| // Copyright Istio Authors |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package loadbalancer |
| |
| import ( |
| "math/rand" |
| "sync" |
| ) |
| |
| import ( |
| "github.com/apache/dubbo-go-pixiu/pkg/test/loadbalancersim/network" |
| ) |
| |
| func NewRoundRobin(conns []*WeightedConnection) network.Connection { |
| // Add instances for each connection based on the weight. |
| var lbConns []*WeightedConnection |
| for _, conn := range conns { |
| for i := uint32(0); i < conn.Weight; i++ { |
| lbConns = append(lbConns, conn) |
| } |
| } |
| |
| // Shuffle the connections. |
| rand.Shuffle(len(lbConns), func(i, j int) { |
| lbConns[i], lbConns[j] = lbConns[j], lbConns[i] |
| }) |
| |
| return &roundRobin{ |
| weightedConnections: newLBConnection("RoundRobinLB", lbConns), |
| } |
| } |
| |
| type roundRobin struct { |
| *weightedConnections |
| |
| next int |
| nextMutex sync.Mutex |
| } |
| |
| func (lb *roundRobin) Request(onDone func()) { |
| // Select the connection to use for this request. |
| lb.nextMutex.Lock() |
| selected := lb.get(lb.next) |
| lb.next = (lb.next + 1) % len(lb.conns) |
| lb.nextMutex.Unlock() |
| |
| lb.doRequest(selected, onDone) |
| } |