46 lines
1.0 KiB
Go
46 lines
1.0 KiB
Go
package main
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import "fmt"
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type Person3 struct {
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Name string
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Age int
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}
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// sliceEscape 切片元素为指针，且切片被返回，元素逃逸
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func sliceEscape() []*Person3 {
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var people []*Person3
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for i := 0; i < 3; i++ {
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person := &Person3{Name: fmt.Sprintf("Person3%d", i), Age: 20 + i}
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people = append(people, person) // person 逃逸
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}
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return people
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}
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// dynamicSlice 切片动态扩容，底层数组逃逸
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func dynamicSlice() []int {
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s := make([]int, 0) // 编译期无法确定最终容量
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for i := 0; i < 100; i++ {
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s = append(s, i) // 扩容时底层数组逃逸
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}
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return s
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}
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// mapEscape 映射值为指针，值逃逸
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func mapEscape() map[string]*Person3 {
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m := make(map[string]*Person3)
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m["alice"] = &Person3{Name: "Alice", Age: 25} // 指针值逃逸
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return m
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}
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func main() {
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people := sliceEscape()
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fmt.Printf("切片元素逃逸：%d个Person\n", len(people))
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s := dynamicSlice()
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fmt.Printf("切片扩容逃逸：len=%d, cap=%d\n", len(s), cap(s))
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m := mapEscape()
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fmt.Printf("映射值逃逸：%+v\n", *m["alice"])
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}
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