grpc-go/xds/internal/balancer/outlierdetection/subconn_wrapper.go

69 lines
2.2 KiB
Go

/*
*
* Copyright 2022 gRPC 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 outlierdetection
import (
"unsafe"
"google.golang.org/grpc/balancer"
"google.golang.org/grpc/internal/buffer"
"google.golang.org/grpc/resolver"
)
// subConnWrapper wraps every created SubConn in the Outlier Detection Balancer,
// to help track the latest state update from the underlying SubConn, and also
// whether or not this SubConn is ejected.
type subConnWrapper struct {
balancer.SubConn
// addressInfo is a pointer to the subConnWrapper's corresponding address
// map entry, if the map entry exists.
addressInfo unsafe.Pointer // *addressInfo
// These two pieces of state will reach eventual consistency due to sync in
// run(), and child will always have the correctly updated SubConnState.
// latestState is the latest state update from the underlying SubConn. This
// is used whenever a SubConn gets unejected.
latestState balancer.SubConnState
ejected bool
scUpdateCh *buffer.Unbounded
// addresses is the list of address(es) this SubConn was created with to
// help support any change in address(es)
addresses []resolver.Address
}
// eject causes the wrapper to report a state update with the TRANSIENT_FAILURE
// state, and to stop passing along updates from the underlying subchannel.
func (scw *subConnWrapper) eject() {
scw.scUpdateCh.Put(&ejectionUpdate{
scw: scw,
isEjected: true,
})
}
// uneject causes the wrapper to report a state update with the latest update
// from the underlying subchannel, and resume passing along updates from the
// underlying subchannel.
func (scw *subConnWrapper) uneject() {
scw.scUpdateCh.Put(&ejectionUpdate{
scw: scw,
isEjected: false,
})
}