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28163 Commits

Author SHA1 Message Date
Brad Fitzpatrick
35d342b4fa net/http: remove some TODOs
Change-Id: Iaf200ba9a308bc8f511eec4a70dbeb014bf5fdc3
Reviewed-on: https://go-review.googlesource.com/22690
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-05-02 16:20:12 +00:00
Emmanuel Odeke
53fd522c0d all: make copyright headers consistent with one space after period
Follows suit with https://go-review.googlesource.com/#/c/20111.

Generated by running
$ grep -R 'Go Authors.  All' * | cut -d":" -f1 | while read F;do perl -pi -e 's/Go
Authors.  All/Go Authors. All/g' $F;done

The code in cmd/internal/unvendor wasn't changed.

Fixes #15213

Change-Id: I4f235cee0a62ec435f9e8540a1ec08ae03b1a75f
Reviewed-on: https://go-review.googlesource.com/21819
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-02 13:43:18 +00:00
Ian Lance Taylor
e50346d26a cmd/cgo, misc/cgo/test: make -Wdeclaration-after-statement clean
I got a complaint that cgo output triggers warnings with
-Wdeclaration-after-statement.  I don't think it's worth testing for
this--C has permitted declarations after statements since C99--but it is
easy enough to fix.  It may break again; so it goes.

This CL also fixes errno handling to avoid getting confused if the tsan
functions happen to change the global errno variable.

Change-Id: I0ec7c63a6be5653ef44799d134c8d27cb5efa441
Reviewed-on: https://go-review.googlesource.com/22686
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-02 04:42:12 +00:00
Michael Hudson-Doyle
45f39fb467 cmd/link: pass -Wl,-z,relro to host linker in -buildmode=PIE
Fixes #15485

Change-Id: I8e9314be91db89873130b232b589a284822e6643
Reviewed-on: https://go-review.googlesource.com/22687
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-05-02 04:38:52 +00:00
Keith Randall
5325fbc7db cmd/compile: don't SSA any variables when -N
Turn SSAing of variables off when compiling with optimizations off.
This helps keep variable names around that would otherwise be
optimized away.

Fixes #14744

Change-Id: I31db8cf269c068c7c5851808f13e5955a09810ca
Reviewed-on: https://go-review.googlesource.com/22681
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-05-02 04:16:45 +00:00
Mikio Hara
5776c20164 net/http: gofmt -w -s
Change-Id: I7e07888e90c7449f119e74b97995efcd7feef76e
Reviewed-on: https://go-review.googlesource.com/22682
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-05-02 01:31:53 +00:00
Keith Randall
ade0eb2f06 cmd/compile: fix reslice
:= is the wrong thing here.  The new variable masks the old
variable so we allocate the slice afresh each time around the loop.

Change-Id: I759c30e1bfa88f40decca6dd7d1e051e14ca0844
Reviewed-on: https://go-review.googlesource.com/22679
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
2016-05-01 22:11:45 +00:00
Brad Fitzpatrick
24c05e7e69 net/http: fix typo in comment
Change-Id: I753e62879a56582a9511e3f34fdeac929202efbf
Reviewed-on: https://go-review.googlesource.com/22680
Reviewed-by: Ralph Corderoy <ralph@inputplus.co.uk>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-05-01 18:34:22 +00:00
Brad Fitzpatrick
ca8b627072 net/http: add Response.Uncompressed bool
The Transport's automatic gzip uncompression lost information in the
process (the compressed Content-Length, if known). Normally that's
okay, but it's not okay for reverse proxies which have to be able to
generate a valid HTTP response from the Transport's provided
*Response.

Reverse proxies should normally be disabling compression anyway and
just piping the compressed pipes though and not wasting CPU cycles
decompressing them. So also document that on the new Uncompressed
field.

Then, using the new field, fix Response.Write to not inject a bogus
"Connection: close" header when it doesn't see a transfer encoding or
content-length.

Updates #15366 (the http2 side remains, once this is submitted)

Change-Id: I476f40aa14cfa7aa7b3bf99021bebba4639f9640
Reviewed-on: https://go-review.googlesource.com/22671
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-01 06:29:57 +00:00
Brad Fitzpatrick
a9cf0b1e1e net/http: provide access to the listener address an HTTP request arrived on
This adds a context key named LocalAddrContextKey (for now, see #15229) to
let users access the net.Addr of the net.Listener that accepted the connection
that sent an HTTP request. This is similar to ServerContextKey which provides
access to the *Server. (A Server may have multiple Listeners)

Fixes #6732

Change-Id: I74296307b68aaaab8df7ad4a143e11b5227b5e62
Reviewed-on: https://go-review.googlesource.com/22672
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-01 06:06:07 +00:00
Brad Fitzpatrick
abc1472d78 net/http: add Transport.IdleConnTimeout
Don't keep idle HTTP client connections open forever. Add a new knob,
Transport.IdleConnTimeout, and make the default be 90 seconds. I
figure 90 seconds is more than a minute, and less than infinite, and I
figure enough code has things waking up once a minute polling APIs.

This also removes the Transport's idleCount field which was unused and
redundant with the size of the idleLRU map (which was actually used).

Change-Id: Ibb698a9a9a26f28e00a20fe7ed23f4afb20c2322
Reviewed-on: https://go-review.googlesource.com/22670
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-01 05:47:09 +00:00
Brad Fitzpatrick
0ab78df9ea net/http: fix a few crashes with a ClientTrace with nil funcs
And add a test.

