Support Adapter removal and add @ runtime: Handle INDEX_ADDED and INDEX_REMOVED Mgmt events

C++ DBTManager detects INDEX_ADDED and INDEX_REMOVED Mgmt events

@INDEX_ADDED reception in the event reader, a new processAdapterAdded() thread is spawned
initializing the adapter as usual and maintaining adding its AdapterInfo artifact.
Then all user INDEX_ADDED callbacks are called from this thread,
after the new AdapterInfo entry has been added.

@INDEX_REMOVED here the matching AdapterInfo entry is simply removed

DBTAdapter naturally also listens to INDEX_REMOVED,
simply closing its instance and hence rendering it isValid() = false.

+++

On close(), Java's DBTAdapter will remove itself
from the DBTManager's adapter list.
This removal will happen automatically,
if INDEX_REMOVED is received - see below.

On the Java side, DBTManager listens to:

@INDEX_REMOVED here the matching adapter instance is simply removed

@INDEX_ADDED and @NEW_SETTINGS(POWERED) checks whether the matching adapter instance
exists and creates a new one added to the adapters list if necessary.

@NEW_SETTINGS(POWERED) has been added here as well, since a user could
chose to close the adapter if POWERED off and hence removing itself
from the DBTManager adapter list.

Hence NEW_SETTINGS(POWERED) will add a new adapter instance, if none exists.

+++

Due to this new concurrent use-case of the adapter list,
the list is now a CopyOnWriteArrayList instance supporting lock-free fast reads.
Mutations of the list occur rarely, hopefully ;-).

On the C++, the AdapterInfo is a jau::cow_vector and the callbacks are
store in a jau::cow_vector as well (MgmtAdapterEventCallbackList).
Hence both share the same properties w/ the Java side: Fast lock-free reads.

2 files changed, 98 insertions, 52 deletions

diff --git a/examples/direct_bt_scanner10/dbt_scanner10.cpp b/examples/direct_bt_scanner10/dbt_scanner10.cpp
index b89c498b..9a9d162b 100644
--- a/examples/direct_bt_scanner10/dbt_scanner10.cpp
+++ b/examples/direct_bt_scanner10/dbt_scanner10.cpp
@@ -506,40 +506,54 @@ static bool startDiscovery(DBTAdapter *a, std::string msg) {
     return HCIStatusCode::SUCCESS == status;
 }
 
-void test(int dev_id) {
-    bool done = false;
-
-    timestamp_t0 = getCurrentMilliseconds();
-
-    DBTAdapter adapter(dev_id); // given dev_id >= 0 or default adapter (1st powered)
-    if( !adapter.hasDevId() ) {
-        fprintf(stderr, "Default adapter not available.\n");
-        exit(1);
+static std::shared_ptr<DBTAdapter> createAdapter(const int dev_id0) {
+    // pre-validate dev_id availability
+    int dev_id;
+    DBTManager & mngr = DBTManager::get(BTMode::LE);
+    if( 0 > dev_id0 ) {
+        dev_id = mngr.getDefaultAdapterDevID();
+    } else if( nullptr != mngr.getAdapterInfo(dev_id0) ) {
+        dev_id = dev_id0;
+    } else {
+        dev_id = -1;
+    }
+    if( 0 > dev_id ) {
+        fprintf(stderr, "Adapter not available (1): Request %d, deduced %d\n", dev_id0, dev_id);
+        return nullptr;
     }
-    if( !adapter.isValid() ) {
-        fprintf(stderr, "Adapter invalid.\n");
-        exit(1);
+
+    std::shared_ptr<DBTAdapter> adapter(new DBTAdapter(dev_id)); // given dev_id >= 0 or default adapter (1st powered)
+    if( !adapter->hasDevId() ) {
+        fprintf(stderr, "Adapter not available (2): %d\n", dev_id); // should have been covered above
+        return nullptr;
     }
-    if( !adapter.isEnabled() ) {
-        fprintf(stderr, "Adapter not enabled: device %s, address %s: %s\n",
-                adapter.getName().c_str(), adapter.getAddressString().c_str(), adapter.toString().c_str());
-        exit(1);
+    if( !adapter->isPowered() ) { // should have been covered above
+        fprintf(stderr, "Adapter not powered (2): %s\n", adapter->toString().c_str());
+        return nullptr;
     }
-    fprintf(stderr, "Using adapter: device %s, address %s: %s\n",
-        adapter.getName().c_str(), adapter.getAddressString().c_str(), adapter.toString().c_str());
+    fprintf(stderr, "Using adapter: %s\n", adapter->toString().c_str());
 
