This is a semantic but no API change. It is a cleaner
implementation of pure filtering. Applications that
need function bodies stripped can easily do this them-
selves.

R=rsc
CC=golang-dev
https://golang.org/cl/5206046

Removed the URL form parameter "f=text" in favor of a more
flexible mode parameter "m" which now accepts a list of mode
flags as documented in doc.go.

Fixes #1784.

R=rsc
CC=golang-dev
https://golang.org/cl/5227041

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5231041

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5207044

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/5208042

R=golang-dev, rsc, dsymonds
CC=golang-dev
https://golang.org/cl/5209045

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5211045

This CL introduces the go.Example type and go.Examples functions that
are used to represent and extract code samples from Go source.

They should be of the form:

// Output of this function.
func ExampleFoo() {
        fmt.Println("Output of this function.")
}

It also modifies godoc to read example code from _test.go files,
and include them in the HTML output with JavaScript-driven toggles.

It also implements testing of example functions with gotest.
The stdout/stderr is compared against the output comment on the
function.

This CL includes examples for the sort.Ints function and the
sort.SortInts type. After patching this CL in and re-building go/doc
and godoc, try
        godoc -http=localhost:6060
and visit http://localhost:6060/pkg/sort/

R=gri, r, rsc
CC=golang-dev
https://golang.org/cl/5137041

Allows passing extra fds to the child process.

Fixes #2329

R=rsc, dsymonds
CC=golang-dev
https://golang.org/cl/5162050

Fixes #2336.

R=golang-dev, dsymonds, rsc
CC=golang-dev
https://golang.org/cl/5222042

R=golang-dev, bradfitz, dsymonds, gri
CC=golang-dev
https://golang.org/cl/5223043

See discussion at https://groups.google.com/d/topic/golang-dev/RAKiqi44GEU/discussion

R=golang-dev, bradfitz, dvyukov, rogpeppe, r, r, borman
CC=golang-dev
https://golang.org/cl/5071044

R=golang-dev, gri
CC=golang-dev, miki.tebeka
https://golang.org/cl/5225042

Linux/amd64, 2 x Intel Xeon E5620, 8 HT cores, 2.40GHz
benchmark                    old ns/op    new ns/op    delta
BenchmarkFinalizer              420.00       261.00  -37.86%
BenchmarkFinalizer-2            985.00       201.00  -79.59%
BenchmarkFinalizer-4           1077.00       244.00  -77.34%
BenchmarkFinalizer-8           1155.00       180.00  -84.42%
BenchmarkFinalizer-16          1182.00       184.00  -84.43%

BenchmarkFinalizerRun          2128.00      1378.00  -35.24%
BenchmarkFinalizerRun-2        1655.00      1418.00  -14.32%
BenchmarkFinalizerRun-4        1634.00      1522.00   -6.85%
BenchmarkFinalizerRun-8        2213.00      1581.00  -28.56%
BenchmarkFinalizerRun-16       2424.00      1599.00  -34.03%

Darwin/amd64, Intel L9600, 2 cores, 2.13GHz
benchmark                    old ns/op    new ns/op    delta
BenchmarkChanCreation          1451.00       926.00  -36.18%
BenchmarkChanCreation-2        3124.00      1412.00  -54.80%
BenchmarkChanCreation-4        6121.00      2628.00  -57.07%

BenchmarkFinalizer              684.00       420.00  -38.60%
BenchmarkFinalizer-2          11195.00       398.00  -96.44%
BenchmarkFinalizer-4          15862.00       654.00  -95.88%

BenchmarkFinalizerRun          2025.00      1397.00  -31.01%
BenchmarkFinalizerRun-2        3920.00      1447.00  -63.09%
BenchmarkFinalizerRun-4        9471.00      1545.00  -83.69%

R=golang-dev, cw, rsc
CC=golang-dev
https://golang.org/cl/4963057

The malloc sample trigger was not being set in a
new m, so the first allocation in each new m - the
goroutine structure - was being sampled with
probability 1 instead of probability sizeof(G)/rate,
an oversampling of about 5000x for the default
rate of 1 MB.  This bug made pprof graphs show
far more G allocations than there actually were.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5224041

Fixes #2337.
Unfortunate sequence of events is:
1. maxcpu=2, mcpu=1, grunning=1
2. starttheworld creates an extra M:
   maxcpu=2, mcpu=2, grunning=1
4. the goroutine calls runtime.GOMAXPROCS(1)
   maxcpu=1, mcpu=2, grunning=1
5. since it sees mcpu>maxcpu, it calls gosched()
6. schedule() deschedules the goroutine:
   maxcpu=1, mcpu=1, grunning=0
7. schedule() call getnextandunlock() which
   fails to pick up the goroutine again,
   because canaddcpu() fails, because mcpu==maxcpu
8. then it sees that grunning==0,
   reports deadlock and terminates

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5191044

R=golang-dev, alex.brainman
CC=golang-dev
https://golang.org/cl/5201042

R=rsc, jp, hectorchu
CC=golang-dev
https://golang.org/cl/4962051

therefore unlikely that there is a good use for its string version
LastBoundaryInString. Yet, the implemenation of this method would complicate
things a bit as it would require the introduction for another interface and
some duplication of code. Removing it seems a better choice.

