148 lines
3.4 KiB
Go
148 lines
3.4 KiB
Go
// Copyright 2018 The gVisor Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// +build !amd64
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package atomicbitops
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import (
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"sync/atomic"
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)
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// AndUint32 atomically applies bitwise and operation to *addr with val.
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func AndUint32(addr *uint32, val uint32) {
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for {
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o := atomic.LoadUint32(addr)
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n := o & val
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if atomic.CompareAndSwapUint32(addr, o, n) {
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break
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}
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}
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}
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// OrUint32 atomically applies bitwise or operation to *addr with val.
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func OrUint32(addr *uint32, val uint32) {
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for {
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o := atomic.LoadUint32(addr)
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n := o | val
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if atomic.CompareAndSwapUint32(addr, o, n) {
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break
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}
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}
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}
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// XorUint32 atomically applies bitwise xor operation to *addr with val.
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func XorUint32(addr *uint32, val uint32) {
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for {
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o := atomic.LoadUint32(addr)
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n := o ^ val
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if atomic.CompareAndSwapUint32(addr, o, n) {
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break
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}
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}
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}
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// CompareAndSwapUint32 is like sync/atomic.CompareAndSwapUint32, but returns
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// the value previously stored at addr.
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func CompareAndSwapUint32(addr *uint32, old, new uint32) (prev uint32) {
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for {
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prev = atomic.LoadUint32(addr)
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if prev != old {
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return
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}
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if atomic.CompareAndSwapUint32(addr, old, new) {
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return
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}
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}
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}
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// AndUint64 atomically applies bitwise and operation to *addr with val.
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func AndUint64(addr *uint64, val uint64) {
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for {
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o := atomic.LoadUint64(addr)
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n := o & val
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if atomic.CompareAndSwapUint64(addr, o, n) {
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break
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}
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}
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}
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// OrUint64 atomically applies bitwise or operation to *addr with val.
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func OrUint64(addr *uint64, val uint64) {
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for {
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o := atomic.LoadUint64(addr)
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n := o | val
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if atomic.CompareAndSwapUint64(addr, o, n) {
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break
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}
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}
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}
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// XorUint64 atomically applies bitwise xor operation to *addr with val.
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func XorUint64(addr *uint64, val uint64) {
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for {
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o := atomic.LoadUint64(addr)
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n := o ^ val
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if atomic.CompareAndSwapUint64(addr, o, n) {
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break
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}
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}
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}
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// CompareAndSwapUint64 is like sync/atomic.CompareAndSwapUint64, but returns
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// the value previously stored at addr.
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func CompareAndSwapUint64(addr *uint64, old, new uint64) (prev uint64) {
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for {
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prev = atomic.LoadUint64(addr)
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if prev != old {
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return
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}
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if atomic.CompareAndSwapUint64(addr, old, new) {
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return
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}
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}
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}
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// IncUnlessZeroInt32 increments the value stored at the given address and
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// returns true; unless the value stored in the pointer is zero, in which case
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// it is left unmodified and false is returned.
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func IncUnlessZeroInt32(addr *int32) bool {
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for {
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v := atomic.LoadInt32(addr)
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if v == 0 {
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return false
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}
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if atomic.CompareAndSwapInt32(addr, v, v+1) {
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return true
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}
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}
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}
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// DecUnlessOneInt32 decrements the value stored at the given address and
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// returns true; unless the value stored in the pointer is 1, in which case it
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// is left unmodified and false is returned.
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func DecUnlessOneInt32(addr *int32) bool {
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for {
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v := atomic.LoadInt32(addr)
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if v == 1 {
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return false
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}
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if atomic.CompareAndSwapInt32(addr, v, v-1) {
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return true
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}
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}
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}
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