← Back
Editing: stackobj.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 }
Save File
Cancel