mirror of
https://github.com/ceph/ceph-csi.git
synced 2024-12-26 23:10:22 +00:00
e46099a504
Signed-off-by: Huamin Chen <hchen@redhat.com>
181 lines
4.4 KiB
Go
181 lines
4.4 KiB
Go
/*
|
|
*
|
|
* Copyright 2017 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 grpc
|
|
|
|
import (
|
|
"context"
|
|
"io"
|
|
"sync"
|
|
|
|
"google.golang.org/grpc/balancer"
|
|
"google.golang.org/grpc/codes"
|
|
"google.golang.org/grpc/grpclog"
|
|
"google.golang.org/grpc/internal/channelz"
|
|
"google.golang.org/grpc/internal/transport"
|
|
"google.golang.org/grpc/status"
|
|
)
|
|
|
|
// pickerWrapper is a wrapper of balancer.Picker. It blocks on certain pick
|
|
// actions and unblock when there's a picker update.
|
|
type pickerWrapper struct {
|
|
mu sync.Mutex
|
|
done bool
|
|
blockingCh chan struct{}
|
|
picker balancer.Picker
|
|
|
|
// The latest connection happened.
|
|
connErrMu sync.Mutex
|
|
connErr error
|
|
}
|
|
|
|
func newPickerWrapper() *pickerWrapper {
|
|
bp := &pickerWrapper{blockingCh: make(chan struct{})}
|
|
return bp
|
|
}
|
|
|
|
func (bp *pickerWrapper) updateConnectionError(err error) {
|
|
bp.connErrMu.Lock()
|
|
bp.connErr = err
|
|
bp.connErrMu.Unlock()
|
|
}
|
|
|
|
func (bp *pickerWrapper) connectionError() error {
|
|
bp.connErrMu.Lock()
|
|
err := bp.connErr
|
|
bp.connErrMu.Unlock()
|
|
return err
|
|
}
|
|
|
|
// updatePicker is called by UpdateBalancerState. It unblocks all blocked pick.
|
|
func (bp *pickerWrapper) updatePicker(p balancer.Picker) {
|
|
bp.mu.Lock()
|
|
if bp.done {
|
|
bp.mu.Unlock()
|
|
return
|
|
}
|
|
bp.picker = p
|
|
// bp.blockingCh should never be nil.
|
|
close(bp.blockingCh)
|
|
bp.blockingCh = make(chan struct{})
|
|
bp.mu.Unlock()
|
|
}
|
|
|
|
func doneChannelzWrapper(acw *acBalancerWrapper, done func(balancer.DoneInfo)) func(balancer.DoneInfo) {
|
|
acw.mu.Lock()
|
|
ac := acw.ac
|
|
acw.mu.Unlock()
|
|
ac.incrCallsStarted()
|
|
return func(b balancer.DoneInfo) {
|
|
if b.Err != nil && b.Err != io.EOF {
|
|
ac.incrCallsFailed()
|
|
} else {
|
|
ac.incrCallsSucceeded()
|
|
}
|
|
if done != nil {
|
|
done(b)
|
|
}
|
|
}
|
|
}
|
|
|
|
// pick returns the transport that will be used for the RPC.
|
|
// It may block in the following cases:
|
|
// - there's no picker
|
|
// - the current picker returns ErrNoSubConnAvailable
|
|
// - the current picker returns other errors and failfast is false.
|
|
// - the subConn returned by the current picker is not READY
|
|
// When one of these situations happens, pick blocks until the picker gets updated.
|
|
func (bp *pickerWrapper) pick(ctx context.Context, failfast bool, opts balancer.PickOptions) (transport.ClientTransport, func(balancer.DoneInfo), error) {
|
|
var (
|
|
p balancer.Picker
|
|
ch chan struct{}
|
|
)
|
|
|
|
for {
|
|
bp.mu.Lock()
|
|
if bp.done {
|
|
bp.mu.Unlock()
|
|
return nil, nil, ErrClientConnClosing
|
|
}
|
|
|
|
if bp.picker == nil {
|
|
ch = bp.blockingCh
|
|
}
|
|
if ch == bp.blockingCh {
|
|
// This could happen when either:
|
|
// - bp.picker is nil (the previous if condition), or
|
|
// - has called pick on the current picker.
|
|
bp.mu.Unlock()
|
|
select {
|
|
case <-ctx.Done():
|
|
return nil, nil, ctx.Err()
|
|
case <-ch:
|
|
}
|
|
continue
|
|
}
|
|
|
|
ch = bp.blockingCh
|
|
p = bp.picker
|
|
bp.mu.Unlock()
|
|
|
|
subConn, done, err := p.Pick(ctx, opts)
|
|
|
|
if err != nil {
|
|
switch err {
|
|
case balancer.ErrNoSubConnAvailable:
|
|
continue
|
|
case balancer.ErrTransientFailure:
|
|
if !failfast {
|
|
continue
|
|
}
|
|
return nil, nil, status.Errorf(codes.Unavailable, "%v, latest connection error: %v", err, bp.connectionError())
|
|
default:
|
|
// err is some other error.
|
|
return nil, nil, toRPCErr(err)
|
|
}
|
|
}
|
|
|
|
acw, ok := subConn.(*acBalancerWrapper)
|
|
if !ok {
|
|
grpclog.Infof("subconn returned from pick is not *acBalancerWrapper")
|
|
continue
|
|
}
|
|
if t, ok := acw.getAddrConn().getReadyTransport(); ok {
|
|
if channelz.IsOn() {
|
|
return t, doneChannelzWrapper(acw, done), nil
|
|
}
|
|
return t, done, nil
|
|
}
|
|
grpclog.Infof("blockingPicker: the picked transport is not ready, loop back to repick")
|
|
// If ok == false, ac.state is not READY.
|
|
// A valid picker always returns READY subConn. This means the state of ac
|
|
// just changed, and picker will be updated shortly.
|
|
// continue back to the beginning of the for loop to repick.
|
|
}
|
|
}
|
|
|
|
func (bp *pickerWrapper) close() {
|
|
bp.mu.Lock()
|
|
defer bp.mu.Unlock()
|
|
if bp.done {
|
|
return
|
|
}
|
|
bp.done = true
|
|
close(bp.blockingCh)
|
|
}
|