[dev.garbage] all: merge dev.cc into dev.garbage
The garbage collector is now written in Go.
There is plenty to clean up (just like on dev.cc).
all.bash passes on darwin/amd64, darwin/386, linux/amd64, linux/386.
TBR=rlh
R=austin, rlh, bradfitz
CC=golang-codereviews
https://golang.org/cl/173250043
diff --git a/src/runtime/lfstack.go b/src/runtime/lfstack.go
new file mode 100644
index 0000000..a4ad8a1
--- /dev/null
+++ b/src/runtime/lfstack.go
@@ -0,0 +1,36 @@
+// Copyright 2012 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.
+
+// Lock-free stack.
+// The following code runs only on g0 stack.
+
+package runtime
+
+import "unsafe"
+
+func lfstackpush(head *uint64, node *lfnode) {
+ node.pushcnt++
+ new := lfstackPack(node, node.pushcnt)
+ for {
+ old := atomicload64(head)
+ node.next = old
+ if cas64(head, old, new) {
+ break
+ }
+ }
+}
+
+func lfstackpop(head *uint64) unsafe.Pointer {
+ for {
+ old := atomicload64(head)
+ if old == 0 {
+ return nil
+ }
+ node, _ := lfstackUnpack(old)
+ next := atomicload64(&node.next)
+ if cas64(head, old, next) {
+ return unsafe.Pointer(node)
+ }
+ }
+}
