github.com/aacfactory/fns@v1.2.86-0.20240310083819-80d667fc0a17/commons/spinlock/spinlock.go (about)

     1  /*
     2   * Copyright 2023 Wang Min Xiang
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   * 	http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   *
    16   */
    17  
    18  package spinlock
    19  
    20  import (
    21  	"runtime"
    22  	"sync"
    23  	"sync/atomic"
    24  )
    25  
    26  type Locker struct {
    27  	_    sync.Mutex
    28  	lock uintptr
    29  }
    30  
    31  func (l *Locker) Lock() {
    32  	backoff := 1
    33  	for !l.TryLock() {
    34  		for i := 0; i < backoff; i++ {
    35  			runtime.Gosched()
    36  		}
    37  		if backoff < 128 {
    38  			backoff *= 2
    39  		}
    40  	}
    41  }
    42  
    43  func (l *Locker) Unlock() {
    44  	atomic.StoreUintptr(&l.lock, 0)
    45  }
    46  
    47  func (l *Locker) TryLock() bool {
    48  	return atomic.CompareAndSwapUintptr(&l.lock, 0, 1)
    49  }