The unsynchronized accesses to mheap_.arena_used in the concurrent
part of the garbage collector look like a problem waiting to happen.
In fact, they are safe, but the reason is somewhat subtle and
undocumented. This commit documents this reasoning.
Related to issue #9984.
Change-Id: Icdbf2329c1aa11dbe2396a71eb5fc2a85bd4afd5
Reviewed-on: https://go-review.googlesource.com/11254
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Historically we have declined to try to provide real support for URLs
that contain %2F in the path, but they seem to be popping up more
often, especially in (arguably ill-considered) REST APIs that shoehorn
entire paths into individual path elements.
The obvious thing to do is to introduce a URL.RawPath field that
records the original encoding of Path and then consult it during
URL.String and URL.RequestURI. The problem with the obvious thing
is that it breaks backward compatibility: if someone parses a URL
into u, modifies u.Path, and calls u.String, they expect the result
to use the modified u.Path and not the original raw encoding.
Split the difference by treating u.RawPath as a hint: the observation
is that there are many valid encodings of u.Path. If u.RawPath is one
of them, use it. Otherwise compute the encoding of u.Path as before.
If a client does not use RawPath, the only change will be that String
selects a different valid encoding sometimes (the original passed
to Parse).
This ensures that, for example, HTTP requests use the exact
encoding passed to http.Get (or http.NewRequest, etc).
Also add new URL.EscapedPath method for access to the actual
escaped path. Clients should use EscapedPath instead of
reading RawPath directly.
All the old workarounds remain valid.
Fixes#5777.
Might help #9859.
Fixes#7356.
Fixes#8767.
Fixes#8292.
Fixes#8450.
Fixes#4860.
Fixes#10887.
Fixes#3659.
Fixes#8248.
Fixes#6658.
Reduces need for #2782.
Change-Id: I77b88f14631883a7d74b72d1cf19b0073d4f5473
Reviewed-on: https://go-review.googlesource.com/11302
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The test was translated from shell incorrectly,
and it depended on having hg installed, which
may not be the case.
Moved repo to GitHub, updated code, and fixed
go list ... command to be expected to succeed.
Fixes test for #8181.
Change-Id: I7f3e8fb20cd16cac5ed24de6fd952003bc5e08d4
Reviewed-on: https://go-review.googlesource.com/11301
Reviewed-by: Ian Lance Taylor <iant@golang.org>
In the parser, the shift value is always a uint64.
Change-Id: I9b50295a9f7d174ed1f6f9baf78ec0ed43db417f
Reviewed-on: https://go-review.googlesource.com/11322
Reviewed-by: Andrew Gerrand <adg@golang.org>
A header of ": value" results in an empty key. Do not add
it to the headers, because RFC7230 (section 3.2) says that
field-names are tokens, which are one or more characters.
Fixes#11205.
Change-Id: I883be89da1489dc84f98523786b019d1d0169d46
Reviewed-on: https://go-review.googlesource.com/11242
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Most important: skip test on darwin/arm64 for unclear reasons.
First cut at the test missed this feature of go doc: when asking for
the docs for a type, include any function that looks like it constructs
a that type as a return value.
Change-Id: I124e7695e5d365e2b12524b541a9a4e6e0300fbc
Reviewed-on: https://go-review.googlesource.com/11295
Reviewed-by: Rob Pike <r@golang.org>
Some Linux kernels apparently have a sysctl that prohibits
nonprivileged processes from creating user namespaces. If we see a
failure for that reason, skip the test.
Fixes#11261.
Change-Id: I82dfcaf475eea4eaa387941373ce7165df4848ad
Reviewed-on: https://go-review.googlesource.com/11269
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
nacl is really giving a hard time. avoid all external dependencies in the test.
Worked with trybots, failed in the build. No explanation, but this should fix it.
TBR=rsc
Change-Id: Icb644286dbce88f17ee3d96ad90efba34a80a92d
Reviewed-on: https://go-review.googlesource.com/11291
Reviewed-by: Rob Pike <r@golang.org>
Refactor main a bit to make it possible to run tests without an exec every time.
(Makes a huge difference in run time.)
Add a silver test. Not quite golden, since it looks for pieces rather than the
full output, and also includes tests for what should not appear.
Fixes#10920.
