tidb action 代码
文件路径：/util/memory/action.go
/ 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,
/ 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 memory
import (
"fmt"
"sync"
"sync/atomic"
"github.com/pingcap/tidb/errno"
"github.com/pingcap/tidb/util/dbterror"
"github.com/pingcap/tidb/util/logutil"
"go.uber.org/zap"
)
/ ActionOnExceed is the action taken when memory usage exceeds memory quota.
/ NOTE: All the implementors should be thread-safe.
type ActionOnExceed interface {
/ Action will be called when memory usage exceeds memory quota by the
/ corresponding Tracker.
Action(t *Tracker)
/ SetLogHook binds a log hook which will be triggered and log an detailed
/ message for the out-of-memory sql.
SetLogHook(hook func(uint64))
/ SetFallback sets a fallback action which will be triggered if itself has
/ already been triggered.
SetFallback(a ActionOnExceed)
/ GetFallback get the fallback action of the Action.
GetFallback() ActionOnExceed
/ GetPriority get the priority of the Action.
GetPriority() int64
/ SetFinished sets the finished state of the Action.
SetFinished()
/ IsFinished returns the finished state of the Action.
IsFinished() bool
}
/ BaseOOMAction manages the fallback action for all Action.
type BaseOOMAction struct {
fallbackAction ActionOnExceed
finished int32
}
/ SetFallback sets a fallback action which will be triggered if itself has
/ already been triggered.
func (b *BaseOOMAction) SetFallback(a ActionOnExceed) {
b.fallbackAction = a
}
/ SetFinished sets the finished state of the Action.
func (b *BaseOOMAction) SetFinished() {
atomic.StoreInt32(&b.finished, 1)
}
/ IsFinished returns the finished state of the Action.
func (b *BaseOOMAction) IsFinished() bool {
return atomic.LoadInt32(&b.finished) == 1
}
/ GetFallback get the fallback action and remove finished fallback.
func (b *BaseOOMAction) GetFallback() ActionOnExceed {
for b.fallbackAction != nil && b.fallbackAction.IsFinished() {
b.SetFallback(b.fallbackAction.GetFallback())
}
return b.fallbackAction
}
/ Default OOM Action priority.
const (
DefPanicPriority = iota
DefLogPriority
DefSpillPriority
DefRateLimitPriority
)
/ LogOnExceed logs a warning only once when memory usage exceeds memory quota.
type LogOnExceed struct {
logHook func(uint64)
BaseOOMAction
ConnID uint64
mutex sync.Mutex / For synchronization.
acted bool
}
/ SetLogHook sets a hook for LogOnExceed.
func (a *LogOnExceed) SetLogHook(hook func(uint64)) {
a.logHook = hook
}
/ Action logs a warning only once when memory usage exceeds memory quota.
func (a *LogOnExceed) Action(t *Tracker) {
a.mutex.Lock()
defer a.mutex.Unlock()
if !a.acted {
a.acted = true
if a.logHook == nil {
logutil.BgLogger().Warn("memory exceeds quota",
zap.Error(errMemExceedThreshold.GenWithStackByArgs(t.label, t.BytesConsumed(), t.GetBytesLimit(), t.String())))
return
}
a.logHook(a.ConnID)
}
}
/ GetPriority get the priority of the Action
func (*LogOnExceed) GetPriority() int64 {
return DefLogPriority
}
/ PanicOnExceed panics when memory usage exceeds memory quota.
type PanicOnExceed struct {
logHook func(uint64)
BaseOOMAction
ConnID uint64
mutex sync.Mutex / For synchronization.
acted bool
}
/ SetLogHook sets a hook for PanicOnExceed.
func (a *PanicOnExceed) SetLogHook(hook func(uint64)) {
a.logHook = hook
}
/ Action panics when memory usage exceeds memory quota.
func (a *PanicOnExceed) Action(_ *Tracker) {
a.mutex.Lock()
if !a.acted {
if a.logHook != nil {
a.logHook(a.ConnID)
}
}
a.acted = true
a.mutex.Unlock()
panic(PanicMemoryExceed + fmt.Sprintf("[conn_id=%d]", a.ConnID))
}
/ GetPriority get the priority of the Action
func (*PanicOnExceed) GetPriority() int64 {
return DefPanicPriority
}
var (
errMemExceedThreshold = dbterror.ClassUtil.NewStd(errno.ErrMemExceedThreshold)
)
const (
/ PanicMemoryExceed represents the panic message when out of memory quota.
PanicMemoryExceed string = "Out Of Memory Quota!"
)