R=r
CC=golang-dev
https://golang.org/cl/5182044

R=bradfitz
CC=golang-dev
https://golang.org/cl/5208041

R=rsc, dsymonds
CC=golang-dev
https://golang.org/cl/5204041

binary.BenchmarkPutUvarint32 20000000	 85.6 ns/op
binary.BenchmarkPutUvarint64 10000000	299   ns/op

R=rsc
CC=golang-dev
https://golang.org/cl/5148049

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5190045

R=golang-dev, rsc, r
CC=golang-dev
https://golang.org/cl/5181045

Major changes between hybi-08 and hybi-13
- hybi-08 uses Sec-WebSocket-Origin, but hybi-13 uses Origin
- hybi-13 introduces new close status codes.

hybi-17 spec (editorial changes of hybi-13) mentions
- if a server doesn't support the requested version, it MUST respond
  with Sec-WebSocket-Version headers containing all available versions.
- client MUST close the connection upon receiving a masked frame
- server MUST close the connection upon receiving a non-masked frame
note that hybi-17 still uses "Sec-WebSocket-Version: 13"

see http://code.google.com/p/pywebsocket/wiki/WebSocketProtocolSpec
for changes between spec drafts.

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5147043

R=adg, cw, lvd
CC=golang-dev
https://golang.org/cl/5168046

of methods.

R=r, mpvl
CC=golang-dev
https://golang.org/cl/5166045

R=rsc, r
CC=golang-dev
https://golang.org/cl/5192043

Set the runtime ncpu based on the hw.ncpu sysctl.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5191043

This can work only if there is no type info required to initialize the decoder,
but it's easy and gains a few percent in the basic benchmarks by avoiding
bufio when it's a bytes.Buffer - a testing-only scenario, I admit.
Add a comment about what Decode expects from the input.

R=rsc
CC=golang-dev
https://golang.org/cl/5165048

Must use case-sensitive search to identify keywords.

Fixes #2287.

R=bradfitz
CC=golang-dev
https://golang.org/cl/5182043

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5127052

When ncpu < 2, work.nproc is always 1 which results in infinite helper
threads being created if gomaxprocs > 1 and MaxGcproc > 1. Avoid this
by using the same limits as imposed helpgc().

R=golang-dev, rsc, dvyukov
CC=golang-dev
https://golang.org/cl/5176044

This change adds the osyield and usleep
functions and code to read the number of
processors from /dev/sysstat.

I also changed SysAlloc to return nil
when brk fails (it was returning -1).

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5177049

lib/codereview: Unable to use vim for 'hg change' from windows console
reload(sys) break workaround for windows.
see:
http://mercurial.selenic.com/bts/issue2888
http://mercurial.selenic.com/bts/issue1452
Also does not work with backslash paths.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5150054

This requires making the .dynamic section writable, as the
dynamic linker will change the value of the DT_DEBUG tag at
runtime.  The DT_DEBUG tag is used by gdb to find all loaded
shared libraries.

R=rsc
CC=golang-dev
https://golang.org/cl/5189044

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5131055

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/5185045

Fixes #2324.

R=r, r
CC=golang-dev
https://golang.org/cl/5180044

The loop recognizer uses the standard dominance
frontiers but gets confused by dead code, which
has a (not explicitly set) rpo number of 0, meaning it
looks like the head of the function, so it dominates
everything.  If the loop recognizer encounters dead
code while tracking backward through the graph
it fails to recognize where it started as a loop, and
then the optimizer does not registerize values loaded
inside that loop.  Fix by checking rpo against rpo2r.

Separately, run a quick pass over the generated
code to squash JMPs to JMP instructions, which
are convenient to emit during code generation but
difficult to read when debugging the -S output.
A side effect of this pass is to eliminate dead code,
so the output files may be slightly smaller and the
optimizer may have less work to do.
There is no semantic effect, because the linkers
flatten JMP chains and delete dead instructions
when laying out the final code.  Doing it here too
just makes the -S output easier to read and more
like what the final binary will contain.

The "dead code breaks loop finding" bug is thus
fixed twice over.  It seemed prudent to fix loopit
separately just in case dead code ever sneaks back
in for one reason or another.

R=ken2
CC=golang-dev
https://golang.org/cl/5190043