diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..24a9221
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,53 @@
+Copyright for package goroutine.
+=====================================================================
+Copyright (c) 2015 Huan Du
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+=====================================================================
+
+Copyright notice for golang source code.
+=====================================================================
+Copyright (c) 2012 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+=====================================================================
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..0492e41
--- /dev/null
+++ b/README.md
@@ -0,0 +1,31 @@
+# Hacking goroutine #
+
+Package goroutine is merely a hack.
+It exports goroutine id to outside so that you can use it for whatever purpose.
+However, it's highly recommended to not use this package in your daily life.
+It may be broken at any go release as it's a hack.
+
+## Usage ##
+
+Get the latest version through `go get -u github.com/huandu/goroutine`.
+
+Get current goroutine id with `goroutine.GoroutineId()`.
+
+```go
+// Get id of current goroutine.
+var id int64 = goroutine.GoroutineId()
+println(id)
+```
+
+See [godoc](https://godoc.org/github.com/huandu/goroutine) for more details.
+
+## Caveats ##
+
+Package goroutine is not well tested due to lack of test machines.
+
+Tested platforms.
+* go1.5.1 + Darwin (Mac OSX 10.11.1) + amd64 CPU
+
+## License ##
+
+This package is licensed under MIT license. See LICENSE for details.
diff --git a/arch_386.go b/arch_386.go
new file mode 100644
index 0000000..8dab3eb
--- /dev/null
+++ b/arch_386.go
@@ -0,0 +1,8 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goroutine
+
+type uintreg uint32
+type intptr int32 // TODO(rsc): remove
diff --git a/arch_amd64.go b/arch_amd64.go
new file mode 100644
index 0000000..58b788f
--- /dev/null
+++ b/arch_amd64.go
@@ -0,0 +1,8 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goroutine
+
+type uintreg uint64
+type intptr int64 // TODO(rsc): remove
diff --git a/arch_amd64p32.go b/arch_amd64p32.go
new file mode 100644
index 0000000..a61f307
--- /dev/null
+++ b/arch_amd64p32.go
@@ -0,0 +1,8 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goroutine
+
+type uintreg uint64
+type intptr int32 // TODO(rsc): remove
diff --git a/arch_arm.go b/arch_arm.go
new file mode 100644
index 0000000..8dab3eb
--- /dev/null
+++ b/arch_arm.go
@@ -0,0 +1,8 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goroutine
+
+type uintreg uint32
+type intptr int32 // TODO(rsc): remove
diff --git a/arch_arm64.go b/arch_arm64.go
new file mode 100644
index 0000000..58b788f
--- /dev/null
+++ b/arch_arm64.go
@@ -0,0 +1,8 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goroutine
+
+type uintreg uint64
+type intptr int64 // TODO(rsc): remove
diff --git a/arch_ppc64.go b/arch_ppc64.go
new file mode 100644
index 0000000..58b788f
--- /dev/null
+++ b/arch_ppc64.go
@@ -0,0 +1,8 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goroutine
+
+type uintreg uint64
+type intptr int64 // TODO(rsc): remove
diff --git a/arch_ppc64le.go b/arch_ppc64le.go
new file mode 100644
index 0000000..58b788f
--- /dev/null
+++ b/arch_ppc64le.go
@@ -0,0 +1,8 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goroutine
+
+type uintreg uint64
+type intptr int64 // TODO(rsc): remove
diff --git a/doc.go b/doc.go
new file mode 100644
index 0000000..1845ef1
--- /dev/null
+++ b/doc.go
@@ -0,0 +1,8 @@
+// Copyright 2015 Huan Du. All rights reserved.
+// Use of this source code is governed by a MIT
+// license that can be found in the LICENSE file.
+
+// Package goroutine is merely a hack. Don't use it if you can.
+//
+// Package goroutine exports goroutine id. Do whatever you want with care.
+package goroutine
diff --git a/go_tls.h b/go_tls.h
new file mode 100644
index 0000000..6a707cf
--- /dev/null
+++ b/go_tls.h
@@ -0,0 +1,22 @@
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifdef GOARCH_arm
+#define LR R14
+#endif
+
+#ifdef GOARCH_amd64
+#define	get_tls(r)	MOVQ TLS, r
+#define	g(r)	0(r)(TLS*1)
+#endif
+
+#ifdef GOARCH_amd64p32
+#define	get_tls(r)	MOVL TLS, r
+#define	g(r)	0(r)(TLS*1)
+#endif
+
+#ifdef GOARCH_386
+#define	get_tls(r)	MOVL TLS, r
+#define	g(r)	0(r)(TLS*1)
+#endif
diff --git a/info.go b/info.go
new file mode 100644
index 0000000..0fae335
--- /dev/null
+++ b/info.go
@@ -0,0 +1,14 @@
+// Copyright 2015 Huan Du. All rights reserved.
+// Use of this source code is governed by a MIT
+// license that can be found in the LICENSE file.