Updates #12580

Change-Id: Ia7eaba09b8e7fd0eddbcaefb948d01ab10af876e
Reviewed-on: https://go-review.googlesource.com/22659
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-01 05:46:39 +00:00
Brad Fitzpatrick
b3a130e81a net/http: document some errors more, mark ErrWriteAfterFlush as unused
Fixes #15150

Change-Id: I1a892d5b0516a37dac050d3bb448e0a2571db16e
Reviewed-on: https://go-review.googlesource.com/22658
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-05-01 05:27:31 +00:00
Josh Bleecher Snyder
d713e8e806 archive/zip: improve BenchmarkCompressedZipGarbage
Before this CL:

$ go test -bench=CompressedZipGarbage -count=5 -run=NONE archive/zip
BenchmarkCompressedZipGarbage-8        50  20677087 ns/op   42973 B/op      47 allocs/op
BenchmarkCompressedZipGarbage-8       100  20584764 ns/op   24294 B/op      47 allocs/op
BenchmarkCompressedZipGarbage-8        50  20859221 ns/op   42973 B/op      47 allocs/op
BenchmarkCompressedZipGarbage-8       100  20901176 ns/op   24294 B/op      47 allocs/op
BenchmarkCompressedZipGarbage-8        50  21282409 ns/op   42973 B/op      47 allocs/op

The B/op number is effectively meaningless. There
is a surprisingly large one-time cost that gets
divided by the number of iterations that your
machine can get through in a second.

This CL discards the first run, which helps.
It is not a panacea. Running with -benchtime=10s
will allow the sync.Pool to be emptied,
which brings the problem back.
However, since there are more iterations to divide
the cost through, it’s not quite as bad,
and running with a high benchtime is rare.

This CL changes the meaning of the B/op number,
which is unfortunate, since it won’t have the
same order of magnitude as previous Go versions.
But it wasn’t really comparable before anyway,
since it didn’t have any reliable meaning at all.

After this CL:

$ go test -bench=CompressedZipGarbage -count=5 -run=NONE archive/zip
BenchmarkCompressedZipGarbage-8   	     100	  20881890 ns/op	    5616 B/op	      47 allocs/op
BenchmarkCompressedZipGarbage-8   	      50	  20622757 ns/op	    5616 B/op	      47 allocs/op
BenchmarkCompressedZipGarbage-8   	      50	  20628193 ns/op	    5616 B/op	      47 allocs/op
BenchmarkCompressedZipGarbage-8   	     100	  20756612 ns/op	    5616 B/op	      47 allocs/op
BenchmarkCompressedZipGarbage-8   	     100	  20639774 ns/op	    5616 B/op	      47 allocs/op

Change-Id: Iedee04f39328974c7fa272a6113d423e7ffce50f
Reviewed-on: https://go-review.googlesource.com/22585
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-05-01 04:42:00 +00:00
Brad Fitzpatrick
3836354f11 doc: update go1.7.txt
Change-Id: I53dd5affc3a1e1f741fe44c7ce691bb2cd432764
Reviewed-on: https://go-review.googlesource.com/22657
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-05-01 04:20:30 +00:00
Cherry Zhang
3b0b30727c cmd/internal/obj/mips, cmd/link: add support TLS relocation for mips64x
a new relocation R_ADDRMIPSTLS is added, which resolves to 16-bit offset
of a TLS address on mips64x.

Change-Id: Ic60d0e1ba49ff1c433cead242f5884677ab227a5
Reviewed-on: https://go-review.googlesource.com/19804
Reviewed-by: Minux Ma <minux@golang.org>
2016-05-01 03:36:19 +00:00
Austin Clements
77c7f12438 runtime: update some comments
This updates some comments that became out of date when we moved the
mark bit out of the heap bitmap and started using the high bit for the
first word as a scan/dead bit.

Change-Id: I4a572d16db6114cadff006825466c1f18359f2db
Reviewed-on: https://go-review.googlesource.com/22662
Reviewed-by: Rick Hudson <rlh@golang.org>
2016-05-01 03:31:50 +00:00
Cherry Zhang
5d002dbc21 runtime/cgo: add linux/mips64x cgo support
MIPS N64 ABI passes arguments in registers R4-R11, return value in R2.
R16-R23, R28, R30 and F24-F31 are callee-save. gcc PIC code expects
to be called with indirect call through R25.

Change-Id: I24f582b4b58e1891ba9fd606509990f95cca8051
Reviewed-on: https://go-review.googlesource.com/19805
Reviewed-by: Minux Ma <minux@golang.org>
2016-05-01 02:39:50 +00:00
Cherry Zhang
073d292c45 cmd/link, runtime: add external linking support for linux/mips64x
Fixes #12560

Change-Id: Ic2004fc7b09f2dbbf83c41f8c6307757c0e1676d
Reviewed-on: https://go-review.googlesource.com/19803
Reviewed-by: Minux Ma <minux@golang.org>
2016-05-01 02:38:37 +00:00
Frits van Bommel
b13b249f43 cmd/compile: Improve readability of HTML produced by GOSSAFUNC
Factor out the Aux/AuxInt handling in (*Value).LongString() and
use it in (*Value).LongHTML() as well.
This especially improves readability of auxFloat32, auxFloat64,
and auxSymValAndOff values which would otherwise be printed as
opaque integers.
This change also makes LongString() slightly less verbose by
eliding offsets that are zero (as is very often the case).

Additionally, ensure the HTML is interpreted as UTF-8 so that
non-ASCII characters (especially the "middle dots" in some symbols)
show up correctly.

