BleveIndexBatch100 4.90s ± 3% 4.88s ± 2% ~ (p=0.627 n=25+24)
CompileTemplate 204ms ± 1% 205ms ± 0% +0.22% (p=0.010 n=24+23)
CompileUnicode 77.8ms ± 2% 78.0ms ± 1% ~ (p=0.236 n=25+24)
CompileGoTypes 729ms ± 0% 731ms ± 0% +0.26% (p=0.000 n=24+24)
CompileCompiler 3.52s ± 0% 3.52s ± 1% ~ (p=0.152 n=25+25)
CompileSSA 8.06s ± 1% 8.05s ± 0% ~ (p=0.192 n=25+24)
CompileFlate 132ms ± 1% 132ms ± 1% ~ (p=0.373 n=24+24)
CompileGoParser 163ms ± 1% 164ms ± 1% +0.32% (p=0.003 n=24+25)
CompileReflect 453ms ± 1% 455ms ± 1% +0.39% (p=0.000 n=22+22)
CompileTar 181ms ± 1% 181ms ± 1% +0.20% (p=0.029 n=24+21)
CompileXML 244ms ± 1% 244ms ± 1% ~ (p=0.065 n=24+24)
CompileStdCmd 15.8s ± 2% 15.7s ± 2% ~ (p=0.059 n=23+24)
FoglemanFauxGLRenderRotateBoat 13.4s ±11% 12.8s ± 0% ~ (p=0.377 n=25+24)
FoglemanPathTraceRenderGopherIter1 18.6s ± 0% 18.6s ± 0% ~ (p=0.696 n=23+24)
GopherLuaKNucleotide 28.7s ± 4% 28.6s ± 5% ~ (p=0.700 n=25+25)
MarkdownRenderXHTML 250ms ± 1% 248ms ± 1% -1.01% (p=0.000 n=24+24)
[Geo mean] 1.60s 1.60s -0.11%
(https://perf.golang.org/search?q=upload:20200517.6)
For #38702.
Change-Id: I8af1fefd5fbf7b9cb665b98f9c4b73d1d08eea81
Reviewed-on: https://go-review.googlesource.com/c/go/+/234100
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Now the only thing it does is to track versions. Move it to ctxt.
And delete sym.Symbols.
Change-Id: Ie6b974f9bf79c4f33ace02213dcb89463eadd26a
Reviewed-on: https://go-review.googlesource.com/c/go/+/234884
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
The go/build package uses the "go" tool from the user's environment,
but its tests should not assume that that tool is in any particular
state, let alone appropriate for running the test.
Instead, explicitly use testenv.GoTool, adding it to $PATH in a
TestMain when necessary.
Fixes#39199Fixes#39198
Change-Id: I56618a55ced473e75dd96eeb3a8f7084e2e64d02
Reviewed-on: https://go-review.googlesource.com/c/go/+/234880
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alexander Rakoczy <alex@golang.org>
When a locked M wants to start a new M, it hands off to the template
thread to actually call clone and start the thread. The template thread
is lazily created the first time a thread is locked (or if cgo is in
use).
stoplockedm will release the P (_Pidle), then call handoffp to give the
P to another M. In the case of a pending STW, one of two things can
happen:
1. handoffp starts an M, which does acquirep followed by schedule, which
will finally enter _Pgcstop.
2. handoffp immediately enters _Pgcstop. This only occurs if the P has
no local work, GC work, and no spinning M is required.
If handoffp starts an M, and must create a new M to do so, then newm
will simply queue the M on newmHandoff for the template thread to do the
clone.
When a stop-the-world is required, stopTheWorldWithSema will start the
stop and then wait for all Ps to enter _Pgcstop. If the template thread
is not fully created because startTemplateThread gets stopped, then
another stoplockedm may queue an M that will never get created, and the
handoff P will never leave _Pidle. Thus stopTheWorldWithSema will wait
forever.
A sequence to trigger this hang when STW occurs can be visualized with
two threads:
T1 T2
------------------------------- -----------------------------
LockOSThread LockOSThread
haveTemplateThread == 0
startTemplateThread
haveTemplateThread = 1
newm haveTemplateThread == 1
preempt -> schedule g.m.lockedExt++
gcstopm -> _Pgcstop g.m.lockedg = ...
park g.lockedm = ...
return
... (any code)
preempt -> schedule
stoplockedm
releasep -> _Pidle
handoffp
startm (first 3 handoffp cases)
newm
g.m.lockedExt != 0
Add to newmHandoff, return
park
Note that the P in T2 is stuck sitting in _Pidle. Since the template
thread isn't running, the new M will not be started complete the
transition to _Pgcstop.
To resolve this, we disable preemption around the assignment of
haveTemplateThread and the creation of the template thread in order to
guarantee that if handTemplateThread is set then the template thread
will eventually exist, in the presence of stops.
Fixes#38931
Change-Id: I50535fbbe2f328f47b18e24d9030136719274191
Reviewed-on: https://go-review.googlesource.com/c/go/+/232978
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
