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Introducing Go 1.6

Brad Fitzpatrick

@bradfitz

bradfitz@golang.org

https://www.youtube.com/watch?v=4Dr8FXs9aJM

​

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Go 1.6

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Go 1.6

Feb 2016

(couple days ago)

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Introducing Go 1.6

Brad Fitzpatrick

@bradfitz

bradfitz@golang.org

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Introducing Go 1.6:

asymptotically approaching boring

Brad Fitzpatrick

@bradfitz

bradfitz@golang.org

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Introducing Go 1.6:

asymptotically approaching boring

Brad Fitzpatrick

@bradfitz

bradfitz@golang.org

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History

And Go’s release cycle

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Go 1.5

Aug 2015

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Go 1.4

Dec 2014

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Go 1.3

Jun 2014

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Go 1.2

Dec 2013

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Go 1.1

May 2013

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Go 1

Mar 2012

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Go 1.6

Feb 2016

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Go 1.7

Aug 2016

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Go 1.8

Feb 2017

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Go 1.9

Aug 2017

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Go 2.0 !!!

Feb 2018

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Generics!

​

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Sum Types!

​

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List comprehensions!

​

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Immutability!

​

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Rationalizing

[]byte vs string

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Rationalizing

new() vs make()

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Rationalizing

:= vs var

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VFS layer,

os.File becomes an interface

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~memory

@ownership!

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Data races statically impossible!

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Years of mistakes revisited...

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Tons of feature requests resolved...

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YAYAYAYAYAYAYAYAYAYAYAYAYAYAYAYAYAYAYAYAYAYAYAY

Are you excited yet!?!?

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Sorry.

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I lied.

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Go 1.9

Aug 2017

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Go 1.10

Feb 2018

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Go 1.11

Aug 2018

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etc.

​

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So… when is Go 2?

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No plans.

Maybe never.

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http://brenda1eye.blogspot.com/2009_05_01_archive.html

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http://hawkeview.blogspot.in/2010/05/great-gopher-war.html

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https://twitter.com/jrstahl/status/591656618275819520

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Previous Language Additions

(was it ever not boring?)

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Go 1

Mar 2012

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Go 1

  • append([]byte, string…)
  • disallow close on receive-only channels
  • composite literal type ellison
  • goroutines during init
  • the rune type
  • the error type (interface type in global scope!)
  • delete(m, k)
  • random map iteration order
  • struct equality
  • copying structs with unexported fields
  • ….

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Go 1.1

May 2013

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Go 1.1

  • method values!

type T struct { … once sync.Once … }

func (t *T) init() { … }

func (t *T) method() {

t.once.Do(t.init) // t.init of type func(); t curried

  • terminating statement rule
    • no more panic(“unreachable”)

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Go 1.2

Dec 2013

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Go 1.2

  • guaranteed crash on nil pointer dereferences in all cases
  • three-index slices

slice := array[off:len:cap]

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Go 1.3

Jun 2016

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Go 1.3

  • no language changes

​

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Go 1.4

Dec 2014

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Go 1.4

  • for range x { … }
  • spec clarification & compiler fix: no double dereference on:�var x **T = nil�x.M()

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Go 1.5

Aug 2015

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Go 1.5

  • Map literal type elision:

m := map[Point]string{

{1, 2}: "Foo",

{3, 4}: "Bar",

}

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Go 1.6

Feb 2016

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Go 1.6

  • no language changes

​

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Thank you!

Questions?

​

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[ Excitement, pre-Go1 ]

weekly.*, r56, r57, etc

[ Go 1.x era ]

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https://twitter.com/jrstahl/status/591656618275819520

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Boring?

If you’re a language nerd.

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Boring is exciting!

If you like stability.

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Stable foundation

→

build stuff on top

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“Go”

​

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Language

Standard Library

Runtime

Tools

Ecosystem

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Language

Basically frozen.

​

golang.org/ref/spec

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Standard Library

Increasingly frozen.

External packages preferred.

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Runtime

Garbage Collector,

maps, channels,

goroutine scheduler

​

Active development.

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Tools

cmd/compile, gccgo, godoc, go doc, go vet, gofmt,

goimports, guru, gorename, …

​

Active development.

