How to get time.Tick to tick immediately

Unfortunately, it seems that Go developers will not add such functionality in any foreseeable future, so we have to cope…

There are two common ways to use tickers:

for loop

Given something like this:

ticker := time.NewTicker(period)
defer ticker.Stop()
for <- ticker.C {
    ...
}

Use:

ticker := time.NewTicker(period)
defer ticker.Stop()
for ; true; <- ticker.C {
    ...
}

for–select loop

Given something like this:

interrupt := make(chan os.Signal, 1)
signal.Notify(interrupt, os.Interrupt)

ticker := time.NewTicker(period)
defer ticker.Stop()

loop:
for {
    select {
        case <- ticker.C: 
            f()
        case <- interrupt:
            break loop
    }
}

Use:

interrupt := make(chan os.Signal, 1)
signal.Notify(interrupt, os.Interrupt)

ticker := time.NewTicker(period)
defer ticker.Stop()

loop:
for {
    f()

    select {
        case <- ticker.C: 
            continue
        case <- interrupt:
            break loop
    }
}

Why not just use time.Tick()?

While Tick is useful for clients that have no need to shut down the Ticker, be aware that without a way to shut it down the underlying Ticker cannot be recovered by the garbage collector; it “leaks”.

https://golang.org/pkg/time/#Tick