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18530 Commits

Author SHA1 Message Date
Austin Clements
f90d802b61 cmd/compile: avoid temporary in race mode with slice and append
Currently when the race detector is enabled, orderexpr always creates
a temporary for slice and append operations. This used to be necessary
because the race detector had a different code path for slice
assignment that required this temporary. Unfortunately, creating this
temporary inhibits the optimization that eliminates write barriers
when a slice is assigned only to change its length or cap. For most
code, this is bad for performance, and in go:nowritebarrier functions
in the runtime, this can mean the difference between compiling and not
compiling.

Now the race detector uses the regular slice assignment code, so
creating this temporary is no longer necessary.

Change-Id: I296042e1edc571b77c407f709c2ff9091c4aa795
Reviewed-on: https://go-review.googlesource.com/10456
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-28 17:39:26 +00:00
Austin Clements
4a1957d0aa runtime: use stripped test environment for TestGdbPython
Most runtime tests that invoke the compiler to build a sub-test binary
do so with a special environment constructed by testEnv that strips
out environment variables that should apply to the test but not to the
build.

Fix TestGdbPython to use this test environment when invoking go build,
like other tests do.

Change-Id: Iafdf89d4765c587cbebc427a5d61cb8a7e71b326
Reviewed-on: https://go-review.googlesource.com/10455
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-28 17:39:08 +00:00
Robert Griesemer
0c02b33acd math/big: fix latent decimal conversion bug
A decimal represented 0.0 with a 0-length mantissa and undefined
exponent, but the formatting code assumes a valid zero exponent
if the float value is 0.0. The code worked because we allocate a
new decimal value each time and because there's no rounding that
lead to 0.0.

Change-Id: Ifd771d7709de83b87fdbf141786286b4c3e13d4f
Reviewed-on: https://go-review.googlesource.com/10448
Reviewed-by: Alan Donovan <adonovan@google.com>
2015-05-28 16:02:32 +00:00
Ryan Brown
5ee552815c cmd/link/internal/ld: Skip combining dwarf for darwin/arm.
Change-Id: I3a6df0a76d57db7cb6910f4179a6ce380f219a37
Reviewed-on: https://go-review.googlesource.com/10442
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-28 12:04:35 +00:00
Shenghou Ma
0f27b91522 cmd/internal/obj: make arm64 use RegTo2 instead of a full fledged Addr To2
It shrinks Prog type from 448 bytes down to 376 bytes on amd64.

It also makes sense, because I don't know of any modern architecture
that have instructions which can write to two destinations, none of
which is a register (even x86 doesn't have such instructions).

Change-Id: I3061f1c9ac93d79ee2b92ecb9049641d0e0f6300
Reviewed-on: https://go-review.googlesource.com/10330
Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-28 01:09:38 +00:00
Brad Fitzpatrick
4e4c1f9c4d cmd/dist: don't run go list when running a specific test
This speeds up sharded builds notably, by 1 second * the number of
tests.

Change-Id: Ib0295c31e4974f3003f72cb16c48949812b6f22b
Reviewed-on: https://go-review.googlesource.com/10460
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-28 00:31:37 +00:00
Robert Griesemer
635cd91eb4 math/big: more cleanups (msbxx, nlzxx functions)
Change-Id: Ibace718452b6dc029c5af5240117f5fc794c38cf
Reviewed-on: https://go-review.googlesource.com/10388
Reviewed-by: Alan Donovan <adonovan@google.com>
2015-05-27 22:10:15 +00:00
Robert Griesemer
0858d8847d math/big: removed TODO, cleanups
- factor out handling of sign
- rename bstring, pstring to fmtB, fmtP consistent with fmtE, fmtF
- move all float-to-string conversion functions into ftoa.go
- no functional changes

Change-Id: I5970ecb874dc9c387630b59147d90bda16a5d8e6
Reviewed-on: https://go-review.googlesource.com/10387
Reviewed-by: Alan Donovan <adonovan@google.com>
2015-05-27 22:09:47 +00:00
Robert Griesemer
acd82d5017 strconv: minor internal comment fix
Change-Id: I590ac9e976d4044d1f4f280137ea9b38851a9fc2
Reviewed-on: https://go-review.googlesource.com/10424
Reviewed-by: Alan Donovan <adonovan@google.com>
2015-05-27 22:02:02 +00:00
Brad Fitzpatrick
553f45a61e archive/zip: sanity check the TOC's declared number of files
Fixes #10956

Change-Id: If8517094f04250c4f722e1e899a237eb6e170eb9
Reviewed-on: https://go-review.googlesource.com/10421
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
2015-05-27 18:14:58 +00:00
David Chase
05d8f1d166 cmd/compile: propagate correct line numbers in treecopy
Added a lineno parameter to treecopy and listtreecopy
(ignored if = 0).  When nodes are copied the copy is
assigned the non-zero lineno (normally this would be
the destination).

Fixes #8183

Change-Id: Iffb767a745093fb89aa08bf8a7692c2f0122be98
Reviewed-on: https://go-review.googlesource.com/10334
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-27 17:29:15 +00:00
Michael Hudson-Doyle
c949cff6a7 cmd/internal/ld: do not depend on local symbols to read a type's gcdata
We already read the address of a gcmask/gcprog out of the type data, but I
didn't know how many bytes to read. But it turns out that it's easy to
calculate, so change to do that. This means that we no longer depend on the
local symbols being present, allowing me to strip the shared libraries for
distribution and make them a lot smaller.

As a bonus, this makes LSym another 24 bytes smaller, down to 296 bytes now.

Change-Id: I379d359e28d63afae6753efd23efdf1fbb716992
Reviewed-on: https://go-review.googlesource.com/10377
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-27 14:11:16 +00:00
Michael Hudson-Doyle
bcc1870fcf cmd/internal/ld: store the libraries a shared library was linked against in a note
The motivation for this is the innocuous looking test case that is added. This
creates a stack exe -> libdep2.so -> libdep.so -> libruntime.so. The problem
comes from the fact that a function from libdep.so gets inlined all the way
into exe. This (unsurprisingly) means that the object file for exe references
symbols from libdep.so, which means that -ldep needs to be passed when linking
exe and it isn't. The fix is simply to pass it -- there is no harm in passing
it when it's not needed.

The thing is, it's not clear at all in the current code to see how the linker
can know that libdep2 is linked against libdep. It could look through the
DT_NEEDED entries in libdep2 and try to guess which are Go libraries, but it
feels better to be explicit. So this adds another SHT_NOTE section that lists
the shared libraries a shared library was linked against, and makes sure the
complete set of depended upon shared libraries is passed to the external
linker.

Change-Id: I79aa6f98b4db4721d657a7eb7b7f062269bf49e2
Reviewed-on: https://go-review.googlesource.com/10376
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-27 13:25:32 +00:00
Håvard Haugen
02f4084299 archive/tar: don't panic on negative file size
Fixes #10959.
Fixes #10960.

Change-Id: I9a81a0e2b8275338d0d1c3f7f7265e0fd91f3de2
Reviewed-on: https://go-review.googlesource.com/10402
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Symonds <dsymonds@golang.org>
2015-05-27 11:52:04 +00:00
Michael Hudson-Doyle
65518032b9 cmd/link/internal/ld: put abi hash into a note
This makes for a more stable API for tools (including cmd/link itself) to
extract the abi hash from a shared library and makes it possible at all for a
library that has had the local symbol table removed.

The existing note-writing code only supports writing notes into the very start
of the object file so they are easy to find in core dumps. This doesn't apply
to the "go" notes and means that all notes have to fit into a fixed size
budget. That's annoying now we have more notes (and the next CL will add
another one) so this does a little bit of work to make adding notes that do not
have to go at the start of the file easier and moves the writing of the package
list note over to that mechanism, which lets me revert a hack that increased
the size budget mentioned above for -buildmode=shared builds.

Change-Id: I6077a68d395c8a2bc43dec8506e73c71ef77d9b9
Reviewed-on: https://go-review.googlesource.com/10375
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-27 04:48:29 +00:00
Michael Hudson-Doyle
cf2736c4c5 cmd/link: replace interface{} fields with concrete types
The LSym.Section and Section.Elfsect fields were defined as interface{} but
always had the same concrete type (*Section and *ElfShdr respectively) so just
define them with that type. Reduces size of LSym from 328 to 320 bytes and
reduces best-of-10 maxresident size from 246028k to 238036k when linking
libstd.so.

Change-Id: Ie7112c53e4c2c7ce5fe233b81372aa5633f572e8
Reviewed-on: https://go-review.googlesource.com/10410
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-27 04:03:32 +00:00
Ryan Brown
bc89ad598e cmd/internal/objfile: Skip mach-o debug symbols.
This allows objdump to disassemble gcc generated binaries on OS X 10.6.

Change-Id: I1a5bfbf7c252e78215ef1f122520689d5ce6ddca
Reviewed-on: https://go-review.googlesource.com/10383
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-26 23:00:00 +00:00
Brad Fitzpatrick
fad25c29a1 archive/zip: verify number of File bytes read at EOF
Fixes #10957

Change-Id: I75fe25133dfcebd1682a8058b1c354ec894cc997
Reviewed-on: https://go-review.googlesource.com/10384
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-26 22:18:21 +00:00
Ian Lance Taylor
b2f95a167a cmd/link/internal/amd64: -buildmode=c-archive forces external link mode
At some point this code should probably move to cmd/link/internal/ld,
but at least for now just handle c-archive like c-shared.

Change-Id: Ic17656529cb0fe189a37f15e670350ab13bb5276
Reviewed-on: https://go-review.googlesource.com/10385
Reviewed-by: Andrew Gerrand <adg@golang.org>
2015-05-26 21:49:45 +00:00
Alexandre Cesaro
1defd227bd net/mail: add AddressParser type
Add the AddressParser type to allow decoding any charset in
mail addresses.

Fixes #7079

Change-Id: Ic34efb3e3d804a4e17149a6c38cfd73f5f275ab7
Reviewed-on: https://go-review.googlesource.com/10392
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-05-26 16:50:35 +00:00
Russ Cox
972a478ddf cmd/compile: don't cater to race detector in write barriers
The new lower-level barriers work fine and don't need special handling,
because they appear to the race detector as (visible) ordinary assignments.

Change-Id: I7477d73a3deecbebf68716580678c595cc4151e3
Reviewed-on: https://go-review.googlesource.com/10316
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-26 13:50:08 +00:00
Ian Lance Taylor
714291f2d8 cmd/link/internal/ld: if -v, display external linker output
It can be useful when debugging to be able to see what the external
linker is doing even when it succeeds.  In particular this permits
passing -v to the external linker to see precisely what it is doing.

Change-Id: Ifed441912d97bbebea20303fdb899e140b380215
Reviewed-on: https://go-review.googlesource.com/10363
Reviewed-by: Minux Ma <minux@golang.org>
2015-05-26 03:59:14 +00:00
Ian Lance Taylor
ac7ffdfa10 cmd/go: permit C files if the package uses SWIG
They will be compiled and added to the archive, just as though the
package used cgo.  In effect all SWIG packages now use cgo anyhow.

