Add ChangedAdapterSetCallback (C++), ChangedAdapterSetListener (Java) for [DBT|Bluetooth]Manager, enabling fully event driven workflow w/ adapter add/remove

9 files changed, 418 insertions, 84 deletions

diff --git a/api/direct_bt/DBTAdapter.hpp b/api/direct_bt/DBTAdapter.hpp
index 532f9e2d..86fcbc16 100644
--- a/api/direct_bt/DBTAdapter.hpp
+++ b/api/direct_bt/DBTAdapter.hpp
@@ -280,7 +280,7 @@ namespace direct_bt {
              * Using the default adapter device
              * <p>
              * The default adapter is either the first POWERED adapter,
-             * or the one with index == dev_id == 0.
+             * or none - in which case this instance !isValid()
              * </p>
              */
             DBTAdapter() noexcept;
@@ -297,7 +297,7 @@ namespace direct_bt {
              * or the default adapter device if dev_id < 0.
              * <p>
              * The default adapter is either the first POWERED adapter,
-             * or the one with index == dev_id == 0.
+             * or none - in which case this instance !isValid().
              * </p>
              *
              * @param[in] dev_id an already identified HCI device id
diff --git a/api/direct_bt/DBTManager.hpp b/api/direct_bt/DBTManager.hpp
index c1b351d2..7d28344f 100644
--- a/api/direct_bt/DBTManager.hpp
+++ b/api/direct_bt/DBTManager.hpp
@@ -136,6 +136,57 @@ namespace direct_bt {
     };
 
     /**
+     * Callback function to receive change events regarding the system's adapter set,
+     * e.g. about a removed or added adapter due to user interaction or 'cold reset'.
+     * <p>
+     * When a new callback is added, all available adapter's will be reported as added,
+     * this allows a fully event driven workflow.
+     * </p>
+     * <p>
+     * Note that the 'adapter added' callback, i.e. 'added==true',
+     * is performed on a dedicated thread allowing the user to perform complex operations.
+     * </p>
+     * <p>
+     * User shall not perform complex operations on the 'adapter removed' callback,
+     * i.e. 'added==false'.
+     * </p>
+     *
+     * @param added true if adapter was newly added, otherwise removed from system
+     * @param adapterInfo the adapter's AdapterInfo, inclusive the dev_id
+     * @return ignored
+     * @see ChangedAdapterSetCallback
+     * @see DBTManager::addChangedAdapterSetCallback()
+     * @see DBTManager::removeChangedAdapterSetCallback()
+     */
+    typedef bool (*ChangedAdapterSetFunc)(bool added, const AdapterInfo& adapterInfo);
+
+    /**
+     * Callback jau::FunctionDef to receive change events regarding the system's adapter set,
+     * e.g. about a removed or added adapter due to user interaction or 'cold reset'.
+     * <p>
+     * When a new callback is added, all available adapter's will be reported as added,
+     * this allows a fully event driven workflow.
+     * </p>
+     * <p>
+     * Note that the 'adapter added' callback, i.e. 'added==true',
+     * is performed on a dedicated thread allowing the user to perform complex operations.
+     * </p>
+     * <p>
+     * User shall not perform complex operations on the 'adapter removed' callback,
+     * i.e. 'added==false'.
+     * </p>
+     *
+     * @param added true if adapter was newly added, otherwise removed from system
+     * @param adapterInfo the adapter's AdapterInfo, inclusive the dev_id
+     * @return ignored
+     * @see ChangedAdapterSetFunc
+     * @see DBTManager::addChangedAdapterSetCallback()
+     * @see DBTManager::removeChangedAdapterSetCallback()
+     */
+    typedef jau::FunctionDef<bool, bool, const AdapterInfo&> ChangedAdapterSetCallback;
+    typedef jau::cow_vector<ChangedAdapterSetCallback> ChangedAdapterSetCallbackList;
+
+    /**
      * A thread safe singleton handler of the Linux Kernel's BlueZ manager control channel.
      * <p>
      * Implementation utilizes a lock free ringbuffer receiving data within its separate thread.
@@ -187,6 +238,8 @@ namespace direct_bt {
                 return static_cast<uint16_t>(opc) < mgmtAdapterEventCallbackLists.size();
             }
 
+            ChangedAdapterSetCallbackList mgmtChangedAdapterSetCallbackList;
+
             jau::cow_vector<std::shared_ptr<AdapterInfo>> adapterInfos;
             void mgmtReaderThreadImpl() noexcept;
 