Change-Id: Ie26221df876faa056d322b3e423af63f33cd109d
Reviewed-on: https://go-review.googlesource.com/22641
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Frits van Bommel <fvbommel@gmail.com>
2016-05-01 02:38:17 +00:00
Cherry Zhang
981395103e cmd/internal/obj/mips et al.: introduce SB register on mips64x
SB register (R28) is introduced for access external addresses with shorter
instruction sequences. It is loaded at entry points. External data within
2G of SB can be accessed this way.

cmd/internal/obj: relocaltion R_ADDRMIPS is split into two relocations
R_ADDRMIPS and R_ADDRMIPSU, handling the low 16 bits and the "upper" 16
bits of external addresses, respectively, since the instructios may not
be adjacent. It might be better if relocation Variant could be used.

cmd/link/internal/mips64: support new relocations.

cmd/compile/internal/mips64: reserve SB register.

runtime: initialize SB register at entry points.

Change-Id: I5f34868f88c5a9698c042a8a1f12f76806c187b9
Reviewed-on: https://go-review.googlesource.com/19802
Reviewed-by: Minux Ma <minux@golang.org>
2016-05-01 02:36:46 +00:00
Cherry Zhang
8dc0444a04 cmd/asm, cmd/internal/obj/mips: add an alias of RSB on mips64x
Change-Id: I724ce0a48c1aeed14267c049fa415a6fa2fffbcf
Reviewed-on: https://go-review.googlesource.com/19864
Reviewed-by: Minux Ma <minux@golang.org>
2016-05-01 02:36:37 +00:00
Cherry Zhang
a409fb80b0 cmd/internal/obj/mips, runtime: change REGTMP to R23
Leave R28 to SB register, which will be introduced in CL 19802.

Change-Id: I1cf7a789695c5de664267ec8086bfb0b043ebc14
Reviewed-on: https://go-review.googlesource.com/19863
Reviewed-by: Minux Ma <minux@golang.org>
2016-05-01 02:36:28 +00:00
Cherry Zhang
9bc1e2065c cmd/asm/internal/asm/testdata: remove WORD $foo(SB) from mips64.s
on mips64, address is 64 bit, not a WORD. also it is never used anywhere.

Change-Id: Ic6bf6d6a21c8d2f1eb7bfe9efc5a29186ec2a8ef
Reviewed-on: https://go-review.googlesource.com/19801
Reviewed-by: Minux Ma <minux@golang.org>
2016-05-01 02:36:09 +00:00
Brad Fitzpatrick
81b2ea4d34 net/http: add Transport.MaxIdleConns limit
The HTTP client had a limit for the maximum number of idle connections
per-host, but not a global limit.

This CLs adds a global idle connection limit too,
Transport.MaxIdleConns.

All idle conns are now also stored in a doubly-linked list. When there
are too many, the oldest one is closed.

Fixes #15461

Change-Id: I72abbc28d140c73cf50f278fa70088b45ae0deef
Reviewed-on: https://go-review.googlesource.com/22655
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-01 00:12:20 +00:00
Brad Fitzpatrick
38cfaa5f0a net/http: expand documentation of Server.MaxHeaderBytes
Clarify that it includes the RFC 7230 "request-line".

Fixes #15494

Change-Id: I9cc5dd5f2d85ebf903229539208cec4da5c38d04
Reviewed-on: https://go-review.googlesource.com/22656
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-04-30 23:36:35 +00:00
Kevin Burke
4e0cd1eeef database/sql: clone data for named []byte types
Previously named byte types like json.RawMessage could get dirty
database memory from a call to Scan. These types would activate a
code path that didn't clone the byte data coming from the database
before assigning it. Another thread could then overwrite the byte
array in src, which has unexpected consequences.

Originally reported by Jason Moiron; the patch and test are his
suggestions. Fixes #13905.

Change-Id: Iacfef61cbc9dd51c8fccef9b2b9d9544c77dd0e0
Reviewed-on: https://go-review.googlesource.com/22393
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-30 18:40:36 +00:00
Austin Clements
a20fd1f6ba runtime: reclaim scan/dead bit in first word
With the switch to separate mark bitmaps, the scan/dead bit for the
first word of each object is now unused. Reclaim this bit and use it
as a scan/dead bit, just like words three and on. The second word is
still used for checkmark.

This dramatically simplifies heapBitsSetTypeNoScan and hasPointers,
since they no longer need different cases for 1, 2, and 3+ word
objects. They can instead just manipulate the heap bitmap for the
first word and be done with it.

In order to enable this, we change heapBitsSetType and runGCProg to
always set the scan/dead bit to scan for the first word on every code
path. Since these functions only apply to types that have pointers,
there's no need to do this conditionally: it's *always* necessary to
set the scan bit in the first word.

We also change every place that scans an object and checks if there
are more pointers. Rather than only checking morePointers if the word
is >= 2, we now check morePointers if word != 1 (since that's the
checkmark word).

Looking forward, we should probably reclaim the checkmark bit, too,
but that's going to be quite a bit more work.

Tested by setting doubleCheck in heapBitsSetType and running all.bash
on both linux/amd64 and linux/386, and by running GOGC=10 all.bash.

This particularly improves the FmtFprintf* go1 benchmarks, since they
do a large amount of noscan allocation.

