1) data races are different from race conditions. and data races are what this sanitizer detects. 2) data races are undefined behavior in C, but: 3) they don'

1) data races are different from race conditions. and data races are what this sanitizer detects. 2) data races are undefined behavior in C, but: 3) they don't necessarily translate to bugs in practice. for example: https://godbolt.org/z/Z9RvpB https://godbolt.org/z/Z9RvpB this is a data race, but in practice everything works as expected. in cases like this, fixing the data race adds overhead without giving us much benefit.