Avoiding Premature Program Termination in Go Long Running Processes

In Go, one can encounter a situation where a long running program, with its logic executed within concurrent goroutines, terminates prematurely when the main function exits. To prevent this undesirable behavior, developers seek best practices for keeping the main function from terminating, thereby ensuring the program's continued operation.

One method commonly employed is the creation of a channel and delaying the exit of the main function by receiving on that channel. However, this approach presents challenges if all goroutines become inactive.

Instead, a recommended approach is to implement an indefinite blocking mechanism within the main function. By using a select {} statement, the main function blocks forever, preventing program termination.

Consider the following demonstration:

package main

import (
    "fmt"
    "time"
)

func main() {
    go forever()
    select {} // block forever
}

func forever() {
    for {
        fmt.Printf("%v \n", time.Now())
        time.Sleep(time.Second)
    }
}

In this improved example, the main function employs the select {} statement to block indefinitely, allowing goroutines like forever() to continue their operation without risk of premature program termination.