Add pprof annotations to roomserver worker goroutines

roomserver/internal/input/input_events.go

@@ -22,6 +22,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"runtime/pprof"
 	"time"
 
 	"github.com/neilalexander/harmony/roomserver/storage/tables"
@@ -116,6 +117,10 @@ func (r *Inputer) processRoomEvent(
 		})
 	}
 
+	// Set goroutine labels, useful for pprof CPU profiles, useful for CPU
+	// pprof profiles to find out where time is being spent.
+	pprof.SetGoroutineLabels(context.WithValue(ctx, "room_id", event.RoomID().String()))
+
 	// Don't waste time processing the event if the room doesn't exist.
 	// A room entry locally will only be created in response to a create
 	// event.