thx. you are right. I make a mistake. I negleck that my func will be called by mass goroutine, it will get the same seed and the same sequence
在 2019年6月27日星期四 UTC+8上午11:07:28，Kurtis Rader写道： > > Works for me: https://play.golang.org/p/zD5F7gp41re > > Like Burak I suspect you are initializing the RNG in a tight loop. Since > `time.Now().Unix()` has a resolution of one second you end up generating > the same initial value every time through the loop until the current time > advances to the next second. > > On Wed, Jun 26, 2019 at 7:48 PM Chou Yan <yan.ch...@gmail.com > <javascript:>> wrote: > >> like this: >> r:=rand.New(rand.NewSource(time.Now().Unix())) >> for { >> r.Intn(96) >> } >> I know the same seed will generate the same sequence. But I don't know >> why it generate mass same number when I use seed of 'time.Now().Unix()', >> But when I use seed of 'time.Now().UnixNano()', It will not. >> I suspect what this is related to the seqence rand algorithm,But I have >> no relevant evidence >> >> 在 2019年6月27日星期四 UTC+8上午10:32:38，Burak Serdar写道： >>> >>> On Wed, Jun 26, 2019 at 8:17 PM Chou Yan <yan.ch...@gmail.com> wrote: >>> > >>> > I use: >>> > r:=rand.New(rand.NewSource(time.Now().Unix())) >>> > r..Intn(96) >>> >>> How are you generating multiple random numbers? If your loop that >>> generates these numbers include the r:=rand.New(...), then you're >>> essentially seeding the random number generator with the same number, >>> because the program ends before time.Now().Unix() returns a different >>> value every second. >>> >>> Move the r:=rand.New(...) outsite the for loop. >>> >>> > I got: >>> > >>> > and val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 39 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > rand val: 82 >>> > ... >>> > mass common sequential number . >>> > But if I change that： >>> > r:=rand.New(rand.NewSource(time.Now().UnixNano())) >>> > It will not happen. >>> > Why does this happened? and how do I choose it between >>> time.Now().Unix() or UnixNano()? >>> > >>> > -- >>> > 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 golan...@googlegroups.com. >>> > To view this discussion on the web visit >>> https://groups.google.com/d/msgid/golang-nuts/ce0671c5-f2df-42d9-a7af-bdef939e6d6d%40googlegroups.com. >>> >>> >>> > For more options, visit https://groups.google.com/d/optout. >>> >> -- >> 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 golan...@googlegroups.com <javascript:>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/golang-nuts/99351298-7843-4556-b422-8635eb96c936%40googlegroups.com >> >> <https://groups.google.com/d/msgid/golang-nuts/99351298-7843-4556-b422-8635eb96c936%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > > > -- > Kurtis Rader > Caretaker of the exceptional canines Junior and Hank > -- 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/1e5a8486-ef43-4258-8ffc-d21dc542638f%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