@@ -226,6 +279,18 @@ namespace direct_bt {
             bool mgmtEvPinCodeRequestCB(std::shared_ptr<MgmtEvent> e) noexcept;
             bool mgmtEvUserPasskeyRequestCB(std::shared_ptr<MgmtEvent> e) noexcept;
 
+            /**
+             * Adds the given AdapterInfo if representing a new dev_id.
+             * @return true if newly added dev_id, otherwise false if dev_id already exists.
+             */
+            bool addAdapterInfo(std::shared_ptr<AdapterInfo> ai) noexcept;
+
+            /**
+             * Removes the AdapterInfo with the given dev_id
+             * @return the removed instance or nullptr if not found.
+             */
+            std::shared_ptr<AdapterInfo> removeAdapterInfo(const uint16_t dev_id) noexcept;
+
         public:
             /**
              * Retrieves the singleton instance.
@@ -296,18 +361,6 @@ namespace direct_bt {
             std::shared_ptr<AdapterInfo> getAdapterInfo(const uint16_t dev_id) const noexcept;
 
             /**
-             * Adds the given AdapterInfo if representing a new dev_id.
-             * @return true if newly added dev_id, otherwise false if dev_id already exists.
-             */
-            bool addAdapterInfo(std::shared_ptr<AdapterInfo> ai) noexcept;
-
-            /**
-             * Removes the AdapterInfo with the given dev_id
-             * @return the removed instance or nullptr if not found.
-             */
-            std::shared_ptr<AdapterInfo> removeAdapterInfo(const uint16_t dev_id) noexcept;
-
-            /**
              * Returns the current BTMode of given adapter dev_idx or BTMode::NONE if dev_id adapter is not available.
              */
             BTMode getCurrentBTMode(uint16_t dev_id) const noexcept;
@@ -410,6 +463,56 @@ namespace direct_bt {
 
             /** Manually send a MgmtEvent to all of its listeners. */
             void sendMgmtEvent(std::shared_ptr<MgmtEvent> event) noexcept;
+
+            /** ChangedAdapterSetCallback handling */
+
+            /**
+             * Adds the given ChangedAdapterSetCallback to this manager.
+             * <p>
+             * When a new callback is added, all available adapter's will be reported as added,
+             * this allows a fully event driven workflow.
+             * </p>
+             * <p>
+             * Note that the 'adapter added' callback, i.e. 'added==true',
+             * is performed on a dedicated thread allowing the user to perform complex operations.
+             * </p>
+             * <p>
+             * User shall not perform complex operations on the 'adapter removed' callback,
+             * i.e. 'added==false'.
+             * </p>
+             */
+            void addChangedAdapterSetCallback(const ChangedAdapterSetCallback & l);
+
+            /**
+             * Remove the given ChangedAdapterSetCallback from this manager.
+             * @param l the to be removed element
+             * @return the number of removed elements
+             */
+            int removeChangedAdapterSetCallback(const ChangedAdapterSetCallback & l);
+
+            /**
+             * Adds the given ChangedAdapterSetFunc to this manager.
+             * <p>
+             * When a new callback is added, all available adapter's will be reported as added,
+             * this allows a fully event driven workflow.
+             * </p>
+             * <p>
+             * Note that the 'adapter added' callback, i.e. 'added==true',
+             * is performed on a dedicated thread allowing the user to perform complex operations.
+             * </p>
+             * <p>
+             * User shall not perform complex operations on the 'adapter removed' callback,
+             * i.e. 'added==false'.
+             * </p>
+             */
+            void addChangedAdapterSetCallback(ChangedAdapterSetFunc f);
+
+            /**
+             * Remove the given ChangedAdapterSetFunc from this manager.
+             * @param l the to be removed element
+             * @return the number of removed elements
+             */
+            int removeChangedAdapterSetCallback(ChangedAdapterSetFunc f);
     };
 
 } // namespace direct_bt
diff --git a/examples/direct_bt_scanner10/dbt_scanner10.cpp b/examples/direct_bt_scanner10/dbt_scanner10.cpp
index 9a9d162b..4c95f823 100644
--- a/examples/direct_bt_scanner10/dbt_scanner10.cpp
+++ b/examples/direct_bt_scanner10/dbt_scanner10.cpp
@@ -506,16 +506,20 @@ static bool startDiscovery(DBTAdapter *a, std::string msg) {
     return HCIStatusCode::SUCCESS == status;
 }
 
