[#1628] fixed realtime panic on concurrent clients iteration

apis/realtime.go

@@ -15,6 +15,7 @@ import (
 	"github.com/pocketbase/pocketbase/forms"
 	"github.com/pocketbase/pocketbase/models"
 	"github.com/pocketbase/pocketbase/resolvers"
+	"github.com/pocketbase/pocketbase/tools/routine"
 	"github.com/pocketbase/pocketbase/tools/search"
 	"github.com/pocketbase/pocketbase/tools/subscriptions"
 )
@@ -43,10 +44,14 @@ func (api *realtimeApi) connect(c echo.Context) error {
 	client := subscriptions.NewDefaultClient()
 	api.app.SubscriptionsBroker().Register(client)
 	defer func() {
-		api.app.OnRealtimeDisconnectRequest().Trigger(&core.RealtimeDisconnectEvent{
+		disconnectEvent := &core.RealtimeDisconnectEvent{
 			HttpContext: c,
 			Client:      client,
-		})
+		}
+
+		if err := api.app.OnRealtimeDisconnectRequest().Trigger(disconnectEvent); err != nil && api.app.IsDebug() {
+			log.Println(err)
+		}
 
 		api.app.SubscriptionsBroker().Unregister(client.Id())
 	}()
@@ -259,21 +264,27 @@ func (api *realtimeApi) bindEvents() {
 
 	api.app.OnModelAfterCreate().PreAdd(func(e *core.ModelEvent) error {
 		if record, ok := e.Model.(*models.Record); ok {
-			api.broadcastRecord("create", record)
+			if err := api.broadcastRecord("create", record); err != nil && api.app.IsDebug() {
+				log.Println(err)
+			}
 		}
 		return nil
 	})
 
 	api.app.OnModelAfterUpdate().PreAdd(func(e *core.ModelEvent) error {
 		if record, ok := e.Model.(*models.Record); ok {
-			api.broadcastRecord("update", record)
+			if err := api.broadcastRecord("update", record); err != nil && api.app.IsDebug() {
+				log.Println(err)
+			}
 		}
 		return nil
 	})
 
 	api.app.OnModelBeforeDelete().Add(func(e *core.ModelEvent) error {
 		if record, ok := e.Model.(*models.Record); ok {
-			api.broadcastRecord("delete", record)
+			if err := api.broadcastRecord("delete", record); err != nil && api.app.IsDebug() {
+				log.Println(err)
+			}
 		}
 		return nil
 	})
@@ -370,6 +381,8 @@ func (api *realtimeApi) broadcastRecord(action string, record *models.Record) er
 	encodedData := string(dataBytes)
 
 	for _, client := range clients {
+		client := client
+
 		for subscription, rule := range subscriptionRuleMap {
 			if !client.HasSubscription(subscription) {
 				continue
@@ -398,7 +411,11 @@ func (api *realtimeApi) broadcastRecord(action string, record *models.Record) er
 				}
 			}
 
-			client.Channel() <- msg
+			routine.FireAndForget(func() {
+				if !client.IsDiscarded() {
+					client.Channel() <- msg
+				}
+			})
 		}
 	}