GetQueuedCompletionStatusEx allows to dequeue a batch of completion
notifications, which is more efficient than dequeueing one by one.

benchmark                           old ns/op    new ns/op    delta
BenchmarkClientServerParallel4         100605        90945   -9.60%
BenchmarkClientServerParallel4-2        90225        74504  -17.42%

R=golang-dev, alex.brainman
CC=golang-dev
https://golang.org/cl/12436044

This allows to skip GetQueuedCompletionStatus if an IO operation completes synchronously.
benchmark                    old ns/op    new ns/op    delta
BenchmarkTCP4Persistent          27669        25863   -6.53%
BenchmarkTCP4Persistent-2        18173        15908  -12.46%
BenchmarkTCP4Persistent-4        10390         9766   -6.01%

R=golang-dev, mikioh.mikioh, alex.brainman
CC=golang-dev
https://golang.org/cl/12409044

Fixes #5896.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12645043

Fixes #6058.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12643043

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/12642043

s/commandLine/CommandLine/g

Fixes #4209.

R=golang-dev, dsymonds, bradfitz
CC=golang-dev
https://golang.org/cl/12587043

Fixes bug 6055.

R=golang-dev, bradfitz, dvyukov, khr
CC=golang-dev
https://golang.org/cl/12536045

In prep for Robert's forthcoming cmd/api rewrite which
depends on the go.tools subrepo, we'll need to be more
careful about how and when we run cmd/api.

Rather than implement this policy in both run.bash and
run.bat, this change moves the policy and mechanism into
cmd/api/run.go, which will then evolve.

The plan is in a TODO in run.go.

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/12482044

Fixes #6061.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12609043

The test takes up to 64 seconds on windows builders.
I've tried to reduce number of iterations in the test,
but it does not affect run time.
Fixes #6054.

R=golang-dev, alex.brainman
CC=golang-dev
https://golang.org/cl/12531043

Previously, all word aligned locations in the local variables
area were scanned as conservative roots.  With this change, a
bitmap is generated describing the locations of pointer values
in local variables.

With this change the argument bitmap information has been
changed to only store information about arguments.  The locals
member, has been removed.  In its place, the bitmap data for
local variables is now used to store the size of locals.  If
the size is negative, the magnitude indicates the size of the
local variables area.

R=rsc
CC=golang-dev
https://golang.org/cl/12328044

Remove NOPROF/DUPOK from everything.

Edits done with a script, except pclinetest.asm which depended
on the DUPOK flag on main().

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12613044

There were some issues with the code sometimes using base64.StdEncoding,
and sometimes base64.URLEncoding.
Encoding basic authentication is now always done by the same code.

Fixes #5970.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12397043

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12620043

The gc compiler only gives an error about an unused label if
it has not given any errors in an earlier pass.  Remove all
unused labels in this test because they don't test anything
useful and they cause gccgo to give unexpected errors.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12580044

The gc compiler only gives an error about fallthrough in a
type switch if it has not given any errors in an earlier pass.
Remove all functions in this test that use fallthrough in a
type switch because they don't test anything useful and they
cause gccgo to give unexpected errors.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12614043

We can then include this file in assembly to replace
cryptic constants like "7" with meaningful constants
like "(NOPROF|DUPOK|NOSPLIT)".

Converting just pkg/runtime/asm*.s for now.  Dropping NOPROF
and DUPOK from lots of places where they aren't needed.
More .s files to come in a subsequent changelist.

A nonzero number in the textflag field now means
"has not been converted yet".

R=golang-dev, daniel.morsing, rsc, khr
CC=golang-dev
https://golang.org/cl/12568043

Fixes #6063

R=golang-dev, r, dave
CC=dvyukov, golang-dev
https://golang.org/cl/12586043

HTTP/1.0 connections are closed implicitly, unless otherwise specified.

Note that this change does not test or fix "request too large" responses.
Reasoning: (a) it complicates tests and fixes, (b) they should be rare,
and (c) this is just a minor wire optimization, and thus not really worth worrying
about in this context.

Fixes #5955.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12435043

A response to a HEAD request is supposed to look the same as a
response to a GET request, just without a body.

HEAD requests are incredibly rare in the wild.

The Go net/http package has so far treated HEAD requests
specially: a Write on our default ResponseWriter returned
ErrBodyNotAllowed, telling handlers that something was wrong.
This was to optimize the fast path for HEAD requests, but:

1) because HEAD requests are incredibly rare, they're not
   worth having a fast path for.

2) Letting the http.Handler handle but do nop Writes is still
   very fast.

3) this forces ugly error handling into the application.
   e.g. https://code.google.com/p/go/source/detail?r=6f596be7a31e
   and related.

4) The net/http package nowadays does Content-Type sniffing,
   but you don't get that for HEAD.

5) The net/http package nowadays does Content-Length counting
   for small (few KB) responses, but not for HEAD.

6) ErrBodyNotAllowed was useless. By the time you received it,
   you had probably already done all your heavy computation
   and I/O to calculate what to write.

So, this change makes HEAD requests like GET requests.

We now count content-length and sniff content-type for HEAD
requests. If you Write, it doesn't return an error.

If you want a fast-path in your code for HEAD, you have to do
it early and set all the response headers yourself. Just like
before. If you choose not to Write in HEAD requests, be sure
to set Content-Length if you know it. We won't write
"Content-Length: 0" because you might've just chosen to not
write (or you don't know your Content-Length in advance).

Fixes #5454

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/12583043

Leftovers from 11699043

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12558046

Thanks to c.emil.hessman@gmail.com for pointing out the error.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12572043

If the padding is huge, we crashed by blowing the buffer. That's easy: make sure
we have a big enough buffer by allocating in problematic cases.
Zero padding floats was just wrong in general: the space would appear in the
middle.