Change-Id: I5d5a28ed0ec4295f24036b2834218bc980f080d0
Reviewed-on: https://go-review.googlesource.com/10146
Reviewed-by: Minux Ma <minux@golang.org>
2015-05-26 03:58:10 +00:00
David Crawshaw
0b36e1272d androidtest.bash: clean up stale GOROOT
Fixes #10806

Change-Id: I1be1f28ad60c913105d8417c42ec1b262f101f72
Reviewed-on: https://go-review.googlesource.com/10391
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-05-25 20:53:26 +00:00
Elias Naur
8017ace496 runtime: don't always block all signals on OpenBSD
Implement the changes from CL 10173 on OpenBSD.

Change-Id: I2db1cd8141fd392a34753a1b8113e2e0401173b9
Reviewed-on: https://go-review.googlesource.com/10342
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-23 17:42:43 +00:00
Mikio Hara
eeb64b7fef net: adjust dual stack support on dragonfly
As mentioned in
http://gitweb.dragonflybsd.org/dragonfly.git/commit/727ccde8cce813911d885b7f6ed749dcea68a886,
DragonFly BSD is dropping support for IPv6 IPv4-mapped address.
Unfortunately, on some released versions we see the kernels pretend to
support the feature but actually not (unless tweaking some kernel states
via sysctl.)

To avoid unpredictable behavior, the net package assumes that all
DragonFly BSD kernels don't support IPv6 IPv4-mapped address.

Fixes #10764.

Change-Id: Ic7af3651e0372ec03774432fbb6b2eb0c455e994
Reviewed-on: https://go-review.googlesource.com/10071
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-23 05:22:57 +00:00
Mikio Hara
cca39ff3b1 net: don't show verbose information when -test.v=false
Updates #10845.

Change-Id: I4cec670c7db88c50a6e5619e611744e161d73b3c
Reviewed-on: https://go-review.googlesource.com/10131
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-23 01:13:51 +00:00
Robert Griesemer
2df1ccdbc6 math/big: Always print exponent sign when using 'p' exponent for Floats.
Float.Format supports the 'b' and 'p' format, both of which print
a binary ('p') exponent. The 'b' format always printed a sign ('+'
or '-') for the exponent; the 'p' format only printed a negative
sign for the exponent. This change makes the two consistent. It
also makes the 'p' format easier to read if the exponent is >= 0.

Also:
- Comments added elsewhere.

Change-Id: Ifd2e01bdafb3043345972ca22a90248d055bd29b
Reviewed-on: https://go-review.googlesource.com/10359
Reviewed-by: Alan Donovan <adonovan@google.com>
2015-05-22 23:12:51 +00:00
Robert Griesemer
1893d3b320 cmd/compile/internal/big: update and apply vendor.bash
Package-external tests must use the vendored math/big package, not
the original one, otherwise tests may fail if there are discrepancies
in the implementation.

Change-Id: Ic5f0489aa6420ffea1f488633453f871ce1f0f66
Reviewed-on: https://go-review.googlesource.com/10380
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-22 22:46:44 +00:00
Robert Griesemer
75250a9f79 cmd/compile/internal/gc: simplify mpgetflt (remove switch and indirection)
Change-Id: I6ae3534defdae9367e1b856dbb8e846c3263a758
Reviewed-on: https://go-review.googlesource.com/10358
Reviewed-by: Alan Donovan <adonovan@google.com>
2015-05-22 21:23:04 +00:00
Robert Griesemer
bd7c1f1fb3 cmd/compile/internal/gc: correctly use Float32 in mpgetfltN
This resolves the compiler part of issue #10321.

Change-Id: I44b9909f992b37dd34b1c5292decd12de3d3a65e
Reviewed-on: https://go-review.googlesource.com/10355
Reviewed-by: Alan Donovan <adonovan@google.com>
2015-05-22 21:20:14 +00:00
Shenghou Ma
1c0498fc05 go/build: make ArchChar always return "?" to match docs
Change-Id: I56f825f81aead9ded7af07a02188a52d3650ccf8
Reviewed-on: https://go-review.googlesource.com/10333
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-05-22 21:19:49 +00:00
Robert Griesemer
db0594b633 cmd/compile/internal/big: update to latest version (run sh vendor.bash)
No manual code changes.

This will permit addressing the compiler aspect of issue #10321 in a
subsequent change.

Change-Id: I3376dc38cafa0ec98bf54de33293015d0183cc82
Reviewed-on: https://go-review.googlesource.com/10354
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2015-05-22 21:16:02 +00:00
Robert Griesemer
5ffbca4823 math/big: fix Float.Float64 conversion for denormal corner cases
- This change uses the same code as for Float32 and fixes the case
  of a number that gets rounded up to the smallest denormal.

- Enabled correspoding test case.

Change-Id: I8aac874a566cd727863a82717854f603fbdc26c6
Reviewed-on: https://go-review.googlesource.com/10352
Reviewed-by: Alan Donovan <adonovan@google.com>
2015-05-22 21:10:43 +00:00
Robert Griesemer
8de8925c77 math/big: add more Float.Float64 conversion tests
- structure the Float64 conversion tests the same way as for Float32
- add additional test cases, including one that exposes a current issue
  (currently disabled, same issue as was fixed for Float32)

The Float64 fix will be in a subsequent change for easier reviewing.

Change-Id: I95dc9e8d1f6b6073a98c7bc2289e6d3248fc3420
Reviewed-on: https://go-review.googlesource.com/10351
Reviewed-by: Alan Donovan <adonovan@google.com>
2015-05-22 21:06:01 +00:00
Robert Griesemer
79afb43a0a math/big: fix Float.Float32 conversion for denormal corner cases
The existing code was incorrect for numbers that after rounding would
become the smallest denormal float32 (instead the result was 0). This
caused all.bash to fail if Float32() were used in the compiler for
constant arithmetic (there's currently a work-around - see also issue
10321.

This change fixes the implementation of Float.Float32 and adds
corresponding test cases. Float32 and Float64 diverge at this point.
For ease of review, this change only fixes Float32. Float64 will be
made to match in a subsequent change.

Fixes #10321.

Change-Id: Iccafe37c1593a4946bc552e4ad2045f69be62d80
Reviewed-on: https://go-review.googlesource.com/10350
Reviewed-by: Alan Donovan <adonovan@google.com>
2015-05-22 21:05:25 +00:00
Elias Naur
84cfba17c2 runtime: don't always unblock all signals
Ian proposed an improved way of handling signals masks in Go, motivated
by a problem where the Android java runtime expects certain signals to
be blocked for all JVM threads. Discussion here

https://groups.google.com/forum/#!topic/golang-dev/_TSCkQHJt6g

Ian's text is used in the following:

A Go program always needs to have the synchronous signals enabled.
These are the signals for which _SigPanic is set in sigtable, namely
SIGSEGV, SIGBUS, SIGFPE.

A Go program that uses the os/signal package, and calls signal.Notify,
needs to have at least one thread which is not blocking that signal,
but it doesn't matter much which one.

Unix programs do not change signal mask across execve.  They inherit
signal masks across fork.  The shell uses this fact to some extent;
for example, the job control signals (SIGTTIN, SIGTTOU, SIGTSTP) are
blocked for commands run due to backquote quoting or $().

Our current position on signal masks was not thought out.  We wandered
into step by step, e.g., http://golang.org/cl/7323067 .

This CL does the following:

Introduce a new platform hook, msigsave, that saves the signal mask of
the current thread to m.sigsave.

Call msigsave from needm and newm.

In minit grab set up the signal mask from m.sigsave and unblock the
essential synchronous signals, and SIGILL, SIGTRAP, SIGPROF, SIGSTKFLT
(for systems that have it).

In unminit, restore the signal mask from m.sigsave.

The first time that os/signal.Notify is called, start a new thread whose
only purpose is to update its signal mask to make sure signals for
signal.Notify are unblocked on at least one thread.

The effect on Go programs will be that if they are invoked with some
non-synchronous signals blocked, those signals will normally be
ignored.  Previously, those signals would mostly be ignored.  A change
in behaviour will occur for programs started with any of these signals
blocked, if they receive the signal: SIGHUP, SIGINT, SIGQUIT, SIGABRT,
SIGTERM.  Previously those signals would always cause a crash (unless
using the os/signal package); with this change, they will be ignored
if the program is started with the signal blocked (and does not use
the os/signal package).

./all.bash completes successfully on linux/amd64.

OpenBSD is missing the implementation.

Change-Id: I188098ba7eb85eae4c14861269cc466f2aa40e8c
Reviewed-on: https://go-review.googlesource.com/10173
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-22 20:24:08 +00:00
Dave Cheney
994b2d4645 net: fix panic in TestDialerDualStack
This change ensures that the test does not try to close dual stack
listeners which have not yet been opened.

Spotted in crash here
http://build.golang.org/log/e5843777df400868ce708b7f00c50dc32c2ec478

Change-Id: I79d513e166effb3e018e2b9dfc23751d92fcbe4b
Reviewed-on: https://go-review.googlesource.com/10371
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-22 03:27:59 +00:00
David Chase
e5060c7f75 cmd/internal/gc: move check for large-hence-heap-allocated types into escape analysis
Before this change, the check for too-large arrays (and other large
types) occurred after escape analysis.  If the data moved off stack
and onto the heap contained any pointers, it would therefore escape,
but because the too-large check occurred after escape analysis this
would not be recorded and a stack pointer would leak to the heap
(see the modified escape_array.go for an example).

Some of these appear to remain, in calls to typecheck from within walk.

Also corrected a few comments in escape_array.go about "BAD"
analysis that is now done correctly.

Enhanced to move aditional EscNone-but-large-so-heap checks into esc.c.

Change-Id: I770c111baff28a9ed5f8beb601cf09dacc561b83
Reviewed-on: https://go-review.googlesource.com/10268
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-22 02:13:54 +00:00
David Chase
b19ec6842d cmd/internal/gc: make indirect calls properly escape-y
Indirect function and method calls should leak everything,
but they didn't.

This fix had no particular effect on the cost of running the
compiler on html/template/*.go and added a single new "escape"
to the standard library:

    syscall/syscall_unix.go:85: &b[0] escapes to heap
in
	if errno := m.munmap(uintptr(unsafe.Pointer(&b[0])),
	                     uintptr(len(b))); errno != nil {

Added specific escape testing to escape_calls.go
(and verified that it fails without this patch)

I also did a little code cleanup around the changes in esc.c.

Fixes #10925

Change-Id: I9984b701621ad4c49caed35b01e359295c210033
Reviewed-on: https://go-review.googlesource.com/10295
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-22 01:36:11 +00:00
Robert Griesemer
c344f751fc math/big: gofmt nat_test.go
Was apparently checked in by https://go-review.googlesource.com/#/c/9253/
without being gofmt-ed.

TBR: agl

Change-Id: I4d011dbaa15b7c5e73ca71f724f32951a0302dae
Reviewed-on: https://go-review.googlesource.com/10353
Reviewed-by: Robert Griesemer <gri@golang.org>
2015-05-22 01:09:34 +00:00
Vlad Krasnov
9279684908 math/big: Simple Montgomery Multiplication to accelerate Mod-Exp
On Haswell I measure anywhere between 2X to 3.5X speedup for RSA.
I believe other architectures will also greatly improve.
In the future may be upgraded by dedicated assembly routine.

