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![Keith Randall](/assets/img/avatar_default.png)
Allocate a long linked list on the stack. This tests both lots of live stack objects, and lots of intra-stack pointers to those objects. Change-Id: I169e067416455737774851633b1e5367e10e1cf2 Reviewed-on: https://go-review.googlesource.com/c/135296 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Cherry Zhang <cherryyz@google.com>
84 lines
1.6 KiB
Go
84 lines
1.6 KiB
Go
// run
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// Copyright 2018 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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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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// linked list up the stack, to test lots of stack objects.
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type T struct {
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// points to a heap object. Test will make sure it isn't freed.
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data *int64
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// next pointer for a linked list of stack objects
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next *T
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// duplicate of next, to stress test the pointer buffers
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// used during stack tracing.
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next2 *T
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}
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func main() {
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makelist(nil, 10000)
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}
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func makelist(x *T, n int64) {
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if n%2 != 0 {
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panic("must be multiple of 2")
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}
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if n == 0 {
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runtime.GC()
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i := int64(1)
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for ; x != nil; x, i = x.next, i+1 {
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// Make sure x.data hasn't been collected.
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if got := *x.data; got != i {
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panic(fmt.Sprintf("bad data want %d, got %d", i, got))
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}
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}
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return
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}
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// Put 2 objects in each frame, to test intra-frame pointers.
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// Use both orderings to ensure the linked list isn't always in address order.
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var a, b T
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if n%3 == 0 {
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a.data = newInt(n)
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a.next = x
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a.next2 = x
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b.data = newInt(n - 1)
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b.next = &a
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b.next2 = &a
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x = &b
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} else {
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b.data = newInt(n)
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b.next = x
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b.next2 = x
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a.data = newInt(n - 1)
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a.next = &b
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a.next2 = &b
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x = &a
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}
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makelist(x, n-2)
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}
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// big enough and pointer-y enough to not be tinyalloc'd
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type NotTiny struct {
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n int64
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p *byte
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}
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// newInt allocates n on the heap and returns a pointer to it.
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func newInt(n int64) *int64 {
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h := &NotTiny{n: n}
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p := &h.n
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escape = p
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return p
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}
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var escape *int64
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