Files
tidb/pkg/ddl/ddl_workerpool.go

90 lines
2.2 KiB
Go

// Copyright 2022 PingCAP, Inc.
//
// 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 ddl
import (
"github.com/ngaut/pools"
"github.com/pingcap/errors"
"github.com/pingcap/tidb/pkg/ddl/logutil"
"go.uber.org/atomic"
)
// workerPool is used to new worker.
type workerPool struct {
t jobType
exit atomic.Bool
resPool *pools.ResourcePool
}
func newDDLWorkerPool(resPool *pools.ResourcePool, tp jobType) *workerPool {
return &workerPool{
t: tp,
exit: *atomic.NewBool(false),
resPool: resPool,
}
}
// get gets workerPool from context resource pool.
// Please remember to call put after you finished using workerPool.
func (wp *workerPool) get() (*worker, error) {
if wp.exit.Load() {
return nil, errors.Errorf("workerPool is closed")
}
// no need to protect wp.resPool
resource, err := wp.resPool.TryGet()
if err != nil {
return nil, errors.Trace(err)
}
if resource == nil {
return nil, nil
}
worker := resource.(*worker)
return worker, nil
}
// put returns workerPool to context resource pool.
func (wp *workerPool) put(wk *worker) {
if wp.exit.Load() {
return
}
// no need to protect wp.resPool, even the wp.resPool is closed, the ctx still need to
// put into resPool, because when resPool is closing, it will wait all the ctx returns, then resPool finish closing.
wp.resPool.Put(wk)
}
// close clean up the workerPool.
func (wp *workerPool) close() {
// prevent closing resPool twice.
if wp.exit.Load() {
return
}
wp.exit.Store(true)
logutil.DDLLogger().Info("closing workerPool")
wp.resPool.Close()
}
// tp return the type of backfill worker pool.
func (wp *workerPool) tp() jobType {
return wp.t
}
func (wp *workerPool) available() int {
return int(wp.resPool.Available())
}