Fix crash on S4 when running Satellite and Position updates concurrently

This was caused due to unsynchronized access of data between two threads.
The Java satellite updates were sent before the receiving Qt thread could
finish its regular startup. As a consequence the received updates could
not be mapped to a receiving C++ class.

This patch synchronizes the startup and setup of the two threads and
ensures that the relvant data setup on the C++ side is done before the
update thread is started.

In addition some minor debug helpers were added for future references.

Task-number: QTBUG-39082
Change-Id: I1f24ddfcef038fa000801ddb6a3ea0959370f0d3
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>

2 files changed, 23 insertions, 11 deletions

diff --git a/src/plugins/position/android/jar/src/org/qtproject/qt5/android/positioning/QtPositioning.java b/src/plugins/position/android/jar/src/org/qtproject/qt5/android/positioning/QtPositioning.java
index f5725813..f2babd08 100644
--- a/src/plugins/position/android/jar/src/org/qtproject/qt5/android/positioning/QtPositioning.java
+++ b/src/plugins/position/android/jar/src/org/qtproject/qt5/android/positioning/QtPositioning.java
@@ -187,17 +187,18 @@ public class QtPositioning implements LocationListener
             try {
                 boolean exceptionOccurred = false;
                 QtPositioning positioningListener = new QtPositioning();
-                positioningListener.setActiveLooper(true);
                 positioningListener.nativeClassReference = androidClassKey;
                 positioningListener.expectedProviders = locationProvider;
                 positioningListener.isSatelliteUpdate = false;
+                //start update thread
+                positioningListener.setActiveLooper(true);
 
                 if (updateInterval == 0)
                     updateInterval = 1000; //don't update more often than once per second
 
                 positioningListener.updateIntervalTime = updateInterval;
                 if ((locationProvider & QT_GPS_PROVIDER) > 0) {
-                    Log.d(TAG, "Regular updates using GPS");
+                    Log.d(TAG, "Regular updates using GPS " + updateInterval);
                     try {
                         locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
                                                        updateInterval, 0,
@@ -210,7 +211,7 @@ public class QtPositioning implements LocationListener
                 }
 
                 if ((locationProvider & QT_NETWORK_PROVIDER) > 0) {
-                    Log.d(TAG, "Regular updates using network");
+                    Log.d(TAG, "Regular updates using network " + updateInterval);
                     try {
                         locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,
                                                        updateInterval, 0,
@@ -263,11 +264,12 @@ public class QtPositioning implements LocationListener
             try {
                 boolean exceptionOccurred = false;
                 QtPositioning positioningListener = new QtPositioning();
-                positioningListener.setActiveLooper(true);
                 positioningListener.nativeClassReference = androidClassKey;
                 positioningListener.isSingleUpdate = true;
                 positioningListener.expectedProviders = locationProvider;
                 positioningListener.isSatelliteUpdate = false;
+                //start update thread
+                positioningListener.setActiveLooper(true);
 
                 if ((locationProvider & QT_GPS_PROVIDER) > 0) {
                     Log.d(TAG, "Single update using GPS");
@@ -321,10 +323,11 @@ public class QtPositioning implements LocationListener
                 boolean exceptionOccurred = false;
                 QtPositioning positioningListener = new QtPositioning();
                 positioningListener.isSatelliteUpdate = true;
-                positioningListener.setActiveLooper(true);
                 positioningListener.nativeClassReference = androidClassKey;
                 positioningListener.expectedProviders = 1; //always satellite provider
                 positioningListener.isSingleUpdate = isSingleRequest;
+                //start update thread
+                positioningListener.setActiveLooper(true);
 
                 if (updateInterval == 0)
                     updateInterval = 1000; //don't update more often than once per second
@@ -385,9 +388,14 @@ public class QtPositioning implements LocationListener
                 if (isSatelliteUpdate)
                     looperThread.isSatelliteListener(true);
 
+                long start = System.currentTimeMillis();
                 looperThread.start();
+
+                //busy wait but lasts ~20-30 ms only
                 while (!looperThread.isReady());
-                Thread.sleep(1000);
+
+                long stop = System.currentTimeMillis();
+                Log.d(TAG, "Looper Thread startup time in ms: " + (stop-start));
             } else {
                 looperThread.quitLooper();
             }
@@ -411,7 +419,6 @@ public class QtPositioning implements LocationListener
         {
             Looper.prepare();
             Handler handler = new Handler();
-            looperRunning = true;
 
             if (isSatelliteLooper) {
                 try {
@@ -422,8 +429,13 @@ public class QtPositioning implements LocationListener
             }
 
             posLooper = Looper.myLooper();
+            synchronized (this) {
+                looperRunning = true;
+            }
             Looper.loop();
-            looperRunning = false;
+            synchronized (this) {
+                looperRunning = false;
+            }
         }
 
         public void quitLooper()
@@ -433,7 +445,7 @@ public class QtPositioning implements LocationListener
             looper().quit();
         }
 
-        public boolean isReady()
+        public synchronized boolean isReady()
         {
             return looperRunning;
         }
diff --git a/src/plugins/position/android/src/jnipositioning.cpp b/src/plugins/position/android/src/jnipositioning.cpp
index afae1c8e..d3cce65b 100644
--- a/src/plugins/position/android/src/jnipositioning.cpp
+++ b/src/plugins/position/android/src/jnipositioning.cpp
@@ -459,7 +459,7 @@ static void positionUpdated(JNIEnv *env, jobject /*thiz*/, jobject location, jin
 
     QGeoPositionInfoSourceAndroid *source = AndroidPositioning::idToPosSource()->value(androidClassKey);
     if (!source) {
-        qFatal("positionUpdated: source == 0");
+        qWarning("positionUpdated: source == 0");
         return;
     }
 
@@ -479,7 +479,7 @@ static void locationProvidersDisabled(JNIEnv *env, jobject /*thiz*/, jint androi
     if (!source)
         source = AndroidPositioning::idToSatSource()->value(androidClassKey);
     if (!source) {
-        qFatal("locationProvidersDisabled: source == 0");
+        qWarning("locationProvidersDisabled: source == 0");
         return;
     }