Previously, we used to write the "hangup" message to
the TCP connection control file to be able to close
a connection, while waking up the readers.

The "hangup" message closes the TCP connection with a
RST message. This is a problem when closing a connection
consecutively to a write, because the reader may not have
time to acknowledge the message before the connection is
closed, resulting in loss of data.

We use a "close" message, newly implemented in the Plan 9
kernel to be able to close a TCP connection gracefully with a FIN.

Updates #15464.

Change-Id: I2050cc72fdf7a350bc6c9128bae7d14af11e599c
Reviewed-on: https://go-review.googlesource.com/31271
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #16502.

Change-Id: Id8e117a724d73cd51844c06d47bbeba61f8dc827
Reviewed-on: https://go-review.googlesource.com/31324Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>

Fixes #16404.

Change-Id: Iabaeeef3eff2fff6e5ed2d6bc9ef9c2f6d1cb5e7
Reviewed-on: https://go-review.googlesource.com/31332Reviewed-by: Ian Lance Taylor <iant@golang.org>

The comments added for Go 1.7 are very close.
Make explicit that they only apply if the timer is
not known to have expired already.

Fixes #14038.

Change-Id: I6a38be7b2015e1571fc477e18444a8cee38aab29
Reviewed-on: https://go-review.googlesource.com/31350Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #14139.

Change-Id: I6d2181720c38582b3d2160e94c7593a6cb4fc60f
Reviewed-on: https://go-review.googlesource.com/31321Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

cmd.StdinPipe returns an io.WriteCloser.
It's reasonable to expect the caller not to call Write and Close simultaneously,
but there is an implicit Close in cmd.Wait that's not obvious.
We already synchronize the implicit Close in cmd.Wait against
any explicit Close from the caller. Also synchronize that implicit
Close against any explicit Write from the caller.

Fixes #9307.

Change-Id: I8561e9369d6e5ac88dfbca1175549f6dfa04b8ac
Reviewed-on: https://go-review.googlesource.com/31148Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

In the zero Time, the (not user visible) nil *Location indicates UTC.
In the result of t.UTC() and other ways to create times in specific
zones, UTC is indicated by a non-nil *Location, specifically &utcLoc.
This creates a representation ambiguity exposed by comparison with ==
or reflect.DeepEqual or the like.

Change time.Time representation to use only nil, never &utcLoc,
to represent UTC. This eliminates the ambiguity.

Fixes #15716.

Change-Id: I7dcc2c20ce6b073e1daae323d3e49d17d1d52802
Reviewed-on: https://go-review.googlesource.com/31144Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This change documents that the InterfaceAddrs function is less usable on
multi-homed IP nodes because of the lack of network interface
identification information.

Also updates documentation on exposed network interface API.

Fixes #14518.

Change-Id: I5e86606f8019ab475eb5d385bd797b052cba395d
Reviewed-on: https://go-review.googlesource.com/31371Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Creates a ColumnType structure that can be extended in to future.
Allow drivers to implement what makes sense for the database.

Fixes #16652

Change-Id: Ieb1fd64eac1460107b1d3474eba5201fa300a4ec
Reviewed-on: https://go-review.googlesource.com/29961
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Check for and call the special printing and format methods such as String
at printing depth 0 when printing the concrete value of a reflect.Value.

Fixes: #16015

Change-Id: I23bd2927255b60924e5558321e98dd4a95e11c4c
Reviewed-on: https://go-review.googlesource.com/30753Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Martin Möhrmann <martisch@uos.de>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This CL changes how the http1 Server reads from the client.

The goal of this change is to make the Request.Context given to Server
Handlers become done when the TCP connection dies (has seen any read
or write error). I didn't finish that for Go 1.7 when Context was
added to http package.

We can't notice the peer disconnect unless we're blocked in a Read
call, though, and previously we were only doing read calls as needed,
when reading the body or the next request. One exception to that was
the old pre-context CloseNotifier mechanism.

The implementation of CloseNotifier has always been tricky. The past
few releases have contained the complexity and moved the
reading-from-TCP-conn logic into the "connReader" type. This CL
extends connReader to make sure that it's always blocked in a Read
call, at least once the request body has been fully consumed.

In the process, this deletes all the old CloseNotify code and unifies
it with the context cancelation code. The two notification mechanisms
are nearly identical, except the CloseNotify path always notifies on
the arrival of pipelined HTTP/1 requests. We might want to change that
in a subsequent commit. I left a TODO for that. For now there's no
change in behavior except that the context now cancels as it was
supposed to.