+
+package goroutine
+
+func getg() *g
+
+// GoroutineId return id of current goroutine.
+// It's guaranteed to be unique globally during app's life time.
+func GoroutineId() int64 {
+    gp := getg()
+    return gp.goid
+}
diff --git a/info_386.s b/info_386.s
new file mode 100644
index 0000000..603b5c4
--- /dev/null
+++ b/info_386.s
@@ -0,0 +1,13 @@
+// Copyright 2015 Huan Du. All rights reserved.
+// Use of this source code is governed by a MIT
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "go_tls.h"
+#include "textflag.h"
+
+TEXT ·getg(SB), NOSPLIT, $0-4
+    get_tls(CX)
+    MOVL g(CX), AX
+    MOVL AX, ret+0(FP)
+    RET
diff --git a/info_amd64.s b/info_amd64.s
new file mode 100644
index 0000000..86c3361
--- /dev/null
+++ b/info_amd64.s
@@ -0,0 +1,13 @@
+// Copyright 2015 Huan Du. All rights reserved.
+// Use of this source code is governed by a MIT
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "go_tls.h"
+#include "textflag.h"
+
+TEXT ·getg(SB), NOSPLIT, $0-8
+    get_tls(CX)
+    MOVQ g(CX), AX
+    MOVQ AX, ret+0(FP)
+    RET
diff --git a/info_amd64p32.s b/info_amd64p32.s
new file mode 100644
index 0000000..a50c333
--- /dev/null
+++ b/info_amd64p32.s
@@ -0,0 +1,5 @@
+// Copyright 2015 Huan Du. All rights reserved.
+// Use of this source code is governed by a MIT
+// license that can be found in the LICENSE file.
+
+#include "info_amd64.s"
diff --git a/info_arm.s b/info_arm.s
new file mode 100644
index 0000000..552d7ce
--- /dev/null
+++ b/info_arm.s
@@ -0,0 +1,10 @@
+// Copyright 2015 Huan Du. All rights reserved.
+// Use of this source code is governed by a MIT
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "textflag.h"
+
+TEXT ·getg(SB), NOSPLIT, $0-4
+    MOVW g, ret+0(FP)
+    RET
diff --git a/info_arm64.s b/info_arm64.s
new file mode 100644
index 0000000..2d0feb0
--- /dev/null
+++ b/info_arm64.s
@@ -0,0 +1,12 @@
+// Copyright 2015 Huan Du. All rights reserved.
+// Use of this source code is governed by a MIT
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "go_tls.h"
+#include "textflag.h"
+
+TEXT ·getg(SB), NOSPLIT, $0-8
+    get_tls(R0)
+    MOVQ R0, ret+0(FP)
+    RET
diff --git a/info_test.go b/info_test.go
new file mode 100644
index 0000000..16f34ee
--- /dev/null
+++ b/info_test.go
@@ -0,0 +1,47 @@
+// Copyright 2015 Huan Du. All rights reserved.
+// Use of this source code is governed by a MIT
+// license that can be found in the LICENSE file.
+
+package goroutine
+
+import (
+    "testing"
+    "time"
+    "fmt"
+    "math/rand"
+)
+
+func TestGoroutineIdConsistency(t *testing.T) {
+    cnt := 10
+    exit := make(chan error)
+
+    for i := 0; i < cnt; i++ {
+        go func(n int) {
+            id1 := GoroutineId()
+            time.Sleep(time.Duration(rand.Int63n(100)) * time.Millisecond)
+            id2 := GoroutineId()
+
+            if id1 != id2 {
+                exit <- fmt.Errorf("Inconsistent goroutine id. [old:%v] [new:%v]", id1, id2)
+                return
+            }
+
+            exit <- nil
+        }(i)
+    }
+
+    failed := false
+
+    for i := 0; i < cnt; i++ {
+        err := <-exit
+
+        if err != nil {
+            t.Logf("Found error. [err:%v]", err)
+            failed = true
+        }
+    }
+
+    if failed {
+        t.Fatalf("Test failed.")
+    }
+}
diff --git a/opaque.go b/opaque.go
new file mode 100644
index 0000000..8b79a1f
--- /dev/null
+++ b/opaque.go
@@ -0,0 +1,75 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goroutine
+
+import "unsafe"
+
+const ptrSize = 4 << (^uintptr(0) >> 63)             // unsafe.Sizeof(uintptr(0)) but an ideal const
+const regSize = 4 << (^uintreg(0) >> 63)             // unsafe.Sizeof(uintreg(0)) but an ideal const
+
+type mcache struct {}
+type typeAlg struct {}
+type traceBuf struct {}
+
+type gcMarkWorkerMode int
+
+type persistentAlloc struct {
+	base unsafe.Pointer
+	off  uintptr
+}
+
+// A wbufptr holds a workbuf*, but protects it from write barriers.
+// workbufs never live on the heap, so write barriers are unnecessary.
+// Write barriers on workbuf pointers may also be dangerous in the GC.
