IOSchedulerRoster:

* Lock the notification service and check HasListeners(), so we don't prepare
  an event message needlessly.
* The on-stack buffer for the event message was too small for I/O operation
  related events. Now a larger buffer belonging to the roster object is used.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34737 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/kernel/device_manager/IOScheduler.cpp

@@ -910,9 +910,13 @@ void
 IOSchedulerRoster::Notify(uint32 eventCode, const IOScheduler* scheduler,
 	IORequest* request, IOOperation* operation)
 {
-	char eventBuffer[128];
+	AutoLocker<DefaultNotificationService> locker(fNotificationService);
+
+	if (!fNotificationService.HasListeners())
+		return;
+
 	KMessage event;
-	event.SetTo(eventBuffer, sizeof(eventBuffer), IO_SCHEDULER_MONITOR);
+	event.SetTo(fEventBuffer, sizeof(fEventBuffer), IO_SCHEDULER_MONITOR);
 	event.AddInt32("event", eventCode);
 	event.AddPointer("scheduler", scheduler);
 	if (request != NULL) {
@@ -921,7 +925,7 @@ IOSchedulerRoster::Notify(uint32 eventCode, const IOScheduler* scheduler,
 			event.AddPointer("operation", operation);
 	}
 
-	fNotificationService.Notify(event, eventCode);
+	fNotificationService.NotifyLocked(event, eventCode);
 }
 
 

src/system/kernel/device_manager/IOScheduler.h

@@ -182,6 +182,7 @@ private:
 			int32				fNextID;
 			IOSchedulerList		fSchedulers;
 			DefaultNotificationService fNotificationService;
+			char				fEventBuffer[256];
 
 	static	IOSchedulerRoster	sDefaultInstance;
 };