Built-in benchmarks i5-4278U turbo off:

benchmark                         old ns/op     new ns/op     delta
BenchmarkRSA2048Decrypt           6696649       3073769       -54.10%
Benchmark3PrimeRSA2048Decrypt     4472340       1669080       -62.68%

Change-Id: I17df84f85e34208f990665f9f90ea671695b2add
Reviewed-on: https://go-review.googlesource.com/9253
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
Reviewed-by: Vlad Krasnov <vlad@cloudflare.com>
Run-TryBot: Adam Langley <agl@golang.org>
2015-05-22 00:25:25 +00:00
Russ Cox
001438bdfe runtime: fix callwritebarrier
Given a call frame F of size N where the return values start at offset R,
callwritebarrier was instructing heapBitsBulkBarrier to scan the block
of memory [F+R, F+R+N). It should only scan [F+R, F+N). The extra N-R
bytes scanned might lead into the next allocated block in memory.
Because the scan was consulting the heap bitmap for type information,
scanning into the next block normally "just worked" in the sense of
not crashing.

Scanning the extra N-R bytes of memory is a problem mainly because
it causes the GC to consider pointers that might otherwise not be
considered, leading it to retain objects that should actually be freed.
This is very difficult to detect.

Luckily, juju turned up a case where the heap bitmap and the memory
were out of sync for the block immediately after the call frame, so that
heapBitsBulkBarrier saw an obvious non-pointer where it expected a
pointer, causing a loud crash.

Why is there a non-pointer in memory that the heap bitmap records as
a pointer? That is more difficult to answer. At least one way that it
could happen is that allocations containing no pointers at all do not
update the heap bitmap. So if heapBitsBulkBarrier walked out of the
current object and into a no-pointer object and consulted those bitmap
bits, it would be misled. This doesn't happen in general because all
the paths to heapBitsBulkBarrier first check for the no-pointer case.
This may or may not be what happened, but it's the only scenario
I've been able to construct.

I tried for quite a while to write a simple test for this and could not.
It does fix the juju crash, and it is clearly an improvement over the
old code.

Fixes #10844.

Change-Id: I53982c93ef23ef93155c4086bbd95a4c4fdaac9a
Reviewed-on: https://go-review.googlesource.com/10317
Reviewed-by: Austin Clements <austin@google.com>
2015-05-21 19:14:03 +00:00
Austin Clements
a5c3bbe0b4 runtime: eliminate write barrier from adjustpointers
Currently adjustpointers invokes a write barrier for every stack slot
it updates. This is safe---the write barrier always does nothing
because the new value is never a heap pointer---but it's unnecessary
overhead in performance and complexity.

Fix this by rewriting adjustpointers to work with *uintptrs instead of
*unsafe.Pointers. As an added bonus, this makes the code cleaner.

name                   old mean              new mean              delta
BinaryTree17            3.35s × (0.98,1.01)   3.33s × (0.99,1.02)    ~    (p=0.095 n=20+19)
Fannkuch11              2.49s × (1.00,1.01)   2.52s × (0.99,1.01)  +1.23% (p=0.000 n=19+20)
FmtFprintfEmpty        52.2ns × (0.99,1.02)  52.2ns × (0.99,1.02)    ~    (p=0.766 n=19+19)
FmtFprintfString        181ns × (0.99,1.02)   179ns × (0.99,1.01)  -1.06% (p=0.000 n=20+19)
FmtFprintfInt           177ns × (0.99,1.01)   173ns × (0.99,1.02)  -2.26% (p=0.000 n=17+20)
FmtFprintfIntInt        300ns × (0.99,1.01)   302ns × (0.99,1.01)  +0.76% (p=0.000 n=19+20)
FmtFprintfPrefixedInt   253ns × (0.99,1.02)   256ns × (0.99,1.01)  +0.96% (p=0.000 n=20+19)
FmtFprintfFloat         334ns × (0.99,1.02)   334ns × (1.00,1.01)    ~    (p=0.243 n=20+19)
FmtManyArgs            1.16µs × (0.99,1.01)  1.17µs × (0.99,1.02)  +0.88% (p=0.000 n=20+20)
GobDecode              9.16ms × (0.99,1.02)  9.18ms × (1.00,1.00)  +0.21% (p=0.048 n=20+17)
GobEncode              7.03ms × (0.99,1.01)  7.05ms × (0.99,1.01)    ~    (p=0.091 n=19+19)
Gzip                    374ms × (0.99,1.01)   372ms × (0.99,1.02)  -0.50% (p=0.008 n=18+20)
Gunzip                 92.9ms × (0.99,1.01)  92.5ms × (1.00,1.01)  -0.47% (p=0.002 n=19+19)
HTTPClientServer       53.1µs × (0.98,1.01)  52.5µs × (0.99,1.01)  -0.98% (p=0.000 n=20+19)
JSONEncode             17.4ms × (0.99,1.02)  17.5ms × (0.99,1.01)    ~    (p=0.061 n=19+20)
JSONDecode             66.0ms × (0.99,1.02)  64.7ms × (0.99,1.01)  -1.87% (p=0.000 n=20+20)
Mandelbrot200          3.94ms × (1.00,1.01)  3.95ms × (1.00,1.01)    ~    (p=0.799 n=18+19)
GoParse                3.89ms × (0.99,1.02)  3.86ms × (0.99,1.01)  -0.70% (p=0.016 n=20+19)
RegexpMatchEasy0_32     102ns × (0.99,1.02)   102ns × (1.00,1.01)    ~    (p=0.557 n=20+18)
RegexpMatchEasy0_1K     353ns × (0.99,1.02)   341ns × (0.99,1.01)  -3.38% (p=0.000 n=20+20)
RegexpMatchEasy1_32    85.0ns × (0.99,1.02)  85.0ns × (0.99,1.01)    ~    (p=0.851 n=19+20)
RegexpMatchEasy1_1K     521ns × (0.99,1.02)   506ns × (1.00,1.01)  -2.85% (p=0.000 n=20+18)
RegexpMatchMedium_32    142ns × (0.99,1.02)   141ns × (1.00,1.01)  -1.17% (p=0.000 n=20+19)
RegexpMatchMedium_1K   42.8µs × (0.99,1.01)  42.3µs × (0.99,1.01)  -1.07% (p=0.000 n=20+19)
RegexpMatchHard_32     2.17µs × (0.99,1.01)  2.16µs × (1.00,1.01)  -0.51% (p=0.042 n=20+18)
RegexpMatchHard_1K     65.6µs × (0.99,1.01)  64.8µs × (1.00,1.00)  -1.21% (p=0.000 n=20+17)
Revcomp                 581ms × (0.99,1.04)   536ms × (1.00,1.01)  -7.71% (p=0.000 n=20+18)
Template               77.2ms × (0.99,1.01)  76.8ms × (0.99,1.01)    ~    (p=0.426 n=20+18)
TimeParse               369ns × (0.99,1.02)   371ns × (1.00,1.01)    ~    (p=0.117 n=20+19)
TimeFormat              371ns × (0.99,1.02)   391ns × (0.99,1.01)  +5.33% (p=0.000 n=20+19)

Change-Id: I5b952ba577ac4365c8c87db837c5804a1e30b7be
Reviewed-on: https://go-review.googlesource.com/10293
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-21 18:35:49 +00:00
Josh Bleecher Snyder
1378173785 cmd/internal/obj: remove F3t field from Prog
F3t was effectively a local variable.
Remove it.

This shrinks obj.Prog from 456 to 448 bytes,
which places it in a smaller malloc class.

This reduces the memory usage of the compiler
while compiling the rotate tests by ~2.75%.

Change-Id: I31cc9dd67269851a430b56bcc7d255c9349eb522
Reviewed-on: https://go-review.googlesource.com/10255
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-05-21 18:28:50 +00:00
Russ Cox
216e5c747d cmd/go: set correct install location for cmd/compile and cmd/link
Without this, they install to $GOROOT/bin.

Change-Id: Iae4b8f59c8392f6abd841490e56922738089f8d4
Reviewed-on: https://go-review.googlesource.com/10297
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-21 17:41:42 +00:00
Russ Cox
cf932cd897 all: retire architecture letter in file names, public API
This CL removes the remaining visible uses of the "architecture letter" concept.
(They are no longer in tool names nor in source directory names.)

Because the architecture letter concept is now gone, delete GOCHAR
from "go env" output, and change go/build.ArchChar to return an
error always.

The architecture letter is still used in the compiler and linker sources
as a clumsy architecture enumeration, but that use is not visible to
Go users and can be cleaned up separately.

Change-Id: I4d97a38f372003fb610c9c5241bea440d9dbeb8d
Reviewed-on: https://go-review.googlesource.com/10289
Reviewed-by: Rob Pike <r@golang.org>
2015-05-21 17:32:17 +00:00
Russ Cox
0f4132c907 all: build and use go tool compile, go tool link
This CL fixes the build to use the newly created go tool compile
and go tool link in place of go tool 5g, go tool 5l, and so on.

See golang-dev thread titled "go tool compile, etc" for background.

Although it was not a primary motivation, this conversion does
reduce the wall clock time and cpu time required for make.bash
by about 10%.

Change-Id: I79cbbdb676cab029db8aeefb99a53178ff55f98d
Reviewed-on: https://go-review.googlesource.com/10288
Reviewed-by: Rob Pike <r@golang.org>
2015-05-21 17:32:03 +00:00
Russ Cox
17eba6e6b7 cmd/compile, cmd/link: create from 5g, 5l, etc
Trivial merging of 5g, 6g, ... into go tool compile,
and similarlly 5l, 6l, ... into go tool link.
The files compile/main.go and link/main.go are new.
Everything else in those directories is a move followed by
change of imports and package name.

This CL breaks the build. Manual fixups are in the next CL.

See golang-dev thread titled "go tool compile, etc" for background.

Change-Id: Id35ff5a5859ad9037c61275d637b1bd51df6828b
Reviewed-on: https://go-review.googlesource.com/10287
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Rob Pike <r@golang.org>
2015-05-21 17:31:51 +00:00
Russ Cox
2a141dedc4 cmd/link: move to cmd/newlink
In preparation for making the current linker cmd/link.
If cmd/newlink is ever completed, it can be moved back.

See golang-dev thread titled "go tool compile, etc" for background.