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Ecosystem

External packages, compilers, tools.

​

Exploding.

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Excitement elsewhere

excitement higher in the stack,

and in non-language areas of the foundation

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Excitement besides

the language...

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Go 1

Mar 2012

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golang.org/doc/go1compat

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Go 1 compatibility promise

  • your old March 2012 programs still work
  • we can add stuff
  • we can NOT change the language or standard library

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Go 1: the beginning of tooling

  • cmd/go
  • go get
  • go install
  • go build
  • go test
  • etc

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Go 1.1

May 2013

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Go 1.1

  • int is 64-bit on 64-bit systems; address large heaps
  • race detector
  • +build constraints
  • more platforms (more OS/arch)
  • faster
  • stdlib growth, improvements

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Go 1.2

Dec 2013

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Go 1.2

  • performance
  • test coverage
  • goroutine preemption

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Go 1.3

Jun 2016

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Go 1.3

  • more platforms
  • contiguous stacks (mostly)
  • precise GC (mostly)
  • start of linker rewrite, speed
  • performance improvements
  • GC latency

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Go 1.4

Dec 2014

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Go 1.4

  • more platforms
  • much of runtime translated/ported from C to Go
  • fully precise GC
  • always contiguous stacks
  • stack sizes now 2KB instead of 8KB (previously 4KB)
  • write barrier for pointer assignments

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Go 1.5

Aug 2015

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Go 1.5

  • all C is gone
  • the compiler, linker, assembler, and runtime now all in Go
  • entirely new GC (Garbage Collector)
    • concurrent, much lower pause times
    • goal: 10ms worst case pause
  • automatic GOMAXPROCS
  • internal packages
  • vendor support in cmd/go
  • go doc (separate from godoc)

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Go 1.6

Feb 2016

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Go 1.6

  • no language changes

​

but….

​

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Go 1.6: More Platforms

Current OS support:

  • Windows, OSX (darwin), Android, iOS, NaCl, DragonflyBSD, FreeBSD, Linux, NetBSD, OpenBSD, Plan 9, Solaris/Illumos

Current and new architecture support:

  • Intel (386 and amd64), arm (ARMv5, v6, v7), arm64, 64 bit PowerPC (big and little endian), 64 bit MIPS (big and little endian)

​

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Go 1.6: Garbage Collector

Refined.

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Go 1.6: cgo memory sharing

Defined.

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Go 1.6: automatic HTTP/2

client & server

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image by @igrigorik

Demo: http2.golang.org/gophertiles (video)

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http.Get, Client.Post, Do, etc.

no changes

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http.ListenAndServeTLS

no changes

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Use TLS!

LetsEncrypt, ACME, Caddy = Free!

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Go 1.6: template package

now

with

​

less auto-generated

whitespace

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Go 1.6: template package

{{now -}}

{{with -}}

​

{{- less}} {{- auto-generated -}}

{{- whitespace}}

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Go 1.6: template package

now with less auto-generated whitespace

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Go 1.6: template package

and {{block}}

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Go 1.6: faster

crypto, compression, sorting, etc.

more escape analysis

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Go 1.6: map misuse detection

best-effort, always-on check of concurrent R+W, W+W

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Go 1.6: Windows timer resolution

better battery life on Windows

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Go 1.6: stdlib changes

~50 things mentioned in release notes

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So now what?

​

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Go 1.6.1

the “whoops!” release

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Go 1.7

Hacking time! Started this morning!

Due Aug 2016

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Go 1.7: SSA

faster, smaller generated code

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$ find . -name '*.rules'

./src/cmd/compile/internal/ssa/gen/AMD64.rules

./src/cmd/compile/internal/ssa/gen/generic.rules

​

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// constant folding

(Neg8 (Const8 [c])) -> (Const8 [-c])

(Neg16 (Const16 [c])) -> (Const16 [-c])

(Neg32 (Const32 [c])) -> (Const32 [-c])

(Neg64 (Const64 [c])) -> (Const64 [-c])

​

// canonicalize: swap arguments for commutative operations when one argument is a constant.

