Java DBTAdapter + DBTDevice close @ JVM shutdown: Avoid all interaction, native dtor (deleteImpl) cleans up.

Shortcut of 'close' take-down @ JVM shutdown, avoiding any potential deadlocks.

However, all device's and adapter's deleteImpl() gets issued,
allowing the native adapter's destructor to be called for orderly device cleanup.

3 files changed, 54 insertions, 31 deletions

diff --git a/java/direct_bt/tinyb/DBTAdapter.java b/java/direct_bt/tinyb/DBTAdapter.java
index 637fec05..46879a67 100644
--- a/java/direct_bt/tinyb/DBTAdapter.java
+++ b/java/direct_bt/tinyb/DBTAdapter.java
@@ -87,24 +87,41 @@ public class DBTAdapter extends DBTObject implements BluetoothAdapter
 
     @Override
     public synchronized void close() {
+        close(false);
+    }
+
+    /* pp */ synchronized void close(final boolean isShutdown) {
         if( !isValid() ) {
             return;
         }
-        stopDiscovery();
+        if( !isShutdown ) { // avoid all interaction @ JVM shutdown, native dtor (deleteImpl) cleans up.
 
-        final List<BluetoothDevice> devices = getDevices();
-        for(final Iterator<BluetoothDevice> id = devices.iterator(); id.hasNext(); ) {
-            final BluetoothDevice d = id.next();
-            d.close();
-        }
+            // mute all listener first
+            removeAllStatusListener();
+            disableDiscoverableNotifications();
+            disableDiscoveringNotifications();
+            disablePairableNotifications();
+            disablePoweredNotifications();
+
+            stopDiscovery();
+
+            final List<BluetoothDevice> devices = getDevices();
+            for(final Iterator<BluetoothDevice> id = devices.iterator(); id.hasNext(); ) {
+                final DBTDevice d = (DBTDevice) id.next();
+                d.close( false );
+            }
+
+            // done in native dtor: removeDevicesImpl();
 
-        removeAllStatusListener();
-        disableDiscoverableNotifications();
-        disableDiscoveringNotifications();
-        disablePairableNotifications();
-        disablePoweredNotifications();
+        } else {
 
-        removeDevicesImpl();
+            final List<BluetoothDevice> devices = getDevices();
+            for(final Iterator<BluetoothDevice> id = devices.iterator(); id.hasNext(); ) {
+                final DBTDevice d = (DBTDevice) id.next();
+                d.close( true );
+            }
+
+        }
         discoveredDevices.clear();
 
         super.close();
diff --git a/java/direct_bt/tinyb/DBTDevice.java b/java/direct_bt/tinyb/DBTDevice.java
index a98636bb..1f9ec3be 100644
--- a/java/direct_bt/tinyb/DBTDevice.java
+++ b/java/direct_bt/tinyb/DBTDevice.java
@@ -233,30 +233,36 @@ public class DBTDevice extends DBTObject implements BluetoothDevice
 
     @Override
     public synchronized void close() {
+        close(false);
+    }
+
+    /* pp */ synchronized void close(final boolean isShutdown) {
         if( !isValid() ) {
             return;
         }
-        disconnect();
+        if( !isShutdown ) { // avoid all interaction @ JVM shutdown, native dtor (deleteImpl) cleans up.
+            disconnect();
 
-        disableConnectedNotifications();
-        disableRSSINotifications();
-        disableManufacturerDataNotifications();
-        disableServicesResolvedNotifications();
+            disableConnectedNotifications();
+            disableRSSINotifications();
+            disableManufacturerDataNotifications();
+            disableServicesResolvedNotifications();
 
-        disableBlockedNotifications();
-        disableBlockedNotificationsImpl();
-        disablePairedNotifications();
-        disablePairedNotificationsImpl();
-        disableServiceDataNotifications();
-        disableTrustedNotifications();
-        // FIXME disableTrustedNotificationsImpl();
+            disableBlockedNotifications();
+            disableBlockedNotificationsImpl();
+            disablePairedNotifications();
+            disablePairedNotificationsImpl();
+            disableServiceDataNotifications();
+            disableTrustedNotifications();
+            // FIXME disableTrustedNotificationsImpl();
 
-        clearServiceCache();
+            clearServiceCache();
 
-        final DBTAdapter a = getAdapter();
-        if( null != a ) {
-            a.removeStatusListener(statusListener);
-            a.removeDiscoveredDevice(this);
+            final DBTAdapter a = getAdapter();
+            if( null != a ) {
+                a.removeStatusListener(statusListener);
+                a.removeDiscoveredDevice(this);
+            }
         }
         super.close();
     }
diff --git a/java/direct_bt/tinyb/DBTManager.java b/java/direct_bt/tinyb/DBTManager.java
index 8dee59a5..45faed64 100644
--- a/java/direct_bt/tinyb/DBTManager.java
+++ b/java/direct_bt/tinyb/DBTManager.java
@@ -315,8 +315,8 @@ public class DBTManager implements BluetoothManager
     @Override
     public void shutdown() {
         for(final Iterator<BluetoothAdapter> ia= adapters.iterator(); ia.hasNext(); ) {
-            final BluetoothAdapter a = ia.next();
-            a.close();
+            final DBTAdapter a = (DBTAdapter)ia.next();
+            a.close( true );
         }
         adapters.clear();
         deleteImpl(nativeInstance);