mirror of
https://github.com/golang/go
synced 2024-11-23 04:40:09 -07:00
9a8372f8bd
The previous CL introduced stack objects. This CL removes the old ambiguously live liveness analysis. After this CL we're relying on stack objects exclusively. Update a bunch of liveness tests to reflect the new world. Fixes #22350 Change-Id: I739b26e015882231011ce6bc1a7f426049e59f31 Reviewed-on: https://go-review.googlesource.com/c/134156 Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Cherry Zhang <cherryyz@google.com>
58 lines
975 B
Go
58 lines
975 B
Go
// run
|
|
|
|
// Copyright 2018 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"runtime"
|
|
)
|
|
|
|
type HeapObj [8]int64
|
|
|
|
type StkObj struct {
|
|
h *HeapObj
|
|
}
|
|
|
|
var n int
|
|
var c int = -1
|
|
|
|
func gc() {
|
|
// encourage heap object to be collected, and have its finalizer run.
|
|
runtime.GC()
|
|
runtime.GC()
|
|
runtime.GC()
|
|
n++
|
|
}
|
|
|
|
func main() {
|
|
f()
|
|
gc() // prior to stack objects, heap object is not collected until here
|
|
if c < 0 {
|
|
panic("heap object never collected")
|
|
}
|
|
if c != 1 {
|
|
panic(fmt.Sprintf("expected collection at phase 1, got phase %d", c))
|
|
}
|
|
}
|
|
|
|
func f() {
|
|
var s StkObj
|
|
s.h = new(HeapObj)
|
|
runtime.SetFinalizer(s.h, func(h *HeapObj) {
|
|
// Remember at what phase the heap object was collected.
|
|
c = n
|
|
})
|
|
g(&s)
|
|
gc()
|
|
}
|
|
|
|
func g(s *StkObj) {
|
|
gc() // heap object is still live here
|
|
runtime.KeepAlive(s)
|
|
gc() // heap object should be collected here
|
|
}
|