-static std::shared_ptr<DBTAdapter> createAdapter(const int dev_id0) {
+static std::shared_ptr<DBTAdapter> createAdapter(const int dev_id0, const bool validate_dev_id) {
     // 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;
+    if( validate_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;
+        }
     } else {
-        dev_id = -1;
+        dev_id = dev_id0;
     }
     if( 0 > dev_id ) {
         fprintf(stderr, "Adapter not available (1): Request %d, deduced %d\n", dev_id0, dev_id);
@@ -531,7 +535,6 @@ static std::shared_ptr<DBTAdapter> createAdapter(const int dev_id0) {
         fprintf(stderr, "Adapter not powered (2): %s\n", adapter->toString().c_str());
         return nullptr;
     }
-    fprintf(stderr, "Using adapter: %s\n", adapter->toString().c_str());
 
     adapter->addStatusListener(std::shared_ptr<AdapterStatusListener>(new MyAdapterStatusListener()));
 
@@ -548,12 +551,68 @@ static std::shared_ptr<DBTAdapter> createAdapter(const int dev_id0) {
     return adapter;
 }
 
-void test(int dev_id) {
+static jau::cow_vector<std::shared_ptr<DBTAdapter>> adapterList;
+
+static std::shared_ptr<DBTAdapter> getAdapter(const uint16_t dev_id) {
+    std::shared_ptr<std::vector<std::shared_ptr<DBTAdapter>>> snapshot = adapterList.get_snapshot();
+    auto begin = snapshot->begin();
+    auto it = std::find_if(begin, snapshot->end(), [&](std::shared_ptr<DBTAdapter> const& p) -> bool {
+        return p->dev_id == dev_id;
+    });
+    if ( it == std::end(*snapshot) ) {
+        return nullptr;
+    } else {
+        return *it;
+    }
+}
+static int removeAdapter(const uint16_t dev_id) {
+    const std::lock_guard<std::recursive_mutex> lock(adapterList.get_write_mutex());
+    std::shared_ptr<std::vector<std::shared_ptr<DBTAdapter>>> store = adapterList.copy_store();
+    int count = 0;
+    for(auto it = store->begin(); it != store->end(); ) {
+        if ( (*it)->dev_id == dev_id ) {
+            it = store->erase(it);
+            count++;
+        } else {
+            ++it;
+        }
+    }
+    if( 0 < count ) {
+        adapterList.set_store(std::move(store));
+    }
+    return count;
+}
+
+static bool myChangedAdapterSetFunc(const bool added, const AdapterInfo& adapterInfo) {
+    if( added ) {
+        std::shared_ptr<DBTAdapter> pre = getAdapter(adapterInfo.dev_id);
+        if( nullptr != pre ) {
+            fprintf(stderr, "****** Adapter ADDED__: Not new %s\n", pre->toString().c_str());
+        } else {
+            if( adapterInfo.isCurrentSettingBitSet(AdapterSetting::POWERED) ) {
+                std::shared_ptr<DBTAdapter> adapter = createAdapter(adapterInfo.dev_id, false /* validate_dev_id */);
+                if( nullptr != adapter ) {
+                    adapterList.push_back(adapter);
+                    fprintf(stderr, "****** Adapter ADDED__: Created %s\n", adapter->toString().c_str());
+                }
+            } else {
+                fprintf(stderr, "****** Adapter ADDED__: Ignored %s\n", adapterInfo.toString().c_str());
+            }
+        }
+    } else {
+        const int count = removeAdapter(adapterInfo.dev_id);
+        fprintf(stderr, "****** Adapter REMOVED: count %d, %s\n", count, adapterInfo.toString().c_str());
+    }
+    return true;
+}
+
+void test() {
     bool done = false;
 
     timestamp_t0 = getCurrentMilliseconds();
 
-    std::shared_ptr<DBTAdapter> adapter = createAdapter(dev_id);
+    DBTManager & mngr = DBTManager::get(BTMode::LE);
+    mngr.addChangedAdapterSetCallback(myChangedAdapterSetFunc);
 
     while( !done ) {
         if( 0 == MULTI_MEASUREMENTS ||
@@ -566,28 +625,22 @@ void test(int dev_id) {
             printDevicesProcessed("****** DevicesProcessed ");
             done = true;
         } else {
-            // 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: %s\n", adapter->toString().c_str());
-    if( nullptr != adapter ) {
+
+    jau::for_each_cow(adapterList, [](std::shared_ptr<DBTAdapter>& adapter) {
+        fprintf(stderr, "****** EOL Adapter's Devices - pre close: %s\n", adapter->toString().c_str());
         adapter->printSharedPtrListOfDevices();
         adapter->close();
         fprintf(stderr, "****** EOL Adapter's Devices - post close\n");
         adapter->printSharedPtrListOfDevices();
+    });
+    fprintf(stderr, "****** EOL Adapter's Devices - post close all\n");
+
+    {
+        int count = mngr.removeChangedAdapterSetCallback(myChangedAdapterSetFunc);
+        fprintf(stderr, "****** EOL Removed ChangedAdapterSetCallback %d\n", count);
     }
 }
 