Change-Id: I6a4951cc14e61763379754a10b0cc3484d30c267
Reviewed-on: https://go-review.googlesource.com/11272
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Rob Pike <r@golang.org>
All of the heavy-lifting was done by minux@, with his external-linking support
for darwin/arm64: golang.org/cl/8781
Change-Id: I7c9fbc19246f418c065c92fb2c13c00026ff0f82
Reviewed-on: https://go-review.googlesource.com/11127
Run-TryBot: Srdjan Petrovic <spetrovic@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
When GO15VENDOREXPERIMENT=1 is in the environment,
this CL changes the resolution of import paths according to
the Go 1.5 vendor proposal:
If there is a source directory d/vendor, then,
when compiling a source file within the subtree rooted at d,
import "p" is interpreted as import "d/vendor/p" if that exists.
When there are multiple possible resolutions,
the most specific (longest) path wins.
The short form must always be used: no import path can
contain “/vendor/” explicitly.
Import comments are ignored in vendored packages.
The goal of these changes is to allow authors to vendor (copy) external
packages into their source trees without any modifications to the code.
This functionality has been achieved in tools like godep, nut, and gb by
requiring GOPATH manipulation. This alternate directory-based approach
eliminates the need for GOPATH manipulation and in keeping with the
go command's use of directory layout-based configuration.
The flag allows experimentation with these vendoring semantics once
Go 1.5 is released, without forcing them on by default. If the experiment
is deemed a success, the flag will default to true in Go 1.6 and then be
removed in Go 1.7.
For more details, see the original proposal by Keith Rarick at
https://groups.google.com/d/msg/golang-dev/74zjMON9glU/dGhnoi2IMzsJ.
Change-Id: I2c6527e777d14ac6dc43c53e4b3ff24f3279216e
Reviewed-on: https://go-review.googlesource.com/10923
Reviewed-by: Andrew Gerrand <adg@golang.org>
The -importmap option takes an argument of the form old=new
and specifies that import "old" should be interpreted as if it said
import "new". The option may be repeated to specify multiple mappings.
This option is here to support the go command's new -vendor flag.
Change-Id: I31b4ed4249b549982a720bf61bb230462b33c59b
Reviewed-on: https://go-review.googlesource.com/10922
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Currently its possible for the garbage collector to observe
uninitialized memory or stale heap bitmap bits on weakly ordered
architectures such as ARM and PPC. On such architectures, the stores
that zero newly allocated memory and initialize its heap bitmap may
move after a store in user code that makes the allocated object
observable by the garbage collector.
To fix this, add a "publication barrier" (also known as an "export
barrier") before returning from mallocgc. This is a store/store
barrier that ensures any write done by user code that makes the
returned object observable to the garbage collector will be ordered
after the initialization performed by mallocgc. No barrier is
necessary on the reading side because of the data dependency between
loading the pointer and loading the contents of the object.
Fixes one of the issues raised in #9984.
Change-Id: Ia3d96ad9c5fc7f4d342f5e05ec0ceae700cd17c8
Reviewed-on: https://go-review.googlesource.com/11083
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Martin Capitanio <capnm9@gmail.com>
Reviewed-by: Russ Cox <rsc@golang.org>
These tests were broken by https://go-review.googlesource.com/#/c/11227/
which fixed the LZW encoder to reject invalid input.
For TestNoPalette, the LZW encoder with a litWidth of 2 now rejects an
input byte of 128, so we change 128 to 3, as 3 <= (1<<2 - 1).
For TestPixelOutsidePaletteRange, the LZW encoder similarly rejects an
input byte of 255. Prior to golang.org/cl/11227, the encoder (again with
a litWidth of 2) accepted the 255 input byte, but masked it with (1<<2 -
1), so that the 255 test case was effectively the same as the 3 test
case. After that LZW CL, the 255 input byte is simply invalid, so we
remove it as a test case. The test still tests pixels outside of the
palette range, since 3 >= the length of the global palette, which is 2.
Change-Id: I50be9623ace016740e34801549c15f83671103eb
Reviewed-on: https://go-review.googlesource.com/11273
Reviewed-by: David Symonds <dsymonds@golang.org>
This is a documentation fix that reflects the current reality.
Fixes#9673.
