Here are a few question-based titles that fit your provided text: * **Go WaitGroup and Channels: Why Does My Program Not Exit?** * **Stuck in a Loop: How to Properly Close Channels in Go with WaitGro

Channel Not Closed, Program Stalled

In your Go application using sync.WaitGroup and channels, you've encountered an issue where the program doesn't exit even after waiting for all goroutines to complete.

Problem Details

Your code utilizes a WaitGroup to track goroutine completion and a channel to transmit fetched symbol names. However, the fetchedSymbols channel remains open indefinitely, preventing the loop in main from terminating.

Solution

1. Signal Channel Closure with WaitGroup: Employ the WaitGroup used for tracking goroutine completion to signal when to close the channel. Introduce a goroutine that waits for WaitGroup to reach zero and then closes the channel.

<code class="go">go func() {
    wg.Wait()
    close(fetchedSymbols)
}()</code>

2. Remove Unnecessary Blocking: The range loop over fetchedSymbols already blocks until the channel is closed, making any additional channel or WaitGroup redundant. Hence, remove the following code:

<code class="go">for {
    select {
    case symbol := <-fetchedSymbols:
        fmt.Println("fetched", symbol)
    }
}</code>

3. Close deferrals: Remember to close deferrals in the fetchSymbol goroutine to ensure that requests and file writes are finalized before exiting.

With these modifications, your code will now correctly exit after all symbol quotes are fetched and stored.

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