**Why Does My Golang Program Using WaitGroup and Channels Run Indefinitely?**

WaitGroup and Channel Usage in Golang Program

This Golang program utilizes sync.WaitGroup and channels to achieve efficient goroutine execution and data collection. However, it encounters an issue where the program doesn't exit after completing its tasks. This article delves into the problem and provides a solution.

The program involves retrieving stock quotes for a list of symbols and then saving the results to files. It employs a combination of goroutines and channels to execute the fetching process concurrently, with a WaitGroup to track the completion of all tasks. However, the program falls into an infinite loop because the fetchedSymbols channel remains open indefinitely.

To resolve this issue, the program needs to close the fetchedSymbols channel after all the goroutines have finished their tasks. The WaitGroup, which already keeps track of the goroutine completion, can be utilized for this purpose. By adding a go func() wrapper that closes the channel when the WaitGroup reaches zero, the issue is resolved.

The modified section of code is as follows:

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

for response := range fetchedSymbols {
    fmt.Println("fetched " + response)
}

...</code>

The added go func() routine waits for the WaitGroup to reach zero, indicating that all goroutines have completed their tasks. It then closes the fetchedSymbols channel, allowing the range loop in main to exit as expected and allowing the program to complete execution.

This improved program effectively utilizes WaitGroup and channels for concurrent goroutine execution and data retrieval, and it exits gracefully after completing all necessary tasks.

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