Switch to sync.Map because go maps are unsound

model/experiments.go

@@ -6,15 +6,20 @@ import "sync"
 // examples of experiments include File Sharing, Profile Images and Groups.
 type Experiments struct {
 	enabled     bool
-	experiments map[string]bool
-	lock        sync.Mutex
+	experiments sync.Map
 }
 
 // InitExperiments encapsulates a set of experiments separate from their storage in GlobalSettings.
 func InitExperiments(enabled bool, experiments map[string]bool) Experiments {
+
+	var syncExperiments sync.Map
+	for experiment, set := range experiments {
+		syncExperiments.Store(experiment, set)
+	}
+
 	return Experiments{
 		enabled:     enabled,
-		experiments: experiments,
+		experiments: syncExperiments,
 	}
 }
 
@@ -28,12 +33,9 @@ func (e *Experiments) IsEnabled(experiment string) bool {
 		return false
 	}
 
-	// go will sometimes panic if we do not lock this read-only map...
-	e.lock.Lock()
-	defer e.lock.Unlock()
-	enabled, exists := e.experiments[experiment]
+	enabled, exists := e.experiments.Load(experiment)
 	if !exists {
 		return false
 	}
-	return enabled
+	return enabled.(bool)
 }