37 lines
905 B
Go
37 lines
905 B
Go
package main
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import (
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"fmt"
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"runtime"
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"sync/atomic"
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"time"
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)
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type TestData struct{ Value int }
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func main() {
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var gcTriggered int32
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blackObj := &struct{ ref *TestData }{}
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done := make(chan struct{})
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go func() {
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time.Sleep(5 * time.Millisecond)
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whiteObj := &TestData{Value: 42}
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runtime.SetFinalizer(whiteObj, func(o *TestData) {
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if atomic.LoadInt32(&gcTriggered) == 1 {
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fmt.Printf("❌ 验证失败：whiteObj 被回收！值=%d\n", o.Value)
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}
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})
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blackObj.ref = whiteObj // 触发写屏障（由运行时自动处理）
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fmt.Println("✅ 业务线程：黑色对象引用新白色对象")
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close(done)
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}()
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atomic.StoreInt32(&gcTriggered, 1)
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runtime.GC() // 触发含并发标记的 GC
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<-done
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fmt.Println("✅ 验证通过：新对象存活（写屏障将其标灰纳入扫描）")
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fmt.Println("💡 原理：运行时写屏障拦截赋值，将 whiteObj 标灰")
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}
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