tidb ddl_workerpool 代码
文件路径：/ddl/ddl_workerpool.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/util/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.resPool == nil {
return nil, nil
}
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.resPool == nil || 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() || wp.resPool == nil {
return
}
wp.exit.Store(true)
logutil.BgLogger().Info("[ddl] closing workerPool")
wp.resPool.Close()
}
/ tp return the type of backfill worker pool.
func (wp *workerPool) tp() jobType {
return wp.t
}
/ backfilWorkerPool is used to new backfill worker.
type backfilWorkerPool struct {
exit atomic.Bool
resPool *pools.ResourcePool
}
func newBackfillWorkerPool(resPool *pools.ResourcePool) *backfilWorkerPool {
return &backfilWorkerPool{
exit: *atomic.NewBool(false),
resPool: resPool,
}
}
/ setCapacity changes the capacity of the pool.
/ A setCapacity of 0 is equivalent to closing the backfilWorkerPool.
func (bwp *backfilWorkerPool) setCapacity(capacity int) error {
return bwp.resPool.SetCapacity(capacity)
}
/ get gets backfilWorkerPool from context resource pool.
/ Please remember to call put after you finished using backfilWorkerPool.
func (bwp *backfilWorkerPool) get() (*backfillWorker, error) {
if bwp.resPool == nil {
return nil, nil
}
if bwp.exit.Load() {
return nil, errors.Errorf("backfill worker pool is closed")
}
/ no need to protect bwp.resPool
resource, err := bwp.resPool.TryGet()
if err != nil {
return nil, errors.Trace(err)
}
if resource == nil {
return nil, nil
}
worker := resource.(*backfillWorker)
return worker, nil
}
/ put returns workerPool to context resource pool.
func (bwp *backfilWorkerPool) put(wk *backfillWorker) {
if bwp.resPool == nil || bwp.exit.Load() {
return
}
/ No need to protect bwp.resPool, even the bwp.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.
bwp.resPool.Put(wk)
}
/ close clean up the backfilWorkerPool.
func (bwp *backfilWorkerPool) close() {
/ Prevent closing resPool twice.
if bwp.resPool == nil || bwp.exit.Load() {
return
}
bwp.exit.Store(true)
logutil.BgLogger().Info("[ddl] closing workerPool")
bwp.resPool.Close()
}