+type wbufptr uintptr
+
+// A gcWork provides the interface to produce and consume work for the
+// garbage collector.
+//
+// A gcWork can be used on the stack as follows:
+//
+//     var gcw gcWork
+//     disable preemption
+//     .. call gcw.put() to produce and gcw.get() to consume ..
+//     gcw.dispose()
+//     enable preemption
+//
+// Or from the per-P gcWork cache:
+//
+//     (preemption must be disabled)
+//     gcw := &getg().m.p.ptr().gcw
+//     .. call gcw.put() to produce and gcw.get() to consume ..
+//     if gcphase == _GCmarktermination {
+//         gcw.dispose()
+//     }
+//
+// It's important that any use of gcWork during the mark phase prevent
+// the garbage collector from transitioning to mark termination since
+// gcWork may locally hold GC work buffers. This can be done by
+// disabling preemption (systemstack or acquirem).
+type gcWork struct {
+	// Invariant: wbuf is never full or empty
+	wbuf wbufptr
+
+	// Bytes marked (blackened) on this gcWork. This is aggregated
+	// into work.bytesMarked by dispose.
+	bytesMarked uint64
+
+	// Scan work performed on this gcWork. This is aggregated into
+	// gcController by dispose.
+	scanWork int64
+}
+
+// Information from the compiler about the layout of stack frames.
+type bitvector struct {
+	n        int32 // # of bits
+	bytedata *uint8
+}
+
+type slice struct {
+	array unsafe.Pointer
+	len   int
+	cap   int
+}
diff --git a/runtime2.go b/runtime2.go
new file mode 100644
index 0000000..736bedc
--- /dev/null
+++ b/runtime2.go
@@ -0,0 +1,699 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goroutine
+
+import "unsafe"
+
+/*
+ * defined constants
+ */
+const (
+	// G status
+	//
+	// If you add to this list, add to the list
+	// of "okay during garbage collection" status
+	// in mgcmark.go too.
+	_Gidle            = iota // 0
+	_Grunnable               // 1 runnable and on a run queue
+	_Grunning                // 2
+	_Gsyscall                // 3
+	_Gwaiting                // 4
+	_Gmoribund_unused        // 5 currently unused, but hardcoded in gdb scripts
+	_Gdead                   // 6
+	_Genqueue                // 7 Only the Gscanenqueue is used.
+	_Gcopystack              // 8 in this state when newstack is moving the stack
+	// the following encode that the GC is scanning the stack and what to do when it is done
+	_Gscan = 0x1000 // atomicstatus&~Gscan = the non-scan state,
+	// _Gscanidle =     _Gscan + _Gidle,      // Not used. Gidle only used with newly malloced gs
+	_Gscanrunnable = _Gscan + _Grunnable //  0x1001 When scanning completes make Grunnable (it is already on run queue)
+	_Gscanrunning  = _Gscan + _Grunning  //  0x1002 Used to tell preemption newstack routine to scan preempted stack.
+	_Gscansyscall  = _Gscan + _Gsyscall  //  0x1003 When scanning completes make it Gsyscall
+	_Gscanwaiting  = _Gscan + _Gwaiting  //  0x1004 When scanning completes make it Gwaiting
+	// _Gscanmoribund_unused,               //  not possible
+	// _Gscandead,                          //  not possible
+	_Gscanenqueue = _Gscan + _Genqueue //  When scanning completes make it Grunnable and put on runqueue
+)
+
+const (
+	// P status
+	_Pidle    = iota
+	_Prunning // Only this P is allowed to change from _Prunning.
+	_Psyscall
+	_Pgcstop
+	_Pdead
+)
+
+// The next line makes 'go generate' write the zgen_*.go files with
+// per-OS and per-arch information, including constants
+// named goos_$GOOS and goarch_$GOARCH for every
+// known GOOS and GOARCH. The constant is 1 on the
+// current system, 0 otherwise; multiplying by them is
+// useful for defining GOOS- or GOARCH-specific constants.
+//go:generate go run gengoos.go
+
+type mutex struct {
+	// Futex-based impl treats it as uint32 key,
+	// while sema-based impl as M* waitm.
+	// Used to be a union, but unions break precise GC.
+	key uintptr
+}
+
+type note struct {
+	// Futex-based impl treats it as uint32 key,
+	// while sema-based impl as M* waitm.
+	// Used to be a union, but unions break precise GC.
+	key uintptr
+}
+
+type _string struct {
+	str *byte
+	len int
+}
+
+type funcval struct {
+	fn uintptr
+	// variable-size, fn-specific data here
+}
+
+type iface struct {
+	tab  *itab
+	data unsafe.Pointer
+}
+
+type eface struct {
+	_type *_type
+	data  unsafe.Pointer
+}
+
+// The guintptr, muintptr, and puintptr are all used to bypass write barriers.
+// It is particularly important to avoid write barriers when the current P has
+// been released, because the GC thinks the world is stopped, and an
+// unexpected write barrier would not be synchronized with the GC,
+// which can lead to a half-executed write barrier that has marked the object
+// but not queued it. If the GC skips the object and completes before the
+// queuing can occur, it will incorrectly free the object.
