github.com/cloudwego/kitex@v0.9.0/pkg/loadbalance/lbcache/shared_ticker.go (about)

     1  /*
     2   * Copyright 2021 CloudWeGo Authors
     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 lbcache
    18  
    19  import (
    20  	"sync"
    21  	"time"
    22  
    23  	"golang.org/x/sync/singleflight"
    24  
    25  	"github.com/cloudwego/kitex/pkg/utils"
    26  )
    27  
    28  var (
    29  	// insert, not delete
    30  	sharedTickers    sync.Map
    31  	sharedTickersSfg singleflight.Group
    32  )
    33  
    34  func getSharedTicker(b *Balancer, refreshInterval time.Duration) *utils.SharedTicker {
    35  	sti, ok := sharedTickers.Load(refreshInterval)
    36  	if ok {
    37  		st := sti.(*utils.SharedTicker)
    38  		st.Add(b)
    39  		return st
    40  	}
    41  	v, _, _ := sharedTickersSfg.Do(refreshInterval.String(), func() (interface{}, error) {
    42  		st := utils.NewSharedTicker(refreshInterval)
    43  		sharedTickers.Store(refreshInterval, st)
    44  		return st, nil
    45  	})
    46  	st := v.(*utils.SharedTicker)
    47  	// Add without singleflight,
    48  	// because we need all refreshers those call this function to add themselves to SharedTicker
    49  	st.Add(b)
    50  	return st
    51  }