Go Race

A race condition occurs in Go when two or more goroutines try to access the same resource. It may happen when a variable attempts to read and write the resource without any regard to other routines.

Go Race Condition Example

Output:

foo:  0 Count:  1 bar:  0 Count:  1 foo:  1 Count:  2 foo:  2 Count:  3 foo:  3 Count:  4 bar:  1 Count:  2 foo:  4 Count:  5 foo:  5 Count:  6 foo:  6 Count:  7 bar:  2 Count:  3 bar:  3 Count:  4 bar:  4 Count:  5 foo:  7 Count:  8 foo:  8 Count:  9 bar:  5 Count:  6 bar:  6 Count:  7 foo:  9 Count:  10 bar:  7 Count:  8 bar:  8 Count:  9 bar:  9 Count:  10 last count value  10 

As you can see in the above example, the count resource is accessed by 2 go routines. Each routine iterates to 10 times. In such case, the count variable should be 20 at last. But it is not so because it is simulating race condition.