59 lines
1.4 KiB
Go
59 lines
1.4 KiB
Go
// Copyright 2022 PingCAP, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package gctuner
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import (
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"runtime"
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"go.uber.org/atomic"
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)
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type finalizerCallback func()
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type finalizer struct {
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ref *finalizerRef
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callback finalizerCallback
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stopped atomic.Int32
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}
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type finalizerRef struct {
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parent *finalizer
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}
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func finalizerHandler(f *finalizerRef) {
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// stop calling callback
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if f.parent.stopped.Load() > 0 {
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return
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}
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f.parent.callback()
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runtime.SetFinalizer(f, finalizerHandler)
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}
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// newFinalizer return a finalizer object and caller should save it to make sure it will not be gc.
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// the go runtime promise the callback function should be called every gc time.
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func newFinalizer(callback finalizerCallback) *finalizer {
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f := &finalizer{
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callback: callback,
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}
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f.ref = &finalizerRef{parent: f}
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runtime.SetFinalizer(f.ref, finalizerHandler)
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f.ref = nil // trigger gc
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return f
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}
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func (f *finalizer) stop() {
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f.stopped.Store(1)
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}
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