An analyser that reports captured variable references in goroutine closures.
Goroutines that run function closures can capture reference variables from outer scopes which could lead to data races. This analyzer checks closures run by goroutines and reports uses of all variables declared in outer scopes, as well as arguments to the closure with a pointer type.
Given the following program:
package main
func main() {}
type Record struct{}
func (r *Record) reticulateSplines() {}
type Spline struct {
Curvature float64
}
func (r *Record) CapturedReference() {
capturedReference := 0
spline := &Spline{Curvature: 5.0}
go func(s *Spline) {
capturedReference += 1 // closure captures the variable
// 'capturedReference' in a goroutine, which could
// lead to data races
if capturedReference > 0 {
r.reticulateSplines() // goroutine closure captures 'r'
}
s.Curvature = 3.0 // 's' is a pointer type which could
// lead to data races
}(spline)
}the analyser produces the following results:
$ gocapturedrefrace ./...
package_doc_example.go:17:10: reference s in goroutine closure
package_doc_example.go:18:3: captured reference capturedReference in goroutine closure
package_doc_example.go:22:6: captured reference capturedReference in goroutine closure
package_doc_example.go:23:4: captured reference r in goroutine closure
$ go install gopkg.teddywing.com/capturedrefrace/cmd/gocapturedrefrace@latest
Copyright © 2023 Teddy Wing. Licensed under the GNU GPLv3+ (see the included COPYING file).