Change-Id: Ie436b277dfd1b68b13c67813d29c238d2c23b820
Reviewed-on: https://go-review.googlesource.com/11221
Reviewed-by: Russ Cox <rsc@golang.org>
Indent the temporary file source code embedded in go_test.go, so that
we don't have temporary Go code in the first column.
No real changes to the tests, just formatting.
Change-Id: I416b4a812c8db452ea61afe63a00989ec598c228
Reviewed-on: https://go-review.googlesource.com/10926
Reviewed-by: Russ Cox <rsc@golang.org>
Spell out what will happen if a declaration and definition is included
in the same file, should help people who run into duplicate symbol
errors and search for relevant keywords.
This edit is based on opening issue #11263 erroneously.
Change-Id: I0645a9433b8668d2ede9b9a3f6550d802c26388b
Reviewed-on: https://go-review.googlesource.com/11247
Reviewed-by: Ian Lance Taylor <iant@golang.org>
A frame that tries to use the global palette when it has
not been given should result in an error, not an image
with no palette at all.
Fixes#11150.
Change-Id: If0c3a201a0ac977eee2b7a5dc68930c0c5787f40
Reviewed-on: https://go-review.googlesource.com/11064
Reviewed-by: Nigel Tao <nigeltao@golang.org>
Add sentences to the docs explaining the limit on input
bytes implicit in the choice of litWidth, and the fact that
compress and decompress litWidth must match.
Fixes#11142.
Change-Id: I20cfb4df35739f7bfeb50b92c78249df3d47942c
Reviewed-on: https://go-review.googlesource.com/11063
Reviewed-by: Nigel Tao <nigeltao@golang.org>
Some latency regressions have crept into our system over the past few
weeks. This CL fixes those by having the mark phase more aggressively
blacken objects so that the mark termination phase, a STW phase, has less
work to do. Three approaches were taken when the mark phase believes
it has no more work to do, ie all the work buffers are empty.
If things have gone well the mark phase is correct and there is
in fact little or no work. In that case the following items will
take very little time. If the mark phase is wrong this CL will
ferret that work out and give the mark phase a chance to deal with
it concurrently before mark termination begins.
When the mark phase first appears to be out of work, it does three things:
1) It switches from allocating white to allocating black to reduce the
number of unmarked objects reachable only from stacks.
2) It flushes and disables per-P GC work caches so all work must be in
globally visible work buffers.
3) It rescans the global roots---the BSS and data segments---so there
are fewer objects to blacken during mark termination. We do not rescan
stacks at this point, though that could be done in a later CL.
After these steps, it again drains the global work buffers.
On a lightly loaded machine the garbage benchmark has reduced the
number of GC cycles with latency > 10 ms from 83 out of 4083 cycles
down to 2 out of 3995 cycles. Maximum latency was reduced from
60+ msecs down to 20 ms.
Change-Id: I152285b48a7e56c5083a02e8e4485dd39c990492
Reviewed-on: https://go-review.googlesource.com/10590
Reviewed-by: Austin Clements <austin@google.com>
When a method is called using the Type.Method(receiver, args...) syntax
without the receiver, or enough arguments, provide the more helpful
error message "not enough arguments in call to method expression
Type.Method" instead of the old message "not enough arguments in call
to Type.Method".
Fixes#8385
Change-Id: Id5037eb1ee5fa93687d4a6557b4a8233b29e9df2
Reviewed-on: https://go-review.googlesource.com/2193
Reviewed-by: Russ Cox <rsc@golang.org>
It's easy for someone who wants a time bigger than any
valid time to reach for time.Unix(1<<63-1, 0), so it
makes sense to explicit say such value is not valid.
Fixes#10906 (again).
Change-Id: If71e32472ae40d86c30e629b982406040a73c4c7
Reviewed-on: https://go-review.googlesource.com/10266
Reviewed-by: Russ Cox <rsc@golang.org>
The Slicing-By-8 [1] algorithm has much performance improvements than
current approach. This patch only uses it for IEEE, which is the most
common case in practice.
There is the benchmark on Mac OS X 10.9:
benchmark old MB/s new MB/s speedup
BenchmarkIEEECrc1KB 349.40 353.03 1.01x
BenchmarkIEEECrc4KB 351.55 934.35 2.66x
BenchmarkCastagnoliCrc1KB 7037.58 7392.63 1.05x
This algorithm need 8K lookup table, so it's enabled only for block
larger than 4K.
