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d9a0579156
The test is inherently racy and vulnerable to starvation, and within all.bash on some platforms that means it flakes. Test is kept because it can be useful standalone to verify behavior of GOEXPERIMENT=preeemptibleloops, and there is likely to be further development of this feature in the future. There's also some question as to why it is flaking, because though technically this is permitted, it's very odd in this simple case. Fixes #18589. Change-Id: Ia0dd9037285c4a03122da4012c96981c9cc43b60 Reviewed-on: https://go-review.googlesource.com/35051 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Russ Cox <rsc@golang.org>
96 lines
1.9 KiB
Go
96 lines
1.9 KiB
Go
// +build !nacl,disabled
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// buildrun -t 10 -gcflags=-d=ssa/insert_resched_checks/on,ssa/check/on
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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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// Test is disabled because it flakes when run in all.bash
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// on some platforms, but is useful standalone to verify
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// that rescheduling checks are working (and we may wish
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// to investigate the flake, since it suggests that the
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// loop rescheduling check may not work right on those
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// platforms).
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// This checks to see that call-free infinite loops do not
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// block garbage collection. IF YOU RUN IT STANDALONE without
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// -gcflags=-d=ssa/insert_resched_checks/on in a not-experimental
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// build, it should hang.
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package main
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import (
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"runtime"
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)
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var someglobal1 int
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var someglobal2 int
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var someglobal3 int
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//go:noinline
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func f() {}
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func standinacorner1() {
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for someglobal1&1 == 0 {
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someglobal1++
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someglobal1++
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}
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}
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func standinacorner2(i int) {
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// contains an irreducible loop containing changes to memory
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if i != 0 {
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goto midloop
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}
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loop:
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if someglobal2&1 != 0 {
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goto done
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}
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someglobal2++
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midloop:
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someglobal2++
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goto loop
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done:
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return
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}
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func standinacorner3() {
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for someglobal3&1 == 0 {
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if someglobal3&2 != 0 {
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for someglobal3&3 == 2 {
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someglobal3++
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someglobal3++
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someglobal3++
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someglobal3++
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}
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}
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someglobal3++
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someglobal3++
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someglobal3++
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someglobal3++
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}
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}
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func main() {
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go standinacorner1()
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go standinacorner2(0)
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go standinacorner3()
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// println("About to stand in a corner1")
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for someglobal1 == 0 {
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runtime.Gosched()
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}
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// println("About to stand in a corner2")
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for someglobal2 == 0 {
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runtime.Gosched()
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}
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// println("About to stand in a corner3")
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for someglobal3 == 0 {
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runtime.Gosched()
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}
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// println("About to GC")
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runtime.GC()
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// println("Success")
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}
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