As a bonus that fell out for free, a Handler can now use CloseNotifier
and Hijack together in the same request now.

Fixes #15224 (make http1 Server always in a Read, like http2)
Fixes #15927 (cancel context when underlying connection closes)
Updates #9763 (CloseNotifier + Hijack)

Change-Id: I972cf6ecbab7f1230efe8cc971e89f8e6e56196b
Reviewed-on: https://go-review.googlesource.com/31173
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This change enables the ChaCha20-Poly1305 cipher suites by default. This
changes the default ClientHello and thus requires updating all the
tests.

Change-Id: I6683a2647caaff4a11f9e932babb6f07912cad94
Reviewed-on: https://go-review.googlesource.com/30958
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

GetConfigForClient allows the tls.Config to be updated on a per-client
basis.

Fixes #16066.
Fixes #15707.
Fixes #15699.

Change-Id: I2c675a443d557f969441226729f98502b38901ea
Reviewed-on: https://go-review.googlesource.com/30790
Run-TryBot: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #13737.

Change-Id: Ib655dbf06f44709f687f8a2410c80f31e4075f13
Reviewed-on: https://go-review.googlesource.com/31322
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #16460.

Change-Id: Ie9d5f725d2d7e8210ab6f7604a5a05fc49f707de
Reviewed-on: https://go-review.googlesource.com/31331
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

It's the same as %#x not %x.

Just a documentation change; tests already cover it.

Fixes #17322

Change-Id: Ia9db229f781f9042ac5c0bb824e3d7a26fb74ec5
Reviewed-on: https://go-review.googlesource.com/31254Reviewed-by: Russ Cox <rsc@golang.org>

In addition to the DecimalConversion benchmark, that exercises the
String method of the internal decimal type on a range of small shifts,
add a few benchmarks for the big.Float String method. They can be used
to obtain more realistic data on the real-world performance of
big.Float printing.

Change-Id: I7ada324e7603cb1ce7492ccaf3382db0096223ba
Reviewed-on: https://go-review.googlesource.com/31275Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #17030.

Change-Id: Ic7f237ac7553ae0176929056e64b01667ed59066
Reviewed-on: https://go-review.googlesource.com/31351
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This will cause godoc to correctly render these docs,
since go/doc.ToHTML requires no punctuation for headings.

Change-Id: Ic95245147d3585f2ccc59d4424fcab17d2a5617b
Reviewed-on: https://go-review.googlesource.com/31319Reviewed-by: Rob Pike <r@golang.org>

Fixes #17461

Change-Id: I9954f6ae46c7e15560d7460841be8f2bc37233a9
Reviewed-on: https://go-review.googlesource.com/31121Reviewed-by: Adam Langley <agl@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The comments about pcln functions are obsolete since those functions
now live in cmd/internal/obj. The copyright header is redundant with
the existing one at the top of the file.

Change-Id: I568fd3d259253a0d8eb3b0a157d008df1b5de106
Reviewed-on: https://go-review.googlesource.com/31315Reviewed-by: Ian Lance Taylor <iant@golang.org>

all.bash passes with -debugtramp=2 (except the unavoidable
disassembly test as we change instructions). And successfully
build k8s.io/kubernetes/cmd/hyperkube in both internal linking
and external linking mode.

Fixes #17028.

Change-Id: Ic8fac6a394488155c5eba9215662db1c1086e24b
Reviewed-on: https://go-review.googlesource.com/31143Reviewed-by: David Chase <drchase@google.com>

Although an AEAD, in general, can be used concurrently in both the seal
and open directions, TLS is easier. Since the transport keys are
different for different directions in TLS, an AEAD will only ever be
used in one direction. Thus we don't need separate buffers for seal and
open because they can never happen concurrently.

Also, fix the nonce size to twelve bytes since the fixed-prefix
construction for AEADs is superseded and will never be used for anything
else now.

Change-Id: Ibbf6c6b1da0e639f4ee0e3604410945dc7dcbb46
Reviewed-on: https://go-review.googlesource.com/30959
Run-TryBot: Adam Langley <agl@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This reverts commit c6185aa6. That
commit seems to be causing flaky failures on the builders. See
discussion on the original thread: https://golang.org/cl/25159.

Change-Id: I26e72d962d4efdcee28a0bc61a53f246b046df77
Reviewed-on: https://go-review.googlesource.com/31316
Run-TryBot: Adam Langley <agl@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

This change adds support for the ChaCha20-Poly1305 AEAD to crypto/tls,
as specified in https://tools.ietf.org/html/rfc7905.

