015.go_routine

Go Goroutines & Channels

Concept

Goroutines are lightweight threads of execution. Channels are typed conduits for safe communication and synchronization between goroutines. Together, they enable concurrent processing without explicit locks or condition variables.

References

• https://gobyexample.com/goroutines
• https://gobyexample.com/channels
• https://go.dev/tour/concurrency/1

Quest

Objective

Implement a basic concurrent request-response flow where a "Client" sends a request to a "Server" running in a separate goroutine, and waits for the response via a channel.

Requirements

SendRequest (Client)

• Function: SendRequest(input string) string
• Create an unbuffered string channel.
• Start the Server function in a new goroutine (go Server(...)), passing the input and the channel.
• Block and wait for the response from the channel.
• Return the received response.

Server (Server)

• Function: Server(request string, response chan string)
• Runs concurrently (invoked with go).
• Format the output string as "processed: <request>".
• Send the formatted string into the response channel.
• Do not close the channel.

Inputs

• input: The raw request string (e.g., "ping").

Outputs

• Returns the processed string (e.g., "processed: ping").

Examples

• SendRequest("hello")
  1. Channel created.
  2. go Server("hello", ch) starts.
  3. SendRequest blocks on <-ch.
  4. Server sends "processed: hello".
  5. SendRequest unblocks and returns "processed: hello".

Testing

To run the tests, execute the following command from the root directory:

go test -v ./quests/015.go_routine

Or from the quest directory:

go test -v

Expected output:

=== RUN   TestSendRequest
--- PASS: TestSendRequest (0.00s)
PASS