Change-Id: I4029580f470038240c5181a37ea4202ba971f9ef
Reviewed-on: https://go-review.googlesource.com/10286
Reviewed-by: Rob Pike <r@golang.org>
2015-05-21 17:31:40 +00:00
Ryan Brown
be59731d9f cmd/internal/ld: output dwarf in external link mode on darwin
Fixes #8973

Change-Id: I746fae430db6d8f9ebd33586b8cffcb31d688cc8
Reviewed-on: https://go-review.googlesource.com/10284
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-21 17:27:32 +00:00
Rick Hudson
5b66e5d0d8 runtime: turn work buffer tracing off by default
During development we ran with monitoring code turned
on by default. This CL turns the work buffer monitoring
off. Performance change on most go1 benchmarks is small
or insignificant.

name                   old mean              new mean              delta
BinaryTree17            3.35s × (0.99,1.01)   3.35s × (0.99,1.01)    ~    (p=0.841 n=5+5)
Fannkuch11              2.59s × (1.00,1.01)   2.55s × (1.00,1.00)  -1.65% (p=0.008 n=5+5)
FmtFprintfEmpty        52.5ns × (0.99,1.02)  53.2ns × (0.98,1.01)    ~    (p=0.063 n=5+5)
FmtFprintfString        181ns × (1.00,1.00)   180ns × (1.00,1.00)  -0.55% (p=0.029 n=4+4)
FmtFprintfInt           176ns × (1.00,1.01)   174ns × (1.00,1.00)  -0.91% (p=0.000 n=5+4)
FmtFprintfIntInt        298ns × (1.00,1.00)   299ns × (1.00,1.00)    ~    (p=0.143 n=4+4)
FmtFprintfPrefixedInt   250ns × (1.00,1.01)   246ns × (1.00,1.00)  -1.68% (p=0.000 n=5+4)
FmtFprintfFloat         340ns × (1.00,1.00)   340ns × (1.00,1.01)    ~    (p=0.643 n=5+5)
FmtManyArgs            1.16µs × (1.00,1.00)  1.15µs × (1.00,1.00)  -0.47% (p=0.016 n=5+5)
GobDecode              9.22ms × (1.00,1.00)  9.23ms × (1.00,1.00)    ~    (p=0.841 n=5+5)
GobEncode              7.00ms × (1.00,1.01)  7.09ms × (0.99,1.01)  +1.26% (p=0.016 n=5+5)
Gzip                    387ms × (1.00,1.00)   389ms × (0.99,1.02)    ~    (p=1.000 n=5+5)
Gunzip                 97.8ms × (1.00,1.00)  98.3ms × (1.00,1.00)  +0.51% (p=0.016 n=5+4)
HTTPClientServer       52.6µs × (1.00,1.01)  52.7µs × (1.00,1.01)    ~    (p=1.000 n=5+5)
JSONEncode             18.0ms × (0.99,1.02)  17.9ms × (1.00,1.00)    ~    (p=0.310 n=5+5)
JSONDecode             64.8ms × (0.99,1.02)  63.6ms × (1.00,1.00)  -1.94% (p=0.008 n=5+5)
Mandelbrot200          4.05ms × (1.00,1.00)  4.05ms × (1.00,1.00)    ~    (p=0.421 n=5+5)
GoParse                3.86ms × (1.00,1.01)  3.84ms × (0.99,1.01)    ~    (p=0.421 n=5+5)
RegexpMatchEasy0_32     101ns × (1.00,1.00)   102ns × (0.99,1.02)    ~    (p=0.238 n=4+5)
RegexpMatchEasy0_1K     346ns × (1.00,1.01)   345ns × (1.00,1.00)    ~    (p=0.333 n=5+4)
RegexpMatchEasy1_32    87.3ns × (0.99,1.02)  87.4ns × (1.00,1.00)    ~    (p=0.190 n=5+4)
RegexpMatchEasy1_1K     520ns × (1.00,1.00)   520ns × (1.00,1.01)    ~    (p=1.000 n=4+5)
RegexpMatchMedium_32    143ns × (1.00,1.00)   142ns × (1.00,1.00)  -0.70% (p=0.029 n=4+4)
RegexpMatchMedium_1K   43.2µs × (1.00,1.01)  43.2µs × (1.00,1.00)    ~    (p=0.841 n=5+5)
RegexpMatchHard_32     2.24µs × (1.00,1.01)  2.23µs × (1.00,1.01)  -0.63% (p=0.048 n=5+5)
RegexpMatchHard_1K     68.7µs × (1.00,1.00)  68.3µs × (1.00,1.00)  -0.56% (p=0.008 n=5+5)
Revcomp                 577ms × (1.00,1.01)   579ms × (1.00,1.00)    ~    (p=0.151 n=5+5)
Template               74.9ms × (1.00,1.00)  76.5ms × (1.00,1.00)  +2.11% (p=0.008 n=5+5)
TimeParse               359ns × (1.00,1.00)   362ns × (1.00,1.00)  +0.72% (p=0.008 n=5+5)
TimeFormat              369ns × (1.00,1.00)   371ns × (1.00,1.01)    ~    (p=0.071 n=5+5)

Change-Id: I4206a3f77a3d1450966b7a62ea7597aec44cb72f
Reviewed-on: https://go-review.googlesource.com/10294
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2015-05-21 16:09:24 +00:00
Austin Clements
719efc70eb runtime: make runtime.callers walk calling G, not g0
Currently runtime.callers invokes gentraceback with the pc and sp of
the G it is called from, but always passes g0 even if it was called
from a regular g. Right now this has no ill effects because
runtime.callers does not use either callback argument or the
_TraceJumpStack flag, but it makes the code fragile and will break
some upcoming changes.

Fix this by lifting the getg() call outside of the systemstack in
runtime.callers.

Change-Id: I4e1e927961c0e0cd4dcf28693be47df7bae9e122
Reviewed-on: https://go-review.googlesource.com/10292
Reviewed-by: Daniel Morsing <daniel.morsing@gmail.com>
Reviewed-by: Rick Hudson <rlh@golang.org>
2015-05-21 16:06:37 +00:00
Shenghou Ma
91191e7b7b encoding/gob: fix docs
Fixes #10908.

Change-Id: I5ac4bd90204bc230610dcced47ce5b2253e5a004
Reviewed-on: https://go-review.googlesource.com/10250
Reviewed-by: Rob Pike <r@golang.org>
2015-05-20 22:34:08 +00:00
Mikio Hara
49894be7b1 net: document that ListenMulticastUDP is for simple applications
Also mentions golang.org/x/net/ipv4 and golang.org/x/net/ipv6.

Change-Id: I653deac7a5e2b129237655a72d6c91207f1b1685
Reviewed-on: https://go-review.googlesource.com/9779
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-20 22:30:52 +00:00
Alan Donovan
ceb8fe45da go/parser: parse incomplete selection "fmt." as a blank selection "fmt._"
Formerly it would return a BadExpr.

This prevents partial syntax from being discarded, and makes the error
recovery logic more consistent with other places where an identifier
was expected but not found.

+ test

Change-Id: I223c0c0589e7ceb7207ae951b8f71b9275a1eb73
Reviewed-on: https://go-review.googlesource.com/10269
Reviewed-by: Robert Griesemer <gri@golang.org>
2015-05-20 20:57:49 +00:00
Rob Pike
8401b19e7e cmd/doc: fix handling of paths like ./fmt
An error in string slice offsets caused the loop to run forever if the
first character in the argument was a period.

Fixes #10833.

Change-Id: Iefb6aac5cff8864fe93d08e2600cb07d82c6f6df
Reviewed-on: https://go-review.googlesource.com/10285
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-20 20:53:14 +00:00
Rick Hudson
197aa9e64d runtime: remove unused quiesce code
This is dead code. If you want to quiesce the system the
preferred way is to use forEachP(func(*p){}).

Change-Id: Ic7677a5dd55e3639b99e78ddeb2c71dd1dd091fa
Reviewed-on: https://go-review.googlesource.com/10267
Reviewed-by: Austin Clements <austin@google.com>
2015-05-20 17:56:44 +00:00
Michael Hudson-Doyle
ae3e3610d5 cmd/go: change Package.Shlib to be the absolute path of the shared library
Makes little difference internally but makes go list output more useful.

Change-Id: I1fa1f839107de08818427382b2aef8dc4d765b36
Reviewed-on: https://go-review.googlesource.com/10192
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
2015-05-20 14:52:36 +00:00
Mikio Hara
7eec656bfd net: fix the series of TestLookup and external tests
On Windows, we need to make sure that the node under test has external
connectivity.

Fixes #10795.

Change-Id: I99f2336180c7b56474fa90a4a6cdd5a6c4dd3805
Reviewed-on: https://go-review.googlesource.com/10006
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-20 07:54:37 +00:00
Mikio Hara
17177a0daa net: fix data race in TestSocket{Conn,PacketConn}
Fixes #10891.

Change-Id: Ie432c9c5520ac29cea8fe6452628ec467567eea5
Reviewed-on: https://go-review.googlesource.com/10194
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-20 07:24:09 +00:00
Josh Bleecher Snyder
7bdb4a28a8 Revert "cmd/internal/ld: output dwarf in external link mode on darwin"
This reverts commit 8b83306cf2.

Change-Id: I3fb998bdf11eceef13e3997e336d86e7c5d47a60
Reviewed-on: https://go-review.googlesource.com/10254
Reviewed-by: Minux Ma <minux@golang.org>
2015-05-19 23:54:06 +00:00
Shenghou Ma
791bb4f5ae cmd/internal/gc: handle 64-bit const i/j/k in cgen_slice on ARM
386 is not affected because it doesn't use ginscmp.

Fixes #10843.

Change-Id: I1b3a133bd1e5fabc85236f15d060dbaa4c391cf3
Reviewed-on: https://go-review.googlesource.com/10116
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-19 22:58:51 +00:00
Didier Spezia
a1c1a763bc html/template: fix string iteration in replacement operations
In css, js, and html, the replacement operations are implemented
by iterating on strings (rune by rune). The for/range
statement is used. The length of the rune is required
and added to the index to properly slice the string.

This is potentially wrong because there is a discrepancy between
the result of utf8.RuneLen and the increment of the index
(set by the for/range statement). For invalid strings,
utf8.RuneLen('\ufffd') == 3, while the index is incremented
only by 1 byte.

htmlReplacer triggers a panic at slicing time for some
invalid strings.

Use a more robust iteration mechanism based on
utf8.DecodeRuneInString, and make sure the same
pattern is used for all similar functions in this
package.

Fixes #10799

Change-Id: Ibad3857b2819435d9fa564f06fc2ca8774102841
Reviewed-on: https://go-review.googlesource.com/10105
Reviewed-by: Rob Pike <r@golang.org>
2015-05-19 22:45:50 +00:00
Shenghou Ma
d6bbcea22a cmd/go: fix build
Change-Id: Ib6c121414c74f8a40eb87a52af8737502ce7216d
Reviewed-on: https://go-review.googlesource.com/10265
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2015-05-19 22:29:57 +00:00
Austin Clements
f763da3d34 cmd/internal/gc: remove incorrect "write barrier prohibited" error
Commit 9c9e36b pushed these errors down to where the write barriers
are actually emitted, but forgot to remove the original error that was
being pushed down.

Change-Id: I751752a896e78fb9e63d69f88e7fb8d1ff5d344c
Reviewed-on: https://go-review.googlesource.com/10264
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-19 21:03:01 +00:00
Alexander Zolotov
b3241912ff cmd/go: run gofmt from current GOROOT
The existing implementation executes `gofmt` binary from PATH
environment variable on invocation `go fmt` command.
Relying on PATH might lead to confusions for users with several Go installations.
It's more appropriate to run `gofmt` from GOBIN (if defined) or GOROOT.

