You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
88 lines
2.3 KiB
88 lines
2.3 KiB
// Copyright 2018 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,
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package ddl
|
|
|
|
import (
|
|
"sync"
|
|
|
|
"github.com/ngaut/pools"
|
|
"github.com/pingcap/errors"
|
|
"github.com/pingcap/parser/mysql"
|
|
"github.com/pingcap/tidb/sessionctx"
|
|
"github.com/pingcap/tidb/util/logutil"
|
|
"github.com/pingcap/tidb/util/mock"
|
|
)
|
|
|
|
// sessionPool is used to new session.
|
|
type sessionPool struct {
|
|
mu struct {
|
|
sync.Mutex
|
|
closed bool
|
|
}
|
|
resPool *pools.ResourcePool
|
|
}
|
|
|
|
func newSessionPool(resPool *pools.ResourcePool) *sessionPool {
|
|
return &sessionPool{resPool: resPool}
|
|
}
|
|
|
|
// get gets sessionctx from context resource pool.
|
|
// Please remember to call put after you finished using sessionctx.
|
|
func (sg *sessionPool) get() (sessionctx.Context, error) {
|
|
if sg.resPool == nil {
|
|
return mock.NewContext(), nil
|
|
}
|
|
|
|
sg.mu.Lock()
|
|
if sg.mu.closed {
|
|
sg.mu.Unlock()
|
|
return nil, errors.Errorf("sessionPool is closed.")
|
|
}
|
|
sg.mu.Unlock()
|
|
|
|
// no need to protect sg.resPool
|
|
resource, err := sg.resPool.Get()
|
|
if err != nil {
|
|
return nil, errors.Trace(err)
|
|
}
|
|
|
|
ctx := resource.(sessionctx.Context)
|
|
ctx.GetSessionVars().SetStatusFlag(mysql.ServerStatusAutocommit, true)
|
|
ctx.GetSessionVars().InRestrictedSQL = true
|
|
return ctx, nil
|
|
}
|
|
|
|
// put returns sessionctx to context resource pool.
|
|
func (sg *sessionPool) put(ctx sessionctx.Context) {
|
|
if sg.resPool == nil {
|
|
return
|
|
}
|
|
|
|
// no need to protect sg.resPool, even the sg.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.
|
|
sg.resPool.Put(ctx.(pools.Resource))
|
|
}
|
|
|
|
// close clean up the sessionPool.
|
|
func (sg *sessionPool) close() {
|
|
sg.mu.Lock()
|
|
defer sg.mu.Unlock()
|
|
// prevent closing resPool twice.
|
|
if sg.mu.closed || sg.resPool == nil {
|
|
return
|
|
}
|
|
logutil.BgLogger().Info("[ddl] closing sessionPool")
|
|
sg.resPool.Close()
|
|
sg.mu.closed = true
|
|
}
|
|
|