We can see about 2.6x improvement for IEEE.
Change-Id: I7f786d20f0949245e4aa101d7921669f496ed0f7
Reviewed-on: https://go-review.googlesource.com/1863
Reviewed-by: Russ Cox <rsc@golang.org>
Check that if a version is declared, for example
in '<?xml version="XX" ?>', version must be '1.0'.
Change-Id: I16ba9f78873a5f31977dcf75ac8e671fe6c08280
Reviewed-on: https://go-review.googlesource.com/8961
Reviewed-by: Russ Cox <rsc@golang.org>
When the scanner receives a non-whitespace character in stateEndTop,
it creates an error message and caches it to return on the next
transition. nextValue() uses the scanner to sub-scan for a value
inside a larger JSON structure. Since stateEndTop is triggered
*after* the ending byte, whatever character immediately follows the
sub-value gets pulled into the scanner's state machine as well.
Even though it is not used and doesn't cause an error, it does
cause the state machine to allocate an error that will never be used.
The fix is to probe the state machine with whitespace after
scanEndObject or scanEndArray to see if the next character would
result in a scanEnd state transition. If so, we can return right
away without processing the next character and avoid triggering
an allocation.
benchmark old ns/op new ns/op delta
BenchmarkCodeEncoder 17022194 16611336 -2.41%
BenchmarkCodeMarshal 18443250 18090144 -1.91%
BenchmarkCodeDecoder 61502053 61010936 -0.80%
BenchmarkCodeUnmarshal 61410829 60363605 -1.71%
BenchmarkCodeUnmarshalReuse 59124836 58361772 -1.29%
BenchmarkUnmarshalString 602 603 +0.17%
BenchmarkUnmarshalFloat64 535 537 +0.37%
BenchmarkUnmarshalInt64 482 482 +0.00%
BenchmarkIssue10335 1206 799 -33.75%
BenchmarkSkipValue 17605751 18355391 +4.26%
BenchmarkEncoderEncode 612 604 -1.31%
benchmark old MB/s new MB/s speedup
BenchmarkCodeEncoder 114.00 116.82 1.02x
BenchmarkCodeMarshal 105.21 107.27 1.02x
BenchmarkCodeDecoder 31.55 31.81 1.01x
BenchmarkCodeUnmarshal 31.60 32.15 1.02x
BenchmarkSkipValue 111.63 107.07 0.96x
benchmark old allocs new allocs delta
BenchmarkIssue10335 11 4 -63.64%
BenchmarkEncoderEncode 2 2 +0.00%
benchmark old bytes new bytes delta
BenchmarkIssue10335 376 272 -27.66%
BenchmarkEncoderEncode 40 40 +0.00%
Fixes#10335
Change-Id: I3d4f2b67f7a038adfb33ba48bb6b680f528baf18
Reviewed-on: https://go-review.googlesource.com/9074
Reviewed-by: Russ Cox <rsc@golang.org>
Suggest running 'go help gopath' when the running 'go install .'
and the folder is outside of GOPATH.
Added link to 'https://golang.org/doc/code.html' in gopath help
for more information.
Example output:
% go install .
go install: no install location for directory f:\x\badmessage outside GOPATH
please run 'go help gopath' for more information
% go help gopath
... SNIP ...
See https://golang.org/doc/code.html for an example.
Fixes#8457
Change-Id: I0ef6ee3c65bb12af2168eafeb757258aa3835664
Reviewed-on: https://go-review.googlesource.com/9258
Reviewed-by: Russ Cox <rsc@golang.org>
Check for errors when reading the headers following the pax headers.
Fixes#11169.
Change-Id: Ifec4a949ec8df8b49fa7cb7a67eb826fe2282ad8
Reviewed-on: https://go-review.googlesource.com/11031
Reviewed-by: Russ Cox <rsc@golang.org>
Return a meaningful message when a profile is empty.
Also rename "IO blocking" to "Network blocking",
currently only network blocking is captured.
Fixes#11098
Change-Id: Ib6f1292b8ade4805756fcb6696ba1fca8f9f39a9
Reviewed-on: https://go-review.googlesource.com/11243
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
There were two issues.
1. Delayed EvGoSysExit could have been emitted during TraceStart,
while it had not yet emitted EvGoInSyscall.