name                      old time/op    new time/op    delta
BinaryTree17-12              2.34s ± 1%     2.38s ± 1%  +1.70%  (p=0.000 n=17+19)
Fannkuch11-12                2.09s ± 0%     2.09s ± 1%    ~     (p=0.276 n=17+16)
FmtFprintfEmpty-12          44.9ns ± 2%    44.8ns ± 2%    ~     (p=0.340 n=19+18)
FmtFprintfString-12          127ns ± 0%     125ns ± 0%  -1.57%  (p=0.000 n=16+15)
FmtFprintfInt-12             128ns ± 0%     122ns ± 1%  -4.45%  (p=0.000 n=15+20)
FmtFprintfIntInt-12          207ns ± 1%     193ns ± 0%  -6.55%  (p=0.000 n=19+14)
FmtFprintfPrefixedInt-12     197ns ± 1%     191ns ± 0%  -2.93%  (p=0.000 n=17+18)
FmtFprintfFloat-12           263ns ± 0%     248ns ± 1%  -5.88%  (p=0.000 n=15+19)
FmtManyArgs-12               794ns ± 0%     779ns ± 1%  -1.90%  (p=0.000 n=18+18)
GobDecode-12                7.14ms ± 2%    7.11ms ± 1%    ~     (p=0.072 n=20+20)
GobEncode-12                5.85ms ± 1%    5.82ms ± 1%  -0.49%  (p=0.000 n=20+20)
Gzip-12                      218ms ± 1%     215ms ± 1%  -1.22%  (p=0.000 n=19+19)
Gunzip-12                   36.8ms ± 0%    36.7ms ± 0%  -0.18%  (p=0.006 n=18+20)
HTTPClientServer-12         77.1µs ± 4%    77.1µs ± 3%    ~     (p=0.945 n=19+20)
JSONEncode-12               15.6ms ± 1%    15.9ms ± 1%  +1.68%  (p=0.000 n=18+20)
JSONDecode-12               55.2ms ± 1%    53.6ms ± 1%  -2.93%  (p=0.000 n=17+19)
Mandelbrot200-12            4.05ms ± 1%    4.05ms ± 0%    ~     (p=0.306 n=17+17)
GoParse-12                  3.14ms ± 1%    3.10ms ± 1%  -1.31%  (p=0.000 n=19+18)
RegexpMatchEasy0_32-12      69.3ns ± 1%    70.0ns ± 0%  +0.89%  (p=0.000 n=19+17)
RegexpMatchEasy0_1K-12       237ns ± 1%     236ns ± 0%  -0.62%  (p=0.000 n=19+16)
RegexpMatchEasy1_32-12      69.5ns ± 1%    70.3ns ± 1%  +1.14%  (p=0.000 n=18+17)
RegexpMatchEasy1_1K-12       377ns ± 1%     366ns ± 1%  -3.03%  (p=0.000 n=15+19)
RegexpMatchMedium_32-12      107ns ± 1%     107ns ± 2%    ~     (p=0.318 n=20+19)
RegexpMatchMedium_1K-12     33.8µs ± 3%    33.5µs ± 1%  -1.04%  (p=0.001 n=20+19)
RegexpMatchHard_32-12       1.68µs ± 1%    1.73µs ± 0%  +2.50%  (p=0.000 n=20+18)
RegexpMatchHard_1K-12       50.8µs ± 1%    52.0µs ± 1%  +2.50%  (p=0.000 n=19+18)
Revcomp-12                   381ms ± 1%     385ms ± 1%  +1.00%  (p=0.000 n=17+18)
Template-12                 64.9ms ± 3%    62.6ms ± 1%  -3.55%  (p=0.000 n=19+18)
TimeParse-12                 324ns ± 0%     328ns ± 1%  +1.25%  (p=0.000 n=18+18)
TimeFormat-12                345ns ± 0%     334ns ± 0%  -3.31%  (p=0.000 n=15+17)
[Geo mean]                  52.1µs         51.5µs       -1.00%

Change-Id: I13e74da3193a7f80794c654f944d1f0d60817049
Reviewed-on: https://go-review.googlesource.com/22632
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-30 16:49:54 +00:00
Austin Clements
d5e3d08b3a runtime: use morePointers and isPointer in more places
This makes this code better self-documenting and makes it easier to
find these places in the future.

Change-Id: I31dc5598ae67f937fb9ef26df92fd41d01e983c3
Reviewed-on: https://go-review.googlesource.com/22631
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-30 16:49:50 +00:00
Austin Clements
a5d3f7ece9 runtime: avoid conditional execution in morePointers and isPointer
heapBits.bits is carefully written to produce good machine code. Use
it in heapBits.morePointers and heapBits.isPointer to get good machine
code there, too.

Change-Id: I208c7d0d38697e7a22cad67f692162589b75f1e2
Reviewed-on: https://go-review.googlesource.com/22630
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-30 16:49:47 +00:00
Keith Randall
7a60a962b9 cmd/compile: ecx is reserved for PIC, don't let peep work on it
Fixes #15496

Change-Id: Ieb5be1caa4b1c23e23b20d56c1a0a619032a9f5d
Reviewed-on: https://go-review.googlesource.com/22652
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-30 05:59:54 +00:00
Michael Munday
58f52cbb79 runtime: fix cgocallback_gofunc on ppc64x
Fix issues introduced in 5f9a870.

Change-Id: Ia75945ef563956613bf88bbe57800a96455c265d
Reviewed-on: https://go-review.googlesource.com/22661
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-04-30 03:49:22 +00:00
Ian Lance Taylor
9fe572e509 runtime: fix cgocallback_gofunc argument passing on arm64
Change-Id: I4b34bcd5cde71ecfbb352b39c4231de6168cc7f3
Reviewed-on: https://go-review.googlesource.com/22651
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <munday@ca.ibm.com>
2016-04-29 23:10:52 +00:00
Matthew Dempsky
36b6c03827 root: remove dev.garbage file
Change-Id: I99b2ca52824341d986090f5c78ab4f396594bcdf
Reviewed-on: https://go-review.googlesource.com/22660
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-04-29 23:02:58 +00:00
Ian Lance Taylor
5f9a870bf1 cmd/cgo, runtime, runtime/cgo: use cgo context function
Add support for the context function set by runtime.SetCgoTraceback.
The context function was added in CL 17761, without support.
This CL is the support.

This CL has not been tested for real C code, as a working context
function for C code requires unwind support that does not seem to exist.
I wanted to get the CL out before the freeze.

