Pelen Li, Boehm covers your specific case: "there is no reason to believe that a currently working program with “benign races” will continue to work when it is recompiled. Perhaps most surprisingly, this includes even the case of potentially concurrent writes of the same value by different threads."
Peter On Wed, Feb 9, 2022 at 9:17 AM peterGo <go.peter...@gmail.com> wrote: > Pelen Li, > > Always fix your data races. You should consider the results of data races > as undefined. > > Dmitry Vyukov, who implemented the Go race detector, once wrote an > interesting article with the title: "Benign data races: what could possibly > go wrong?" > > https://twitter.com/dvyukov/status/288858957827682304 > > The Go Blog: Introducing the Go Race Detector > Dmitry Vyukov and Andrew Gerrand > 26 June 2013 > > https://go.dev/blog/race-detector > > Hans-J. Boehm wrote: "there is no reason to believe that a currently > working program with “benign races” will continue to work when it is > recompiled." > > How to miscompile programs with “benign” data races > Hans-J. Boehm > HP Laboratories > > https://www.usenix.org/legacy/event/hotpar11/tech/final_files/Boehm.pdf > > Nonetheless many programmers clearly believe, along with [15] that certain > kinds of data races can be safely ignored in practice because they will > produce expected results with all reasonable implementations. Here we show > that all kinds of C or C++ source-level “benign” races discussed in the > literature can in fact lead to incorrect execution as a result of perfectly > reasonable compiler transformations, or when the program is moved to a > different hardware platform. Thus there is no reason to believe that a > currently working program with “benign races” will continue to work when it > is recompiled. Perhaps most surprisingly, this includes even the case of > potentially concurrent writes of the same value by different threads. > > And so on. > > Peter > > On Wednesday, February 9, 2022 at 3:21:26 AM UTC-5 penglo...@gmail.com > wrote: > >> I want to set a value with the index of the slice. I don't really care if >> there are multiple goroutines cover the value with each other, because the >> value is same. >> >> Can i just ignore this DataRace Warning? I don't know if this will cause >> panic. >> >> *Here's my example:* >> I defined a structure with slice, and a Add() function for it. sample >> like this: >> ```go >> package test_slice >> >> type SliceObj struct { >> set []uint >> } >> >> func New(length int64) *SliceObj { >> return &SliceObj{ >> set: make([]uint, length), >> } >> } >> >> func (b *SliceObj) Add(i uint) { >> b.set[i] = i >> } >> ``` >> >> And then i make a main file to test it, like this: >> ```go >> package main >> >> import ( >> "time" >> >> "test_slice" >> ) >> >> func main() { >> s := test_slice.New(1000000) >> go func() { >> s.Add(10) >> }() >> s.Add(10) >> >> time.Sleep(3 * time.Second) >> } >> ``` >> >> *And data race is detected:* >> *(*I know the reason of this warning, but I don't know if I can ignore it >> *)* >> ================== >> WARNING: DATA RACE >> Write at 0x00c000180050 by goroutine 18: >> test_slice.(*SliceObj).Add() >> test_slice.go:27 +0x68 >> main.main.func1() >> test.go:25 +0x36 >> >> Previous write at 0x00c000180050 by main goroutine: >> test_slice.(*SliceObj).Add() >> test_slice.go:27 +0xfd >> main.main() >> test.go:27 +0xcb >> >> Goroutine 18 (running) created at: >> main.main() >> test.go:24 +0xca >> ================== >> Found 1 data race(s) >> exit status 66 >> > -- > You received this message because you are subscribed to a topic in the > Google Groups "golang-nuts" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/golang-nuts/ai0eQtnas7A/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > golang-nuts+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/golang-nuts/2594a018-872a-4d54-8ede-c769042e99b5n%40googlegroups.com > <https://groups.google.com/d/msgid/golang-nuts/2594a018-872a-4d54-8ede-c769042e99b5n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/CAOBWp8do4njo%2B56hb7PJ-4RdXxV%2B0KGUVwv9zRC%3Dgd3bm%2BSM_g%40mail.gmail.com.
