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go/src/runtime/lfstack.go
Dave Cheney 9cc9e95b28 Revert "runtime: merge lfstack{Pack,Unpack} into one file"
This broke solaris, which apparently does use the upper 17 bits of the address space.

This reverts commit 3b02c5b1b6.

Change-Id: Iedfe54abd0384960845468205f20191a97751c0b
Reviewed-on: https://go-review.googlesource.com/21652
Reviewed-by: Dave Cheney <dave@cheney.net>
2016-04-07 14:05:24 +00:00

44 lines
975 B
Go

// 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)
}
}
}