github.com/cloudwego/frugal@v0.1.15/internal/utils/list.go (about)

     1  /*
     2   * Copyright 2023 ByteDance Inc.
     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  package utils
    18  
    19  import (
    20      `sync/atomic`
    21      `unsafe`
    22  )
    23  
    24  /* ListNode can be used to save references */
    25  type ListNode struct{
    26      value unsafe.Pointer
    27      next  *ListNode
    28  }
    29  
    30  /* Prepend creates a new node with value=p and adds it at the beginning of this list */
    31  func (n *ListNode) Prepend(p unsafe.Pointer) {
    32      for {
    33          oldNext := atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&n.next)))
    34          newNode := &ListNode{
    35              value: p,
    36              next: (*ListNode)(oldNext),
    37          }
    38          success := atomic.CompareAndSwapPointer(
    39              (*unsafe.Pointer)(unsafe.Pointer(&n.next)),
    40              oldNext,
    41              unsafe.Pointer(newNode),
    42          )
    43          if success {
    44              break
    45          }
    46      }
    47  }