detec and fix race condition

Makefile

@@ -1,8 +1,8 @@
 test:
- go test -cover ./...
+ go test ./...
 
-install: test
- go install checkip.go
+run: test
+ go run -race ./checkip.go 91.228.166.47
 
-run: install
- checkip 91.228.166.47
+install: run
+ go install ./checkip.go

README.md

@@ -156,7 +156,7 @@ Checkip is easy to extend. If you want to add a new way of checking IP addresses
 Typical workflow:
 
 ```
-make run # test, install and run
+make run # test and run
 
 git commit -m "backwards compatible bug fix" main.go
 

cli/cli.go

@@ -15,26 +15,36 @@ import (
 )
 
 // Run runs checks concurrently against the ippaddr.
-func Run(checks []check.Func, ipaddr net.IP) (Checks, []error) {
- var results Checks
- var errors []error
+func Run(checkFuncs []check.Func, ipaddr net.IP) (Checks, []error) {
+ var checksMu struct {
+ sync.Mutex
+ checks []check.Check
+ }
+ var errorsMu struct {
+ sync.Mutex
+ errors []error
+ }
 
  var wg sync.WaitGroup
- for _, chk := range checks {
+ for _, cf := range checkFuncs {
  wg.Add(1)
- go func(c check.Func) {
+ go func(cf check.Func) {
  defer wg.Done()
- r, err := c(ipaddr)
+ c, err := cf(ipaddr)
  if err != nil {
- errors = append(errors, err)
+ errorsMu.Lock()
+ errorsMu.errors = append(errorsMu.errors, err)
+ errorsMu.Unlock()
  return
  }
- results = append(results, r)
- }(chk)
+ checksMu.Lock()
+ checksMu.checks = append(checksMu.checks, c)
+ checksMu.Unlock()
+ }(cf)
  }
  wg.Wait()
 
- return results, errors
+ return checksMu.checks, errorsMu.errors
 }
 
 // Checks are generic or security information provided by a Check.