Fixes #15499.

Change-Id: Iaa689be90e03f208c40b574eca399e56f3c7ecf1
Reviewed-on: https://go-review.googlesource.com/30957
Run-TryBot: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This change updates the vendored chacha20poly1305 package to match
revision 14f9af67c679edd414f72f13d67c917447113df2 of x/crypto.

Change-Id: I05a4ba86578b0f0cdb1ed7dd50fee3b38bb48cf5
Reviewed-on: https://go-review.googlesource.com/31312
Run-TryBot: Adam Langley <agl@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I34b3650ee9512879ff7528336813a7850c46ea90
Reviewed-on: https://go-review.googlesource.com/31311Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This reverts commit 395d36a6.

Appears to be responsible for builder failures.

Change-Id: Ic6c6307f662767e529060b88704a9f074785d99e
Reviewed-on: https://go-review.googlesource.com/31310
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

This is needed for some of the more complex primality tests
(to filter out exact squares), and while the code is simple the
boundary conditions are not obvious, so it seems worth having
in the library.

Change-Id: Ica994a6b6c1e412a6f6d9c3cf823f9b653c6bcbd
Reviewed-on: https://go-review.googlesource.com/30706
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

Correcting a line in asm_ppc64x.s in the cmpbodyLE function
that originally was R14 but accidentally changed to R4.

Fixes #17488

Change-Id: Id4ca6fb2e0cd81251557a0627e17b5e734c39e01
Reviewed-on: https://go-review.googlesource.com/31266Reviewed-by: Michael Munday <munday@ca.ibm.com>
Run-TryBot: Michael Munday <munday@ca.ibm.com>

Adds the new canMergeLoad function which can be used by rules to
decide whether a load can be merged into an operation. The function
ensures that the merge will not reorder the load relative to memory
operations (for example, stores) in such a way that the block can no
longer be scheduled.

This new function enables transformations such as:

MOVD 0(R1), R2
ADD  R2, R3

to:

ADD  0(R1), R3

The two-operand form of the following instructions can now read a
single memory operand:

 - ADD
 - ADDC
 - ADDW
 - MULLD
 - MULLW
 - SUB
 - SUBC
 - SUBE
 - SUBW
 - AND
 - ANDW
 - OR
 - ORW
 - XOR
 - XORW

Improves SHA3 performance by 6-8%.

Updates #15054.

Change-Id: Ibcb9122126cd1a26f2c01c0dfdbb42fe5e7b5b94
Reviewed-on: https://go-review.googlesource.com/29272
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Inspired by Alberto Donizetti's observations in
https://go-review.googlesource.com/#/c/30099/.

name                 old time/op  new time/op  delta
DecimalConversion-8   138µs ± 1%   136µs ± 2%  -1.85%  (p=0.000 n=10+10)

10 runs each, measured on a Mac Mini, 2.3 GHz Intel Core i7.

Performance improvements varied between -1.25% to -4.4%; -1.85% is
about in the middle of the observed improvement. The generated code
is slightly shorter in the inner loops of the conversion code.

Change-Id: I10fb3b2843da527691c39ad5e5e5bd37ed63e2fa
Reviewed-on: https://go-review.googlesource.com/31250Reviewed-by: Alan Donovan <adonovan@google.com>

GC assists retry if preempted or if they fail to park. However, on the
retry path they currently use stale statistics. In particular, the
retry can use "debtBytes", but debtBytes isn't updated when the debt
changes (since other than retries it is only used once). Also, though
less of a problem, the if the assist ratio has changed while the
assist was blocked, the retry will still use the old assist ratio.

Fix all of this by simply making the retry jump back to where we
compute these statistics, rather than just after.

Change-Id: I2ed8b4f0fc9f008ff060aa926f4334b662ac7d3f
Reviewed-on: https://go-review.googlesource.com/30701Reviewed-by: Rick Hudson <rlh@golang.org>

This puts all of the assist queue-related code together and makes it
easier to modify how the assist queue works.

Change-Id: Id54e06702bdd5a5dd3fef2ce2c14cd7ca215303c
Reviewed-on: https://go-review.googlesource.com/30700Reviewed-by: Rick Hudson <rlh@golang.org>

It's pretty simple.  For:
  e = (interface{})(i)
Do:
  tmp = i.itab
  if tmp != nil {
    tmp = tmp.typ_ // load type from itab
  }
  e = eface{tmp, i.data}

It is smaller and faster than calling the runtime.