I apologize for the length of this CL.  It's mostly plumbing, but
unfortunately the plumbing is processor-specific.

Change-Id: I8ce11a0de9b3dafcc29efd2649d776e93bff0e90
Reviewed-on: https://go-review.googlesource.com/22508
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-29 22:07:36 +00:00
Michael Munday
c717675c35 crypto/cipher, crypto/aes: add s390x implementation of AES-CTR
This commit adds the new 'ctrAble' interface to the crypto/cipher
package. The role of ctrAble is the same as gcmAble but for CTR
instead of GCM. It allows block ciphers to provide optimized CTR
implementations.

The primary benefit of adding CTR support to the s390x AES
implementation is that it allows us to encrypt the counter values
in bulk, giving the cipher message instruction a larger chunk of
data to work on per invocation.

The xorBytes assembly is necessary because xorBytes becomes a
bottleneck when CTR is done in this way. Hopefully it will be
possible to remove this once s390x has migrated to the ssa
backend.

name      old speed     new speed     delta
AESCTR1K  160MB/s ± 6%  867MB/s ± 0%  +442.42%  (p=0.000 n=9+10)

Change-Id: I1ae16b0ce0e2641d2bdc7d7eabc94dd35f6e9318
Reviewed-on: https://go-review.googlesource.com/22195
Reviewed-by: Adam Langley <agl@golang.org>
2016-04-29 21:17:31 +00:00
Michael Munday
2f8475648a crypto/cipher, crypto/aes: add s390x implementation of AES-CBC
This commit adds the cbcEncAble and cbcDecAble interfaces that
can be implemented by block ciphers that support an optimized
implementation of CBC. This is similar to what is done for GCM
with the gcmAble interface.

The cbcEncAble, cbcDecAble and gcmAble interfaces all now have
tests to ensure they are detected correctly in the cipher
package.

name             old speed     new speed      delta
AESCBCEncrypt1K  152MB/s ± 1%  1362MB/s ± 0%  +795.59%   (p=0.000 n=10+9)
AESCBCDecrypt1K  143MB/s ± 1%  1362MB/s ± 0%  +853.00%   (p=0.000 n=10+9)

Change-Id: I715f686ab3686b189a3dac02f86001178fa60580
Reviewed-on: https://go-review.googlesource.com/22523
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
2016-04-29 21:17:09 +00:00
Keith Randall
cd956576ae cmd/compile: make vet happy with ssa code
Fixes #15488

Change-Id: I054eb1e1c859de315e3cdbdef5428682bce693fd
Reviewed-on: https://go-review.googlesource.com/22609
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-04-29 18:49:23 +00:00
Rick Hudson
56b5491262 Merge remote-tracking branch 'origin/dev.garbage'
This commit moves the GC from free list allocation to
bit mark allocation. Instead of using the bitmaps
generated during the mark phases to generate free
list and then using the free lists for allocation we
allocate directly from the bitmaps.

The change in the garbage benchmark

name              old time/op  new time/op  delta
XBenchGarbage-12  2.22ms ± 1%  2.13ms ± 1%  -3.90%  (p=0.000 n=18+18)

Change-Id: I17f57233336f0ca5ef5404c3be4ecb443ab622aa
2016-04-29 13:56:44 -04:00
Rick Hudson
e9eaa181fc [dev.garbage] runtime: simplify nextFreeFast so it is inlined
nextFreeFast is currently not inlined by the compiler due
to its size and complexity. This CL simplifies
nextFreeFast by letting the slow path handle (nextFree)
handle a corner cases.

Change-Id: Ia9c5d1a7912bcb4bec072f5fd240f0e0bafb20e4
Reviewed-on: https://go-review.googlesource.com/22598
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
2016-04-29 16:47:11 +00:00
David Chase
d8d33514f9 cmd/compile: Move divconst_test out of test/bench/go1
This is necessary to avoid disrupting the go1 suite and gives
us a place to put other tests of basic compiler function and
correctness.

Change-Id: I36933819ff2bfe6a2121fff2be9a98efd2123d9a
Reviewed-on: https://go-review.googlesource.com/22597
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-29 16:20:18 +00:00
Keith Randall
fa9435cdff cmd/compile: clean up rewrite rules
Break really long lines.
Add spacing to line up columns.

In AMD64, put all the optimization rules after all the
lowering rules.

Change-Id: I45cc7368bf278416e67f89e74358db1bd4326a93
Reviewed-on: https://go-review.googlesource.com/22470
Reviewed-by: David Chase <drchase@google.com>
2016-04-29 16:16:32 +00:00
Austin Clements
b3579c095e [dev.garbage] runtime: revive sweep fast path
sweep used to skip mcental.freeSpan (and its locking) if it didn't
find any new free objects. We lost that optimization when the
freed-object counting changed in dad83f7 to count total free objects
instead of newly freed objects.

The previous commit brings back counting of newly freed objects, so we
can easily revive this optimization by checking that count (like we
used to) instead of the total free objects count.

Change-Id: I43658707a1c61674d0366124d5976b00d98741a9
Reviewed-on: https://go-review.googlesource.com/22596
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>
2016-04-29 15:25:28 +00:00
Austin Clements
d97625ae9e [dev.garbage] runtime: fix nfree accounting
Commit 8dda1c4 changed the meaning of "nfree" in sweep from the number
of newly freed objects to the total number of free objects in the
span, but didn't update where sweep added nfree to c.local_nsmallfree.
Hence, we're over-accounting the number of frees. This is causing
TestArrayHash to fail with "too many allocs NNN - hash not balanced".

Fix this by computing the number of newly freed objects and adding
that to c.local_nsmallfree, so it behaves like it used to. Computing
this requires a small tweak to mallocgc: apparently we've never set
s.allocCount when allocating a large object; fix this by setting it to
1 so sweep doesn't get confused.

