Unexpected race condition in goroutines with channels in Go 1.20
I'm optimizing some code but I've been banging my head against this for hours... I can't seem to get I'm refactoring my project and I'm encountering an unexpected race condition when using goroutines and channels in my Go application, specifically version 1.20. I have a producer function that sends integers to a channel, and a consumer function that processes these integers, but sometimes it seems like the consumer reads `0` instead of the actual number produced. Here’s a simplified version of my code: ```go package main import ( "fmt" "sync" ) func producer(ch chan<- int, wg *sync.WaitGroup) { defer wg.Done() for i := 1; i <= 10; i++ { ch <- i fmt.Println("Produced:", i) } } func consumer(ch <-chan int, wg *sync.WaitGroup) { defer wg.Done() for val := range ch { fmt.Println("Consumed:", val) // Simulating some processing delay if val == 5 { val = 0 // Intentionally setting to 0 to simulate unexpected behavior } } } func main() { ch := make(chan int) var wg sync.WaitGroup wg.Add(1) go producer(ch, &wg) wg.Add(1) go consumer(ch, &wg) wg.Wait() close(ch) } ``` I’ve tried running the code with the `-race` flag, but it doesn't seem to report any issues. I suspect that the consumer may be reading from the channel after it has been closed, but I'm not sure how to correctly synchronize the handling of the channel. What can I do to ensure that the consumer only processes valid values and handles the channel correctly without encountering race conditions or reading `0` unexpectedly? Any insights into best practices for managing goroutines with channels would be greatly appreciated. This is part of a larger microservice I'm building. I'm working on a REST API that needs to handle this. What would be the recommended way to handle this? For context: I'm using Go on CentOS. Any feedback is welcome!