+//
+// We tried using special assignment functions invoked only when not
+// holding a running P, but then some updates to a particular memory
+// word went through write barriers and some did not. This breaks the
+// write barrier shadow checking mode, and it is also scary: better to have
+// a word that is completely ignored by the GC than to have one for which
+// only a few updates are ignored.
+//
+// Gs, Ms, and Ps are always reachable via true pointers in the
+// allgs, allm, and allp lists or (during allocation before they reach those lists)
+// from stack variables.
+
+// A guintptr holds a goroutine pointer, but typed as a uintptr
+// to bypass write barriers. It is used in the Gobuf goroutine state
+// and in scheduling lists that are manipulated without a P.
+//
+// The Gobuf.g goroutine pointer is almost always updated by assembly code.
+// In one of the few places it is updated by Go code - func save - it must be
+// treated as a uintptr to avoid a write barrier being emitted at a bad time.
+// Instead of figuring out how to emit the write barriers missing in the
+// assembly manipulation, we change the type of the field to uintptr,
+// so that it does not require write barriers at all.
+//
+// Goroutine structs are published in the allg list and never freed.
+// That will keep the goroutine structs from being collected.
+// There is never a time that Gobuf.g's contain the only references
+// to a goroutine: the publishing of the goroutine in allg comes first.
+// Goroutine pointers are also kept in non-GC-visible places like TLS,
+// so I can't see them ever moving. If we did want to start moving data
+// in the GC, we'd need to allocate the goroutine structs from an
+// alternate arena. Using guintptr doesn't make that problem any worse.
+type guintptr uintptr
+
+func (gp guintptr) ptr() *g   { return (*g)(unsafe.Pointer(gp)) }
+func (gp *guintptr) set(g *g) { *gp = guintptr(unsafe.Pointer(g)) }
+// func (gp *guintptr) cas(old, new guintptr) bool {
+// 	return casuintptr((*uintptr)(unsafe.Pointer(gp)), uintptr(old), uintptr(new))
+// }
+
+type puintptr uintptr
+
+func (pp puintptr) ptr() *p   { return (*p)(unsafe.Pointer(pp)) }
+func (pp *puintptr) set(p *p) { *pp = puintptr(unsafe.Pointer(p)) }
+
+type muintptr uintptr
+
+func (mp muintptr) ptr() *m   { return (*m)(unsafe.Pointer(mp)) }
+func (mp *muintptr) set(m *m) { *mp = muintptr(unsafe.Pointer(m)) }
+
+type gobuf struct {
+	// The offsets of sp, pc, and g are known to (hard-coded in) libmach.
+	sp   uintptr
+	pc   uintptr
+	g    guintptr
+	ctxt unsafe.Pointer // this has to be a pointer so that gc scans it
+	ret  uintreg
+	lr   uintptr
+	bp   uintptr // for GOEXPERIMENT=framepointer
+}
+
+// Known to compiler.
+// Changes here must also be made in src/cmd/internal/gc/select.go's selecttype.
+type sudog struct {
+	g           *g
+	selectdone  *uint32
+	next        *sudog
+	prev        *sudog
+	elem        unsafe.Pointer // data element
+	releasetime int64
+	nrelease    int32  // -1 for acquire
+	waitlink    *sudog // g.waiting list
+}
+
+type gcstats struct {
+	// the struct must consist of only uint64's,
+	// because it is casted to uint64[].
+	nhandoff    uint64
+	nhandoffcnt uint64
+	nprocyield  uint64
+	nosyield    uint64
+	nsleep      uint64
+}
+
+type libcall struct {
+	fn   uintptr
+	n    uintptr // number of parameters
+	args uintptr // parameters
+	r1   uintptr // return values
+	r2   uintptr
+	err  uintptr // error number
+}
+
+// describes how to handle callback
+type wincallbackcontext struct {
+	gobody       unsafe.Pointer // go function to call
+	argsize      uintptr        // callback arguments size (in bytes)
+	restorestack uintptr        // adjust stack on return by (in bytes) (386 only)
+	cleanstack   bool
+}
+
+// Stack describes a Go execution stack.
+// The bounds of the stack are exactly [lo, hi),
+// with no implicit data structures on either side.
+type stack struct {
+	lo uintptr
+	hi uintptr
+}
+
+// stkbar records the state of a G's stack barrier.
+type stkbar struct {
+	savedLRPtr uintptr // location overwritten by stack barrier PC
+	savedLRVal uintptr // value overwritten at savedLRPtr
+}
+
+type g struct {
+	// Stack parameters.
+	// stack describes the actual stack memory: [stack.lo, stack.hi).
+	// stackguard0 is the stack pointer compared in the Go stack growth prologue.
+	// It is stack.lo+StackGuard normally, but can be StackPreempt to trigger a preemption.
+	// stackguard1 is the stack pointer compared in the C stack growth prologue.