@@ -595,7 +648,6 @@ void test(int dev_id) {
 
 int main(int argc, char *argv[])
 {
-    int dev_id = -1; // default
     BTMode btMode = BTMode::NONE;
     bool waitForEnter=false;
 
@@ -612,8 +664,6 @@ int main(int argc, char *argv[])
             setenv("direct_bt.hci", argv[++i], 1 /* overwrite */);
         } else if( !strcmp("-dbt_mgmt", argv[i]) && argc > (i+1) ) {
             setenv("direct_bt.mgmt", argv[++i], 1 /* overwrite */);
-        } else if( !strcmp("-dev_id", argv[i]) && argc > (i+1) ) {
-            dev_id = atoi(argv[++i]);
         } else if( !strcmp("-btmode", argv[i]) && argc > (i+1) ) {
             btMode = getBTMode(argv[++i]);
             if( BTMode::NONE != btMode ) {
@@ -650,7 +700,7 @@ int main(int argc, char *argv[])
     }
     fprintf(stderr, "pid %d\n", getpid());
 
-    fprintf(stderr, "Run with '[-dev_id <adapter-index>] [-btmode LE|BREDR|DUAL] "
+    fprintf(stderr, "Run with '[-btmode LE|BREDR|DUAL] "
                     "[-disconnect] [-enableGATTPing] [-count <number>] [-single] [-show_update_events] [-quiet] "
                     "[-resetEachCon connectionCount] "
                     "(-mac <device_address>)* (-wl <device_address>)* "
@@ -670,7 +720,6 @@ int main(int argc, char *argv[])
     fprintf(stderr, "USE_WHITELIST %d\n", USE_WHITELIST);
     fprintf(stderr, "SHOW_UPDATE_EVENTS %d\n", SHOW_UPDATE_EVENTS);
     fprintf(stderr, "QUIET %d\n", QUIET);
-    fprintf(stderr, "dev_id %d\n", dev_id);
     fprintf(stderr, "btmode %s\n", getBTModeString(btMode).c_str());
 
     printList( "waitForDevice: ", waitForDevices);
@@ -680,7 +729,7 @@ int main(int argc, char *argv[])
         getchar();
     }
     fprintf(stderr, "****** TEST start\n");
-    test(dev_id);
+    test();
     fprintf(stderr, "****** TEST end\n");
     if( true ) {
         // Just for testing purpose, i.e. triggering DBTManager::close() within the test controlled app,
diff --git a/examples/java/DBTScanner10.java b/examples/java/DBTScanner10.java
index 7c490f24..78283bc9 100644
--- a/examples/java/DBTScanner10.java
+++ b/examples/java/DBTScanner10.java
@@ -30,7 +30,10 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Consumer;
+import java.util.function.Predicate;
 
 import org.tinyb.AdapterSettings;
 import org.tinyb.BluetoothAdapter;
@@ -54,6 +57,7 @@ import org.tinyb.HCIStatusCode;
 import org.tinyb.HCIWhitelistConnectType;
 import org.tinyb.PairingMode;
 import org.tinyb.ScanType;
+import org.tinyb.BluetoothManager.ChangedAdapterSetListener;
 
 import direct_bt.tinyb.DBTManager;
 
@@ -87,8 +91,6 @@ public class DBTScanner10 {
     boolean SHOW_UPDATE_EVENTS = false;
     boolean QUIET = false;
 
-    int dev_id = -1; // use default
-
     int shutdownTest = 0;
 
     static void printf(final String format, final Object... args) {
@@ -525,25 +527,10 @@ public class DBTScanner10 {
         return HCIStatusCode.SUCCESS == status;
     }
 
-    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;
-        }
-
+    private boolean initAdapter(final BluetoothAdapter adapter) {
         if( !adapter.isPowered() ) { // should have been covered above
             println("Adapter not powered (2): "+adapter.toString());
-            return null;
+            return false;
         }
         println("Using adapter: "+adapter.toString());
 
