github.com/bytedance/gopkg@v0.0.0-20240514070511-01b2cbcf35e1/collection/skipmap/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 skipmap 16 17 import "sync/atomic" 18 19 const ( 20 fullyLinked = 1 << iota 21 marked 22 ) 23 24 // concurrent-safe bitflag. 25 type bitflag struct { 26 data uint32 27 } 28 29 func (f *bitflag) SetTrue(flags uint32) { 30 for { 31 old := atomic.LoadUint32(&f.data) 32 if old&flags != flags { 33 // Flag is 0, need set it to 1. 34 n := old | flags 35 if atomic.CompareAndSwapUint32(&f.data, old, n) { 36 return 37 } 38 continue 39 } 40 return 41 } 42 } 43 44 func (f *bitflag) SetFalse(flags uint32) { 45 for { 46 old := atomic.LoadUint32(&f.data) 47 check := old & flags 48 if check != 0 { 49 // Flag is 1, need set it to 0. 50 n := old ^ check 51 if atomic.CompareAndSwapUint32(&f.data, old, n) { 52 return 53 } 54 continue 55 } 56 return 57 } 58 } 59 60 func (f *bitflag) Get(flag uint32) bool { 61 return (atomic.LoadUint32(&f.data) & flag) != 0 62 } 63 64 func (f *bitflag) MGet(check, expect uint32) bool { 65 return (atomic.LoadUint32(&f.data) & check) == expect 66 }