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https://github.com/golang/go
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ca4089ad62
We're dropping this behavior in favor of runtime.KeepAlive. Implement runtime.KeepAlive as an intrinsic. Update #15843 Change-Id: Ib60225bd30d6770ece1c3c7d1339a06aa25b1cbc Reviewed-on: https://go-review.googlesource.com/28310 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com>
40 lines
849 B
Go
40 lines
849 B
Go
// run
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// Copyright 2016 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build amd64
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package main
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import "runtime"
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type big [10 << 20]byte
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func f(x *big, start int64) {
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if delta := inuse() - start; delta < 9<<20 {
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println("after alloc: expected delta at least 9MB, got: ", delta)
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}
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runtime.KeepAlive(x)
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x = nil
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if delta := inuse() - start; delta > 1<<20 {
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println("after drop: expected delta below 1MB, got: ", delta)
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}
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x = new(big)
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if delta := inuse() - start; delta < 9<<20 {
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println("second alloc: expected delta at least 9MB, got: ", delta)
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}
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runtime.KeepAlive(x)
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}
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func main() {
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x := inuse()
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f(new(big), x)
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}
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func inuse() int64 {
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runtime.GC()
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var st runtime.MemStats
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runtime.ReadMemStats(&st)
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return int64(st.Alloc)
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}
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