+	// It is stack.lo+StackGuard on g0 and gsignal stacks.
+	// It is ~0 on other goroutine stacks, to trigger a call to morestackc (and crash).
+	stack       stack   // offset known to runtime/cgo
+	stackguard0 uintptr // offset known to liblink
+	stackguard1 uintptr // offset known to liblink
+
+	_panic         *_panic // innermost panic - offset known to liblink
+	_defer         *_defer // innermost defer
+	m              *m      // current m; offset known to arm liblink
+	stackAlloc     uintptr // stack allocation is [stack.lo,stack.lo+stackAlloc)
+	sched          gobuf
+	syscallsp      uintptr        // if status==Gsyscall, syscallsp = sched.sp to use during gc
+	syscallpc      uintptr        // if status==Gsyscall, syscallpc = sched.pc to use during gc
+	stkbar         []stkbar       // stack barriers, from low to high
+	stkbarPos      uintptr        // index of lowest stack barrier not hit
+	param          unsafe.Pointer // passed parameter on wakeup
+	atomicstatus   uint32
+	stackLock      uint32 // sigprof/scang lock; TODO: fold in to atomicstatus
+	goid           int64
+	waitsince      int64  // approx time when the g become blocked
+	waitreason     string // if status==Gwaiting
+	schedlink      guintptr
+	preempt        bool   // preemption signal, duplicates stackguard0 = stackpreempt
+	paniconfault   bool   // panic (instead of crash) on unexpected fault address
+	preemptscan    bool   // preempted g does scan for gc
+	gcscandone     bool   // g has scanned stack; protected by _Gscan bit in status
+	gcscanvalid    bool   // false at start of gc cycle, true if G has not run since last scan
+	throwsplit     bool   // must not split stack
+	raceignore     int8   // ignore race detection events
+	sysblocktraced bool   // StartTrace has emitted EvGoInSyscall about this goroutine
+	sysexitticks   int64  // cputicks when syscall has returned (for tracing)
+	sysexitseq     uint64 // trace seq when syscall has returned (for tracing)
+	lockedm        *m
+	sig            uint32
+	writebuf       []byte
+	sigcode0       uintptr
+	sigcode1       uintptr
+	sigpc          uintptr
+	gopc           uintptr // pc of go statement that created this goroutine
+	startpc        uintptr // pc of goroutine function
+	racectx        uintptr
+	waiting        *sudog // sudog structures this g is waiting on (that have a valid elem ptr)
+	readyg         *g     // scratch for readyExecute
+
+	// Per-G gcController state
+	gcalloc    uintptr // bytes allocated during this GC cycle
+	gcscanwork int64   // scan work done (or stolen) this GC cycle
+}
+
+type mts struct {
+	tv_sec  int64
+	tv_nsec int64
+}
+
+type mscratch struct {
+	v [6]uintptr
+}
+
+type m struct {
+	g0      *g     // goroutine with scheduling stack
+	morebuf gobuf  // gobuf arg to morestack
+	divmod  uint32 // div/mod denominator for arm - known to liblink
+
+	// Fields not known to debuggers.
+	procid        uint64     // for debuggers, but offset not hard-coded
+	gsignal       *g         // signal-handling g
+	sigmask       [4]uintptr // storage for saved signal mask
+	tls           [4]uintptr // thread-local storage (for x86 extern register)
+	mstartfn      func()
+	curg          *g       // current running goroutine
+	caughtsig     guintptr // goroutine running during fatal signal
+	p             puintptr // attached p for executing go code (nil if not executing go code)
+	nextp         puintptr
+	id            int32
+	mallocing     int32
+	throwing      int32
+	preemptoff    string // if != "", keep curg running on this m
+	locks         int32
+	softfloat     int32
+	dying         int32
+	profilehz     int32
+	helpgc        int32
+	spinning      bool // m is out of work and is actively looking for work
+	blocked       bool // m is blocked on a note
+	inwb          bool // m is executing a write barrier
+	printlock     int8
+	fastrand      uint32
+	ncgocall      uint64 // number of cgo calls in total
+	ncgo          int32  // number of cgo calls currently in progress
+	park          note
+	alllink       *m // on allm
+	schedlink     muintptr
+	machport      uint32 // return address for mach ipc (os x)
+	mcache        *mcache
+	lockedg       *g
+	createstack   [32]uintptr // stack that created this thread.
+	freglo        [16]uint32  // d[i] lsb and f[i]
+	freghi        [16]uint32  // d[i] msb and f[i+16]
+	fflag         uint32      // floating point compare flags
+	locked        uint32      // tracking for lockosthread
+	nextwaitm     uintptr     // next m waiting for lock
+	waitsema      uintptr     // semaphore for parking on locks
+	waitsemacount uint32
+	waitsemalock  uint32
+	gcstats       gcstats
+	needextram    bool
+	traceback     uint8
+	waitunlockf   unsafe.Pointer // todo go func(*g, unsafe.pointer) bool
+	waitlock      unsafe.Pointer
+	waittraceev   byte
+	waittraceskip int
+	startingtrace bool
+	syscalltick   uint32
+	//#ifdef GOOS_windows
+	thread uintptr // thread handle
+	// these are here because they are too large to be on the stack
+	// of low-level NOSPLIT functions.