Fixes #10755

Change-Id: I56d42a747319c766f2911508fab3994c3a366d12
Reviewed-on: https://go-review.googlesource.com/9900
Reviewed-by: Rob Pike <r@golang.org>
2015-05-19 20:54:34 +00:00
Ryan Brown
8b83306cf2 cmd/internal/ld: output dwarf in external link mode on darwin
Fixes #8973

Change-Id: Idd53fc6d9e6971ae31ed72a3df3cfdce0bfbc1fd
Reviewed-on: https://go-review.googlesource.com/8661
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
2015-05-19 20:34:06 +00:00
Russ Cox
9c9e36b340 cmd/internal/gc: sync nowritebarrier checks and write barrier insertion
Change-Id: I348223d0336e28d95b8e68d7653aa547acc7c9c3
Reviewed-on: https://go-review.googlesource.com/10262
Reviewed-by: Austin Clements <austin@google.com>
2015-05-19 19:20:32 +00:00
Russ Cox
c735064cde cmd/internal/gc: type of str[i] is byte, not uint8
Fixes #8745.

Change-Id: Id0641e3c0f259812b41ed871e83c68740feb2b19
Reviewed-on: https://go-review.googlesource.com/10261
Reviewed-by: Austin Clements <austin@google.com>
2015-05-19 19:20:25 +00:00
Rick Hudson
913db7685e runtime: run background mark helpers only if work is available
Prior to this CL whenever the GC marking was enabled and
a P was looking for work we supplied a G to help
the GC do its marking tasks. Once this G finished all
the marking available it would release the P to find another
available G. In the case where there was no work the P would drop
into findrunnable which would execute the mark helper G which would
immediately return and the P would drop into findrunnable again repeating
the process. Since the P was always given a G to run it never blocks.
This CL first checks if the GC mark helper G has available work and if
not the P immediately falls through to its blocking logic.

Fixes #10901

Change-Id: I94ac9646866ba64b7892af358888bc9950de23b5
Reviewed-on: https://go-review.googlesource.com/10189
Reviewed-by: Austin Clements <austin@google.com>
2015-05-19 15:57:50 +00:00
Austin Clements
f4d51eb2f5 runtime: minor clean up to heapminimum
Currently setGCPercent sets heapminimum to heapminimum*GOGC/100. The
real intent is to set heapminimum to a scaled multiple of a fixed
default heap minimum, not to scale heapminimum based on its current
value. This turns out to be okay because setGCPercent is only called
once and heapminimum is initially set to this default heap minimum.
However, the code as written is confusing, especially since
setGCPercent is otherwise written so it could be called again to
change GOGC. Fix this by introducing a defaultHeapMinimum constant and
using this instead of the current value of heapminimum to compute the
scaled heap minimum.

As part of this, this commit improves the documentation on
heapminimum.

Change-Id: I4eb82c73dc2eb44a6e5a17c780a747a2e73d7493
Reviewed-on: https://go-review.googlesource.com/10181
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-19 15:30:34 +00:00
Russ Cox
8903b3db0e runtime: add fast check for self-loop pointer in scanobject
Addresses a problem reported on the mailing list.

This will come up mainly in programs custom allocators that batch allocations,
but it still helps in our programs, which mainly do not have such allocations.

name                   old mean              new mean              delta
BinaryTree17            5.95s × (0.97,1.03)   5.93s × (0.97,1.04)    ~    (p=0.613)
Fannkuch11              4.46s × (0.98,1.04)   4.33s × (0.99,1.01)  -2.93% (p=0.000)
FmtFprintfEmpty        86.6ns × (0.98,1.03)  86.8ns × (0.98,1.02)    ~    (p=0.523)
FmtFprintfString        290ns × (0.98,1.05)   287ns × (0.98,1.03)    ~    (p=0.061)
FmtFprintfInt           271ns × (0.98,1.04)   286ns × (0.99,1.01)  +5.54% (p=0.000)
FmtFprintfIntInt        495ns × (0.98,1.04)   489ns × (0.99,1.01)  -1.24% (p=0.015)
FmtFprintfPrefixedInt   391ns × (0.99,1.02)   407ns × (0.99,1.01)  +4.00% (p=0.000)
FmtFprintfFloat         578ns × (0.99,1.01)   559ns × (0.99,1.01)  -3.35% (p=0.000)
FmtManyArgs            1.96µs × (0.98,1.05)  1.94µs × (0.99,1.01)  -1.33% (p=0.030)
GobDecode              15.9ms × (0.97,1.05)  15.7ms × (0.99,1.01)  -1.35% (p=0.044)
GobEncode              11.4ms × (0.97,1.05)  11.3ms × (0.98,1.03)    ~    (p=0.141)
Gzip                    658ms × (0.98,1.05)   648ms × (0.99,1.01)  -1.59% (p=0.009)
Gunzip                  144ms × (0.99,1.03)   144ms × (0.99,1.01)    ~    (p=0.867)
HTTPClientServer       92.1µs × (0.97,1.05)  90.3µs × (0.99,1.01)  -1.89% (p=0.005)
JSONEncode             31.0ms × (0.96,1.07)  30.2ms × (0.98,1.03)  -2.66% (p=0.001)
JSONDecode              110ms × (0.97,1.04)   107ms × (0.99,1.01)  -2.59% (p=0.000)
Mandelbrot200          6.15ms × (0.98,1.04)  6.07ms × (0.99,1.02)  -1.32% (p=0.045)
GoParse                6.79ms × (0.97,1.04)  6.74ms × (0.97,1.04)    ~    (p=0.242)
RegexpMatchEasy0_32     158ns × (0.98,1.05)   155ns × (0.99,1.01)  -1.64% (p=0.010)
RegexpMatchEasy0_1K     548ns × (0.97,1.04)   540ns × (0.99,1.01)  -1.34% (p=0.042)
RegexpMatchEasy1_32     133ns × (0.97,1.04)   132ns × (0.97,1.05)    ~    (p=0.466)
RegexpMatchEasy1_1K     899ns × (0.96,1.05)   878ns × (0.99,1.01)  -2.32% (p=0.002)
RegexpMatchMedium_32    250ns × (0.96,1.03)   243ns × (0.99,1.01)  -2.90% (p=0.000)
RegexpMatchMedium_1K   73.4µs × (0.98,1.04)  73.0µs × (0.98,1.04)    ~    (p=0.411)
RegexpMatchHard_32     3.87µs × (0.97,1.07)  3.84µs × (0.98,1.04)    ~    (p=0.273)
RegexpMatchHard_1K      120µs × (0.97,1.08)   117µs × (0.99,1.01)  -2.06% (p=0.010)
Revcomp                 940ms × (0.96,1.07)   924ms × (0.97,1.07)    ~    (p=0.071)
Template                128ms × (0.96,1.05)   128ms × (0.99,1.01)    ~    (p=0.502)
TimeParse               632ns × (0.96,1.07)   616ns × (0.99,1.01)  -2.58% (p=0.001)
TimeFormat              671ns × (0.97,1.06)   657ns × (0.99,1.02)  -2.10% (p=0.002)

In contrast to the one in test/bench/go1 (above), the binarytree program on the
shootout site uses more goroutines, batches allocations, and sets GOMAXPROCS
to runtime.NumCPU()*2.

Using that version, before vs after:

name          old mean             new mean             delta
BinaryTree20  18.6s × (0.96,1.05)  11.3s × (0.98,1.02)  -39.46% (p=0.000)

And Go 1.4 vs after:

name          old mean             new mean             delta
BinaryTree20  13.0s × (0.97,1.02)  11.3s × (0.98,1.02)  -13.21% (p=0.000)

There is still a scheduling problem - the raw run times are hiding the fact that
this chews up 2x the CPU - but we'll take care of that separately.

Change-Id: I3f5da879b24ae73a0d06745381ffb88c3744948b
Reviewed-on: https://go-review.googlesource.com/10220
Reviewed-by: Austin Clements <austin@google.com>
2015-05-19 15:29:40 +00:00
Russ Cox
366ba526e8 cmd/internal/gc: add missing write barrier in append(x, BigStructWithPointers)
Fixes #10897.

Change-Id: I5c2d1f9d26333e2b2a0613ebf496daa465e07c24
Reviewed-on: https://go-review.googlesource.com/10221
Reviewed-by: Austin Clements <austin@google.com>
2015-05-19 15:28:29 +00:00
Shenghou Ma
f3fc8b0245 time: document that not all Unix time can be represented
Fixes #10906.

Change-Id: I7ae25a500df493c1e78183d69d89b3e2a64a0d1a
Reviewed-on: https://go-review.googlesource.com/10223
Reviewed-by: Andrew Gerrand <adg@golang.org>
2015-05-19 06:19:33 +00:00
Aaron Jacobs
b21ff39679 flag: Fix up a package comment a bit.
I think "the flag" was a typo, and the word "after" was repetitive.

Change-Id: I81c034ca11a3a778ff1eb4b3af5b96bc525ab985
Reviewed-on: https://go-review.googlesource.com/10195
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
2015-05-19 02:18:40 +00:00
Josh Bleecher Snyder
82833b313e cmd/internal/gc: rearrange Node fields
Rearrange Node fields to enable better struct packing.
This reduces readability in favor of shrinking
the size of Nodes.

This reduces the size of Node from 328 to 312.
This reduces the memory usage to compile the
rotate tests by about 4.4%.

No functional changes. Passes toolstash -cmp.

Updates #9933.

Change-Id: I2764c5847fb1635ddc898e2ee385d007d67f03c5
Reviewed-on: https://go-review.googlesource.com/10141
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-18 22:52:34 +00:00
Josh Bleecher Snyder
f4ab8203ba cmd/internal/gc: separate Node param fields
Param will be converted from an anonymous to a
named field in a subsequent, automated CL.

Reduces Node size from 368 to 328.
Reduces inuse_space on the rotate tests by about 3%.

No functional changes. Passes toolstash -cmp.

Updates #9933.

Change-Id: I5867b00328abf17ee24aea6ca58876bae9d8bfed
Reviewed-on: https://go-review.googlesource.com/10210
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-18 22:18:29 +00:00
Josh Bleecher Snyder
ddc93398b9 cmd/6g, cmd/internal/gc: use Etype instead of Ostk
Change-Id: Ifda5d84b28717986c93b63767298180a6d6236c0
Reviewed-on: https://go-review.googlesource.com/10140
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-18 21:55:23 +00:00
Josh Bleecher Snyder
2b063bdff1 cmd/internal/gc: make all Node depths int32
Funcdepth was already int32. Make Escloopdepth
and Decldepth also int32 instead of int.

No functional changes for non-absurd code. Passes toolstash -cmp.

Change-Id: I47e145dd732b6a73cfcc6d45956df0dbccdcd999
Reviewed-on: https://go-review.googlesource.com/10129
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-18 20:16:14 +00:00
Josh Bleecher Snyder
79986e24e0 runtime/pprof: write heap statistics to heap profile always
This is a duplicate of CL 9491.
That CL broke the build due to pprof shortcomings
and was reverted in CL 9565.

CL 9623 fixed pprof, so this can go in again.