(Eq64 x (Const64 <t> [c])) && x.Op != OpConst64 -> (Eq64 (Const64 <t> [c]) x)

(Eq32 x (Const32 <t> [c])) && x.Op != OpConst32 -> (Eq32 (Const32 <t> [c]) x)

(Eq16 x (Const16 <t> [c])) && x.Op != OpConst16 -> (Eq16 (Const16 <t> [c]) x)

(Eq8 x (Const8 <t> [c])) && x.Op != OpConst8 -> (Eq8 (Const8 <t> [c]) x)

​

// simplifications

(Or64 x x) -> x

(Or64 (Const64 [0]) x) -> x

(Or8 (Const8 [0]) x) -> x

(Or64 (Const64 [-1]) _) -> (Const64 [-1])

(Or8 (Const8 [-1]) _) -> (Const8 [-1])

(And64 x x) -> x

(And64 (Const64 [-1]) x) -> x

(And64 (Const64 [0]) _) -> (Const64 [0])

(Xor64 x x) -> (Const64 [0])

​

​

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// Lowering arithmetic

(Add64 x y) -> (ADDQ x y)

(AddPtr x y) -> (ADDQ x y)

(Add32 x y) -> (ADDL x y)

(Add16 x y) -> (ADDW x y)

(Add8 x y) -> (ADDB x y)

(Add64F x y) -> (ADDSD x y)

…

(Lsh8x64 <t> x y) -> (ANDB (SHLB <t> x y) (SBBLcarrymask <t> (CMPQconst y [8])))

(Lsh8x32 <t> x y) -> (ANDB (SHLB <t> x y) (SBBLcarrymask <t> (CMPLconst y [8])))

(Lsh8x16 <t> x y) -> (ANDB (SHLB <t> x y) (SBBLcarrymask <t> (CMPWconst y [8])))

(Lsh8x8 <t> x y) -> (ANDB (SHLB <t> x y) (SBBLcarrymask <t> (CMPBconst y [8])))

…

// fold LEAQs together

(LEAQ [off1] {sym1} (LEAQ [off2] {sym2} x)) && canMergeSym(sym1, sym2) ->

(LEAQ [addOff(off1,off2)] {mergeSym(sym1,sym2)} x)

// LEAQ into LEAQ1

(LEAQ1 [off1] {sym1} (LEAQ [off2] {sym2} x) y) && canMergeSym(sym1, sym2) && x.Op != OpSB ->

(LEAQ1 [addOff(off1,off2)] {mergeSym(sym1,sym2)} x y)

(LEAQ1 [off1] {sym1} x (LEAQ [off2] {sym2} y)) && canMergeSym(sym1, sym2) && y.Op != OpSB ->

(LEAQ1 [addOff(off1,off2)] {mergeSym(sym1,sym2)} x y)

​

​

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Rules easy to add…

… sent this morning

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Go 1.7: vendor always on

no more GO15VENDOREXPERIMENT

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Go 1.7: new *.a files

smaller, faster

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Go 1.7: zip-based *.a files

4x smaller $GOPATH/pkg/*

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Go 1.7: binary export data

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Go 1.7: compression optimizations

faster zip/flate

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Go 1.7: smaller binaries

already in progress

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… sent this morning

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Go 1.7: faster builds?

Go 1.5 was unfortunate

Go 1.6’s lack of fix was a little embarrassing

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Go 1.7: new GC tuning, experiments

goroutine-local young gen, maybe?

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Go 1.7: http2 PUSH_PROMISE?

and performance optimizations

(profile + tune frame/TLS record sizes)

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Go 1.7: IDNA?

http.Get(“https://ಹಲೋ.in”)

net.Dial(“tcp”, “ಹಲೋ.in:443”)

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Go 1.7: more architectures

add SPARC64, S390[x]

optimize PPC64 & ARM64 & MIPS64

maybe add RISC-V?

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Go 1.7: little stdlib things

many open Go1.7 feature requests

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Go 1.7: SSA

did I mention SSA?

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Go 1.8

Feb 2017

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Go 1.8: ???

More compiler polish (more SSA),

Better GC

etc.

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Go 1.9: ???

you get the picture

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Go 1.10: ???

you get the picture

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Go 1.x

Solid foundation to build upon

​

Excitement can be found upstairs

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Thank you!

Questions?

​