What is Data Race and Race Condition? What is the difference?

Race Condition — a situation where the behavior of a program depends on the unpredictable order of execution of multiple threads or goroutines, which can lead to errors or incorrect results.

Data Race — a specific case of race condition, where two or more threads access the same variable simultaneously, at least one of them performs a write, and there is no proper synchronization.

The difference is that all data races are race conditions, but not all race conditions involve simultaneous access to data. For example, a race condition can be caused by an incorrect order of function calls or events.

In Go, data races can be detected using the -race flag when running:

go run -race main.go

Example of a data race:

goroutine 1:
  x = 1

goroutine 2:
  fmt.Println(x)

If these operations are performed simultaneously without synchronization, a data race occurs.