+	libcall   libcall
+	libcallpc uintptr // for cpu profiler
+	libcallsp uintptr
+	libcallg  guintptr
+	syscall   libcall // stores syscall parameters on windows
+	//#endif
+	//#ifdef GOOS_solaris
+	perrno *int32 // pointer to tls errno
+	// these are here because they are too large to be on the stack
+	// of low-level NOSPLIT functions.
+	//LibCall	libcall;
+	ts      mts
+	scratch mscratch
+	//#endif
+	//#ifdef GOOS_plan9
+	notesig *int8
+	errstr  *byte
+	//#endif
+}
+
+type p struct {
+	lock mutex
+
+	id          int32
+	status      uint32 // one of pidle/prunning/...
+	link        puintptr
+	schedtick   uint32   // incremented on every scheduler call
+	syscalltick uint32   // incremented on every system call
+	m           muintptr // back-link to associated m (nil if idle)
+	mcache      *mcache
+
+	deferpool    [5][]*_defer // pool of available defer structs of different sizes (see panic.go)
+	deferpoolbuf [5][32]*_defer
+
+	// Cache of goroutine ids, amortizes accesses to runtime·sched.goidgen.
+	goidcache    uint64
+	goidcacheend uint64
+
+	// Queue of runnable goroutines. Accessed without lock.
+	runqhead uint32
+	runqtail uint32
+	runq     [256]*g
+	// runnext, if non-nil, is a runnable G that was ready'd by
+	// the current G and should be run next instead of what's in
+	// runq if there's time remaining in the running G's time
+	// slice. It will inherit the time left in the current time
+	// slice. If a set of goroutines is locked in a
+	// communicate-and-wait pattern, this schedules that set as a
+	// unit and eliminates the (potentially large) scheduling
+	// latency that otherwise arises from adding the ready'd
+	// goroutines to the end of the run queue.
+	runnext guintptr
+
+	// Available G's (status == Gdead)
+	gfree    *g
+	gfreecnt int32
+
+	sudogcache []*sudog
+	sudogbuf   [128]*sudog
+
+	tracebuf *traceBuf
+
+	palloc persistentAlloc // per-P to avoid mutex
+
+	// Per-P GC state
+	gcAssistTime     int64 // Nanoseconds in assistAlloc
+	gcBgMarkWorker   *g
+	gcMarkWorkerMode gcMarkWorkerMode
+
+	// gcw is this P's GC work buffer cache. The work buffer is
+	// filled by write barriers, drained by mutator assists, and
+	// disposed on certain GC state transitions.
+	gcw gcWork
+
+	runSafePointFn uint32 // if 1, run sched.safePointFn at next safe point
+
+	pad [64]byte
+}
+
+const (
+	// The max value of GOMAXPROCS.
+	// There are no fundamental restrictions on the value.
+	_MaxGomaxprocs = 1 << 8
+)
+
+type schedt struct {
+	lock mutex
+
+	goidgen uint64
+
+	midle        muintptr // idle m's waiting for work
+	nmidle       int32    // number of idle m's waiting for work
+	nmidlelocked int32    // number of locked m's waiting for work
+	mcount       int32    // number of m's that have been created
+	maxmcount    int32    // maximum number of m's allowed (or die)
+
+	pidle      puintptr // idle p's
+	npidle     uint32
+	nmspinning uint32
+
+	// Global runnable queue.
+	runqhead guintptr
+	runqtail guintptr
+	runqsize int32
+
+	// Global cache of dead G's.
+	gflock mutex
+	gfree  *g
+	ngfree int32
+
+	// Central cache of sudog structs.
+	sudoglock  mutex
+	sudogcache *sudog
+
+	// Central pool of available defer structs of different sizes.
+	deferlock mutex
+	deferpool [5]*_defer
+
+	gcwaiting  uint32 // gc is waiting to run
+	stopwait   int32
+	stopnote   note
+	sysmonwait uint32
+	sysmonnote note
+	lastpoll   uint64
+
+	// safepointFn should be called on each P at the next GC
+	// safepoint if p.runSafePointFn is set.
+	safePointFn   func(*p)
+	safePointWait int32
+	safePointNote note
+
+	profilehz int32 // cpu profiling rate
+
+	procresizetime int64 // nanotime() of last change to gomaxprocs
+	totaltime      int64 // ∫gomaxprocs dt up to procresizetime
+}
+
+// The m->locked word holds two pieces of state counting active calls to LockOSThread/lockOSThread.
+// The low bit (LockExternal) is a boolean reporting whether any LockOSThread call is active.
+// External locks are not recursive; a second lock is silently ignored.
