golang/test/fixedbugs/issue69110.go

60 lines
1.1 KiB
Go

// run
//go:build !goexperiment.swissmap
// Copyright 2024 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 (
"maps"
_ "unsafe"
)
func main() {
for i := 0; i < 100; i++ {
f()
}
}
const NB = 4
func f() {
// Make a map with NB buckets, at max capacity.
// 6.5 entries/bucket.
ne := NB * 13 / 2
m := map[int]int{}
for i := 0; i < ne; i++ {
m[i] = i
}
// delete/insert a lot, to hopefully get lots of overflow buckets
// and trigger a same-size grow.
ssg := false
for i := ne; i < ne+1000; i++ {
delete(m, i-ne)
m[i] = i
if sameSizeGrow(m) {
ssg = true
break
}
}
if !ssg {
return
}
// Insert 1 more entry, which would ordinarily trigger a growth.
// We can't grow while growing, so we instead go over our
// target capacity.
m[-1] = -1
// Cloning in this state will make a map with a destination bucket
// array twice the size of the source.
_ = maps.Clone(m)
}
//go:linkname sameSizeGrow runtime.sameSizeGrowForIssue69110Test
func sameSizeGrow(m map[int]int) bool