race.md

Race detection flag

Overview

Data races are among the most common and hardest to debug types of bugs in concurrent systems.

A data race occurs when two goroutines access the same variable concurrently and at least one of the accesses is a write.

Usage

go test -race mypkg // to test the package
go run -race mysrc.go // to run the source file
go build -race mycmd  // to build the command
go install -race mypkg // to install the package

Runtime Overhead

The cost of race detection varies by program, but for a typical program, memory usage may increase by 5-10x and execution time by 2-20x.

Additional information

Race detector docs