The flate library guarantees that the Reader will never read more
bytes than is necessary. This way, the underlying io.Reader will
be left exactly after the last byte of the DEFLATE stream.
Formats like gzip depend on this behavior being true.

As such, inflate conservatively reads the minimum symbol length in
huffSym leading to many individual calls to moreBits. However, if we
take advantage of the fact that every block *must* end with the EOB
symbol, we can choose to read the length of the EOB symbol.
Since the EOB symbol is also the most rare symbol (occuring exactly
once) in a block, we can hypothesize that it is almost as long as
the max symbol length, allowing huffSym to ask for more bits at the
start of every loop. This increases the probabilty that the Huffman
code is decoded on the first iteration of the outer for-loop.

benchmark                              old MB/s     new MB/s     speedup
BenchmarkDecodeDigitsSpeed1e4-4        51.05        54.31        1.06x
BenchmarkDecodeDigitsSpeed1e5-4        58.86        62.24        1.06x
BenchmarkDecodeDigitsSpeed1e6-4        59.63        63.13        1.06x
BenchmarkDecodeDigitsDefault1e4-4      51.94        54.61        1.05x
BenchmarkDecodeDigitsDefault1e5-4      63.70        69.13        1.09x
BenchmarkDecodeDigitsDefault1e6-4      66.08        71.43        1.08x
BenchmarkDecodeDigitsCompress1e4-4     52.25        54.56        1.04x
BenchmarkDecodeDigitsCompress1e5-4     63.34        68.30        1.08x
BenchmarkDecodeDigitsCompress1e6-4     66.84        70.64        1.06x
BenchmarkDecodeTwainSpeed1e4-4         50.74        53.40        1.05x
BenchmarkDecodeTwainSpeed1e5-4         60.77        67.03        1.10x
BenchmarkDecodeTwainSpeed1e6-4         62.08        69.78        1.12x
BenchmarkDecodeTwainDefault1e4-4       53.45        56.40        1.06x
BenchmarkDecodeTwainDefault1e5-4       73.54        79.05        1.07x
BenchmarkDecodeTwainDefault1e6-4       77.68        83.65        1.08x
BenchmarkDecodeTwainCompress1e4-4      53.21        56.15        1.06x
BenchmarkDecodeTwainCompress1e5-4      73.82        77.76        1.05x
BenchmarkDecodeTwainCompress1e6-4      79.23        83.30        1.05x

Change-Id: Ie194925c827988a380b8c2fdd13b13c4faa5d397
Reviewed-on: https://go-review.googlesource.com/15651Reviewed-by: Nigel Tao <nigeltao@golang.org>

* append contents of race1.go to race.go
* delete "Implementation of the race detector API." comment
  from race1.go

Updates #12952

Change-Id: Ibdd9c4dc79a63c3bef69eade9525578063c86c1c
Reviewed-on: https://go-review.googlesource.com/16023
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

PIC code on ppc64le uses R2 as a TOC pointer and when calling a function
through a function pointer must ensure the function pointer is in R12.  These
rules are easy enough to follow unconditionally in our assembly, so do that.

Change-Id: Icfc4e47ae5dfbe15f581cbdd785cdeed6e40bc32
Reviewed-on: https://go-review.googlesource.com/15526Reviewed-by: Ian Lance Taylor <iant@golang.org>

Shared libraries on ppc64le will require a larger minimum stack frame (because
the ABI mandates that the TOC pointer is available at 24(R1)). Part 3 of that
is using a #define in the ppc64 assembly to refer to the size of the fixed
part of the stack (finding all these took me about a week!).

Change-Id: I50f22fe1c47af1ec59da1bd7ea8f84a4750df9b7
Reviewed-on: https://go-review.googlesource.com/15525Reviewed-by: Ian Lance Taylor <iant@golang.org>

Shared libraries on ppc64le will require a larger minimum stack frame (because
the ABI mandates that the TOC pointer is available at 24(R1)). Part 2a of
preparing for that is to have all bits of arch-independent and ppc64-specific
codegen that need to know call a function to find out.

Change-Id: I55899f73037e92227813c491049a3bd6f30bd41f
Reviewed-on: https://go-review.googlesource.com/15524Reviewed-by: Ian Lance Taylor <iant@golang.org>

Shared libraries on ppc64le will require a larger minimum stack frame (because
the ABI mandates that the TOC pointer is available at 24(R1)). So to prepare
for this, make a constant for the fixed part of a stack and use that where
necessary.

