Android lifecycle cleanups

- Differentiate between cpu_pause() when going to menu (and app is still foregrounded, and cpu_pauseBackground()
      when a system backgrounding event has occurred.
    - Destroy/free audio resources owned by CPU thread when background is requested, put CPU thread into waiting upon
      pthread condition to resume.
    - Mobile device now always signals pthread condition to force CPU thread resume from background

Android/app/src/main/java/org/deadc0de/apple2ix/Apple2Activity.java

@@ -41,6 +41,7 @@ public class Apple2Activity extends Activity {
     private final static int MAX_FINGERS = 32;// HACK ...
 
     private String mDataDir = null;
+    private boolean mSetUncaughtExceptionHandler = false;
 
     private Apple2View mView = null;
     private ArrayList<Apple2MenuView> mMenuStack = new ArrayList<Apple2MenuView>();
@@ -76,7 +77,7 @@ public class Apple2Activity extends Activity {
 
     public native void nativeOnResume(boolean isSystemResume);
 
-    public native void nativeOnPause();
+    public native void nativeOnPause(boolean isSystemPause);
 
     public native void nativeOnQuit();
 
@@ -92,7 +93,7 @@ public class Apple2Activity extends Activity {
     // HACK NOTE 2015/02/22 : Apparently native code cannot easily access stuff in the APK ... so copy various resources
     // out of the APK and into the /data/data/... for ease of access.  Because this is FOSS software we don't care about
     // security or DRM for these assets =)
-    private String firstTimeInitialization() {
+    private String _firstTimeInitialization() {
 
         String dataDir = null;
         try {
@@ -153,25 +154,12 @@ public class Apple2Activity extends Activity {
         os.close();
     }
 
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        if (BuildConfig.DEBUG) {
-            StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
-                    .detectDiskReads()
-                    .detectDiskWrites()
-                    .detectAll()
-                    .penaltyLog()
-                    .build());
-            StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()
-                    .detectLeakedSqlLiteObjects()
-                    /*.detectLeakedClosableObjects()*/
-                    .penaltyLog()
-                    .penaltyDeath()
-                    .build());
+    private void _setCustomExceptionHandler() {
+        if (mSetUncaughtExceptionHandler) {
+            return;
         }
-        super.onCreate(savedInstanceState);
+        mSetUncaughtExceptionHandler = true;
 
-        // Immediately set up exception handler ...
         final String homeDir = "/data/data/" + this.getPackageName();
         final Thread.UncaughtExceptionHandler defaultExceptionHandler = Thread.getDefaultUncaughtExceptionHandler();
         Thread.setDefaultUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {
@@ -221,10 +209,30 @@ public class Apple2Activity extends Activity {
                 defaultExceptionHandler.uncaughtException(thread, t);
             }
         });
+    }
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        if (BuildConfig.DEBUG) {
+            StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
+                    .detectDiskReads()
+                    .detectDiskWrites()
+                    .detectAll()
+                    .penaltyLog()
+                    .build());
+            StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()
+                    .detectLeakedSqlLiteObjects()
+                    /*.detectLeakedClosableObjects()*/
+                    .penaltyLog()
+                    .penaltyDeath()
+                    .build());
+        }
+        super.onCreate(savedInstanceState);
 
         Log.e(TAG, "onCreate()");
 
-        mDataDir = firstTimeInitialization();
+        _setCustomExceptionHandler();
+        mDataDir = _firstTimeInitialization();
 
         // get device audio parameters for native OpenSLES
         mSampleRate = DevicePropertyCalculator.getRecommendedSampleRate(this);
@@ -297,7 +305,7 @@ public class Apple2Activity extends Activity {
             }
         } while (apple2MenuView != null);
 
-        nativeOnPause();
+        nativeOnPause(true);
     }
 
     @Override
@@ -372,17 +380,14 @@ public class Apple2Activity extends Activity {
     @Override
     public boolean onTouchEvent(MotionEvent event) {
         do {
+
             Apple2MainMenu mainMenu = mView.getMainMenu();
             if (mainMenu == null) {
                 break;
             }
 
