runtime: make panic possible before malloc is ready

Otherwise startup problems can be difficult to debug.

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/7522046
cmd/dist: support goos,goarch build tags
This is necessary to submit netpoll for linux,386 linux,amd64

R=golang-dev, bradfitz, rsc
CC=golang-dev
https://codereview.appspot.com/7470050
runtime: integrated network poller for linux
vs tip:
BenchmarkTCP4OneShot                    172994        40485  -76.60%
BenchmarkTCP4OneShot-2                   96581        30028  -68.91%
BenchmarkTCP4OneShot-4                   52615        18454  -64.93%
BenchmarkTCP4OneShot-8                   26351        12289  -53.36%
BenchmarkTCP4OneShot-16                  12258        16093  +31.29%
BenchmarkTCP4OneShot-32                  13200        17045  +29.13%

BenchmarkTCP4OneShotTimeout             124814        42932  -65.60%
BenchmarkTCP4OneShotTimeout-2            99090        29040  -70.69%
BenchmarkTCP4OneShotTimeout-4            51860        18455  -64.41%
BenchmarkTCP4OneShotTimeout-8            26100        12073  -53.74%
BenchmarkTCP4OneShotTimeout-16           12198        16654  +36.53%
BenchmarkTCP4OneShotTimeout-32           13438        17143  +27.57%

BenchmarkTCP4Persistent                 115647         7782  -93.27%
BenchmarkTCP4Persistent-2                58024         4808  -91.71%
BenchmarkTCP4Persistent-4                24715         3674  -85.13%
BenchmarkTCP4Persistent-8                16431         2407  -85.35%
BenchmarkTCP4Persistent-16                2336         1875  -19.73%
BenchmarkTCP4Persistent-32                1689         1637   -3.08%

BenchmarkTCP4PersistentTimeout           79754         7859  -90.15%
BenchmarkTCP4PersistentTimeout-2         57708         5952  -89.69%
BenchmarkTCP4PersistentTimeout-4         26907         3823  -85.79%
BenchmarkTCP4PersistentTimeout-8         15036         2567  -82.93%
BenchmarkTCP4PersistentTimeout-16         2507         1903  -24.09%
BenchmarkTCP4PersistentTimeout-32         1717         1627   -5.24%

vs old scheduler:
benchmark                           old ns/op    new ns/op    delta
BenchmarkTCPOneShot                    192244        40485  -78.94%
BenchmarkTCPOneShot-2                   63835        30028  -52.96%
BenchmarkTCPOneShot-4                   35443        18454  -47.93%
BenchmarkTCPOneShot-8                   22140        12289  -44.49%
BenchmarkTCPOneShot-16                  16930        16093   -4.94%
BenchmarkTCPOneShot-32                  16719        17045   +1.95%

BenchmarkTCPOneShotTimeout             190495        42932  -77.46%
BenchmarkTCPOneShotTimeout-2            64828        29040  -55.20%
BenchmarkTCPOneShotTimeout-4            34591        18455  -46.65%
BenchmarkTCPOneShotTimeout-8            21989        12073  -45.10%
BenchmarkTCPOneShotTimeout-16           16848        16654   -1.15%
BenchmarkTCPOneShotTimeout-32           16796        17143   +2.07%

BenchmarkTCPPersistent                  81670         7782  -90.47%
BenchmarkTCPPersistent-2                26598         4808  -81.92%
BenchmarkTCPPersistent-4                15633         3674  -76.50%
BenchmarkTCPPersistent-8                18093         2407  -86.70%
BenchmarkTCPPersistent-16               17472         1875  -89.27%
BenchmarkTCPPersistent-32                7679         1637  -78.68%

BenchmarkTCPPersistentTimeout           83186         7859  -90.55%
BenchmarkTCPPersistentTimeout-2         26883         5952  -77.86%
BenchmarkTCPPersistentTimeout-4         15776         3823  -75.77%
BenchmarkTCPPersistentTimeout-8         18180         2567  -85.88%
BenchmarkTCPPersistentTimeout-16        17454         1903  -89.10%
BenchmarkTCPPersistentTimeout-32         7798         1627  -79.14%

R=golang-dev, iant, bradfitz, dave, rsc
CC=golang-dev
https://codereview.appspot.com/7579044
runtime: do not memprofile settype_flush
Fixes issue 4850.

R=golang-dev, bradfitz, rsc
CC=golang-dev
https://codereview.appspot.com/7745044
net: deflake TestDialTimeout

Fixes issue 3867.
Fixes issue 3307.