@@ -564,18 +551,71 @@ public class DBTScanner10 {
             }
         } else {
             if( !startDiscovery(adapter, "kick-off") ) {
+                return false;
             }
         }
-        return adapter;
+        return true;
     }
 
-    public void runTest(final BluetoothManager manager) {
-        BluetoothAdapter adapter = createAdapter(manager, dev_id);
+    private final List<BluetoothAdapter> adapters = new CopyOnWriteArrayList<BluetoothAdapter>();
+
+    @SuppressWarnings("unused")
+    private BluetoothAdapter getAdapter(final int dev_id) {
+        for( int i=0; i<adapters.size(); i++) {
+            final BluetoothAdapter a = adapters.get(i);
+            if( dev_id == a.getDevID() ) {
+                return a;
+            }
+        }
+        return null;
+    }
+
+    private int removeAdapter(final int dev_id) {
+        // Using removeIf allows performing test on all object and remove within one write-lock cycle
+        final int count[] = { 0 };
+        adapters.removeIf(new Predicate<BluetoothAdapter>() {
+            @Override
+            public boolean test(final BluetoothAdapter t) {
+                if( dev_id == t.getDevID() ) {
+                    count[0]++;
+                    return true;
+                }
+                return false;
+            }
+        });
+        return count[0];
+    }
 
+    private final BluetoothManager.ChangedAdapterSetListener myChangedAdapterSetListener =
+            new BluetoothManager.ChangedAdapterSetListener() {
+                @Override
+                public void adapterAdded(final BluetoothAdapter adapter) {
+                    if( adapter.isPowered() ) {
+                        if( initAdapter( adapter ) ) {
+                            adapters.add(adapter);
+                            println("****** Adapter ADDED__: NewInit " + adapter);
+                        } else {
+                            println("****** Adapter ADDED__: Failed_ " + adapter);
+                        }
+                    } else {
+                        println("****** Adapter ADDED__: Ignored " + adapter);
+                    }
+                }
+
+                @Override
+                public void adapterRemoved(final BluetoothAdapter adapter) {
+                    final int count = removeAdapter(adapter.getDevID());
+                    println("****** Adapter REMOVED: count "+count+", " + adapter);
+                }
+    };
+
+    public void runTest(final BluetoothManager manager) {
         timestamp_t0 = BluetoothUtils.currentTimeMillis();
 
         boolean done = false;
 
+        manager.addChangedAdapterSetListener(myChangedAdapterSetListener);
+
         while( !done ) {
             if( 0 == MULTI_MEASUREMENTS.get() ||
                 ( -1 == MULTI_MEASUREMENTS.get() && !waitForDevices.isEmpty() && devicesProcessed.containsAll(waitForDevices) )
@@ -587,19 +627,6 @@ 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(2000);
                 } catch (final InterruptedException e) {
@@ -608,6 +635,19 @@ public class DBTScanner10 {
             }
         }
 
+        adapters.forEach(new Consumer<BluetoothAdapter>() {
+            @Override
+            public void accept(final BluetoothAdapter a) {
+                println("****** EOL Adapter's Devices - pre_ close: " + a);
+                a.close();
+                println("****** EOL Adapter's Devices - post close: " + a);
+            } } );
+
+        {
+            final int count = manager.removeChangedAdapterSetListener(myChangedAdapterSetListener);
+            println("****** EOL Removed ChangedAdapterSetCallback " + count);
+        }
+
         // All implicit via destructor or shutdown hook!
         // manager.shutdown(); /* implies: adapter.close(); */
     }
@@ -663,8 +703,6 @@ public class DBTScanner10 {
                     test.SHOW_UPDATE_EVENTS = true;
                 } else if( arg.equals("-quiet") ) {
                     test.QUIET = true;
-                } else if( arg.equals("-dev_id") && args.length > (i+1) ) {
-                    test.dev_id = Integer.valueOf(args[++i]).intValue();
                 } else if( arg.equals("-shutdown") && args.length > (i+1) ) {
                     test.shutdownTest = Integer.valueOf(args[++i]).intValue();
                 } else if( arg.equals("-mac") && args.length > (i+1) ) {
@@ -690,7 +728,7 @@ public class DBTScanner10 {
                     test.RESET_ADAPTER_EACH_CONN = Integer.valueOf(args[++i]).intValue();
                 }
             }
-            println("Run with '[-default_dev_id <adapter-index>] [-dev_id <adapter-index>] [-btmode LE|BREDR|DUAL] "+
+            println("Run with '[-btmode LE|BREDR|DUAL] "+
                     "[-bluetoothManager <BluetoothManager-Implementation-Class-Name>] "+
                     "[-disconnect] [-enableGATTPing] [-count <number>] [-single] (-char <uuid>)* [-show_update_events] [-quiet]  "+
                     "[-resetEachCon connectionCount] "+
@@ -714,7 +752,6 @@ public class DBTScanner10 {
         println("SHOW_UPDATE_EVENTS "+test.SHOW_UPDATE_EVENTS);
         println("QUIET "+test.QUIET);
 