-    adapter.addStatusListener(std::shared_ptr<AdapterStatusListener>(new MyAdapterStatusListener()));
+    adapter->addStatusListener(std::shared_ptr<AdapterStatusListener>(new MyAdapterStatusListener()));
 
     if( USE_WHITELIST ) {
         for (auto it = WHITELIST.begin(); it != WHITELIST.end(); ++it) {
-            bool res = adapter.addDeviceToWhitelist(*it, BDAddressType::BDADDR_LE_PUBLIC, HCIWhitelistConnectType::HCI_AUTO_CONN_ALWAYS);
+            bool res = adapter->addDeviceToWhitelist(*it, BDAddressType::BDADDR_LE_PUBLIC, HCIWhitelistConnectType::HCI_AUTO_CONN_ALWAYS);
             fprintf(stderr, "Added to WHITELIST: res %d, address %s\n", res, it->toString().c_str());
         }
     } else {
-        if( !startDiscovery(&adapter, "kick-off") ) {
-            done = true;
+        if( !startDiscovery(adapter.get(), "kick-off") ) {
+            return nullptr;
         }
     }
+    return adapter;
+}
+
+void test(int dev_id) {
+    bool done = false;
+
+    timestamp_t0 = getCurrentMilliseconds();
+
+    std::shared_ptr<DBTAdapter> adapter = createAdapter(dev_id);
 
     while( !done ) {
         if( 0 == MULTI_MEASUREMENTS ||
@@ -552,14 +566,29 @@ void test(int dev_id) {
             printDevicesProcessed("****** DevicesProcessed ");
             done = true;
         } else {
-            std::this_thread::sleep_for(std::chrono::milliseconds(3000));
+            // validate existing adapter
+            if( nullptr != adapter ) {
+                if( !adapter->isValid() /* || !adapter->isPowered() */ ) {
+                    // In case of removed adapter, not just powered-off (soft-reset)
+                    // We could also close adapter on !isPowered() here, but its not required - adapter operational.
+                    adapter->close();
+                    adapter = nullptr; // purge
+                }
+            }
+            // re-create adapter if required
+            if( nullptr == adapter ) {
+                adapter = createAdapter(dev_id);
+            }
+            std::this_thread::sleep_for(std::chrono::milliseconds(2000));
         }
     }
-    fprintf(stderr, "****** EOL Adapter's Devices - pre close\n");
-    adapter.printSharedPtrListOfDevices();
-    adapter.close();
-    fprintf(stderr, "****** EOL Adapter's Devices - post close\n");
-    adapter.printSharedPtrListOfDevices();
+    fprintf(stderr, "****** EOL Adapter's Devices - pre close: %s\n", adapter->toString().c_str());
+    if( nullptr != adapter ) {
+        adapter->printSharedPtrListOfDevices();
+        adapter->close();
+        fprintf(stderr, "****** EOL Adapter's Devices - post close\n");
+        adapter->printSharedPtrListOfDevices();
+    }
 }
 
 #include <cstdio>
diff --git a/examples/java/DBTScanner10.java b/examples/java/DBTScanner10.java
index 5988f5d6..7c490f24 100644
--- a/examples/java/DBTScanner10.java
+++ b/examples/java/DBTScanner10.java
@@ -525,29 +525,27 @@ public class DBTScanner10 {
         return HCIStatusCode.SUCCESS == status;
     }
 
