By default, use unbuffered channels or a buffer size of one. Only use larger buffers when necessary and carefully considered. Unbuffered channels (size 0) or a size of 1 are the most common; a large buffer can hide synchronization issues or lead to memory bloat if misused.
Channels coordinate goroutines. Unbuffered channels ensure strict handoff, and a buffer of one provides minimal queuing. Large buffers, if chosen poorly, might mask deadlocks or produce high memory usage as goroutines pile up sends, making bugs harder to detect.
Side-by-side examples engineers can pattern-match during review.
jobs := make(chan Job, 100) // large buffer without clear need
// Producer
for _, j := range jobList {
jobs <- j // might fill up and block if consumer is slow
}
close(jobs)jobs := make(chan Job) // unbuffered channel
// or jobs := make(chan Job, 1) for a single-item buffer
for _, j := range jobList {
jobs <- j // will block if consumer is not ready, preventing overload
}
close(jobs)jobs := make(chan Job, 100) // large buffer without clear need
// Producer
for _, j := range jobList {
jobs <- j // might fill up and block if consumer is slow
}
close(jobs)jobs := make(chan Job) // unbuffered channel
// or jobs := make(chan Job, 1) for a single-item buffer
for _, j := range jobList {
jobs <- j // will block if consumer is not ready, preventing overload
}
close(jobs)From the same buckets as this rule.