Fixes #6044.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/12498043

Like existing Index, IndexRune, IndexHardN, etc.

R=golang-dev, khr
CC=golang-dev
https://golang.org/cl/12486044

They may call other NOSPLIT routines, and that might
overflow the stack.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/12563043

This CL refactors the existing listenerSockaddr function into several
methods on netFD.

This is in preparation for runtime-integrated network pollster for BSD
variants.

Update #5199

R=golang-dev, dave, alex.brainman, dvyukov, remyoudompheng
CC=golang-dev
https://golang.org/cl/12023043

Updates #6046.
This CL just does maxstring and concatstring. There are other functions
to fix but doing them a few at a time will help isolate any (unlikely)
breakages these changes bring up in architectures I can't test
myself.

R=golang-dev, dave, iant
CC=golang-dev
https://golang.org/cl/12519044

I broke it with the darwin getwd attrlist stuff (0583e9d36dd).
plan9 doesn't have syscall.ENOTSUP.

It's in api/go1.txt as a symbol always available (not context-specific):

pkg syscall, const ENOTSUP Errno

... but plan9 isn't considered by cmd/api, so it only looks
universally available.  Alternatively, we could add a fake ENOTSUP
to plan9, but they were making efforts earlier to clean their
syscall package, so I'd prefer not to dump more in it.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/12509044

This change replaces the hard-coded switch on compression method
in zipfile reader and writer with a map into which users can
register compressors and decompressors in their init()s.

R=golang-dev, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/12421043

Generated by addca.

R=gobot
CC=golang-dev
https://golang.org/cl/12557043

NetBSD and OpenBSD are broken like OS X is. Good to know.

Drop required count from avg/2 to avg/3, because the
Plan 9 builder just barely missed avg/2 in one of its runs.

R=golang-dev, dvyukov
CC=golang-dev
https://golang.org/cl/12548043

It turned out that change 12413043 did not break
any builders. So let's lock this in.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/12545043

Looks like latest FreeBSD doesn't set address family identifer
for RTAX_NETMASK stuff; probably RTAX_GENMASK too, not confirmed.
This CL tries to identify address families by using the length of
each socket address if possible.

The issue is confirmed on FreeBSD 9.1.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12332043

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12508043

Unlike the existing net package own pollster, runtime-integrated
network pollster on BSD variants, actually kqueue, requires a socket
that has beed passed to syscall.Listen previously for a stream
listener.

This CL separates pollDesc.Init (actually runtime_pollOpen) from newFD
to allow control of each state of sockets and adds init method to netFD
instead. Upcoming CLs will rearrange the call order of runtime-integrated
pollster and syscall functions like the following;

- For dialers that open active connections, runtime_pollOpen will be
  called in between syscall.Bind and syscall.Connect.

- For stream listeners that open passive stream connections,
  runtime_pollOpen will be called just after syscall.Listen.

- For datagram listeners that open datagram connections,
  runtime_pollOpen will be called just after syscall.Bind.

This is in preparation for runtime-integrated network pollster for BSD
variants.

Update #5199

R=dvyukov, alex.brainman, minux.ma
CC=golang-dev
https://golang.org/cl/8608044

The current failures were:

fatal error: runtime: stack split during syscall
goroutine 1 [stack split]:
runtime.findnull(0x105a9080)
        /usr/go/src/pkg/runtime/string.goc:14 fp=0x305aefb8
runtime: unexpected return pc for runtime.errstr called from 0x80
runtime.errstr()
        /usr/go/src/pkg/runtime/sys_plan9_386.s:196 +0x2f fp=0x305aefc8

fatal error: runtime: stack split during syscall
goroutine 2 [stack split]:
runtime.nanotime(0x305bff3c)
        /usr/go/src/pkg/runtime/time_plan9_386.c:9 fp=0x305bff34
notetsleep(0x305bff9c, 0xf8475800, 0xd, 0x0, 0x0, ...)
        /usr/go/src/pkg/runtime/lock_sema.c:195 +0x87 fp=0x305bff48
runtime.notetsleepg(0x305bff9c, 0xf8475800, 0xd)
        /usr/go/src/pkg/runtime/lock_sema.c:266 +0xa4 fp=0x305bff68
runtime.MHeap_Scavenger()
        /usr/go/src/pkg/runtime/mheap.c:463 +0xc2 fp=0x305bffd0
runtime.goexit()
        /usr/go/src/pkg/runtime/proc.c:1332 fp=0x305bffd4
created by runtime.main
        /usr/go/src/pkg/runtime/proc.c:168

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/12128043

On 10.6, OS X's fcntl returns EBADF instead of EINVAL.

R=golang-dev, iant, dave
CC=golang-dev
https://golang.org/cl/12493043

Update #6046.
This CL just does findnull and findnullw. There are other functions
to fix but doing them a few at a time will help isolate any (unlikely)
breakages these changes bring up in architectures I can't test
myself.

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/12520043

R=alex.brainman
CC=golang-dev
https://golang.org/cl/12502044

Embed all data necessary for read/write operations directly into netFD.

benchmark                    old ns/op    new ns/op    delta
BenchmarkTCP4Persistent          27669        23341  -15.64%
BenchmarkTCP4Persistent-2        18173        12558  -30.90%
BenchmarkTCP4Persistent-4        10390         7319  -29.56%

This change will intentionally break all builders to see
how many allocations they do per read/write.
This will be fixed soon afterwards.

R=golang-dev, alex.brainman
CC=golang-dev
https://golang.org/cl/12413043