Hello, Sergey. > As I remember doAWTRunLoop process events and selectors in case of > drags/DnD otherwise how we got mouse events? Or I have missed something? In case of DnD we have several nested loops in place: 1. The native Cocoa DnD nested loop. It's started within the NSView dragImage:... call. It processes only the DnD-related events - some mouse events, some key events and flag changed events. This is for the DragSource. 2. To dispatch some DropTarget events on EDT synchronously we start our own nested loop in doAWTRunLoop using the ToolkitThreadBlockedHandler. In this case we do process the events in a nested runLoop. This case might actually be a bug, because we are short-circuiting normal event processing and could "steal" some events from Cocoa. But I would not address this it in this fix.
Without the DnD we use a doAWTRunLoop which does not process events. (Except the case with Single-Threaded Interop with FX). Actually, after some more thinking I believe I should reimplement the fix and follow Anthony's suggestion with a timeout, because my fix is too complex. I'll send a new webrev later today. With best regards. Petr. On 24.12.2013, at 1:41, Sergey Bylokhov <[email protected]> wrote: > Hi, Petr. > On 23.12.2013 16:54, Petr Pchelko wrote: >> The problem: >> nativeSyncQueue synchronizes the native event queue. However, there are >> several situations when a dummy event posted to the native queue is not >> dispatched. These are our own nested loop in doAWTRunLoop and Cocoa's >> internal nested loop in NSView:dragImage. > As I remember doAWTRunLoop process events and selectors in case of > drags/DnD otherwise how we got mouse events? Or I have missed something? > >> >> Solution: >> >> 1. The interruptNativeSyncQueue was introduced. In case we are waiting for >> the native event queue this method interrupts waiting, otherwise it's a >> no-op. This is needed for the following reason: suppose the nativeSyncQueue >> is called on EDT. While the queue is flushed some event was processed which >> caused us to call doAWTRunLoop. As EDT is blocked we would have got a >> deadlock. Interrupting the wait lets EDT flush it's events and lets AppKit >> exit a nested loop. When the nativeSyncQueue is interrupted we do not >> immediately exit realSync, but flush EDT and try to sync native queue again. >> Most likely in this case we would not be in a nested loop and will >> successfully sync a native queue. >> >> 2. A lightweight version of nativeSyncQueue was introduced. This one does >> not flush the event queue, it only flushes a selector queue. This is needed >> to not deadlock when realSync was called during DnD. Suppose nativeSyncQueue >> is called while the app is in the native nested dragging loop. Until >> dragging operation finishes only dragging-related events will be processed. >> So we have no opportunity to flush the queue as our dummy event will be >> blocked by a dragging nested loop. >> >> I've tested it by running almost all awt and swing tests. No new failures, >> some tests start to pass after the fix. >> >> With best regards. Petr. >> >> > > > -- > Best regards, Sergey. >