Change-Id: I447949f4d725003bb82e7d2cf7991c1bca5aa887
Reviewed-on: https://go-review.googlesource.com/15523Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Replace the confusing game where a frame size of $-8 would suppress the
implicit setting up of a stack frame with a nice explicit flag.

The code to set up the function prologue is still a little confusing but better
than it was.

Change-Id: I1d49278ff42c6bc734ebfb079998b32bc53f8d9a
Reviewed-on: https://go-review.googlesource.com/15670Reviewed-by: Minux Ma <minux@golang.org>

This fixes a TODO in (*WordDecoder).Decode by replacing a call to strings.Split with
simple prefix/suffix checking and some custom slicing.

Benchmark results:

benchmark                    old ns/op     new ns/op     delta
BenchmarkQEncodeWord-8       740           693           -6.35%
BenchmarkQDecodeWord-8       1291          727           -43.69%
BenchmarkQDecodeHeader-8     1194          767           -35.76%

benchmark                    old allocs     new allocs     delta
BenchmarkQEncodeWord-8       1              1              +0.00%
BenchmarkQDecodeWord-8       3              2              -33.33%
BenchmarkQDecodeHeader-8     3              2              -33.33%

benchmark                    old bytes     new bytes     delta
BenchmarkQEncodeWord-8       48            48            +0.00%
BenchmarkQDecodeWord-8       128           48            -62.50%
BenchmarkQDecodeHeader-8     128           48            -62.50%

Change-Id: I2d6844c75ec2e2b79be2e49b7fc4ca320b7e84e5
Reviewed-on: https://go-review.googlesource.com/14432Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* rename stack1.go -> stack.go
* prepend contents of stack2.go to stack.go

Updates #12952

Change-Id: I60d409af37162a5a7596c678dfebc2cea89564ff
Reviewed-on: https://go-review.googlesource.com/16008Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Go cannot allow lazy PLT resolution when calling between Go functions because
the lazy resolution can use more stack than is available. Lazy resolution is
disabled by passing -z now to the system linker, but unfortunately was only
passed when linking to a Go shared library. That sounds fine, but the shared
library containing the runtime is not linked to any other Go shared library but
calls main.init and main.main via a PLT, and before this fix this did use lazy
resolution. (For some reason this never caused a problem on intel, but it
breaks on ppc64le). Fortunately the fix is very simple: always pass -z now to
the system linker when dynamically linking Go.

Change-Id: I7806d40aac80dcd1e56b95864d1cfeb1c42614e2
Reviewed-on: https://go-review.googlesource.com/15870Reviewed-by: Ian Lance Taylor <iant@golang.org>

Current http client doesn't support Expect: 100-continue request
header(RFC2616-8/RFC7231-5.1.1). So even if the client have the header,
the head of the request body is consumed prematurely.

Those are my intentions to avoid premature consuming body in this change.
- If http.Request header contains body and Expect: 100-continue
  header, it blocks sending body until it gets the first response.
- If the first status code to the request were 100, the request
  starts sending body. Otherwise, sending body will be cancelled.
- Tranport.ExpectContinueTimeout specifies the amount of the time to
  wait for the first response.

Fixes #3665

Change-Id: I4c04f7d88573b08cabd146c4e822061764a7cd1f
Reviewed-on: https://go-review.googlesource.com/10091
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Ie9ea4af4315a4d0eb69d0569726bb3eca2b397af
Reviewed-on: https://go-review.googlesource.com/16005Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #7782
Fixes #9554
Updates #7237 (original metabug, before we switched to specific bugs)
Updates #11932 (plan9 still doesn't have net I/O deadline support)

Change-Id: I96f311b88b1501d884ebc008fd31ad2cf1e16d75
Reviewed-on: https://go-review.googlesource.com/15941Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David du Colombier <0intro@gmail.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

In net/parse.go we reimplement bytes.IndexByte and strings.IndexByte,
However those are implemented in runtime/$GOARCH_asm.s.
Using versions from runtime should provide performance advantage,
and keep the same code together.