-        println("dev_id "+test.dev_id);
         println("waitForDevice: "+Arrays.toString(test.waitForDevices.toArray()));
         println("characteristicList: "+Arrays.toString(test.charIdentifierList.toArray()));
 
diff --git a/java/direct_bt/tinyb/DBTManager.java b/java/direct_bt/tinyb/DBTManager.java
index 5f663fcd..b7f05fcd 100644
--- a/java/direct_bt/tinyb/DBTManager.java
+++ b/java/direct_bt/tinyb/DBTManager.java
@@ -31,6 +31,8 @@ import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.function.Consumer;
+import java.util.function.Predicate;
 
 import org.tinyb.BluetoothAdapter;
 import org.tinyb.BluetoothDevice;
@@ -43,6 +45,7 @@ import org.tinyb.BluetoothObject;
 import org.tinyb.BluetoothManager;
 import org.tinyb.BluetoothType;
 import org.tinyb.HCIStatusCode;
+import org.tinyb.BluetoothManager.ChangedAdapterSetListener;
 
 public class DBTManager implements BluetoothManager
 {
@@ -151,6 +154,8 @@ public class DBTManager implements BluetoothManager
 
     private long nativeInstance;
     private final List<BluetoothAdapter> adapters = new CopyOnWriteArrayList<BluetoothAdapter>();
+    private final List<ChangedAdapterSetListener> changedAdapterSetListenerList = new CopyOnWriteArrayList<ChangedAdapterSetListener>();
+
     private final Settings settings;
 
     @Override
@@ -277,6 +282,39 @@ public class DBTManager implements BluetoothManager
     @Override
     public boolean getDiscovering() throws BluetoothException { return getDefaultAdapter().getDiscovering(); }
 
+    @Override
+    public final void addChangedAdapterSetListener(final ChangedAdapterSetListener l) {
+        changedAdapterSetListenerList.add(l);
+
+        adapters.forEach(new Consumer<BluetoothAdapter>() {
+            @Override
+            public void accept(final BluetoothAdapter adapter) {
+                changedAdapterSetListenerList.forEach(new Consumer<ChangedAdapterSetListener>() {
+                    @Override
+                    public void accept(final ChangedAdapterSetListener t) {
+                        t.adapterAdded(adapter);
+                    } } );
+            }
+        });
+    }
+
+    @Override
+    public final int removeChangedAdapterSetListener(final ChangedAdapterSetListener l) {
+        // Using removeIf allows performing test on all object and remove within one write-lock cycle
+        final int count[] = { 0 };
+        changedAdapterSetListenerList.removeIf(new Predicate<ChangedAdapterSetListener>() {
+            @Override
+            public boolean test(final ChangedAdapterSetListener t) {
+                if( t.equals(l) ) {
+                    count[0]++;
+                    return true;
+                }
+                return false;
+            }
+        });
+        return count[0];
+    }
+
     private native List<BluetoothAdapter> getAdapterListImpl();
     private native BluetoothAdapter getAdapterImpl(int dev_id);
 
@@ -290,6 +328,14 @@ public class DBTManager implements BluetoothManager
                     System.err.println("DBTManager.removeAdapterCB[dev_id "+dev_id+", opc 0x"+Integer.toHexString(opc_reason)+
                             "]: removed "+a.toString()+", size "+adapters.size());
                 }
+                if( 0x0005 == opc_reason ) {
+                    // MgmtEvent::Opcode::INDEX_REMOVED = 0x0005
+                    changedAdapterSetListenerList.forEach(new Consumer<ChangedAdapterSetListener>() {
+                        @Override
+                        public void accept(final ChangedAdapterSetListener t) {
+                            t.adapterRemoved(a);
+                        } } );
+                }
                 return;
             }
         }
@@ -321,6 +367,14 @@ public class DBTManager implements BluetoothManager
             System.err.println("DBTManager.updatedAdapterCB[dev_id "+dev_id+", opc 0x"+Integer.toHexString(opc_reason)+
                     "]: added "+added+": new "+newInstance.toString()+", size "+adapters.size());
         }
+        if( added && 0x0004 == opc_reason ) {
+            // MgmtEvent::Opcode::INDEX_ADDED = 0x0004
+            changedAdapterSetListenerList.forEach(new Consumer<ChangedAdapterSetListener>() {
+                @Override
+                public void accept(final ChangedAdapterSetListener t) {
+                    t.adapterAdded(newInstance);
+                } } );
+        }
     }
 
