iOS: Rewrite CoreFoundation event-dispatcher

Instead of having separate code-paths for QEventLoop::EventLoopExec
and the non-blocking processEvent() we now have a single Q_FOREVER
loop where the logic can be shared. We make multiple loop-passes,
each time calling CFRunLoopRunInMode with potentially different
arguments, depending on the result of the previous run.

For the EventLoopExec case we'll continue making loop-passes until
the event-loop has been interrupted. For the non-EventLoopExec case,
we respect interruption, but will continue making loop-passes only
until we've processed all events in the queue, optionally waiting
for the initial event if WaitForMoreEvents is set. Limitations in
the CoreFoundation APIs unfortunately force us to keep some state
on whether or not we've processed events and timers for a given
processEvents() pass (with corresponding deferred scheduling of
timers and event source signaling).

The way we handle timers has also been rewritten to no longer defer
the timer activation to a special timer source. The constraint of
CoreFoundation timers is that they can not recurse (re-fire) in a
callback, but that only applies per timer, so using multiple CF
timers allows us to recurse. We still only use a single CF timer
for all the Qt timers though, and only spawn a new CF timer if
the user calls processEvents() inside a timer callback.

This commit removes the logic related to dealing with UITrackingMode,
as that logic was slighly problematic, but the feature will be
added back in a follow-up commit, in line with the new approach.

The result of this commit is that we're passing all event-loop,
event-dispatcher, and timer auto-tests, both for the QtCore dispatcher
and the GUI event-dispatcher.

Change-Id: I3c56fbc7857a25110064681257abb47075b5bd2d
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>

1 files changed, 40 insertions, 11 deletions

diff --git a/src/platformsupport/eventdispatchers/qeventdispatcher_cf_p.h b/src/platformsupport/eventdispatchers/qeventdispatcher_cf_p.h
index e23b8f0ece..bd62927f09 100644
--- a/src/platformsupport/eventdispatchers/qeventdispatcher_cf_p.h
+++ b/src/platformsupport/eventdispatchers/qeventdispatcher_cf_p.h
@@ -76,8 +76,11 @@
 #ifndef QEVENTDISPATCHER_CF_P_H
 #define QEVENTDISPATCHER_CF_P_H
 
+#define DEBUG_EVENT_DISPATCHER 0
+
 #include <QtCore/qabstracteventdispatcher.h>
 #include <QtCore/private/qtimerinfo_unix_p.h>
+#include <QtCore/qdebug.h>
 #include <QtPlatformSupport/private/qcfsocketnotifier_p.h>
 #include <CoreFoundation/CoreFoundation.h>
 
@@ -200,29 +203,55 @@ public:
     void flush();
 
 private:
-    bool m_interrupted;
-
     RunLoopSource<> m_postedEventsRunLoopSource;
-    RunLoopSource<> m_blockingTimerRunLoopSource;
-
-    RunLoopObserver<> m_awakeAndBlockObserver;
+    RunLoopObserver<> m_runLoopActivityObserver;
 
     QTimerInfoList m_timerInfoList;
-    CFRunLoopTimerRef m_runLoopTimerRef;
+    CFRunLoopTimerRef m_runLoopTimer;
+    CFRunLoopTimerRef m_blockedRunLoopTimer;
+    bool m_overdueTimerScheduled;
 
     QCFSocketNotifier m_cfSocketNotifier;
 
-    void processPostedEvents();
-    void processTimers();
+    struct ProcessEventsState
+    {
+        ProcessEventsState(QEventLoop::ProcessEventsFlags f)
+         : flags(f), wasInterrupted(false)
+         , processedPostedEvents(false), processedTimers(false)
+         , deferredWakeUp(false), deferredUpdateTimers(false) {}
 
-    void maybeStartCFRunLoopTimer();
-    void maybeStopCFRunLoopTimer();
+        QEventLoop::ProcessEventsFlags flags;
+        bool wasInterrupted;
+        bool processedPostedEvents;
+        bool processedTimers;
+        bool deferredWakeUp;
+        bool deferredUpdateTimers;
+    };
+
+    ProcessEventsState m_processEvents;
+
+    void processPostedEvents();
+    void processTimers(CFRunLoopTimerRef);
 
     void handleRunLoopActivity(CFRunLoopActivity activity);
 
-    static void nonBlockingTimerRunLoopCallback(CFRunLoopTimerRef, void *info);
+    void updateTimers();
+    void invalidateTimer();
 };
 
 QT_END_NAMESPACE
 
+#if DEBUG_EVENT_DISPATCHER
+extern uint g_eventDispatcherIndentationLevel;
+#define qEventDispatcherDebug() qDebug().nospace() \
+            << qPrintable(QString(QLatin1String("| ")).repeated(g_eventDispatcherIndentationLevel)) \
+            << __FUNCTION__ << "(): "
+#define qIndent() ++g_eventDispatcherIndentationLevel
+#define qUnIndent() --g_eventDispatcherIndentationLevel
+#else
+#define qEventDispatcherDebug() QT_NO_QDEBUG_MACRO()
+#define qIndent()
+#define qUnIndent()
+#endif
+
 #endif // QEVENTDISPATCHER_CF_P_H