2. Delayed EvGoSysExit could have been emitted during next tracing session.
Fixes#10476Fixes#11262
Change-Id: Iab68eb31cf38eb6eb6eee427f49c5ca0865a8c64
Reviewed-on: https://go-review.googlesource.com/9132
Reviewed-by: Russ Cox <rsc@golang.org>
All the other error messages in this package are "lzw: etc".
Change-Id: Ie359a8912d213f92b15f02abc953127380503048
Reviewed-on: https://go-review.googlesource.com/11228
Reviewed-by: David Symonds <dsymonds@golang.org>
In preparation for rename of cgocall_errno into cgocall and
asmcgocall_errno into asmcgocall in the fllowinng CL.
rsc requested CL 9387 to be split into two parts. This is first part.
Change-Id: I7434f0e4b44dd37017540695834bfcb1eebf0b2f
Reviewed-on: https://go-review.googlesource.com/11166
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Work-around issue #11265 and re-enable tests for Plan9.
Change-Id: I3aabb674a149b8eb936f948dd4cda5fd81454646
Reviewed-on: https://go-review.googlesource.com/11194
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This change will brake the build. The immediately following change
contains the necessary adjustments to make it work again. We're
doing this in two steps to expose the manual changes applied.
Change-Id: I225947da23e190b12e12cbd0c5e6e91628de7f53
Reviewed-on: https://go-review.googlesource.com/11151
Reviewed-by: Alan Donovan <adonovan@google.com>
This fixes a hang during runtime.TestTraceStress.
It also fixes double-scan of stacks, which leads to
stack barrier installation failures.
Both of these have shown up as flaky failures on the dashboard.
Fixes#10941.
Change-Id: Ia2a5991ce2c9f43ba06ae1c7032f7c898dc990e0
Reviewed-on: https://go-review.googlesource.com/11089
Reviewed-by: Austin Clements <austin@google.com>
//go:systemstack means that the function must run on the system stack.
Add one use in runtime as a demonstration.
Fixes#9174.
Change-Id: I8d4a509cb313541426157da703f1c022e964ace4
Reviewed-on: https://go-review.googlesource.com/10840
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
I updated some references to 6g, 6l and friends that I came across, as those
programs don't exist anymore. I also fixed some echos in make.rc to match other make.* scripts while I was there.
Change-Id: Ib84532cd4688cf65174dd9869e5d42af98a20a48
Reviewed-on: https://go-review.googlesource.com/11162
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Corrected several issues:
* RFC1951 section 3.2.7 dictates that it is okay for the HDist tree to have a
single code of zero bits. Furthermore, the behavior of the C zlib library
permits empty trees even when there are more than one codes.
* RFC1951 section 3.2.5 shows that HLit codes 286 and 287 are invalid. Thus,
Go's implementation should choke on inputs using these codes.
* RFC1951 section 3.2.5 and 3.2.7 are ambiguous about whether the number of
HDist codes can be greater than 30. The C zlib library (which is the canonical
reference implementation) performs this check here:
62d6112a79/inflate.c (L906)
In addition, a number of test cases were added to the unit tests that exercises
these edge cases. The test cases listed in TestStreams will either fail or
succeed in a manner matching the behaviour of the C zlib version. Given that the
C zlib implementation is the reference for the world, Go's implementation should
match C zlib behaviour.
Fixes#11030
Change-Id: Ic24e4e40ce5832c7e1930249246e86d34bfedaa6
Reviewed-on: https://go-review.googlesource.com/11000
Reviewed-by: Nigel Tao <nigeltao@golang.org>
Also modified test/run.go to ignore messages prefixed <autogenerated>
because those cannot be described with "// ERROR ...", and backed out
patch from issue #9537 because it is no longer necessary. The reasons
described in the 9537 discussion for why escape analysis cannot run
late no longer hold, happily.
Fixes#11053.
Change-Id: Icb14eccdf2e8cde3d0f8fb8a216b765400a96385
Reviewed-on: https://go-review.googlesource.com/11088
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: David Chase <drchase@google.com>
This change reintroduces CL 8523. CL 8523 was reverted because
it broke darwin and netbsd builds. Now that this test is part
of "go tool dist test" command we could skip OSes that fail.
Updates #10360
Change-Id: Iaaeb5b800126492f36415a439c333a218fe4ab67
Reviewed-on: https://go-review.googlesource.com/11119
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
So the tests don't interfere with each other on windows.