Change-Id: I6212184bdf6aa1f2c03ce26d4b63f5b379d8ed0c
Reviewed-on: https://go-review.googlesource.com/15953
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

A TODO to merge is removed from panic1.go.
The rest is appended to panic.go

Updates #12952

Change-Id: Ied4382a455abc20bc2938e34d031802e6b4baf8b
Reviewed-on: https://go-review.googlesource.com/15905Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

It seems that it was called print1.go mistakenly: print.go was deleted
in the same commit:
https://go.googlesource.com/go/+/597b266eafe7d63e9be8da1c1b4813bd2998a11c

Updates #12952

Change-Id: I371e59d6cebc8824857df3f3ee89101147dfffc0
Reviewed-on: https://go-review.googlesource.com/15950Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

string1.go contents are appended to string.go as is

Updates #12952

Change-Id: I30083ba7fdd362d4421e964a494c76ca865bedc2
Reviewed-on: https://go-review.googlesource.com/15951Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Previously with db.maxOpen > 0, db.maxOpen+n failed connection attempts
started concurrently could result in a deadlock. DB.conn and
DB.openNewConnection did not trigger the DB.connectionOpener go routine
after a failed connection attempt. This omission could leave go routines
waiting for DB.connectionOpener forever.

In addition the logic to track the state of the pool was inconsistent.
db.numOpen was sometimes incremented optimistically and sometimes not.
This change harmonizes the logic and eliminates the db.pendingOpens
variable, making the logic easier to understand and maintain.

Fixes #10886

Change-Id: I983c4921a3dacfbd531c3d7f8d2da8a592e9922a
Reviewed-on: https://go-review.googlesource.com/14547Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I3ba6e97089ef6e69ba31dfb632df465859906a74
Reviewed-on: https://go-review.googlesource.com/15940
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I88f80f5914d6e4c179f3d28aa59fc29b7ef0cc66
Reviewed-on: https://go-review.googlesource.com/15960Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

os/signal depends on a few unexported runtime functions. This removes the
assembly stubs it used to get access to these in favour of using
//go:linkname in runtime to make the functions accessible to os/signal.

This is motivated by ppc64le shared libraries, where you cannot BR to a symbol
defined in a shared library (only BL), but it seems like an improvment anyway.

Change-Id: I09361203ce38070bd3f132f6dc5ac212f2dc6f58
Reviewed-on: https://go-review.googlesource.com/15871
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>

This isn't C anymore.  No binary change to pkg/linux_amd64/runtime.a.

Change-Id: I24d66b0f5ac888f432b874aac684b1395e7c8345
Reviewed-on: https://go-review.googlesource.com/15903Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Apply static bounds checking logic during type checking even to
zero-element arrays, but skip synthesized OINDEX nodes that the
compiler has asserted are within bounds (such as the ones generated
while desugaring ORANGE nodes).  This matches the logic in walkexpr
that also skips static bounds checking when Bounded is true.

Passes toolstash/buildall.

Fixes #12944.

Change-Id: I14ba03d71c002bf969d69783bec8d1a8e10e7d75
Reviewed-on: https://go-review.googlesource.com/15902Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

No functional change and passes toolstash/buildall, but eliminates a
13-deep nesting of if statements.

Change-Id: I32e63dcf358c6eb521935f4ee07fbe749278e5ef
Reviewed-on: https://go-review.googlesource.com/15901Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I0255f24f5c5925ea4daa28a28d23606df35d4373
Reviewed-on: https://go-review.googlesource.com/15824Reviewed-by: Andrew Gerrand <adg@golang.org>

Read what a non-empty interface points to.

The deleted lines were added in https://codereview.appspot.com/4810060/,
which attempted to break an infinite loop. That was a long time ago.
If I just delete these lines with current codebase, the test "bug1"
(added in that CL) does not fail.

All new tests fail without this fix.

Fixes #12924

Change-Id: I9370ca44facd6af3019850aa065b936e5a482d37
Reviewed-on: https://go-review.googlesource.com/15809Reviewed-by: Andrew Gerrand <adg@golang.org>

As specified by RFC 2047 section 2, encoded-words may not be more than
75 characters long.

We only enforce this rule when the charset is UTF-8, since multi-bytes
characters must not be split accross encoded-words (see section 5.3).

Fixes #12300

Change-Id: I72a43fc3fe6ddeb3dab54dcdce0837d7ebf658f0
Reviewed-on: https://go-review.googlesource.com/14957
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The clues to this were already there, but as a user I was still unsure.
Make this more explicit.

Change-Id: I68564f3498dcd4897772a303588f03a6b65f111d
Reviewed-on: https://go-review.googlesource.com/15172Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

As correctly mentioned in #11883, encodeState.string and
encodeState.stringBytes never return an error.
This CL removes the error from the function signatures and somewhat
simplifies call sites.