-            Apple2SettingsMenu settingsMenu = mainMenu.getSettingsMenu();
-            Apple2DisksMenu disksMenu = mView.getDisksMenu();
-            if (settingsMenu != null && settingsMenu.isShowing()) {
-                break;
-            }
-            if (disksMenu != null && disksMenu.isShowing()) {
+            Apple2MenuView apple2MenuView = peekApple2View();
+            if (apple2MenuView != null) {
                 break;
             }
 
@@ -441,7 +446,7 @@ public class Apple2Activity extends Activity {
     public synchronized void pushApple2View(Apple2MenuView apple2MenuView) {
         mMenuStack.add(apple2MenuView);
         View menuView = apple2MenuView.getView();
-        nativeOnPause();
+        nativeOnPause(false);
         addContentView(menuView, new FrameLayout.LayoutParams(getWidth(), getHeight()));
     }
 
@@ -456,6 +461,15 @@ public class Apple2Activity extends Activity {
         return apple2MenuView;
     }
 
+    public synchronized Apple2MenuView peekApple2View() {
+        int lastIndex = mMenuStack.size() - 1;
+        if (lastIndex < 0) {
+            return null;
+        }
+
+        return mMenuStack.get(lastIndex);
+    }
+
     public synchronized Apple2MenuView popApple2View(Apple2MenuView apple2MenuView) {
         boolean wasRemoved = mMenuStack.remove(apple2MenuView);
         _disposeApple2View(apple2MenuView);
@@ -495,7 +509,7 @@ public class Apple2Activity extends Activity {
     }
 
     public void maybeQuitApp() {
-        nativeOnPause();
+        nativeOnPause(false);
         if (mQuitDialog == null) {
             mQuitDialog = new AlertDialog.Builder(this).setIcon(R.drawable.ic_launcher).setCancelable(true).setTitle(R.string.quit_really).setMessage(R.string.quit_warning).setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
                 @Override
@@ -527,7 +541,7 @@ public class Apple2Activity extends Activity {
     }
 
     public void maybeReboot() {
-        nativeOnPause();
+        nativeOnPause(false);
         if (mRebootDialog == null) {
             mRebootDialog = new AlertDialog.Builder(this).setIcon(R.drawable.ic_launcher).setCancelable(true).setTitle(R.string.reboot_really).setMessage(R.string.reboot_warning).setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
                 @Override

Android/app/src/main/java/org/deadc0de/apple2ix/Apple2MainMenu.java

@@ -201,7 +201,7 @@ public class Apple2MainMenu {
             return;
         }
 
-        mActivity.nativeOnPause();
+        mActivity.nativeOnPause(false);
 
         mMainMenuPopup.showAtLocation(mParentView, Gravity.CENTER, 0, 0);
     }

Android/jni/jnihooks.c

@@ -30,7 +30,6 @@ enum {
     ANDROID_ACTION_POINTER_UP = 0x6,
 };
 
-static bool nativePaused = false;
 static bool nativeRequestsShowMainMenu = false;
 
 #if TESTING
@@ -161,29 +160,28 @@ void Java_org_deadc0de_apple2ix_Apple2Activity_nativeGraphicsInitialized(JNIEnv
 }
 
 void Java_org_deadc0de_apple2ix_Apple2Activity_nativeOnResume(JNIEnv *env, jobject obj, jboolean isSystemResume) {
-    if (!nativePaused) {
-#warning FIXME ... replace nativePaused check with cpu_isPaused()
+    if (!cpu_isPaused()) {
         return;
     }
     LOG("%s", "native onResume...");
-    if (isSystemResume) {
-        if (video_backend->animation_showPaused) {
-            video_backend->animation_showPaused();
-        }
-    } else {
-        nativePaused = false;
+    if (!isSystemResume) {
         cpu_resume();
     }
 }
 
-void Java_org_deadc0de_apple2ix_Apple2Activity_nativeOnPause(JNIEnv *env, jobject obj) {
-    if (nativePaused) {
+void Java_org_deadc0de_apple2ix_Apple2Activity_nativeOnPause(JNIEnv *env, jobject obj, jboolean isSystemPause) {
+    if (cpu_isPaused()) {
         return;
     }
-    nativePaused = true;
     LOG("%s", "native onPause...");
 