Change-Id: I31902ffd310110da4ffd807c5c06f1117b872dc8
Reviewed-on: https://go-review.googlesource.com/22595
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
2016-04-29 15:25:26 +00:00
Austin Clements
6d11490539 [dev.garbage] runtime: fix allocfreetrace
We broke tracing of freed objects in GODEBUG=allocfreetrace=1 mode
when we removed the sweep over the mark bitmap. Fix it by
re-introducing the sweep over the bitmap specifically if we're in
allocfreetrace mode. This doesn't have to be even remotely efficient,
since the overhead of allocfreetrace is huge anyway, so we can keep
the code for this down to just a few lines.

Change-Id: I9e176b3b04c73608a0ea3068d5d0cd30760ebd40
Reviewed-on: https://go-review.googlesource.com/22592
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
2016-04-29 15:08:21 +00:00
Austin Clements
38f674687a [dev.garbage] runtime: reintroduce no-zeroing optimization
Currently we always zero objects when we allocate them. We used to
have an optimization that would not zero objects that had not been
allocated since the whole span was last zeroed (either by getting it
from the system or by getting it from the heap, which does a bulk
zero), but this depended on the sweeper clobbering the first two words
of each object. Hence, we lost this optimization when the bitmap
sweeper went away.

Re-introduce this optimization using a different mechanism. Each span
already keeps a flag indicating that it just came from the OS or was
just bulk zeroed by the mheap. We can simply use this flag to know
when we don't need to zero an object. This is slightly less efficient
than the old optimization: if a span gets allocated and partially
used, then GC happens and the span gets returned to the mcentral, then
the span gets re-acquired, the old optimization knew that it only had
to re-zero the objects that had been reclaimed, whereas this
optimization will re-zero everything. However, in this case, you're
already paying for the garbage collection, and you've only wasted one
zeroing of the span, so in practice there seems to be little
difference. (If we did want to revive the full optimization, each span
could keep track of a frontier beyond which all free slots are zeroed.
I prototyped this and it didn't obvious do any better than the much
simpler approach in this commit.)

This significantly improves BinaryTree17, which is allocation-heavy
(and runs first, so most pages are already zeroed), and slightly
improves everything else.

name              old time/op  new time/op  delta
XBenchGarbage-12  2.15ms ± 1%  2.14ms ± 1%  -0.80%  (p=0.000 n=17+17)

name                      old time/op    new time/op    delta
BinaryTree17-12              2.71s ± 1%     2.56s ± 1%  -5.73%        (p=0.000 n=18+19)
DivconstI64-12              1.70ns ± 1%    1.70ns ± 1%    ~           (p=0.562 n=18+18)
DivconstU64-12              1.74ns ± 2%    1.74ns ± 1%    ~           (p=0.394 n=20+20)
DivconstI32-12              1.74ns ± 0%    1.74ns ± 0%    ~     (all samples are equal)
DivconstU32-12              1.66ns ± 1%    1.66ns ± 0%    ~           (p=0.516 n=15+16)
DivconstI16-12              1.84ns ± 0%    1.84ns ± 0%    ~     (all samples are equal)
DivconstU16-12              1.82ns ± 0%    1.82ns ± 0%    ~     (all samples are equal)
DivconstI8-12               1.79ns ± 0%    1.79ns ± 0%    ~     (all samples are equal)
DivconstU8-12               1.60ns ± 0%    1.60ns ± 1%    ~           (p=0.603 n=17+19)
Fannkuch11-12                2.11s ± 1%     2.11s ± 0%    ~           (p=0.333 n=16+19)
FmtFprintfEmpty-12          45.1ns ± 4%    45.4ns ± 5%    ~           (p=0.111 n=20+20)
FmtFprintfString-12          134ns ± 0%     129ns ± 0%  -3.45%        (p=0.000 n=18+16)
FmtFprintfInt-12             131ns ± 1%     129ns ± 1%  -1.54%        (p=0.000 n=16+18)
FmtFprintfIntInt-12          205ns ± 2%     203ns ± 0%  -0.56%        (p=0.014 n=20+18)
FmtFprintfPrefixedInt-12     200ns ± 2%     197ns ± 1%  -1.48%        (p=0.000 n=20+18)
FmtFprintfFloat-12           256ns ± 1%     256ns ± 0%  -0.21%        (p=0.008 n=18+20)
FmtManyArgs-12               805ns ± 0%     804ns ± 0%  -0.19%        (p=0.001 n=18+18)
GobDecode-12                7.21ms ± 1%    7.14ms ± 1%  -0.92%        (p=0.000 n=19+20)
GobEncode-12                5.88ms ± 1%    5.88ms ± 1%    ~           (p=0.641 n=18+19)
Gzip-12                      218ms ± 1%     218ms ± 1%    ~           (p=0.271 n=19+18)
Gunzip-12                   37.1ms ± 0%    36.9ms ± 0%  -0.29%        (p=0.000 n=18+17)
HTTPClientServer-12         78.1µs ± 2%    77.4µs ± 2%    ~           (p=0.070 n=19+19)
JSONEncode-12               15.5ms ± 1%    15.5ms ± 0%    ~           (p=0.063 n=20+18)
JSONDecode-12               56.1ms ± 0%    55.4ms ± 1%  -1.18%        (p=0.000 n=19+18)
Mandelbrot200-12            4.05ms ± 0%    4.06ms ± 0%  +0.29%        (p=0.001 n=18+18)
GoParse-12                  3.28ms ± 1%    3.21ms ± 1%  -2.30%        (p=0.000 n=20+20)
RegexpMatchEasy0_32-12      69.4ns ± 2%    69.3ns ± 1%    ~           (p=0.205 n=18+16)
RegexpMatchEasy0_1K-12       239ns ± 0%     239ns ± 0%    ~     (all samples are equal)
RegexpMatchEasy1_32-12      69.4ns ± 1%    69.4ns ± 1%    ~           (p=0.620 n=15+18)
RegexpMatchEasy1_1K-12       370ns ± 1%     369ns ± 2%    ~           (p=0.088 n=20+20)
RegexpMatchMedium_32-12      108ns ± 0%     108ns ± 0%    ~     (all samples are equal)
RegexpMatchMedium_1K-12     33.6µs ± 3%    33.5µs ± 3%    ~           (p=0.718 n=20+20)
RegexpMatchHard_32-12       1.68µs ± 1%    1.67µs ± 2%    ~           (p=0.316 n=20+20)
RegexpMatchHard_1K-12       50.5µs ± 3%    50.4µs ± 3%    ~           (p=0.659 n=20+20)
Revcomp-12                   381ms ± 1%     381ms ± 1%    ~           (p=0.916 n=19+18)
Template-12                 66.5ms ± 1%    65.8ms ± 2%  -1.08%        (p=0.000 n=20+20)
TimeParse-12                 317ns ± 0%     319ns ± 0%  +0.48%        (p=0.000 n=19+12)
TimeFormat-12                338ns ± 0%     338ns ± 0%    ~           (p=0.124 n=19+18)
[Geo mean]                  5.99µs         5.96µs       -0.54%