Change-Id: I0ad27f62f4ec0b6cd53bc8530e4da0eae3e67a6c
Reviewed-on: https://go-review.googlesource.com/31260
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

getArgInfo for reflect.makeFuncStub and reflect.methodValueCall is
necessarily special. These have dynamically determined argument maps
that are stored in their context (that is, their *funcval). These
functions are written to store this context at 0(SP) when called, and
getArgInfo retrieves it from there.

This technique works if getArgInfo is passed an active call frame for
one of these functions. However, getArgInfo is also used in
tracebackdefers, where the "call" is not a true call with an active
stack frame, but a deferred call. In this situation, getArgInfo
currently crashes because tracebackdefers passes a frame with sp set
to 0. However, the entire approach used by getArgInfo is flawed in
this situation because the wrapper has not actually executed, and
hence hasn't saved this metadata to any stack frame.

In the defer case, we know the *funcval from the _defer itself, so we
can fix this by teaching getArgInfo to use the *funcval context
directly when its available, and otherwise get it from the active call
frame.

While we're here, this commit simplifies getArgInfo a bit by making it
play more nicely with the type system. Rather than decoding the
*reflect.methodValue that is the wrapper's context as a *[2]uintptr,
just write out a copy of the reflect.methodValue type in the runtime.

Fixes #16331. Fixes #17471.

Change-Id: I81db4d985179b4a81c68c490cceeccbfc675456a
Reviewed-on: https://go-review.googlesource.com/31138
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

If morestack runs on the g0 or gsignal stack, it currently performs
some abort operation that typically produces a signal (e.g., it does
an INT $3 on x86). This is useful if you're running in a debugger, but
if you're not, the runtime tries to trap this signal, which is likely
to send the program into a deeper spiral of collapse and lead to very
confusing diagnostic output.

Help out people trying to debug without a debugger by making morestack
print an informative message before blowing up.

Change-Id: I2814c64509b137bfe20a00091d8551d18c2c4749
Reviewed-on: https://go-review.googlesource.com/31133
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Per discussion on #12808, it's a bit odd that if you do

	CGO_ENABLED=0 ./make.bash

then you get a toolchain that still tries to use cgo.
So make the CGO_ENABLED setting propagate into
the resulting toolchain as the default setting for that
environment variable, like we do with other variables
like CC and GOROOT.

No reasonable way to test automatically, but I did
test by hand that after the above command, 'go env'
shows CGO_ENABLED=0; before it showed CGO_ENABLED=1.

Fixes #12808.

Change-Id: I26a2fa6cc00e73bde8af7469270b27293392ed71
Reviewed-on: https://go-review.googlesource.com/31141
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This improves the performance for byte.Compare by rewriting
the cmpbody function in runtime/asm_ppc64x.s.  The previous code
had a simple loop which loaded a pair of bytes and compared them,
which is inefficient for long buffers.  The updated function checks
for 8 or 32 byte chunks and then loads and compares double words where
possible.

Because the byte.Compare result indicates greater or less than,
the doubleword loads must take endianness into account, using a
byte reversed load in the little endian case.

Fixes #17433

benchmark                                   old ns/op     new ns/op     delta
BenchmarkBytesCompare/8-16                  13.6          7.16          -47.35%
BenchmarkBytesCompare/16-16                 25.7          7.83          -69.53%
BenchmarkBytesCompare/32-16                 38.1          7.78          -79.58%
BenchmarkBytesCompare/64-16                 63.0          10.6          -83.17%
BenchmarkBytesCompare/128-16                112           13.0          -88.39%
BenchmarkBytesCompare/256-16                211           28.1          -86.68%
BenchmarkBytesCompare/512-16                410           38.6          -90.59%
BenchmarkBytesCompare/1024-16               807           60.2          -92.54%
BenchmarkBytesCompare/2048-16               1601          103           -93.57%

Change-Id: I121acc74fcd27c430797647b8d682eb0607c63eb
Reviewed-on: https://go-review.googlesource.com/30949Reviewed-by: David Chase <drchase@google.com>

To match the language spec, strconv.Unquote needs to strip carriage
returns from the raw string.

Also fixes TestUnquote to not be a noop.

Fixes #15997

Change-Id: I2456f50f2ad3830f37e545f4f6774ced9fe609d7
Reviewed-on: https://go-review.googlesource.com/31210Reviewed-by: Robert Griesemer <gri@golang.org>