Fixes #10659.

Change-Id: If470fc90b3db2ade1d161b4417abd2f5c6c330b8
Reviewed-on: https://go-review.googlesource.com/10212
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2015-05-18 20:02:21 +00:00
Daniel Morsing
19354b9dc8 cmd/pprof/internal/profile: ignore comments when parsing heap profiles
Fixes #10659.

Change-Id: I22dc306ce6f398dd40010ac430928a718d67d466
Reviewed-on: https://go-review.googlesource.com/9623
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-18 19:36:41 +00:00
Rob Pike
6f7b4e8938 cmd/doc: put blank lines around comment for types, etc.
Better layout.

Fixes #10859.

The issue suggests rearranging so the comment comes out
after the methods. I tried this and it looks good but it is less
useful, since the stuff you're probably looking for - the methods
- are scrolled away by the comment. The most important
information should be last because that leaves it on your
screen after the print if the output is long.

Change-Id: I560f992601ccbe2293c347fa1b1018a3f5346c82
Reviewed-on: https://go-review.googlesource.com/10160
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-18 19:32:14 +00:00
Michael Hudson-Doyle
362a40e37d misc/cgo/testshared: rewrite in Go
And fix to work on filesystems with only 1s resolution.

Fixes #10724

Change-Id: Ia07463f090b4290fc27f5953fa94186463d7afc7
Reviewed-on: https://go-review.googlesource.com/9768
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-05-18 18:40:05 +00:00
David Chase
a21cf5b6a2 cmd/internal/gc: extend escape analysis to pointers in slices
Modified esc.go to allow slice literals (before append)
to be non-escaping.  Modified tests to account for changes
in escape behavior and to also test the two cases that
were previously not tested.

Also minor cleanups to debug-printing within esc.go

Allocation stats for running compiler
( cd src/html/template;
  for i in {1..5} ; do
     go tool 6g -memprofile=testzz.${i}.prof  -memprofilerate=1 *.go ;
     go tool pprof -alloc_objects -text  testzz.${i}.prof ;
     done ; )
before about 86k allocations
after  about 83k allocations

Fixes #8972

Change-Id: Ib61dd70dc74adb40d6f6fdda6eaa4bf7d83481de
Reviewed-on: https://go-review.googlesource.com/10118
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-18 15:34:39 +00:00
Austin Clements
f0dd002895 runtime: use separate count and note for forEachP
Currently, forEachP reuses the stopwait and stopnote fields from
stopTheWorld to track how many Ps have not responded to the safe-point
request and to sleep until all Ps have responded.

It was assumed this was safe because both stopTheWorld and forEachP
must occur under the worlsema and hence stopwait and stopnote cannot
be used for both purposes simultaneously and callers could always
determine the appropriate use based on sched.gcwaiting (which is only
set by stopTheWorld). However, this is not the case, since it's
possible for there to be a window between when an M observes that
gcwaiting is set and when it checks stopwait during which stopwait
could have changed meanings. When this happens, the M decrements
stopwait and may wakeup stopnote, but does not otherwise participate
in the forEachP protocol. As a result, stopwait is decremented too
many times, so it may reach zero before all Ps have run the safe-point
function, causing forEachP to wake up early. It will then either
observe that some P has not run the safe-point function and panic with
"P did not run fn", or the remaining P (or Ps) will run the safe-point
function before it wakes up and it will observe that stopwait is
negative and panic with "not stopped".

Fix this problem by giving forEachP its own safePointWait and
safePointNote fields.

One known sequence of events that can cause this race is as
follows. It involves three actors:

G1 is running on M1 on P1. P1 has an empty run queue.

G2/M2 is in a blocked syscall and has lost its P. (The details of this
don't matter, it just needs to be in a position where it needs to grab
an idle P.)

GC just started on G3/M3/P3. (These aren't very involved, they just
have to be separate from the other G's, M's, and P's.)

1. GC calls stopTheWorld(), which sets sched.gcwaiting to 1.

Now G1/M1 begins to enter a syscall:

2. G1/M1 invokes reentersyscall, which sets the P1's status to
   _Psyscall.

3. G1/M1's reentersyscall observes gcwaiting != 0 and calls
   entersyscall_gcwait.

4. G1/M1's entersyscall_gcwait blocks acquiring sched.lock.

Back on GC:

5. stopTheWorld cas's P1's status to _Pgcstop, does other stuff, and
   returns.

6. GC does stuff and then calls startTheWorld().

7. startTheWorld() calls procresize(), which sets P1's status to
   _Pidle and puts P1 on the idle list.

Now G2/M2 returns from its syscall and takes over P1:

8. G2/M2 returns from its blocked syscall and gets P1 from the idle
   list.

9. G2/M2 acquires P1, which sets P1's status to _Prunning.

10. G2/M2 starts a new syscall and invokes reentersyscall, which sets
    P1's status to _Psyscall.

Back on G1/M1:

11. G1/M1 finally acquires sched.lock in entersyscall_gcwait.

At this point, G1/M1 still thinks it's running on P1. P1's status is
_Psyscall, which is consistent with what G1/M1 is doing, but it's
_Psyscall because *G2/M2* put it in to _Psyscall, not G1/M1. This is
basically an ABA race on P1's status.

Because forEachP currently shares stopwait with stopTheWorld. G1/M1's
entersyscall_gcwait observes the non-zero stopwait set by forEachP,
but mistakes it for a stopTheWorld. It cas's P1's status from
_Psyscall (set by G2/M2) to _Pgcstop and proceeds to decrement
stopwait one more time than forEachP was expecting.

Fixes #10618. (See the issue for details on why the above race is safe
when forEachP is not involved.)

Prior to this commit, the command
  stress ./runtime.test -test.run TestFutexsleep\|TestGoroutineProfile
would reliably fail after a few hundred runs. With this commit, it
ran for over 2 million runs and never crashed.

Change-Id: I9a91ea20035b34b6e5f07ef135b144115f281f30
Reviewed-on: https://go-review.googlesource.com/10157
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-18 14:55:47 +00:00
Austin Clements
277acca286 runtime: hold worldsema while starting the world
Currently, startTheWorld releases worldsema before starting the
world. Since startTheWorld can change gomaxprocs after allowing Ps to
run, this means that gomaxprocs can change while another P holds
worldsema.

Unfortunately, the garbage collector and forEachP assume that holding
worldsema protects against changes in gomaxprocs (which it *almost*
does). In particular, this is causing somewhat frequent "P did not run
fn" crashes in forEachP in the runtime tests because gomaxprocs is
changing between the several loops that forEachP does over all the Ps.

Fix this by only releasing worldsema after the world is started.

This relates to issue #10618. forEachP still fails under stress
testing, but much less frequently.

Change-Id: I085d627b70cca9ebe9af28fe73b9872f1bb224ff
Reviewed-on: https://go-review.googlesource.com/10156
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-18 14:55:37 +00:00
Austin Clements
9c44a41dd5 runtime: disallow preemption during startTheWorld
Currently, startTheWorld clears preemptoff for the current M before
starting the world. A few callers increment m.locks around
startTheWorld, presumably to prevent preemption any time during
starting the world. This is almost certainly pointless (none of the
other callers do this), but there's no harm in making startTheWorld
keep preemption disabled until it's all done, which definitely lets us
drop these m.locks manipulations.

Change-Id: I8a93658abd0c72276c9bafa3d2c7848a65b4691a
Reviewed-on: https://go-review.googlesource.com/10155
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-18 14:55:31 +00:00
Austin Clements
a1da255aa0 runtime: factor stoptheworld/starttheworld pattern
There are several steps to stopping and starting the world and
currently they're open-coded in several places. The garbage collector
is the only thing that needs to stop and start the world in a
non-trivial pattern. Replace all other uses with calls to higher-level
functions that implement the entire pattern necessary to stop and
start the world.

This is a pure refectoring and should not change any code semantics.
In the following commits, we'll make changes that are easier to do
with this abstraction in place.

This commit renames the old starttheworld to startTheWorldWithSema.
This is a slight misnomer right now because the callers release
worldsema just before calling this. However, a later commit will swap
these and I don't want to think of another name in the mean time.

Change-Id: I5dc97f87b44fb98963c49c777d7053653974c911
Reviewed-on: https://go-review.googlesource.com/10154
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-18 14:55:25 +00:00
Austin Clements
5f7060afd2 runtime: don't start GC if preemptoff is set
In order to avoid deadlocks, startGC avoids kicking off GC if locks
are held by the calling M. However, it currently fails to check
preemptoff, which is the other way to disable preemption.

Fix this by adding a check for preemptoff.

Change-Id: Ie1083166e5ba4af5c9d6c5a42efdfaaef41ca997
Reviewed-on: https://go-review.googlesource.com/10153
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-18 14:55:18 +00:00
Alex Brainman
e544bee1dd runtime: correct exception stack trace output
It is misleading when stack trace say:

signal arrived during cgo execution

but we are not in cgo call.

Change-Id: I627e2f2bdc7755074677f77f21befc070a101914
Reviewed-on: https://go-review.googlesource.com/9190
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-18 03:09:45 +00:00
Shenghou Ma
0b9866fd56 buildall.bash: exit 1 when make.bash fails
If make.bash fails, there is no point continuing any further.

Fixes #10880.

Change-Id: I350cc16999372422ad3d2e0327d52d467886a5b1
Reviewed-on: https://go-review.googlesource.com/10180
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-05-17 01:40:33 +00:00
Austin Clements
a0fc306023 runtime: eliminate runqvictims and a copy from runqsteal
Currently, runqsteal steals Gs from another P into an intermediate
buffer and then copies those Gs into the current P's run queue. This
intermediate buffer itself was moved from the stack to the P in commit
c4fe503 to eliminate the cost of zeroing it on every steal.

This commit follows up c4fe503 by stealing directly into the current
P's run queue, which eliminates the copy and the need for the
intermediate buffer. The update to the tail pointer is only committed
once the entire steal operation has succeeded, so the semantics of
stealing do not change.

Change-Id: Icdd7a0eb82668980bf42c0154b51eef6419fdd51
Reviewed-on: https://go-review.googlesource.com/9998
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
2015-05-17 01:08:42 +00:00
Shenghou Ma
ab4e7988bb cmd/dist: add -k to "dist test" to keep going after error
Fixes #10336.

Change-Id: Idc3f60851aea590575dc293165d4d6f85ae001bc
Reviewed-on: https://go-review.googlesource.com/9645
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-05-17 00:08:04 +00:00
Russ Cox
6e8bcbbe89 cmd/internal/gc: refine ginscmp comment
Change-Id: I2ebb36c6c5de9d34e52ed523e9c888452591924a
Reviewed-on: https://go-review.googlesource.com/10152
Reviewed-by: Minux Ma <minux@golang.org>
2015-05-16 00:51:52 +00:00
Russ Cox
d36cc02795 reflect: make PtrTo(FuncOf(...)) not crash
Change-Id: Ie67e295bf327126dfdc75b73979fe33fbcb79ad9
Reviewed-on: https://go-review.googlesource.com/10150
Reviewed-by: Austin Clements <austin@google.com>
2015-05-16 00:51:05 +00:00
Russ Cox
512f75e8df runtime: replace GC programs with simpler encoding, faster decoder
Small types record the location of pointers in their memory layout
by using a simple bitmap. In Go 1.4 the bitmap held 4-bit entries,
and in Go 1.5 the bitmap holds 1-bit entries, but in both cases using
a bitmap for a large type containing arrays does not make sense:
if someone refers to the type [1<<28]*byte in a program in such
a way that the type information makes it into the binary, it would be
a waste of space to write a 128 MB (for 4-bit entries) or even 32 MB
(for 1-bit entries) bitmap full of 1s into the binary or even to keep
one in memory during the execution of the program.