Change-Id: I638ffd9d9f178835bbfa499bac20bd7224f1a907
Reviewed-on: https://go-review.googlesource.com/22591
Reviewed-by: Rick Hudson <rlh@golang.org>
2016-04-29 15:08:13 +00:00
Nigel Tao
1fb4e4de26 compress/flate: use a constant hash table size for Best Speed.
This makes compress/flate's version of Snappy diverge from the upstream
golang/snappy version, but the latter has a goal of matching C++ snappy
output byte-for-byte. Both C++ and the asm version of golang/snappy can
use a smaller N for the O(N) zero-initialization of the hash table when
the input is small, even if the pure Go golang/snappy algorithm cannot:
"var table [tableSize]uint16" zeroes all tableSize elements.

For this package, we don't have the match-C++-snappy goal, so we can use
a different (constant) hash table size.

This is a small win, in terms of throughput and output size, but it also
enables us to re-use the (constant size) hash table between
encodeBestSpeed calls, avoiding the cost of zero-initializing the hash
table altogether. This will be implemented in follow-up commits.

This package's benchmarks:
name                    old speed      new speed      delta
EncodeDigitsSpeed1e4-8  72.8MB/s ± 1%  73.5MB/s ± 1%  +0.86%  (p=0.000 n=10+10)
EncodeDigitsSpeed1e5-8  77.5MB/s ± 1%  78.0MB/s ± 0%  +0.69%  (p=0.000 n=10+10)
EncodeDigitsSpeed1e6-8  82.0MB/s ± 1%  82.7MB/s ± 1%  +0.85%   (p=0.000 n=10+9)
EncodeTwainSpeed1e4-8   65.1MB/s ± 1%  65.6MB/s ± 0%  +0.78%   (p=0.000 n=10+9)
EncodeTwainSpeed1e5-8   80.0MB/s ± 0%  80.6MB/s ± 1%  +0.66%   (p=0.000 n=9+10)
EncodeTwainSpeed1e6-8   81.6MB/s ± 1%  82.1MB/s ± 1%  +0.55%  (p=0.017 n=10+10)

Input size in bytes, output size (and time taken) before and after on
some larger files:
1073741824   57269781 (  3183ms)   57269781 (  3177ms) adresser.001
1000000000  391052000 ( 11071ms)  391051996 ( 11067ms) enwik9
1911399616  378679516 ( 13450ms)  378679514 ( 13079ms) gob-stream
8558382592 3972329193 ( 99962ms) 3972329193 ( 91290ms) rawstudio-mint14.tar
 200000000  200015265 (   776ms)  200015265 (   774ms) sharnd.out

Thanks to Klaus Post for the original suggestion on cl/21021.

Change-Id: Ia4c63a8d1b92c67e1765ec5c3c8c69d289d9a6ce
Reviewed-on: https://go-review.googlesource.com/22604
Reviewed-by: Russ Cox <rsc@golang.org>
2016-04-29 14:00:39 +00:00
Dave Cheney
5edcff0134 cmd/compile/internal/gc: bv.go cleanup
Drive by gardening of bv.go.

- Unexport the Bvec type, it is not used outside internal/gc.
  (machine translated with gofmt -r)
- Removed unused constants and functions.
  (driven by cmd/unused)

Change-Id: I3433758ad4e62439f802f4b0ed306e67336d9aba
Reviewed-on: https://go-review.googlesource.com/22602
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-29 13:22:15 +00:00
Cherry Zhang
94e523cb52 misc/cgo/testcarchive: fix C include path for darwin/arm
After CL 22461, c-archive build on darwin/arm is by default compiled
with -shared and installed in pkg/darwin_arm_shared.

Fix build (2nd time...)

Change-Id: Ia2bb09bb6e1ebc9bc74f7570dd80c81d05eaf744
Reviewed-on: https://go-review.googlesource.com/22534
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-29 12:21:27 +00:00
Nigel Tao
d8b7bd6a1f compress/flate: replace "Best Speed" with specialized version
This encoding algorithm, which prioritizes speed over output size, is
based on Snappy's LZ77-style encoder: github.com/golang/snappy

This commit keeps the diff between this package's encodeBestSpeed
function and and Snappy's encodeBlock function as small as possible (see
the diff below). Follow-up commits will improve this package's
performance and output size.

