Hi again guys, I found what was causing the random freeze/crash problem.
Thing is that I didn't know the JNIEnv pointer was thread-dependent. As a result I was using the main thread's JNIEnv in GL thread to call my java layer from c++ With the proper JNIEnv pointer things go smoothly. Thanks for your efforts & time, Florent. 2010/12/15 Bob Kerns <[email protected]> > Ah. That should be easy enough to debug. > > Set a breakpoint at the log statement, and look at the stack. I bet > you're doing something from the UI thread, that doesn't return. Thus > the dialog code never gets run. If the breakpoint is not triggering in > the UI thread, pause the UI thread and see what it is doing at the > time. > > So long as you have something running on the UI thread, it's blocked > for anything else, including dialogs. If you are on the UI thread, > and have some loop going on or something, you're going to need to > return from it before the the Android dialog can be displayed. > > ANRs really aren't that hard to debug, though perhaps not always easy > to fix. Just see what the UI thread is doing. > > On Dec 15, 12:50 am, Цветко ЛАГАЈОВИЋ <[email protected]> > wrote: > > Hi, > > > > Yes sorry, I have not been precise enough. > > > > When I say it's not working, what I meen is that the execution gets > through > > to the Java layer (the Log.i methods get called, and my message is logged > in > > logcat) but the dialog is not displayed, and the application does not > > respond anymore. After some time I get an ANR notification and the app > force > > closes. > > > > Florent. > > > > > > > > > > > > > > > > On Wed, Dec 15, 2010 at 2:28 AM, Bob Kerns <[email protected]> wrote: > > > What does "can't get it to work" mean? > > > > > Is mActivity really a reference to the correct activity? > > > Does is successfully find the method, or take the 'return false;' > > > exit? (Which is rather odd in a void method!) > > > Does it crash? > > > Does it call the Java code, but with a corrupted message? > > > > > If it's that last, I'd look for the usual C++ headaches, such as using > > > a std::string() that has been destructed by the time you use it. > > > > > If it's crashing: Where is it crashing? How is mJNIEnv declared and > > > assigned? > > > > > Have you stepped through it in a debugger? I don't know hard that is > > > to do on a device (or emulator) with the NDK, but you could certainly > > > write a little test app on your PC and test the C++ side there. You'd > > > have to substitute on the Java side, of course; a simple > > > System.out.println("Success: " + pMsg); would suffice. > > > > > If none of that helps, I'd suggest asking the question in a list that > > > relates to the NDK rather than the SDK. You'd find a larger pool of > > > people able to understand and answer your questions on the topic. > > > > > On Dec 14, 10:30 am, Floof <[email protected]> wrote: > > > > Hi list ! > > > > > > I'm having this problem: > > > > > > In my application, I use a GLSurfaceView for 3D rendering. The real > > > > rendering is done by calling native methods, coded in C++. > > > > > > Once in a while (upon user clicks on 3D scene objects) the native > > > > rendering engine should be able to call Java methods (through JNI) > > > > that display a dialog box. > > > > > > I can't get it to work, that's driving me crazy. > > > > > > Here is the native method: > > > > > > [CODE] > > > > void MyCPlusPlusClass::showDialog(const std::string& pMsg) > > > > { > > > > jclass lClass = mJNIEnv->GetObjectClass(mActivity); > > > > if (!lClass) > > > > { > > > > return false; > > > > } > > > > jmethodID lMethId = mJNIEnv->GetMethodID(lClass, > > > > "showMessageDialog", "(Ljava/lang/String;)V"); > > > > if (!lMethId) > > > > { > > > > return false; > > > > } > > > > jstring lJavaString = mJNIEnv->NewStringUTF(pMessage.c_str()); > > > > mJNIEnv->CallVoidMethod(mActivity, lMethId, lJavaString);} > > > > > > [/CODE] > > > > > > Then, the method showMessageDialog, coded in Java, in my activity: > > > > > > [CODE] > > > > public void showMessageDialog(String pMsg) > > > > { > > > > Log.i("Vg", "Create dialog with message " + pMsg); > > > > Log.i("Vg", "Show dialog"); > > > > runOnUiThread( > > > > new Runnable () { > > > > public void run () { > > > > AlertDialog.Builder lAlertBox = new > > > > AlertDialog.Builder(this); > > > > TextView lTextView = new TextView(MyActivity.this); > > > > lTextView.setText(mMessage); > > > > lAlertBox.setView(lTextView); > > > > lAlertBox.setNeutralButton("Ok", MyActivity.this); > > > > lAlertBox.setOnCancelListener(MyActivity.this); > > > > lAlertBox.show(); > > > > } > > > > } > > > > );} > > > > > > [/CODE] > > > > > > I thought this would work, but it doesn't. What am I doing wrong ? > > > > > > Thanks > > > > Florent. > > > > > -- > > > You received this message because you are subscribed to the Google > > > Groups "Android Developers" group. > > > To post to this group, send email to > [email protected] > > > To unsubscribe from this group, send email to > > > [email protected]<android-developers%[email protected]><android-developers%2Bunsubs > [email protected]> > > > For more options, visit this group at > > >http://groups.google.com/group/android-developers?hl=en > > -- > You received this message because you are subscribed to the Google > Groups "Android Developers" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected]<android-developers%[email protected]> > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en > -- You received this message because you are subscribed to the Google Groups "Android Developers" group. 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