For large types containing arrays, it is much more compact to describe
the locations of pointers using a notation that can express repetition
than to lay out a bitmap of pointers. Go 1.4 included such a notation,
called ``GC programs'' but it was complex, required recursion during
decoding, and was generally slow. Dmitriy measured the execution of
these programs writing directly to the heap bitmap as being 7x slower
than copying from a preunrolled 4-bit mask (and frankly that code was
not terribly fast either). For some tests, unrollgcprog1 was seen costing
as much as 3x more than the rest of malloc combined.

This CL introduces a different form for the GC programs. They use a
simple Lempel-Ziv-style encoding of the 1-bit pointer information,
in which the only operations are (1) emit the following n bits
and (2) repeat the last n bits c more times. This encoding can be
generated directly from the Go type information (using repetition
only for arrays or large runs of non-pointer data) and it can be decoded
very efficiently. In particular the decoding requires little state and
no recursion, so that the entire decoding can run without any memory
accesses other than the reads of the encoding and the writes of the
decoded form to the heap bitmap. For recursive types like arrays of
arrays of arrays, the inner instructions are only executed once, not
n times, so that large repetitions run at full speed. (In contrast, large
repetitions in the old programs repeated the individual bit-level layout
of the inner data over and over.) The result is as much as 25x faster
decoding compared to the old form.

Because the old decoder was so slow, Go 1.4 had three (or so) cases
for how to set the heap bitmap bits for an allocation of a given type:

(1) If the type had an even number of words up to 32 words, then
the 4-bit pointer mask for the type fit in no more than 16 bytes;
store the 4-bit pointer mask directly in the binary and copy from it.

(1b) If the type had an odd number of words up to 15 words, then
the 4-bit pointer mask for the type, doubled to end on a byte boundary,
fit in no more than 16 bytes; store that doubled mask directly in the
binary and copy from it.

(2) If the type had an even number of words up to 128 words,
or an odd number of words up to 63 words (again due to doubling),
then the 4-bit pointer mask would fit in a 64-byte unrolled mask.
Store a GC program in the binary, but leave space in the BSS for
the unrolled mask. Execute the GC program to construct the mask the
first time it is needed, and thereafter copy from the mask.

(3) Otherwise, store a GC program and execute it to write directly to
the heap bitmap each time an object of that type is allocated.
(This is the case that was 7x slower than the other two.)

Because the new pointer masks store 1-bit entries instead of 4-bit
entries and because using the decoder no longer carries a significant
overhead, after this CL (that is, for Go 1.5) there are only two cases:

(1) If the type is 128 words or less (no condition about odd or even),
store the 1-bit pointer mask directly in the binary and use it to
initialize the heap bitmap during malloc. (Implemented in CL 9702.)

(2) There is no case 2 anymore.

(3) Otherwise, store a GC program and execute it to write directly to
the heap bitmap each time an object of that type is allocated.

Executing the GC program directly into the heap bitmap (case (3) above)
was disabled for the Go 1.5 dev cycle, both to avoid needing to use
GC programs for typedmemmove and to avoid updating that code as
the heap bitmap format changed. Typedmemmove no longer uses this
type information; as of CL 9886 it uses the heap bitmap directly.
Now that the heap bitmap format is stable, we reintroduce GC programs
and their space savings.

Benchmarks for heapBitsSetType, before this CL vs this CL:

name                    old mean               new mean              delta
SetTypePtr              7.59ns × (0.99,1.02)   5.16ns × (1.00,1.00)  -32.05% (p=0.000)
SetTypePtr8             21.0ns × (0.98,1.05)   21.4ns × (1.00,1.00)     ~    (p=0.179)
SetTypePtr16            24.1ns × (0.99,1.01)   24.6ns × (1.00,1.00)   +2.41% (p=0.001)
SetTypePtr32            31.2ns × (0.99,1.01)   32.4ns × (0.99,1.02)   +3.72% (p=0.001)
SetTypePtr64            45.2ns × (1.00,1.00)   47.2ns × (1.00,1.00)   +4.42% (p=0.000)
SetTypePtr126           75.8ns × (0.99,1.01)   79.1ns × (1.00,1.00)   +4.25% (p=0.000)
SetTypePtr128           74.3ns × (0.99,1.01)   77.6ns × (1.00,1.01)   +4.55% (p=0.000)
SetTypePtrSlice          726ns × (1.00,1.01)    712ns × (1.00,1.00)   -1.95% (p=0.001)
SetTypeNode1            20.0ns × (0.99,1.01)   20.7ns × (1.00,1.00)   +3.71% (p=0.000)
SetTypeNode1Slice        112ns × (1.00,1.00)    113ns × (0.99,1.00)     ~    (p=0.070)
SetTypeNode8            23.9ns × (1.00,1.00)   24.7ns × (1.00,1.01)   +3.18% (p=0.000)
SetTypeNode8Slice        294ns × (0.99,1.02)    287ns × (0.99,1.01)   -2.38% (p=0.015)
SetTypeNode64           52.8ns × (0.99,1.03)   51.8ns × (0.99,1.01)     ~    (p=0.069)
SetTypeNode64Slice      1.13µs × (0.99,1.05)   1.14µs × (0.99,1.00)     ~    (p=0.767)
SetTypeNode64Dead       36.0ns × (1.00,1.01)   32.5ns × (0.99,1.00)   -9.67% (p=0.000)
SetTypeNode64DeadSlice  1.43µs × (0.99,1.01)   1.40µs × (1.00,1.00)   -2.39% (p=0.001)
SetTypeNode124          75.7ns × (1.00,1.01)   79.0ns × (1.00,1.00)   +4.44% (p=0.000)
SetTypeNode124Slice     1.94µs × (1.00,1.01)   2.04µs × (0.99,1.01)   +4.98% (p=0.000)
SetTypeNode126          75.4ns × (1.00,1.01)   77.7ns × (0.99,1.01)   +3.11% (p=0.000)
SetTypeNode126Slice     1.95µs × (0.99,1.01)   2.03µs × (1.00,1.00)   +3.74% (p=0.000)
SetTypeNode128          85.4ns × (0.99,1.01)  122.0ns × (1.00,1.00)  +42.89% (p=0.000)
SetTypeNode128Slice     2.20µs × (1.00,1.01)   2.36µs × (0.98,1.02)   +7.48% (p=0.001)
SetTypeNode130          83.3ns × (1.00,1.00)  123.0ns × (1.00,1.00)  +47.61% (p=0.000)
SetTypeNode130Slice     2.30µs × (0.99,1.01)   2.40µs × (0.98,1.01)   +4.37% (p=0.000)
SetTypeNode1024          498ns × (1.00,1.00)    537ns × (1.00,1.00)   +7.96% (p=0.000)
SetTypeNode1024Slice    15.5µs × (0.99,1.01)   17.8µs × (1.00,1.00)  +15.27% (p=0.000)

The above compares always using a cached pointer mask (and the
corresponding waste of memory) against using the programs directly.
Some slowdown is expected, in exchange for having a better general algorithm.
The GC programs kick in for SetTypeNode128, SetTypeNode130, SetTypeNode1024,
along with the slice variants of those.
It is possible that the cutoff of 128 words (bits) should be raised
in a followup CL, but even with this low cutoff the GC programs are
faster than Go 1.4's "fast path" non-GC program case.

Benchmarks for heapBitsSetType, Go 1.4 vs this CL:

name                    old mean              new mean              delta
SetTypePtr              6.89ns × (1.00,1.00)  5.17ns × (1.00,1.00)  -25.02% (p=0.000)
SetTypePtr8             25.8ns × (0.97,1.05)  21.5ns × (1.00,1.00)  -16.70% (p=0.000)
SetTypePtr16            39.8ns × (0.97,1.02)  24.7ns × (0.99,1.01)  -37.81% (p=0.000)
SetTypePtr32            68.8ns × (0.98,1.01)  32.2ns × (1.00,1.01)  -53.18% (p=0.000)
SetTypePtr64             130ns × (1.00,1.00)    47ns × (1.00,1.00)  -63.67% (p=0.000)
SetTypePtr126            241ns × (0.99,1.01)    79ns × (1.00,1.01)  -67.25% (p=0.000)
SetTypePtr128           2.07µs × (1.00,1.00)  0.08µs × (1.00,1.00)  -96.27% (p=0.000)
SetTypePtrSlice         1.05µs × (0.99,1.01)  0.72µs × (0.99,1.02)  -31.70% (p=0.000)
SetTypeNode1            16.0ns × (0.99,1.01)  20.8ns × (0.99,1.03)  +29.91% (p=0.000)
SetTypeNode1Slice        184ns × (0.99,1.01)   112ns × (0.99,1.01)  -39.26% (p=0.000)
SetTypeNode8            29.5ns × (0.97,1.02)  24.6ns × (1.00,1.00)  -16.50% (p=0.000)
SetTypeNode8Slice        624ns × (0.98,1.02)   285ns × (1.00,1.00)  -54.31% (p=0.000)
SetTypeNode64            135ns × (0.96,1.08)    52ns × (0.99,1.02)  -61.32% (p=0.000)
SetTypeNode64Slice      3.83µs × (1.00,1.00)  1.14µs × (0.99,1.01)  -70.16% (p=0.000)
SetTypeNode64Dead        134ns × (0.99,1.01)    32ns × (1.00,1.01)  -75.74% (p=0.000)
SetTypeNode64DeadSlice  3.83µs × (0.99,1.00)  1.40µs × (1.00,1.01)  -63.42% (p=0.000)
SetTypeNode124           240ns × (0.99,1.01)    79ns × (1.00,1.01)  -67.05% (p=0.000)
SetTypeNode124Slice     7.27µs × (1.00,1.00)  2.04µs × (1.00,1.00)  -71.95% (p=0.000)
SetTypeNode126          2.06µs × (0.99,1.01)  0.08µs × (0.99,1.01)  -96.23% (p=0.000)
SetTypeNode126Slice     64.4µs × (1.00,1.00)   2.0µs × (1.00,1.00)  -96.85% (p=0.000)
SetTypeNode128          2.09µs × (1.00,1.01)  0.12µs × (1.00,1.00)  -94.15% (p=0.000)
SetTypeNode128Slice     65.4µs × (1.00,1.00)   2.4µs × (0.99,1.03)  -96.39% (p=0.000)
SetTypeNode130          2.11µs × (1.00,1.00)  0.12µs × (1.00,1.00)  -94.18% (p=0.000)
SetTypeNode130Slice     66.3µs × (1.00,1.00)   2.4µs × (0.97,1.08)  -96.34% (p=0.000)
SetTypeNode1024         16.0µs × (1.00,1.01)   0.5µs × (1.00,1.00)  -96.65% (p=0.000)
SetTypeNode1024Slice     512µs × (1.00,1.00)    18µs × (0.98,1.04)  -96.45% (p=0.000)

SetTypeNode124 uses a 124 data + 2 ptr = 126-word allocation.
Both Go 1.4 and this CL are using pointer bitmaps for this case,
so that's an overall 3x speedup for using pointer bitmaps.