Fixes#11217
Change-Id: I4b3936bc64c95c7274298d6f137b24a28876b625
Reviewed-on: https://go-review.googlesource.com/11138
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This change allows LookupAddr to use getnameinfo through cgo for working
together with various name services other than DNS.
Fixes#7855.
Change-Id: I5b3b4aefe3d1b904541c3350865734d8cbb1c1c4
Reviewed-on: https://go-review.googlesource.com/3420
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This flag is not needed in the std repo because we don't have
tests requiring it. Remove it before it's frozen into the API.
Change-Id: I18b861eea146ad67e7a3c26ee8be681d8065ef12
Reviewed-on: https://go-review.googlesource.com/11150
Reviewed-by: Alan Donovan <adonovan@google.com>
This makes the behaviour match what happens when duplicate symbols are read
from regular object files and fixes errors about cgoAlwaysFalse when linking
an executable that uses cgo against a shared library.
Change-Id: Ibb8cd8fe3f7813cde504b7483f1e857868d7e063
Reviewed-on: https://go-review.googlesource.com/11117
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TestHostname was re-enabled in CL 10753.
However, on Plan 9 the hostname is not obtained
by executing a "hostname" command, but by reading
the #c/sysname file.
Change-Id: I80c0e303f4983fe39ceb300ad64e2c4a8392b695
Reviewed-on: https://go-review.googlesource.com/11033
Run-TryBot: David du Colombier <0intro@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Currently, when shrinkstack computes whether the halved stack
allocation will have enough room for the stack, it accounts for the
stack space that's actively in use but fails to leave extra room for
the stack guard space. As a result, *if* the minimum stack size is
small enough or the guard large enough, it may shrink the stack and
leave less than enough room to run nosplit functions. If the next
function called after the stack shrink is a nosplit function, it may
overflow the stack without noticing and overwrite non-stack memory.
We don't think this is happening under normal conditions right now.
The minimum stack allocation is 2K and the guard is 640 bytes. The
"worst case" stack shrink is from 4K (4048 bytes after stack barrier
array reservation) to 2K (2016 bytes after stack barrier array
reservation), which means the largest "used" size that will qualify
for shrinking is 4048/4 - 8 = 1004 bytes. After copying, that leaves
2016 - 1004 = 1012 bytes of available stack, which is significantly
more than the guard space.
If we were to reduce the minimum stack size to 1K or raise the guard
space above 1012 bytes, the logic in shrinkstack would no longer leave
enough space.
It's also possible to trigger this problem by setting
firstStackBarrierOffset to 0, which puts stack barriers in a debug
mode that steals away *half* of the stack for the stack barrier array
reservation. Then, the largest "used" size that qualifies for
shrinking is (4096/2)/4 - 8 = 504 bytes. After copying, that leaves
(2096/2) - 504 = 8 bytes of available stack; much less than the
required guard space. This causes failures like those in issue #11027
because func gc() shrinks its own stack and then immediately calls
casgstatus (a nosplit function), which overflows the stack and
overwrites a free list pointer in the neighboring span. However, since
this seems to require the special debug mode, we don't think it's
responsible for issue #11027.
To forestall all of these subtle issues, this commit modifies
shrinkstack to correctly account for the guard space when considering
whether to halve the stack allocation.
Change-Id: I7312584addc63b5bfe55cc384a1012f6181f1b9d
Reviewed-on: https://go-review.googlesource.com/10714
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Issues #10240, #10541, #10941, #11023, #11027 and possibly others are
indicating memory corruption in the runtime. One of the easiest places
to both get corruption and detect it is in the allocator's free lists
since they appear throughout memory and follow strict invariants. This
commit adds a check when sweeping a span that its free list is sane
and, if not, it prints the corrupted free list and panics. Hopefully
this will help us collect more information on these failures.
Change-Id: I6d417bcaeedf654943a5e068bd76b58bb02d4a64
Reviewed-on: https://go-review.googlesource.com/10713
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
The motivation of TestLookupHost was to test codepaths on LookupHost,
LookupIP when we set CGO_ENABLED=1. Now we have serveral tests on those
APIs and their codepaths such as TestLookupGooglePublicDNSAddr,
TestCgoLookupIP, TestGoLookupIP, and the test using the ambiguous source
"localhost" is unnecessary.
