Golang race test
refer: Introducing the Go Race Detector
refer: ThreadSanitizerAlgorithm
Command
在运行go test的时候，1
2
3
4$ go test -race mypkg // test the package
$ go run -race mysrc.go // compile and run the program
$ go build -race mycmd // build the command
$ go install -race mypkg // install the package
-race的原理在于，watch 是否unsynchronized accesses to shared variables.
具体的算法是：ThreadSanitizerAlgorithm
Thread Sanitizer Algorithm
监视每个memory access, unless it can be proven to be race-free or redundant. 使用的函数是，__tsan_read4(addr).
Race-free access
- Read from constant globals (including vtables)
- Accesses to memory that does not escape the current function (and therefore the current thread)
Redundant accesses
- Read that happens before a write to the same location.
race的底层实现基于ThreadSanitizerAlgorithm算法，该算法的大体为，随着线程的时钟递增，创建与当前内存访问相对应的新的Shadow Word。然后状态机迭代存储在Shadow State中的所有Shadow Word。如果其中一个老的Shadow Word与新Shadow Word组成race，则data race被检测出，