Fixes #11883

Change-Id: I1d1853d09631c545b68b5eea86ff7daa2e0ca10b
Reviewed-on: https://go-review.googlesource.com/15836
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This enables HTTP/2 by default (for https only) if the user didn't
configure anything in their NPN/ALPN map. If they're using SPDY or an
alternate http2 or a newer http2 from x/net/http2, we do nothing
and don't use the standard library's vendored copy of x/net/http2.

Upstream remains golang.org/x/net/http2.

Update #6891

Change-Id: I69a8957a021a00ac353f9d7fdb9a40a5b69f2199
Reviewed-on: https://go-review.googlesource.com/15828
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

golang.org/x/net/http2 becomes net/http/h2_bundle.go (using adonovan's
x/tools/cmd/bundle tool), becoming a hidden part of the net/http package.

golang.org/x/net/http2/hpack becomes vendor/golang.org/x/net/http2/hpack.

At git rev 7331ef52 (https://go-review.googlesource.com/15821)

Change-Id: Ia6683e6f91a481b11a778638bf65b6a338744eea
Reviewed-on: https://go-review.googlesource.com/15822Reviewed-by: Andrew Gerrand <adg@golang.org>

The PROXY protocol is supported by several proxy servers such as haproxy
and Amazon ELB.  This protocol allows services running behind a proxy to
learn the remote address of the actual client connecting to the proxy,
by including a single textual line at the beginning of the TCP
connection.
http://www.haproxy.org/download/1.5/doc/proxy-protocol.txt

There are several Go libraries for this protocol (such as
https://github.com/armon/go-proxyproto), which operate by wrapping a
net.Conn with an implementation whose RemoteAddr method reads the
protocol line before returning. This means that RemoteAddr is a blocking
call.

Before this change, http.Serve called RemoteAddr from the main Accepting
goroutine, not from the per-connection goroutine. This meant that it
would not Accept another connection until RemoteAddr returned, which is
not appropriate if RemoteAddr needs to do a blocking read from the
socket first.

Fixes #12943.

Change-Id: I1a242169e6e4aafd118b794e7c8ac45d0d573421
Reviewed-on: https://go-review.googlesource.com/15835Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I2ac6b178e666e34e028001078faf62ce71e12e9d
Reviewed-on: https://go-review.googlesource.com/15834Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Allow all CGI environment settings from the inherited set and default
inherited set to be overridden including PATH by Env.

Change-Id: Ief8d33247b879fa87a8bfd6416d4813116db98de
Reviewed-on: https://go-review.googlesource.com/14959Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

The current fastlog2 testing checks all 64M values in the domain of
interest, which is too much for platforms with no native floating point.

Reduce testing under testing.Short() to speed up builds for those platforms.

Related to #12620

Change-Id: Ie5dcd408724ba91c3b3fcf9ba0dddedb34706cd1
Reviewed-on: https://go-review.googlesource.com/15830Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Joel Sing <jsing@google.com>
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The documentation listing err == EOF can be confusing to newcomers
to the language who are looking for the relevant documentation for
that error.

Change-Id: I301885950d0e1d0fbdf3a1892fca86eac7a0c616
Reviewed-on: https://go-review.googlesource.com/15806Reviewed-by: Andrew Gerrand <adg@golang.org>

Due to #9401, trailing empty fields will occupy at least 1 byte
of space.

Fixes #12884.

Change-Id: I838d3f1a73637e526f5a6dbc348981227d5bb2fd
Reviewed-on: https://go-review.googlesource.com/15660
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Also, handle the case where 'read' returns EINVAL instead of EBADF
when the descriptor is not ready. (android 4.4.4/cyanogenmod, nexus7)

Change-Id: I56c5949d27303d44a4fd0de38951b85e20cef167
Reviewed-on: https://go-review.googlesource.com/15810Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes these warnings from go vet:
buildid_linux.go:25: no formatting directive in Fatalf call
callback.go:180: arg pc[i] for printf verb %p of wrong type: uintptr
env.go:34: possible misuse of unsafe.Pointer
issue7665.go:22: possible misuse of unsafe.Pointer

Change-Id: I83811b9c10c617139713a626b4a34ab05564d4fe
Reviewed-on: https://go-review.googlesource.com/15802Reviewed-by: David Crawshaw <crawshaw@golang.org>

Fixes #12785

Change-Id: Iae4383889298c6a78b1ba41bd2cda70b0758fcba
Reviewed-on: https://go-review.googlesource.com/15737Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>