+// The upper bits of m->locked record the nesting depth of calls to lockOSThread
+// (counting up by LockInternal), popped by unlockOSThread (counting down by LockInternal).
+// Internal locks can be recursive. For instance, a lock for cgo can occur while the main
+// goroutine is holding the lock during the initialization phase.
+const (
+	_LockExternal = 1
+	_LockInternal = 2
+)
+
+type sigtabtt struct {
+	flags int32
+	name  *int8
+}
+
+const (
+	_SigNotify   = 1 << iota // let signal.Notify have signal, even if from kernel
+	_SigKill                 // if signal.Notify doesn't take it, exit quietly
+	_SigThrow                // if signal.Notify doesn't take it, exit loudly
+	_SigPanic                // if the signal is from the kernel, panic
+	_SigDefault              // if the signal isn't explicitly requested, don't monitor it
+	_SigHandling             // our signal handler is registered
+	_SigIgnored              // the signal was ignored before we registered for it
+	_SigGoExit               // cause all runtime procs to exit (only used on Plan 9).
+	_SigSetStack             // add SA_ONSTACK to libc handler
+	_SigUnblock              // unblocked in minit
+)
+
+// Layout of in-memory per-function information prepared by linker
+// See https://golang.org/s/go12symtab.
+// Keep in sync with linker
+// and with package debug/gosym and with symtab.go in package runtime.
+type _func struct {
+	entry   uintptr // start pc
+	nameoff int32   // function name
+
+	args  int32 // in/out args size
+	frame int32 // legacy frame size; use pcsp if possible
+
+	pcsp      int32
+	pcfile    int32
+	pcln      int32
+	npcdata   int32
+	nfuncdata int32
+}
+
+// layout of Itab known to compilers
+// allocated in non-garbage-collected memory
+type itab struct {
+	inter  *interfacetype
+	_type  *_type
+	link   *itab
+	bad    int32
+	unused int32
+	fun    [1]uintptr // variable sized
+}
+
+// Lock-free stack node.
+// // Also known to export_test.go.
+type lfnode struct {
+	next    uint64
+	pushcnt uintptr
+}
+
+type forcegcstate struct {
+	lock mutex
+	g    *g
+	idle uint32
+}
+
+/*
+ * known to compiler
+ */
+const (
+	_Structrnd = regSize
+)
+
+// startup_random_data holds random bytes initialized at startup.  These come from
+// the ELF AT_RANDOM auxiliary vector (vdso_linux_amd64.go or os_linux_386.go).
+var startupRandomData []byte
+
+// extendRandom extends the random numbers in r[:n] to the whole slice r.
+// Treats n<0 as n==0.
+func extendRandom(r []byte, n int) {
+	// if n < 0 {
+	// 	n = 0
+	// }
+	// for n < len(r) {
+	// 	// Extend random bits using hash function & time seed
+	// 	w := n
+	// 	if w > 16 {
+	// 		w = 16
+	// 	}
+	// 	h := memhash(unsafe.Pointer(&r[n-w]), uintptr(nanotime()), uintptr(w))
+	// 	for i := 0; i < ptrSize && n < len(r); i++ {
+	// 		r[n] = byte(h)
+	// 		n++
+	// 		h >>= 8
+	// 	}
+	// }
+}
+
+/*
+ * deferred subroutine calls
+ */
+type _defer struct {
+	siz     int32
+	started bool
+	sp      uintptr // sp at time of defer
+	pc      uintptr
+	fn      *funcval
+	_panic  *_panic // panic that is running defer
+	link    *_defer
+}
+
+/*
+ * panics
+ */
+type _panic struct {
+	argp      unsafe.Pointer // pointer to arguments of deferred call run during panic; cannot move - known to liblink
+	arg       interface{}    // argument to panic
+	link      *_panic        // link to earlier panic
+	recovered bool           // whether this panic is over
+	aborted   bool           // the panic was aborted
+}
+
+/*
+ * stack traces
+ */
+
+type stkframe struct {
+	fn       *_func     // function being run
+	pc       uintptr    // program counter within fn
+	continpc uintptr    // program counter where execution can continue, or 0 if not
+	lr       uintptr    // program counter at caller aka link register
+	sp       uintptr    // stack pointer at pc
+	fp       uintptr    // stack pointer at caller aka frame pointer
+	varp     uintptr    // top of local variables
+	argp     uintptr    // pointer to function arguments
+	arglen   uintptr    // number of bytes at argp
+	argmap   *bitvector // force use of this argmap
+}
+
+const (
+	_TraceRuntimeFrames = 1 << iota // include frames for internal runtime functions.
+	_TraceTrap                      // the initial PC, SP are from a trap, not a return PC from a call
+	_TraceJumpStack                 // if traceback is on a systemstack, resume trace at g that called into it
+)
+
+const (
+	// The maximum number of frames we print for a traceback
+	_TracebackMaxFrames = 100
+)
+
+var (
+	emptystring string
+	allg        **g
+	allglen     uintptr
+	lastg       *g
+	allm        *m
+	allp        [_MaxGomaxprocs + 1]*p
+	gomaxprocs  int32
+	panicking   uint32
+	goos        *int8
+	ncpu        int32
+	signote     note
+	forcegc     forcegcstate
+	sched       schedt
+	newprocs    int32
+
+	// Information about what cpu features are available.