     private native void initImpl(final boolean unifyUUID128Bit, final int btMode) throws BluetoothException;
diff --git a/java/org/tinyb/BluetoothManager.java b/java/org/tinyb/BluetoothManager.java
index b8754303..2a558805 100644
--- a/java/org/tinyb/BluetoothManager.java
+++ b/java/org/tinyb/BluetoothManager.java
@@ -75,6 +75,27 @@ public interface BluetoothManager
         String toString();
     }
 
+
+    /**
+     * Event listener to receive change events regarding the system's {@link BluetoothAdapter} set,
+     * e.g. about a removed or added {@link BluetoothAdapter} due to user interaction or 'cold reset'.
+     * @since 2.0.0
+     * @implNote Not implemented on tinyb.dbus
+     */
+    public static interface ChangedAdapterSetListener {
+        /**
+         * {@link BluetoothAdapter} was added to the system.
+         * @param adapter the newly added {@link BluetoothAdapter} to the system
+         */
+        void adapterAdded(final BluetoothAdapter adapter);
+
+        /**
+         * {@link BluetoothAdapter} was removed from the system.
+         * @param adapter the removed {@link BluetoothAdapter} from the system
+         */
+        void adapterRemoved(final BluetoothAdapter adapter);
+    }
+
     /**
      * Returns this implmentation's {@link Settings}.
      */
@@ -269,6 +290,26 @@ public interface BluetoothManager
     public boolean getDiscovering() throws BluetoothException;
 
     /**
+     * Add the given {@link ChangedAdapterSetListener} to this manager.
+     * <p>
+     * When a new callback is added, all available adapter's will be reported as added,
+     * this allows a fully event driven workflow.
+     * </p>
+     * @since 2.0.0
+     * @implNote Not implemented on tinyb.dbus
+     */
+    void addChangedAdapterSetListener(final ChangedAdapterSetListener l);
+
+    /**
+     * Remove the given {@link ChangedAdapterSetListener} from this manager.
+     * @param l the to be removed element
+     * @return the number of removed elements
+     * @since 2.0.0
+     * @implNote Not implemented on tinyb.dbus
+     */
+    int removeChangedAdapterSetListener(final ChangedAdapterSetListener l);
+
+    /**
      * Release the native memory associated with this object and all related Bluetooth resources.
      * The object should not be used following a call to close
      * <p>
diff --git a/java/tinyb/dbus/DBusManager.java b/java/tinyb/dbus/DBusManager.java
index 0c87ba49..db7e87f7 100644
--- a/java/tinyb/dbus/DBusManager.java
+++ b/java/tinyb/dbus/DBusManager.java
@@ -38,6 +38,7 @@ import org.tinyb.BluetoothObject;
 import org.tinyb.BluetoothManager;
 import org.tinyb.BluetoothType;
 import org.tinyb.HCIStatusCode;
+import org.tinyb.BluetoothManager.ChangedAdapterSetListener;
 
 public class DBusManager implements BluetoothManager
 {
@@ -173,4 +174,10 @@ public class DBusManager implements BluetoothManager
     public void shutdown() {
         delete();
     }
+
+    @Override
+    public final void addChangedAdapterSetListener(final ChangedAdapterSetListener l) {} // FIXME
+
+    @Override
+    public final int removeChangedAdapterSetListener(final ChangedAdapterSetListener l) { return 0; } // FIXME
 }
diff --git a/scripts/run-dbt_scanner10.sh b/scripts/run-dbt_scanner10.sh
index b7e1ba51..decd767a 100644
--- a/scripts/run-dbt_scanner10.sh
+++ b/scripts/run-dbt_scanner10.sh
@@ -11,6 +11,10 @@
 # ../scripts/run-dbt_scanner10.sh -wait -wl C0:26:DA:01:DA:B1 2>&1 | tee ~/scanner-h01-dbt10.log
 # ../scripts/run-dbt_scanner10.sh -wait 2>&1 | tee ~/scanner-h01-dbt10.log
 #
+# To do a BT adapter removal/add via software, assuming the device is '1-4' (Bus 1.Port 4):
+#   echo '1-4' > /sys/bus/usb/drivers/usb/unbind 
+#   echo '1-4' > /sys/bus/usb/drivers/usb/bind 
+
 