This package's speed benchmarks:

name                    old speed      new speed      delta
EncodeDigitsSpeed1e4-8  40.7MB/s ± 0%  73.0MB/s ± 0%   +79.18%  (p=0.008 n=5+5)
EncodeDigitsSpeed1e5-8  33.0MB/s ± 0%  77.3MB/s ± 1%  +134.04%  (p=0.008 n=5+5)
EncodeDigitsSpeed1e6-8  32.1MB/s ± 0%  82.1MB/s ± 0%  +156.18%  (p=0.008 n=5+5)
EncodeTwainSpeed1e4-8   42.1MB/s ± 0%  65.0MB/s ± 0%   +54.61%  (p=0.008 n=5+5)
EncodeTwainSpeed1e5-8   46.3MB/s ± 0%  80.0MB/s ± 0%   +72.81%  (p=0.008 n=5+5)
EncodeTwainSpeed1e6-8   47.3MB/s ± 0%  81.7MB/s ± 0%   +72.86%  (p=0.008 n=5+5)

Here's the milliseconds taken, before and after this commit, to compress
a number of test files:

Go's src/compress/testdata files:

     4          1 e.txt
     8          4 Mark.Twain-Tom.Sawyer.txt

github.com/golang/snappy's benchmark files:

     3          1 alice29.txt
    12          3 asyoulik.txt
     6          1 fireworks.jpeg
     1          1 geo.protodata
     1          0 html
     2          2 html_x_4
     6          3 kppkn.gtb
    11          4 lcet10.txt
     5          1 paper-100k.pdf
    14          6 plrabn12.txt
    17          6 urls.10K

Larger files linked to from
https://docs.google.com/spreadsheets/d/1VLxi-ac0BAtf735HyH3c1xRulbkYYUkFecKdLPH7NIQ/edit#gid=166102500

  2409       3182 adresser.001
 16757      11027 enwik9
 13764      12946 gob-stream
153978      74317 rawstudio-mint14.tar
  4371        770 sharnd.out

Output size is larger. In the table below, the first column is the input
size, the second column is the output size prior to this commit, the
third column is the output size after this commit.

    100003      47707      50006 e.txt
    387851     172707     182930 Mark.Twain-Tom.Sawyer.txt
    152089      62457      66705 alice29.txt
    125179      54503      57274 asyoulik.txt
    123093     122827     123108 fireworks.jpeg
    118588      18574      20558 geo.protodata
    102400      16601      17305 html
    409600      65506      70313 html_x_4
    184320      49007      50944 kppkn.gtb
    426754     166957     179355 lcet10.txt
    102400      82126      84937 paper-100k.pdf
    481861     218617     231988 plrabn12.txt
    702087     241774     258020 urls.10K
1073741824   43074110   57269781 adresser.001
1000000000  365772256  391052000 enwik9
1911399616  340364558  378679516 gob-stream
8558382592 3807229562 3972329193 rawstudio-mint14.tar
 200000000  200061040  200015265 sharnd.out

The diff between github.com/golang/snappy's encodeBlock function and
this commit's encodeBestSpeed function:

1c1,7
< func encodeBlock(dst, src []byte) (d int) {
---
> func encodeBestSpeed(dst []token, src []byte) []token {
> 	// This check isn't in the Snappy implementation, but there, the caller
> 	// instead of the callee handles this case.
> 	if len(src) < minNonLiteralBlockSize {
> 		return emitLiteral(dst, src)
> 	}
>
4c10
< 	// and len(src) <= maxBlockSize and maxBlockSize == 65536.
---
> 	// and len(src) <= maxStoreBlockSize and maxStoreBlockSize == 65535.
65c71
< 			if load32(src, s) == load32(src, candidate) {
---
> 			if s-candidate < maxOffset && load32(src, s) == load32(src, candidate) {
73c79
< 		d += emitLiteral(dst[d:], src[nextEmit:s])
---
> 		dst = emitLiteral(dst, src[nextEmit:s])
90c96
< 			// This is an inlined version of:
---
> 			// This is an inlined version of Snappy's:
93c99,103
< 			for i := candidate + 4; s < len(src) && src[i] == src[s]; i, s = i+1, s+1 {
---
> 			s1 := base + maxMatchLength
> 			if s1 > len(src) {
> 				s1 = len(src)
> 			}
> 			for i := candidate + 4; s < s1 && src[i] == src[s]; i, s = i+1, s+1 {
96c106,107
< 			d += emitCopy(dst[d:], base-candidate, s-base)
---
> 			// matchToken is flate's equivalent of Snappy's emitCopy.
> 			dst = append(dst, matchToken(uint32(s-base-3), uint32(base-candidate-minOffsetSize)))
114c125
< 			if uint32(x>>8) != load32(src, candidate) {
---
> 			if s-candidate >= maxOffset || uint32(x>>8) != load32(src, candidate) {
124c135
< 		d += emitLiteral(dst[d:], src[nextEmit:])
---
> 		dst = emitLiteral(dst, src[nextEmit:])
126c137
< 	return d
---
> 	return dst

This change is based on https://go-review.googlesource.com/#/c/21021/ by
Klaus Post, but it is a separate changelist as cl/21021 seems to have
stalled in code review, and the Go 1.7 feature freeze approaches.

Golang-dev discussion:
https://groups.google.com/d/topic/golang-dev/XYgHX9p8IOk/discussion and
of course cl/21021.

Change-Id: Ib662439417b3bd0b61c2977c12c658db3e44d164
Reviewed-on: https://go-review.googlesource.com/22370
Reviewed-by: Russ Cox <rsc@golang.org>
2016-04-29 06:58:42 +00:00