// 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 runtimeimport ( "runtime/internal/atomic" "unsafe")func lfstackpush(head *uint64, node *lfnode) { node.pushcnt++ new := lfstackPack(node, node.pushcnt) if node1, _ := lfstackUnpack(new); node1 != node { print("runtime: lfstackpush invalid packing: node=", node, " cnt=", hex(node.pushcnt), " packed=", hex(new), " -> node=", node1, "\n") throw("lfstackpush") } for { old := atomic.Load64(head) node.next = old if atomic.Cas64(head, old, new) { break } }}func lfstackpop(head *uint64) unsafe.Pointer { for { old := atomic.Load64(head) if old == 0 { return nil } node, _ := lfstackUnpack(old) next := atomic.Load64(&node.next) if atomic.Cas64(head, old, next) { return unsafe.Pointer(node) } }}
// 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 (
"runtime/internal/atomic"
"unsafe"
)
func lfstackpush(head *uint64, node *lfnode) {
node.pushcnt++
new := lfstackPack(node, node.pushcnt)
if node1, _ := lfstackUnpack(new); node1 != node {
print("runtime: lfstackpush invalid packing: node=", node, " cnt=", hex(node.pushcnt), " packed=", hex(new), " -> node=", node1, "\n")
throw("lfstackpush")
}
for {
old := atomic.Load64(head)
node.next = old
if atomic.Cas64(head, old, new) {
break
}
}
}
func lfstackpop(head *uint64) unsafe.Pointer {
for {
old := atomic.Load64(head)
if old == 0 {
return nil
}
node, _ := lfstackUnpack(old)
next := atomic.Load64(&node.next)
if atomic.Cas64(head, old, next) {
return unsafe.Pointer(node)
}
}
}