+	// Set on startup in asm_{x86,amd64}.s.
+	cpuid_ecx         uint32
+	cpuid_edx         uint32
+	lfenceBeforeRdtsc bool
+
+	goarm uint8 // set by cmd/link on arm systems
+)
+
+// Set by the linker so the runtime can determine the buildmode.
+var (
+	islibrary bool // -buildmode=c-shared
+	isarchive bool // -buildmode=c-archive
+)
+
+/*
+ * mutual exclusion locks.  in the uncontended case,
+ * as fast as spin locks (just a few user-level instructions),
+ * but on the contention path they sleep in the kernel.
+ * a zeroed Mutex is unlocked (no need to initialize each lock).
+ */
+
+/*
+ * sleep and wakeup on one-time events.
+ * before any calls to notesleep or notewakeup,
+ * must call noteclear to initialize the Note.
+ * then, exactly one thread can call notesleep
+ * and exactly one thread can call notewakeup (once).
+ * once notewakeup has been called, the notesleep
+ * will return.  future notesleep will return immediately.
+ * subsequent noteclear must be called only after
+ * previous notesleep has returned, e.g. it's disallowed
+ * to call noteclear straight after notewakeup.
+ *
+ * notetsleep is like notesleep but wakes up after
+ * a given number of nanoseconds even if the event
+ * has not yet happened.  if a goroutine uses notetsleep to
+ * wake up early, it must wait to call noteclear until it
+ * can be sure that no other goroutine is calling
+ * notewakeup.
+ *
+ * notesleep/notetsleep are generally called on g0,
+ * notetsleepg is similar to notetsleep but is called on user g.
+ */
+// bool	runtime·notetsleep(Note*, int64);  // false - timeout
+// bool	runtime·notetsleepg(Note*, int64);  // false - timeout
+
+/*
+ * Lock-free stack.
+ * Initialize uint64 head to 0, compare with 0 to test for emptiness.
+ * The stack does not keep pointers to nodes,
+ * so they can be garbage collected if there are no other pointers to nodes.
+ */
+
+// for mmap, we only pass the lower 32 bits of file offset to the
+// assembly routine; the higher bits (if required), should be provided
+// by the assembly routine as 0.
diff --git a/type.go b/type.go
new file mode 100644
index 0000000..a52108b
--- /dev/null
+++ b/type.go
@@ -0,0 +1,94 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Runtime type representation.
+
+package goroutine
+
+import "unsafe"
+
+// Needs to be in sync with ../cmd/internal/ld/decodesym.go:/^func.commonsize,
+// ../cmd/internal/gc/reflect.go:/^func.dcommontype and
+// ../reflect/type.go:/^type.rtype.
+type _type struct {
+	size       uintptr
+	ptrdata    uintptr // size of memory prefix holding all pointers
+	hash       uint32
+	_unused    uint8
+	align      uint8
+	fieldalign uint8
+	kind       uint8
+	alg        *typeAlg
+	// gcdata stores the GC type data for the garbage collector.
+	// If the KindGCProg bit is set in kind, gcdata is a GC program.
+	// Otherwise it is a ptrmask bitmap. See mbitmap.go for details.
+	gcdata  *byte
+	_string *string
+	x       *uncommontype
+	ptrto   *_type
+	zero    *byte // ptr to the zero value for this type
+}
+
+type method struct {
+	name    *string
+	pkgpath *string
+	mtyp    *_type
+	typ     *_type
+	ifn     unsafe.Pointer
+	tfn     unsafe.Pointer
+}
+
+type uncommontype struct {
+	name    *string
+	pkgpath *string
+	mhdr    []method
+}
+
+type imethod struct {
+	name    *string
+	pkgpath *string
+	_type   *_type
+}
+
+type interfacetype struct {
+	typ  _type
+	mhdr []imethod
+}
+
+type maptype struct {
+	typ           _type
+	key           *_type
+	elem          *_type
+	bucket        *_type // internal type representing a hash bucket
+	hmap          *_type // internal type representing a hmap
+	keysize       uint8  // size of key slot
+	indirectkey   bool   // store ptr to key instead of key itself
+	valuesize     uint8  // size of value slot
+	indirectvalue bool   // store ptr to value instead of value itself
+	bucketsize    uint16 // size of bucket
+	reflexivekey  bool   // true if k==k for all keys
+}
+
+type chantype struct {
+	typ  _type
+	elem *_type
+	dir  uintptr
+}
+
+type slicetype struct {
+	typ  _type
+	elem *_type
+}
+
+type functype struct {
+	typ       _type
+	dotdotdot bool
+	in        slice
+	out       slice
+}
+
+type ptrtype struct {
+	typ  _type
+	elem *_type
+}