I am reading RabbitMQ tutorial and seeing following code:
forever := make(chan bool)
go func() {
for d := range msgs {
log.Printf("Received a message: %s", d.Body)
}
}()
log.Printf(" [*] Waiting for messages. To exit press CTRL+C")
<-forever
What I am interested in is for d := range msgs. How does this for loop handle events? eg. At the app start I have only one message in msgs queue buffer.
Questions:
log.Printf line and wouldn't process events anymore. What can be a reason?
- How would it process next event?
Beside iteration over basic data structures, range in GoLang can also iterate over values received from a channel. Range iterates over each element as it's received from queue and ends only when the channel is closed. The next iteration will happen when the channel (msgs) will receive a value
msgs <- message
- After some playing around with this code I found that it could stuck on log.Printf line and wouldn't process events anymore. What can be a reason?
Considering that there is a blocking channel forever and we have a range that iterates over the msgs channel there are 2 possible actions that are expected:
Either
send message through the msgs channel
msgs <- message
or
send value to forever so it unblocks the process
forever <- false
It seems like the solution is designed to wait and asynchronously process messages through a channel.