SetTypeNode128 uses a 128 data + 2 ptr = 130-word allocation.
Both Go 1.4 and this CL are running the GC program for this case,
so that's an overall 17x speedup when using GC programs (and
I've seen >20x on other systems).

Comparing Go 1.4's SetTypeNode124 (pointer bitmap) against
this CL's SetTypeNode128 (GC program), the slow path in the
code in this CL is 2x faster than the fast path in Go 1.4.

The Go 1 benchmarks are basically unaffected compared to just before this CL.

Go 1 benchmarks, before this CL vs this CL:

name                   old mean              new mean              delta
BinaryTree17            5.87s × (0.97,1.04)   5.91s × (0.96,1.04)    ~    (p=0.306)
Fannkuch11              4.38s × (1.00,1.00)   4.37s × (1.00,1.01)  -0.22% (p=0.006)
FmtFprintfEmpty        90.7ns × (0.97,1.10)  89.3ns × (0.96,1.09)    ~    (p=0.280)
FmtFprintfString        282ns × (0.98,1.04)   287ns × (0.98,1.07)  +1.72% (p=0.039)
FmtFprintfInt           269ns × (0.99,1.03)   282ns × (0.97,1.04)  +4.87% (p=0.000)
FmtFprintfIntInt        478ns × (0.99,1.02)   481ns × (0.99,1.02)  +0.61% (p=0.048)
FmtFprintfPrefixedInt   399ns × (0.98,1.03)   400ns × (0.98,1.05)    ~    (p=0.533)
FmtFprintfFloat         563ns × (0.99,1.01)   570ns × (1.00,1.01)  +1.37% (p=0.000)
FmtManyArgs            1.89µs × (0.99,1.01)  1.92µs × (0.99,1.02)  +1.88% (p=0.000)
GobDecode              15.2ms × (0.99,1.01)  15.2ms × (0.98,1.05)    ~    (p=0.609)
GobEncode              11.6ms × (0.98,1.03)  11.9ms × (0.98,1.04)  +2.17% (p=0.000)
Gzip                    648ms × (0.99,1.01)   648ms × (1.00,1.01)    ~    (p=0.835)
Gunzip                  142ms × (1.00,1.00)   143ms × (1.00,1.01)    ~    (p=0.169)
HTTPClientServer       90.5µs × (0.98,1.03)  91.5µs × (0.98,1.04)  +1.04% (p=0.045)
JSONEncode             31.5ms × (0.98,1.03)  31.4ms × (0.98,1.03)    ~    (p=0.549)
JSONDecode              111ms × (0.99,1.01)   107ms × (0.99,1.01)  -3.21% (p=0.000)
Mandelbrot200          6.01ms × (1.00,1.00)  6.01ms × (1.00,1.00)    ~    (p=0.878)
GoParse                6.54ms × (0.99,1.02)  6.61ms × (0.99,1.03)  +1.08% (p=0.004)
RegexpMatchEasy0_32     160ns × (1.00,1.01)   161ns × (1.00,1.00)  +0.40% (p=0.000)
RegexpMatchEasy0_1K     560ns × (0.99,1.01)   559ns × (0.99,1.01)    ~    (p=0.088)
RegexpMatchEasy1_32     138ns × (0.99,1.01)   138ns × (1.00,1.00)    ~    (p=0.380)
RegexpMatchEasy1_1K     877ns × (1.00,1.00)   878ns × (1.00,1.00)    ~    (p=0.157)
RegexpMatchMedium_32    251ns × (0.99,1.00)   251ns × (1.00,1.01)  +0.28% (p=0.021)
RegexpMatchMedium_1K   72.6µs × (1.00,1.00)  72.6µs × (1.00,1.00)    ~    (p=0.539)
RegexpMatchHard_32     3.84µs × (1.00,1.00)  3.84µs × (1.00,1.00)    ~    (p=0.378)
RegexpMatchHard_1K      117µs × (1.00,1.00)   117µs × (1.00,1.00)    ~    (p=0.067)
Revcomp                 904ms × (0.99,1.02)   904ms × (0.99,1.01)    ~    (p=0.943)
Template                125ms × (0.99,1.02)   127ms × (0.99,1.01)  +1.79% (p=0.000)
TimeParse               627ns × (0.99,1.01)   622ns × (0.99,1.01)  -0.88% (p=0.000)
TimeFormat              655ns × (0.99,1.02)   655ns × (0.99,1.02)    ~    (p=0.976)

For the record, Go 1 benchmarks, Go 1.4 vs this CL:

name                   old mean              new mean              delta
BinaryTree17            4.61s × (0.97,1.05)   5.91s × (0.98,1.03)  +28.35% (p=0.000)
Fannkuch11              4.40s × (0.99,1.03)   4.41s × (0.99,1.01)     ~    (p=0.212)
FmtFprintfEmpty         102ns × (0.99,1.01)    84ns × (0.99,1.02)  -18.38% (p=0.000)
FmtFprintfString        302ns × (0.98,1.01)   303ns × (0.99,1.02)     ~    (p=0.203)
FmtFprintfInt           313ns × (0.97,1.05)   270ns × (0.99,1.01)  -13.69% (p=0.000)
FmtFprintfIntInt        524ns × (0.98,1.02)   477ns × (0.99,1.00)   -8.87% (p=0.000)
FmtFprintfPrefixedInt   424ns × (0.98,1.02)   386ns × (0.99,1.01)   -8.96% (p=0.000)
FmtFprintfFloat         652ns × (0.98,1.02)   594ns × (0.97,1.05)   -8.97% (p=0.000)
FmtManyArgs            2.13µs × (0.99,1.02)  1.94µs × (0.99,1.01)   -8.92% (p=0.000)
GobDecode              17.1ms × (0.99,1.02)  14.9ms × (0.98,1.03)  -13.07% (p=0.000)
GobEncode              13.5ms × (0.98,1.03)  11.5ms × (0.98,1.03)  -15.25% (p=0.000)
Gzip                    656ms × (0.99,1.02)   647ms × (0.99,1.01)   -1.29% (p=0.000)
Gunzip                  143ms × (0.99,1.02)   144ms × (0.99,1.01)     ~    (p=0.204)
HTTPClientServer       88.2µs × (0.98,1.02)  90.8µs × (0.98,1.01)   +2.93% (p=0.000)
JSONEncode             32.2ms × (0.98,1.02)  30.9ms × (0.97,1.04)   -4.06% (p=0.001)
JSONDecode              121ms × (0.98,1.02)   110ms × (0.98,1.05)   -8.95% (p=0.000)
Mandelbrot200          6.06ms × (0.99,1.01)  6.11ms × (0.98,1.04)     ~    (p=0.184)
GoParse                6.76ms × (0.97,1.04)  6.58ms × (0.98,1.05)   -2.63% (p=0.003)
RegexpMatchEasy0_32     195ns × (1.00,1.01)   155ns × (0.99,1.01)  -20.43% (p=0.000)
RegexpMatchEasy0_1K     479ns × (0.98,1.03)   535ns × (0.99,1.02)  +11.59% (p=0.000)
RegexpMatchEasy1_32     169ns × (0.99,1.02)   131ns × (0.99,1.03)  -22.44% (p=0.000)
RegexpMatchEasy1_1K    1.53µs × (0.99,1.01)  0.87µs × (0.99,1.02)  -43.07% (p=0.000)
RegexpMatchMedium_32    334ns × (0.99,1.01)   242ns × (0.99,1.01)  -27.53% (p=0.000)
RegexpMatchMedium_1K    125µs × (1.00,1.01)    72µs × (0.99,1.03)  -42.53% (p=0.000)
RegexpMatchHard_32     6.03µs × (0.99,1.01)  3.79µs × (0.99,1.01)  -37.12% (p=0.000)
RegexpMatchHard_1K      189µs × (0.99,1.02)   115µs × (0.99,1.01)  -39.20% (p=0.000)
Revcomp                 935ms × (0.96,1.03)   926ms × (0.98,1.02)     ~    (p=0.083)
Template                146ms × (0.97,1.05)   119ms × (0.99,1.01)  -18.37% (p=0.000)
TimeParse               660ns × (0.99,1.01)   624ns × (0.99,1.02)   -5.43% (p=0.000)
TimeFormat              670ns × (0.98,1.02)   710ns × (1.00,1.01)   +5.97% (p=0.000)

This CL is a bit larger than I would like, but the compiler, linker, runtime,
and package reflect all need to be in sync about the format of these programs,
so there is no easy way to split this into independent changes (at least
while keeping the build working at each change).

Fixes #9625.
Fixes #10524.

Change-Id: I9e3e20d6097099d0f8532d1cb5b1af528804989a
Reviewed-on: https://go-review.googlesource.com/9888
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Russ Cox <rsc@golang.org>
2015-05-16 00:38:17 +00:00
Didier Spezia
ebe733cb40 text/template: fix race condition on function maps
The Template objects are supposed to be goroutine-safe once they
have been parsed. This includes the text and html ones.

For html/template, the escape mechanism is triggered at execution
time. It may alter the internal structures of the template, so
a mutex protects them against concurrent accesses.

The text/template package is free of any synchronization primitive.

A race condition may occur when nested templates are escaped:
the escape algorithm alters the function maps of the associated
text templates, while a concurrent template execution may access
the function maps in read mode.

The less invasive fix I have found is to introduce a RWMutex in
text/template to protect the function maps. This is unfortunate
but it should be effective.

Fixes #9945

Change-Id: I1edb73c0ed0f1fcddd2f1516230b548b92ab1269
Reviewed-on: https://go-review.googlesource.com/10101
Reviewed-by: Rob Pike <r@golang.org>
2015-05-16 00:32:21 +00:00
Russ Cox
d820d5f3ab runtime: make mapzero not crash on arm
Change-Id: I40e8a4a2e62253233b66f6a2e61e222437292c31
Reviewed-on: https://go-review.googlesource.com/10151
Reviewed-by: Minux Ma <minux@golang.org>
2015-05-15 20:14:41 +00:00
Michael Hudson-Doyle
ddc4c146a4 cmd/internal/ld: prevent creation of .dynamic and .dynsym symbols when externally linking
This allows the removal of a fudge in data.go.

We have to defer the calls to adddynlib on non-Darwin until after we have
decided whether we are externally or internally linking.  The Macho/ELF
separation could do with some cleaning up, but: code freeze.

Fixing this once rather than per-arch is what inspired the previous CLs.

Change-Id: I0166f7078a045dc09827745479211247466c0c54
Reviewed-on: https://go-review.googlesource.com/10002
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-05-15 20:09:12 +00:00