-    cpu_pause();
+    if (isSystemPause) {
+        // going to background
+        cpu_pauseBackground();
+    } else {
+        // going to menu
+        cpu_pause();
+    }
 }
 
 void Java_org_deadc0de_apple2ix_Apple2Activity_nativeRender(JNIEnv *env, jobject obj) {
@@ -191,7 +189,7 @@ void Java_org_deadc0de_apple2ix_Apple2Activity_nativeRender(JNIEnv *env, jobject
         return;
     }
 
-    if (!nativePaused) {
+    if (!cpu_isPaused()) {
         c_keys_handle_input(-1, 0, 0);
     }
 
@@ -289,9 +287,8 @@ jboolean Java_org_deadc0de_apple2ix_Apple2Activity_nativeOnTouch(JNIEnv *env, jo
         return true;
     }
 
-    if (nativePaused) {
+    if (cpu_isPaused()) {
         LOG("UNPAUSING NATIVE CPU THREAD");
-        nativePaused = false;
         cpu_resume();
         return true;
     }

src/common.h

@@ -269,6 +269,16 @@ static const char *log_end = "\n";
         _LOG(__VA_ARGS__); \
     } while (0)
 
+#define RELEASE_BREAK() \
+    do { \
+        /* BOOM */ \
+        char *ptr = (char *)0xABADF000; \
+        *ptr = '\0';\
+        /* or if that worked, just deref NULL */ \
+        ptr = (char *)0x0; \
+        *ptr = '\0'; \
+    } while (0);
+
 #define FREE(x) \
     do { \
         free((x)); \

src/timing.c

@@ -81,7 +81,10 @@ bool alt_speed_enabled = false;
 
 // misc
 volatile uint8_t emul_reinitialize = 1;
-unsigned long emul_reinitialize_audio = 1UL;
+bool emul_reinitialize_audio = 1UL;
+#if MOBILE_DEVICE
+static bool emul_reinitialize_background = true;
+#endif
 pthread_t cpu_thread_id = 0;
 pthread_mutex_t interface_mutex = { 0 };
 pthread_cond_t dbg_thread_cond = PTHREAD_COND_INITIALIZER;
@@ -170,35 +173,48 @@ void timing_toggleCPUSpeed(void) {
 
 void timing_reinitializeAudio(void) {
     assert(cpu_isPaused() || (pthread_self() == cpu_thread_id));
-    __sync_fetch_and_or(&emul_reinitialize_audio, 1UL);
+    emul_reinitialize_audio = true;
 }
 
 void cpu_pause(void) {
+
+    assert(pthread_self() != cpu_thread_id);
     _LOCK_CPU_THREAD();
+#if MOBILE_DEVICE
+    if (emul_reinitialize_background) {
+        RELEASE_LOG("CPU thread already paused ...");
+        _UNLOCK_CPU_THREAD();
+        return;
+    }
+#endif
+
 #ifdef AUDIO_ENABLED
     audio_pause();
 #endif
     is_paused = true;
 }
 
-static void _cpu_thread_really_start(void) {
-    int err = 0;
-    if ( (err = pthread_cond_signal(&cpu_thread_cond)) ) {
-        ERRLOG("pthread_cond_signal : %d", err);
-    }
+#if MOBILE_DEVICE
+void cpu_pauseBackground(void) {
+    assert(pthread_self() != cpu_thread_id);
+    _LOCK_CPU_THREAD();
+    emul_reinitialize_background = true;
+    _UNLOCK_CPU_THREAD();
 }
+#endif
 
 void cpu_resume(void) {
+    assert(pthread_self() != cpu_thread_id);
     assert(cpu_isPaused());
     is_paused = false;
 
-    static pthread_once_t onceToken = PTHREAD_ONCE_INIT;
-    if (onceToken == PTHREAD_ONCE_INIT) {
-        int err = 0;
-        if ( (err = pthread_once(&onceToken, _cpu_thread_really_start)) ) {
-            ERRLOG("pthread_once : %d", err);
-        }
+#if MOBILE_DEVICE
+    int err = pthread_cond_signal(&cpu_thread_cond);
+    if (err) {
+        RELEASE_ERRLOG("pthread_cond_signal : %d", err);
+        RELEASE_BREAK();
     }
+#endif
 