-    public void runTest(final BluetoothManager manager) {
-        final BluetoothAdapter adapter;
-        {
-            final List<BluetoothAdapter> adapters = manager.getAdapters();
-            for(int i=0; i < adapters.size(); i++) {
-                println("Adapter["+i+"]: "+adapters.get(i));
-            }
-            if( adapters.size() <= dev_id ) {
-                println("No adapter dev_id "+dev_id+" available, adapter count "+adapters.size());
-                System.exit(-1);
-            }
-            if( 0 > dev_id ) {
-                adapter = manager.getDefaultAdapter();
-            } else {
-                adapter = adapters.get(dev_id);
-            }
-            if( !adapter.isEnabled() ) {
-                println("Adapter not enabled: device "+adapter.getName()+", address "+adapter.getAddress()+": "+adapter.toString());
-                System.exit(-1);
+    private BluetoothAdapter createAdapter(final BluetoothManager mngr, final int dev_id0) {
+        BluetoothAdapter adapter;
+        if( 0 > dev_id0 ) {
+            adapter = mngr.getDefaultAdapter();
+        } else {
+            adapter = mngr.getAdapter(dev_id0);
+            if( !adapter.isPowered() ) {
+                adapter = mngr.getDefaultAdapter();
             }
         }
+        final int dev_id = null != adapter ? adapter.getDevID() : -1;
+        if( 0 > dev_id ) {
+            println("Adapter not available (1): Request "+dev_id0+", deduced "+dev_id);
+            return null;
+        }
 
-        timestamp_t0 = BluetoothUtils.currentTimeMillis();
+        if( !adapter.isPowered() ) { // should have been covered above
+            println("Adapter not powered (2): "+adapter.toString());
+            return null;
+        }
+        println("Using adapter: "+adapter.toString());
 
         adapter.addStatusListener(statusListener, null);
         adapter.enableDiscoverableNotifications(new BooleanNotification("Discoverable", timestamp_t0));
@@ -558,8 +556,6 @@ public class DBTScanner10 {
 
         adapter.enablePoweredNotifications(new BooleanNotification("Powered", timestamp_t0));
 
-        boolean done = false;
-
         if( USE_WHITELIST ) {
             for(final Iterator<String> wliter = whitelist.iterator(); wliter.hasNext(); ) {
                 final String addr = wliter.next();
@@ -568,9 +564,17 @@ public class DBTScanner10 {
             }
         } else {
             if( !startDiscovery(adapter, "kick-off") ) {
-                done = true;
             }
         }
+        return adapter;
+    }
+
+    public void runTest(final BluetoothManager manager) {
+        BluetoothAdapter adapter = createAdapter(manager, dev_id);
+
+        timestamp_t0 = BluetoothUtils.currentTimeMillis();
+
+        boolean done = false;
 
         while( !done ) {
             if( 0 == MULTI_MEASUREMENTS.get() ||
@@ -583,8 +587,21 @@ public class DBTScanner10 {
                 println("****** DevicesProcessed "+Arrays.toString(devicesProcessed.toArray()));
                 done = true;
             } else {
+                // validate existing adapter
+                if( null != adapter ) {
+                    if( !adapter.isValid() /* || !adapter.isPowered() */ ) {
+                        // In case of removed adapter, not just powered-off (soft-reset)
+                        // We could also close adapter on !isPowered() here, but its not required - adapter operational.
+                        adapter.close();
+                        adapter = null; // purge
+                    }
+                }
+                // re-create adapter if required
+                if( null == adapter ) {
+                    adapter = createAdapter(manager, dev_id);
+                }
                 try {
-                    Thread.sleep(3000);
+                    Thread.sleep(2000);
                 } catch (final InterruptedException e) {
                     e.printStackTrace();
                 }