log telemetry guard details (#4817)

* log telemetry guard details

* nil guard

pkg/telemetry/events.go

@@ -216,6 +216,7 @@ func (t *telemetryService) ParticipantLeft(ctx context.Context,
 					"participant", participant.Identity,
 					"participantID", participant.Sid,
 					"worker", worker,
+					"guard", guard,
 				)
 			}
 		}

pkg/telemetry/statsworker.go

@@ -18,6 +18,7 @@ import (
 	"context"
 	"sync"
 	"time"
+	"unsafe"
 
 	"go.uber.org/zap/zapcore"
 	"google.golang.org/protobuf/types/known/timestamppb"
@@ -32,6 +33,17 @@ type ReferenceGuard struct {
 	activated, released bool
 }
 
+func (r *ReferenceGuard) MarshalLogObject(e zapcore.ObjectEncoder) error {
+	if r != nil {
+		e.AddUintptr("self", uintptr(unsafe.Pointer(r)))
+		e.AddBool("activated", r.activated)
+		e.AddBool("released", r.released)
+	}
+	return nil
+}
+
+// ----------------------------------------
+
 type ReferenceCount struct {
 	count int
 }