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.

1 files changed, 3 insertions, 0 deletions

diff --git a/java/direct_bt/tinyb/DBTAdapter.java b/java/direct_bt/tinyb/DBTAdapter.java
index 62e92930..594760cd 100644
--- a/java/direct_bt/tinyb/DBTAdapter.java
+++ b/java/direct_bt/tinyb/DBTAdapter.java
@@ -121,6 +121,9 @@ public class DBTAdapter extends DBTObject implements BluetoothAdapter
 
         poweredOff();
 
+        // notify manager that this instance is gone for good
+        ((DBTManager)DBTManager.getManager()).removeAdapterCB(dev_id, 0x0100 /* custom opc */);
+
         super.close();
     }