Fixes#11182.
Change-Id: I397c823e1648114d91a229b316477bff2948b4f9
Reviewed-on: https://go-review.googlesource.com/11057
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Sadly examples cannot use the new internal/testenv, so this is
extends the crude build tag restriction in this file.
Change-Id: I49646ca71e45074a917813ae8e612cc715c78be8
Reviewed-on: https://go-review.googlesource.com/11086
Reviewed-by: Robert Griesemer <gri@golang.org>
Unfortunately there's no simple, easy way to make Dial{TCP,UDP} fail
consistently across all platforms. Fow now we skip the test on Solaris.
Change-Id: Ib3c55f670ac6a174fe9ea682dac7aab96b1e9dfb
Reviewed-on: https://go-review.googlesource.com/11058
Reviewed-by: Ian Lance Taylor <iant@golang.org>
dialSerial connects to a list of addresses in sequence. If a
timeout is specified, then each address gets an equal fraction of the
remaining time, with a magic constant (2 seconds) to prevent
"dial a million addresses" from allotting zero time to each.
Normally, net.Dial passes the DNS stub resolver's output to dialSerial.
If an error occurs (like destination/port unreachable), it quickly skips
to the next address, but a blackhole in the network will cause the
connection to hang until the timeout elapses. This is how UNIXy clients
traditionally behave, and is usually sufficient for non-broken networks.
The DualStack flag enables dialParallel, which implements Happy Eyeballs
by racing two dialSerial goroutines, giving the preferred family a
head start (300ms by default). This allows clients to avoid long
timeouts when the network blackholes IPv4 xor IPv6.
Fixes#8453Fixes#8455Fixes#8847
Change-Id: Ie415809c9226a1f7342b0217dcdd8f224ae19058
Reviewed-on: https://go-review.googlesource.com/8768
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Change-Id: Id93b8ab42fa311ce32209734ec9a0813f8736e25
Reviewed-on: https://go-review.googlesource.com/9914
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
The main change is:
golang.org/cl/10800 add pos parameter to Eval; remove New, EvalNode
followed by several cleanups/follow-up fixes:
golang.org/cl/10992 remove global vars in test
golang.org/cl/10994 remove unused scope parameter from NewSignature
golang.org/cl/10995 provide full source file extent to file scope
golang.org/cl/10996 comment fix in resolver.go
golang.org/cl/11004 updated cmd/vet
golang.org/cl/11042 be robust in the presence of incorrect/missing position info
Fixes#9980.
Change-Id: Id4aff688f6a399f76bf92b84c7e793b8da8baa48
Reviewed-on: https://go-review.googlesource.com/11122
Reviewed-by: Alan Donovan <adonovan@google.com>
The problem was not the kernel version as I thought before, it was
that the test used the same number for both the UID and the GID.
Thanks to Chris Siebenmann for debugging this.
Fixes#11220.
Change-Id: Ib5077e182497155e84044683209590ee0f7c9dde
Reviewed-on: https://go-review.googlesource.com/11124
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This CL adds a very long comment explaining how isStale and
the new build IDs work. As part of writing the comment I realized:
// When the go command makes the wrong build decision and does not
// rebuild something it should, users fall back to adding the -a flag.
// Any common use of the -a flag should be considered prima facie evidence
// that isStale is returning an incorrect false result in some important case.
// Bugs reported in the behavior of -a itself should prompt the question
// ``Why is -a being used at all? What bug does that indicate?''
The two uses of -a that are most commonly mentioned in bugs filed
against the go command are:
go install -a ./...
go build -tags netgo -a myprog
Both of these commands now do the right thing without needing -a.
The -a exception we introduced in Go 1.4 was for the first form, and
it broke the second form. Again, neither needs -a anymore, so restore
the old, simpler, easier to explain, less surprising meaning used in Go 1.3:
if -a is given, rebuild EVERYTHING.
See the comment for more justification and history.
Summary of recent CLs (to link bugs to this one):
Fixes#3036. Now 'go install ./...' works.
Fixes#6534. Now 'go install ./...' works.
Fixes#8290. Now 'go install ./...' works.
Fixes#9369. Now 'go build -tags netgo myprog' works.
Fixes#10702. Now using one GOPATH with Go 1.5 and Go 1.6 works.
