The Ticker of the time packet in Golang

This is a creation in Article, where the information may have evolved or changed.

The real scenario is that when you test the order of the receipts, you add a tick and you find the packet dropped.

So let's take a look at an application example:

Package Mainimport ("FMT"    "Runtime"    " Time") Func init () {runtime. Gomaxprocs (runtime. NUMCPU ())}func main () {ch:= Make (chanint,1024x768) go func (Ch Chanint) {         for{val:= <-ch FMT. Printf ("val:%d\n", Val)} } (CH) tick:= time. Newticker (1*Time . Second) forI: =0; I < -; i++ {        Select {         CaseCH <-I: Case<-tick. C:fmt. Printf ("%d:case <-tick. c\n", I)} Time. Sleep ( $*Time.millisecond)} close (ch) tick. Stop ()}

The output results are as follows:

Val:0val:1val:2val:3val:4val:56:case <-tick. Cval:7val:8val:910:case <-tick. Cval:11val:12val:13val:1415:case <-tick. Cval:16val:17val:18val:19

The problem is in this select:

Select {    case ch <- I:    case <-  tick. C:    FMT. Printf ("%d:case <-tick. c\n", i)}

[Tick. C description] When the two case conditions are met, the runtime system will use a pseudo-random algorithm to determine which case will be executed. So when tick. C the condition satisfies the loop, there is some probability that the ch<-i is not sent (although the channel ends are not blocked, satisfies the sending condition)

　Solution 1: once tick. C Random case is randomly executed, ch<-i (not respectable, if more than one is not universal)

Select {    case ch <- I:    case <-  tick. C:        FMT. Printf ("%d:case <-tick. c\n", i)        <- i}

Solution 2: put the tick. C's case is placed in a single select and added a default (guaranteed not to block)

Select {    case ch <- I:}Select  {    case <-  tick. C:        FMT. Printf ("%d:case <-tick. c\n", i)    default:}

The output of both solutions is the desired result:

Val0Val:1Val:2Val:3Val:45: Case<-tick. Cval:5Val:6Val:7Val:8Val:9Ten: Case<-tick. Cval:TenVal: OneVal: AVal: -Val: - the: Case<-tick. Cval: theVal: -Val: -Val: -Val: +