Concurrency safety

[hiendaovinh]

Do you want to request a feature or report a bug?
BUG

What is the current behavior?
DATA RACE

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem.
Running IsAllowed() in multiple goroutine results in WARNING: DATA RACE

Read at 0x00c000b4c6d0 by goroutine 174:
  github.com/ory/ladon.(*Ladon).matcher()
      /go/pkg/mod/github.com/ory/ladon@v1.2.0/ladon.go:36 +0x7d5
  github.com/ory/ladon.(*Ladon).DoPoliciesAllow()
      /go/pkg/mod/github.com/ory/ladon@v1.2.0/ladon.go:82 +0x85e
  github.com/ory/ladon.(*Ladon).IsAllowed()

Previous write at 0x00c000b4c6d0 by goroutine 176:
  github.com/ory/ladon.(*Ladon).matcher()
      /go/pkg/mod/github.com/ory/ladon@v1.2.0/ladon.go:37 +0x80c
  github.com/ory/ladon.(*Ladon).DoPoliciesAllow()
      /go/pkg/mod/github.com/ory/ladon@v1.2.0/ladon.go:82 +0x85e
  github.com/ory/ladon.(*Ladon).IsAllowed()

What is the expected behavior?
It's safe to run concurrently.

Which version of the software is affected?
ory/ladon@v1.2.0

[hiendaovinh]

Guarding Ladon with a mutex lock could be a solution but it might affect the performance.

[aeneasr]

Nice find! A mutex sounds good