A race condition occurs when concurrent goroutines access changing shared data and correctness depends on their uncontrolled ordering. Partial updates or out-of-order mutations can corrupt data or produce runtime errors. section 5.2.2
Recognize and contain the problem by:
- Identifying shared mutable state accessed by multiple goroutines. section 5.2.2
- Protecting the shared resource with sync.Mutex, then unlocking it after use. section 5.2.2
Concurrent word counter
A word-counting tool processes multiple files in separate goroutines while updating one map. Without protection it can fail with “concurrent map writes”; locking the words structure serializes access.



