(Each time you switch, everything needed gets rebuilt.
Switching from Go 1.4 to Go 1.5 will rebuild properly.
Switching from Go 1.5 back to Go 1.4 still needs -a when
invoking the Go 1.4 go command.)
Change-Id: I19f9eb5286efaa50de7c8326602e94604ab572eb
Reviewed-on: https://go-review.googlesource.com/10761
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This causes packages and binaries built by Go 1.5 to look
out of date to Go 1.6 and vice versa, so that when you flip
between different Go versions but keep the same GOPATH,
the right rebuilding happens at each flip.
Go 1.4 binaries will also look out of date to Go 1.5,
but Go 1.5 binaries will not look out of date to Go 1.4
(since Go 1.4 doesn't have anything like this).
People flipping between Go 1.4 and Go 1.5 will still
need to use go install -a every time to flip to Go 1.4,
but not when they flip back to Go 1.5.
Fixes#6534.
Fixes#10702.
Change-Id: I0ae7f268f822d483059a938a4f22846ff9275b4c
Reviewed-on: https://go-review.googlesource.com/10760
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
A workaround for #10460.
Change-Id: I607a556561d509db6de047892f886fb565513895
Reviewed-on: https://go-review.googlesource.com/10819
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Fixes#11131
When running 'go install -buildmode=c-shared', under the circumstances
described in issue #11131, the install command would fail trying to
install cgo headers if they have already been installed (by a previous
call to 'go install -buildmode=c-shared').
Since it's safe to overwrite said headers (according to iant@), this CL
introduces a parameter to builder's 'copy' and 'move' functions that,
if set to 'true', would force the overwriting of already installed
files.
This parameter value is set to 'true' only when installing cgo headers,
for now.
Change-Id: I5bda17ee757066a8e5d2b39f2e8f3a389eb1e4a2
Reviewed-on: https://go-review.googlesource.com/10870
Run-TryBot: Srdjan Petrovic <spetrovic@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The number of CPUs is of value when benchmarking but mostly
noise when testing. The recent change to default to the number
of CPUs available has made the tests noisier and confusing.
Fixes#11200
Change-Id: Ifc87d9ccb4177d73e304fb7ffcef4367bd163c9e
Reviewed-on: https://go-review.googlesource.com/11121
Reviewed-by: Russ Cox <rsc@golang.org>
While we're here, update the documentation and delete variables with no effect.
Change-Id: I4df0d266dff880df61b488ed547c2870205862f0
Reviewed-on: https://go-review.googlesource.com/10790
Reviewed-by: Austin Clements <austin@google.com>
A send on an unbuffered channel to a blocked receiver is the only
case in the runtime where one goroutine writes directly to the stack
of another. The garbage collector assumes that if a goroutine is
blocked, its stack contains no new pointers since the last time it ran.
The send on an unbuffered channel violates this, so it needs an
explicit write barrier. It has an explicit write barrier, but not one that
can handle a write to another stack. Use one that can (based on type bitmap
instead of heap bitmap).
To make this work, raise the limit for type bitmaps so that they are
used for all types up to 64 kB in size (256 bytes of bitmap).
(The runtime already imposes a limit of 64 kB for a channel element size.)
I have been unable to reproduce this problem in a simple test program.
Could help #11035.
Change-Id: I06ad994032d8cff3438c9b3eaa8d853915128af5
Reviewed-on: https://go-review.googlesource.com/10815
Reviewed-by: Austin Clements <austin@google.com>
In generateTrace we check that event timestamp is within the interesting range.
Then later in traceContext.time we double check event time.
However, for some events (e.g. emitSlice) we convert time of ev.Link (slice end) rather than ev itself (slice begin).
Slice end can be outside of the interesting time range, and so traceContext.time crashes.
Remove the check in traceContext.time, check in generateTrace loop is sufficient.
Change-Id: If94e93b5653c5816c0a8dcdd920f15df97616835
Reviewed-on: https://go-review.googlesource.com/11100
Reviewed-by: Andrew Gerrand <adg@golang.org>
Update to tip to fix#11003 (not possible to select events in chromium).
Fixed#11003
Change-Id: Ibba5d39ca809cfd5cb79c9e6d152b00899d49e08
Reviewed-on: https://go-review.googlesource.com/11062
Reviewed-by: Andrew Gerrand <adg@golang.org>