Implement slow fallback

Also adds Travis CI and a bunch of missing license headers.

Author: tamird

.travis.yml

@@ -0,0 +1,8 @@
+language: go
+
+go:
+  - 1.3
+  - 1.4
+  - 1.5
+  - 1.6
+  - 1.7

README.md

@@ -1,4 +1,4 @@
 # goid
 
-Demo of how to programatically retrieve the current goroutine's
-ID. Works for both pre-go1.4 and post-go1.4.
+Programatically retrieve the current goroutine's ID. See [the CI
+configuration](.travis.yml) for supported Go versions.

goid.go

@@ -0,0 +1,35 @@
+// Copyright 2016 Peter Mattis.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+// implied. See the License for the specific language governing
+// permissions and limitations under the License. See the AUTHORS file
+// for names of contributors.
+
+package goid
+
+import (
+	"bytes"
+	"runtime"
+	"strconv"
+)
+
+func ExtractGID(s []byte) int64 {
+	s = s[len("goroutine "):]
+	s = s[:bytes.IndexByte(s, ' ')]
+	gid, _ := strconv.ParseInt(string(s), 10, 64)
+	return gid
+}
+
+// Parse the goid from runtime.Stack() output. Slow, but it works.
+func getSlow() int64 {
+	var buf [64]byte
+	return ExtractGID(buf[:runtime.Stack(buf[:], false)])
+}

goid_go1.5.go

@@ -1,4 +1,20 @@
-// +build go1.5, !go1.6
+// Copyright 2016 Peter Mattis.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+// implied. See the License for the specific language governing
+// permissions and limitations under the License. See the AUTHORS file
+// for names of contributors.
+
+// +build amd64 amd64p32 arm
+// +build go1.5,!go1.6
 
 package goid
 

goid_go1.5plus.s

@@ -1,3 +1,18 @@
+// Copyright 2016 Peter Mattis.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+// implied. See the License for the specific language governing
+// permissions and limitations under the License. See the AUTHORS file
+// for names of contributors.
+
 // Assembly to mimic runtime.getg.
 
 // +build amd64 amd64p32

goid_go1.5plus_arm.s

@@ -1,3 +1,18 @@
+// Copyright 2016 Peter Mattis.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+// implied. See the License for the specific language governing
+// permissions and limitations under the License. See the AUTHORS file
+// for names of contributors.
+
 // Assembly to mimic runtime.getg.
 // This should work on arm64 as well, but it hasn't been tested.
 

goid_go1.6plus.go

@@ -1,3 +1,4 @@
+// +build amd64 amd64p32 arm
 // +build go1.6
 
 package goid

goid_slow.go

@@ -0,0 +1,23 @@
+// Copyright 2016 Peter Mattis.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+// implied. See the License for the specific language governing
+// permissions and limitations under the License. See the AUTHORS file
+// for names of contributors.
+
+// +build go1.4,!go1.5,!amd64,!amd64p32,!arm,!386 go1.5,!go1.6,!amd64,!amd64p32,!arm go1.6,!amd64,!amd64p32,!arm
+
+package goid
+
+// Get returns the id of the current goroutine.
+func Get() int64 {
+	return getSlow()
+}

goid_test.go

@@ -17,26 +17,9 @@ package goid
 
 import (
 	"fmt"
-	"regexp"
-	"runtime"
-	"strconv"
 	"testing"
 )
 
-// Parse the goid from runtime.Stack() output. Slow, but it works.
-var goroutineRE = regexp.MustCompile(`^goroutine\s+(\d+)\s+.*`)
-
-func getSlow() int64 {
-	var buf [1024]byte
-	s := buf[0:runtime.Stack(buf[:], false)]
-	m := goroutineRE.FindSubmatch(s)
-	if m == nil {
-		return -1
-	}
-	v, _ := strconv.ParseInt(string(m[1]), 10, 64)
-	return v
-}
-
 func TestGet(t *testing.T) {
 	ch := make(chan *string, 100)
 	for i := 0; i < cap(ch); i++ {