 sdir=`dirname $(readlink -f $0)`
 rootdir=`dirname $sdir`
diff --git a/src/direct_bt/DBTManager.cpp b/src/direct_bt/DBTManager.cpp
index 85a6e1ee..e84262e9 100644
--- a/src/direct_bt/DBTManager.cpp
+++ b/src/direct_bt/DBTManager.cpp
@@ -886,6 +886,7 @@ void DBTManager::clearAllMgmtEventCallbacks() noexcept {
     for(size_t i=0; i<mgmtAdapterEventCallbackLists.size(); i++) {
         mgmtAdapterEventCallbackLists[i].clear();
     }
+    mgmtChangedAdapterSetCallbackList.clear();
 }
 
 void DBTManager::processAdapterAdded(std::shared_ptr<MgmtEvent> e) noexcept {
@@ -895,6 +896,9 @@ void DBTManager::processAdapterAdded(std::shared_ptr<MgmtEvent> e) noexcept {
         const bool added = addAdapterInfo(ai);
         DBG_PRINT("DBTManager::Adapter[%d] Added %d: %s", dev_id, added, ai->toString().c_str());
         sendMgmtEvent(e);
+        jau::for_each_cow(mgmtChangedAdapterSetCallbackList, [&](ChangedAdapterSetCallback &cb) {
+           cb.invoke(true /* added */, *ai);
+        });
     } else {
         DBG_PRINT("DBTManager::Adapter[%d] Added 0: Init failed", dev_id);
     }
@@ -902,6 +906,9 @@ void DBTManager::processAdapterAdded(std::shared_ptr<MgmtEvent> e) noexcept {
 bool DBTManager::mgmtEvAdapterRemovedCB(std::shared_ptr<MgmtEvent> e) noexcept {
     DBG_PRINT("DBTManager:mgmt:AdapterRemoved: Start %s", e->toString().c_str());
     std::shared_ptr<AdapterInfo> ai = removeAdapterInfo(e->getDevID());
+    jau::for_each_cow(mgmtChangedAdapterSetCallbackList, [&](ChangedAdapterSetCallback &cb) {
+       cb.invoke(false /* added */, *ai);
+    });
     DBG_PRINT("DBTManager:mgmt:AdapterRemoved: End: Removed %s", (nullptr != ai ? ai->toString().c_str() : "none"));
     return true;
 }
@@ -1008,3 +1015,35 @@ bool DBTManager::mgmtEvUserPasskeyRequestCB(std::shared_ptr<MgmtEvent> e) noexce
     (void)event;
     return true;
 }
+
+/**
+ * ChangedAdapterSetCallback handling
+ */
+
+static ChangedAdapterSetCallbackList::equal_comparator _changedAdapterSetCallbackEqComp =
+        [](const ChangedAdapterSetCallback& a, const ChangedAdapterSetCallback& b) -> bool { return a == b; };
+
+
+void DBTManager::addChangedAdapterSetCallback(const ChangedAdapterSetCallback & l) {
+    mgmtChangedAdapterSetCallbackList.push_back(l);
+}
+int DBTManager::removeChangedAdapterSetCallback(const ChangedAdapterSetCallback & l) {
+    return mgmtChangedAdapterSetCallbackList.erase_matching(l, true /* all_matching */, _changedAdapterSetCallbackEqComp);
+}
+
+void DBTManager::addChangedAdapterSetCallback(ChangedAdapterSetFunc f) {
+    addChangedAdapterSetCallback(
+            ChangedAdapterSetCallback(
+                    jau::bindPlainFunc<bool, bool, const AdapterInfo&>(f)
+            ) );
+
+    jau::for_each_cow(adapterInfos, [&](std::shared_ptr<AdapterInfo>& ai) {
+        jau::for_each_cow(mgmtChangedAdapterSetCallbackList, [&](ChangedAdapterSetCallback &cb) {
+           cb.invoke(true /* added */, *ai);
+        });
+    });
+}
+int DBTManager::removeChangedAdapterSetCallback(ChangedAdapterSetFunc f) {
+    ChangedAdapterSetCallback l( jau::bindPlainFunc<bool, bool, const AdapterInfo&>(f) );
+    return mgmtChangedAdapterSetCallbackList.erase_matching(l, true /* all_matching */, _changedAdapterSetCallbackEqComp);
+}