R=bradfitz, dvyukov
CC=golang-dev
https://codereview.appspot.com/7735044

Committer: Brad Fitzpatrick <bradfitz@golang.org>
runtime: refactor os-specific code

thread_GOOS.c becomes os_GOOS.c.

signal_GOOS_GOARCH.c becomes os_GOOS_GOARCH.c,
but with non-GOARCH-specific code moved into os_GOOS.c.

The actual arch-specific signal handler moves into signal_GOARCH.c
to avoid per-GOOS duplication.

New files signal_GOOS_GOARCH.h provide macros for
accessing fields of the very system-specific signal info structs.

Lots moving, but nothing changing.
This is a preliminarly cleanup so I can work on the signal
handling code to fix some open issues without having to
make each change 13 times.

Tested on Linux and OS X, 386 and amd64.
Will fix Plan 9, Windows, and ARM after the fact if necessary.
(Plan 9 and Windows should be fine; ARM will probably have some typos.)

Net effect: -1081 lines of code.

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/7565048
cmd/ld: another use-after-free

This only shows up in the duplicate symbol error message.

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/7486053
runtime, net: fix arm build

Bring net/fd_linux.go back (it was deleted this morning)
because it is still needed for ARM.

Fix a few typos in the runtime reorg.

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/7759046
database/sql: document non-open of Open; add Ping

Fixes issue 4804

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/7819043
runtime: freebsd, netbsd build fixes after reorg

R=golang-dev
CC=golang-dev
https://codereview.appspot.com/7826044
runtime: fix freebsd arm for hash change

Was missing definitions of open, read, close.

R=golang-dev
CC=golang-dev
https://codereview.appspot.com/7828043
runtime: fix build for freebsd/arm after reorg

R=golang-dev
CC=golang-dev
https://codereview.appspot.com/7701046
runtime: fix netbsd again after reorg

This time for sure.
That C file sure looked like a header file to me. :-)

R=golang-dev
CC=golang-dev
https://codereview.appspot.com/7830043
runtime: fix netbsd after reorg (again)

R=golang-dev
CC=golang-dev
https://codereview.appspot.com/7719046
database/sql: associate a mutex with each driver interface

The database/sql/driver docs make this promise:

   "Conn is a connection to a database. It is not used
   concurrently by multiple goroutines."

That promises exists as part of database/sql's overall
goal of making drivers relatively easy to write.

So far this promise has been kept without the use of locks by
being careful in the database/sql package, but sometimes too
careful. (cf. golang.org/issue/3857)

The CL associates a Mutex with each driver.Conn, and with the
interface value progeny thereof. (e.g. each driver.Tx,
driver.Stmt, driver.Rows, driver.Result, etc) Then whenever
those interface values are used, the Locker is locked.

This CL should be a no-op (aside from some new Lock/Unlock
pairs) and doesn't attempt to fix Issue 3857 or Issue 4459,
but should make it much easier in a subsequent CL.

Update issue 3857

R=golang-dev, adg
CC=golang-dev
https://codereview.appspot.com/7803043
misc/dashboard/codereview: add more people.

I picked everyone who has committed a CL on behalf of someone else in recent times.

R=r, rsc
CC=golang-dev
https://codereview.appspot.com/7836044
runtime: use 64-bit negative error code on 64-bit machines

NEGL does a negation of the bottom 32 bits and then zero-extends to 64 bits,
resulting in a negative 32-bit number but a positive 64-bit number.

NEGQ does a full 64-bit negation, so that the result is negative both as
a 32-bit and as a 64-bit number.

This doesn't matter for the functions that are declared to return int32.
It only matters for the ones that return int64 or void* [sic].

This will fix the current incorrect error in the OpenBSD/amd64 build.
The build will still be broken, but it won't report a bogus error.

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7536046
misc/dashboard/codereview: better debugging when some fetches fail.

R=rsc
CC=golang-dev
https://codereview.appspot.com/7836045
CONTRIBUTORS: add Jonathan Nieder (Google CLA)

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7842043
go/build: allow ~ in middle of path, just not at beginning

CL 7799045 relaxed the restriction in cmd/go on ~ in GOPATH
to allow paths with ~ in the middle while continuing to
protect against the common mistake of using GOPATH='~/home'
instead of GOPATH=~/home.  Unfortunately go/build still
filters these paths out:

        $ GOPATH=/tmp/test~ing go build
        test.go:22:2: cannot find package "test" in any of:
                /usr/lib/go/test (from $GOROOT)
                ($GOPATH not set)

So relax the requirement in go/build, too.

R=golang-dev, rsc
CC=golang-dev
https://codereview.appspot.com/7826043

Committer: Russ Cox <rsc@golang.org>