41 lines
853 B
Go
41 lines
853 B
Go
package main
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import (
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"fmt"
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"runtime"
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)
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// badFunc 局部大对象返回，触发逃逸
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func badFunc() []byte {
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buf := make([]byte, 1024*1024) // 1MB对象
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return buf
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}
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// goodFunc 接收外部切片，复用内存，避免逃逸
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func goodFunc(buf []byte) {
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for i := range buf {
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buf[i] = byte(i % 256)
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}
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}
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func main() {
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var stats runtime.MemStats
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// 测试逃逸场景
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runtime.GC()
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for i := 0; i < 50; i++ {
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_ = badFunc()
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}
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runtime.ReadMemStats(&stats)
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fmt.Printf("逃逸场景：堆分配%d MB，GC次数%d\n", stats.HeapAlloc/1024/1024, stats.NumGC)
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// 测试避免逃逸场景
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runtime.GC()
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buf := make([]byte, 1024*1024) // 一次分配，复用
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for i := 0; i < 50; i++ {
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goodFunc(buf)
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}
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runtime.ReadMemStats(&stats)
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fmt.Printf("避免逃逸：堆分配%d MB，GC次数%d\n", stats.HeapAlloc/1024/1024, stats.NumGC)
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}
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