github.com/bytedance/gopkg@v0.0.0-20240514070511-01b2cbcf35e1/collection/skipset/flag.go (about) 1 // Copyright 2021 ByteDance Inc. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package skipset 16 17 import "sync/atomic" 18 19 const ( 20 fullyLinked = 1 << iota 21 marked 22 ) 23 24 type bitflag struct { 25 data uint32 26 } 27 28 func (f *bitflag) SetTrue(flags uint32) { 29 for { 30 old := atomic.LoadUint32(&f.data) 31 if old&flags != flags { 32 // Flag is 0, need set it to 1. 33 n := old | flags 34 if atomic.CompareAndSwapUint32(&f.data, old, n) { 35 return 36 } 37 continue 38 } 39 return 40 } 41 } 42 43 func (f *bitflag) SetFalse(flags uint32) { 44 for { 45 old := atomic.LoadUint32(&f.data) 46 check := old & flags 47 if check != 0 { 48 // Flag is 1, need set it to 0. 49 n := old ^ check 50 if atomic.CompareAndSwapUint32(&f.data, old, n) { 51 return 52 } 53 continue 54 } 55 return 56 } 57 } 58 59 func (f *bitflag) Get(flag uint32) bool { 60 return (atomic.LoadUint32(&f.data) & flag) != 0 61 } 62 63 func (f *bitflag) MGet(check, expect uint32) bool { 64 return (atomic.LoadUint32(&f.data) & check) == expect 65 }