 #ifdef AUDIO_ENABLED
     audio_resume();
@@ -243,20 +259,46 @@ void *cpu_thread(void *dummyptr) {
     unsigned int dbg_cycles_executed = 0;
 #endif
 
-#if !TESTING
-    pthread_mutex_lock(&interface_mutex);
-    int err = 0;
-    LOG("cpu_thread : waiting for splash screen completion...");
-    pthread_cond_wait(&cpu_thread_cond, &interface_mutex);
-    pthread_mutex_unlock(&interface_mutex);
-    LOG("cpu_thread : starting...");
-#endif
-
     do
     {
+#if MOBILE_DEVICE && !TESTING
+        if (emul_reinitialize_background) {
+
+            speaker_destroy();
+            MB_Destroy();
+            audio_shutdown();
+
+            int err = TEMP_FAILURE_RETRY(pthread_mutex_lock(&interface_mutex));
+            if (err) {
+                RELEASE_LOG("Error locking CPU mutex : %d", err);
+                RELEASE_BREAK();
+            }
+
+            is_paused = true;
+            emul_reinitialize_background = false;
+
+            LOG("cpu_thread : waiting for splash screen completion...");
+            err = pthread_cond_wait(&cpu_thread_cond, &interface_mutex);
+            if (err) {
+                RELEASE_LOG("Error waiting for CPU condition : %d", err);
+                RELEASE_BREAK();
+            }
+
+            err = TEMP_FAILURE_RETRY(pthread_mutex_unlock(&interface_mutex));
+            if (err) {
+                RELEASE_LOG("Error unlocking CPU mutex : %d", err);
+                RELEASE_BREAK();
+            }
+
+            LOG("cpu_thread : starting...");
+            emul_reinitialize_audio = true;
+        }
+#endif
+
 #ifdef AUDIO_ENABLED
-        bool reinit_audio = __sync_fetch_and_and(&emul_reinitialize_audio, 0UL);
-        if (reinit_audio) {
+        if (emul_reinitialize_audio) {
+            emul_reinitialize_audio = false;
+
             speaker_destroy();
             MB_Destroy();
             audio_shutdown();
@@ -266,6 +308,7 @@ void *cpu_thread(void *dummyptr) {
             MB_Initialize();
         }
 #endif
+
         if (emul_reinitialize) {
             reinitialize();
         }
@@ -457,6 +500,12 @@ void *cpu_thread(void *dummyptr) {
                 break;
             }
 
+#if MOBILE_DEVICE
+            if (UNLIKELY(emul_reinitialize_background)) {
+                break;
+            }
+#endif
+
             if (UNLIKELY(emulator_shutting_down)) {
                 break;
             }

src/timing.h

@@ -74,7 +74,7 @@ struct timespec timespec_diff(struct timespec start, struct timespec end, bool *
  */
 void timing_toggleCPUSpeed(void);
 
-#if !defined(MOBILE_DEVICE)
+#if !MOBILE_DEVICE
 /*
  * check whether automatic adjusting of CPU speed is configured.
  */
@@ -97,10 +97,26 @@ void timing_reinitializeAudio(void);
 void *cpu_thread(void *ignored);
 
 /*
- * Pause timing/CPU thread
+ * Pause timing/CPU thread.
+ *
+ * This may block for a short amount of time to grab the appropriate mutex.  CPU thread is blocked upon function return,
+ * until call to cpu_resume() is made.
  */
 void cpu_pause(void);
 
+#if MOBILE_DEVICE
+/*
+ * Pause timing/CPU thread because of a system backgrounding event.
+ *
+ * This may block for a short amount of time to grab the appropriate mutex, toggle a dirty bit, and release the mutex.
+ * NOTE: CPU thread is not likely to actually be paused upon function return, (but will be shortly thereafter).
+ *
+ * This should also destroy/free any audio resources (speaker, mockingboard) managed by the CPU thread back to system.
+ * Audio resources will be automatically recreated upon call to cpu_resume()
+ */
+void cpu_pauseBackground(void);
+#endif
+
 /*
  * Resume timing/CPU thread
  */