Have GATT[Service,Characteristic,Descriptor] derived from DBTObject for valid check; Use new JNI getInstance() -> getDBTObject() w/ valid check

12 files changed, 118 insertions, 77 deletions

diff --git a/api/direct_bt/DBTAdapter.hpp b/api/direct_bt/DBTAdapter.hpp
index 727f70f1..682c0e0b 100644
--- a/api/direct_bt/DBTAdapter.hpp
+++ b/api/direct_bt/DBTAdapter.hpp
@@ -247,9 +247,9 @@ namespace direct_bt {
             /**
              * Throws an IllegalStateException if isValid() == false
              */
-            inline void checkValid() const {
+            inline void checkValidAdapter() const {
                 if( !isValid() ) {
-                    throw IllegalStateException("Adapter state invalid: "+toString(), E_FILE_LINE);
+                    throw IllegalStateException("Adapter state invalid: "+aptrHexString(this)+", "+toString(), E_FILE_LINE);
                 }
             }
 
diff --git a/api/direct_bt/DBTTypes.hpp b/api/direct_bt/DBTTypes.hpp
index c5efa3cd..c900e1d0 100644
--- a/api/direct_bt/DBTTypes.hpp
+++ b/api/direct_bt/DBTTypes.hpp
@@ -46,8 +46,8 @@ namespace direct_bt {
     class DBTObject : public JavaUplink
     {
         protected:
-            std::mutex lk;
             std::atomic_bool valid;
+            std::mutex lk;
 
             DBTObject() : valid(true) {}
 
@@ -69,7 +69,16 @@ namespace direct_bt {
                 valid = false;
             }
 
-            bool isValid() const { return valid; }
+            inline bool isValid() const { return valid.load(); }
+
+            /**
+             * Throws an IllegalStateException if isValid() == false
+             */
+            inline void checkValid() const {
+                if( !isValid() ) {
+                    throw IllegalStateException("DBTObject state invalid: "+aptrHexString(this), E_FILE_LINE);
+                }
+            }
     };
 
     /**
diff --git a/api/direct_bt/GATTCharacteristic.hpp b/api/direct_bt/GATTCharacteristic.hpp
index 67274a32..56d00f3b 100644
--- a/api/direct_bt/GATTCharacteristic.hpp
+++ b/api/direct_bt/GATTCharacteristic.hpp
@@ -40,6 +40,8 @@
 #include "OctetTypes.hpp"
 #include "ATTPDUTypes.hpp"
 
+#include "DBTTypes.hpp"
+
 #include "GATTDescriptor.hpp"
 
 #include "JavaUplink.hpp"
@@ -71,7 +73,7 @@ namespace direct_bt {
      * and the value the Characteristics Property, Characteristics Value Handle _and_ Characteristics UUID.
      * </p>
      */
-    class GATTCharacteristic : public JavaUplink {
+    class GATTCharacteristic : public DBTObject {
         private:
             /** Characteristics's service weak back-reference */
             std::weak_ptr<GATTService> wbr_service;
diff --git a/api/direct_bt/GATTDescriptor.hpp b/api/direct_bt/GATTDescriptor.hpp
index 97231526..0eaca70e 100644
--- a/api/direct_bt/GATTDescriptor.hpp
+++ b/api/direct_bt/GATTDescriptor.hpp
@@ -40,7 +40,7 @@
 #include "OctetTypes.hpp"
 #include "ATTPDUTypes.hpp"
 
-#include "JavaUplink.hpp"
+#include "DBTTypes.hpp"
 
 /**
  * - - - - - - - - - - - - - - -
@@ -59,7 +59,7 @@ namespace direct_bt {
     /**
      * BT Core Spec v5.2: Vol 3, Part G GATT: 3.3.3 Characteristic Descriptor
      */
-    class GATTDescriptor : public JavaUplink {
+    class GATTDescriptor : public DBTObject {
         private:
             /** Descriptor's characteristic weak back-reference */
             std::weak_ptr<GATTCharacteristic> wbr_characteristic;
diff --git a/api/direct_bt/GATTService.hpp b/api/direct_bt/GATTService.hpp
index 6f0bc71c..763298bc 100644
--- a/api/direct_bt/GATTService.hpp
+++ b/api/direct_bt/GATTService.hpp
@@ -40,6 +40,8 @@
 #include "OctetTypes.hpp"
 #include "ATTPDUTypes.hpp"
 
+#include "DBTTypes.hpp"
+
 #include "GATTCharacteristic.hpp"
 
 #include "JavaUplink.hpp"
@@ -61,7 +63,7 @@ namespace direct_bt {
      * including its list of Characteristic Declarations,
      * which also may include its client config if available.
      */
-    class GATTService : public JavaUplink {
+    class GATTService : public DBTObject {
         private:
             /** Service's device weak back-reference */
             std::weak_ptr<DBTDevice> wbr_device;
diff --git a/java/jni/direct_bt/DBTAdapter.cxx b/java/jni/direct_bt/DBTAdapter.cxx
index 26b3fbcb..c05c997a 100644
--- a/java/jni/direct_bt/DBTAdapter.cxx
+++ b/java/jni/direct_bt/DBTAdapter.cxx
@@ -373,12 +373,12 @@ jboolean Java_direct_1bt_tinyb_DBTAdapter_addStatusListener(JNIEnv *env, jobject
                 return false;
             }
         }
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
 
         DBTDevice * deviceMatchRef = nullptr;
         if( nullptr != jdeviceMatch ) {
-            deviceMatchRef = getInstance<DBTDevice>(env, jdeviceMatch);
+            deviceMatchRef = getDBTObject<DBTDevice>(env, jdeviceMatch);
             JavaGlobalObj::check(deviceMatchRef->getJavaObject(), E_FILE_LINE);
         }
 
@@ -412,7 +412,7 @@ jboolean Java_direct_1bt_tinyb_DBTAdapter_removeStatusListener(JNIEnv *env, jobj
         }
         setObjectRef<JNIAdapterStatusListener>(env, statusListener, nullptr, "nativeInstance");
 
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
 
         if( ! adapter->removeStatusListener( pre ) ) {
@@ -428,7 +428,7 @@ jboolean Java_direct_1bt_tinyb_DBTAdapter_removeStatusListener(JNIEnv *env, jobj
 
 jint Java_direct_1bt_tinyb_DBTAdapter_removeAllStatusListener(JNIEnv *env, jobject obj) {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
 
         return adapter->removeAllStatusListener();
@@ -440,7 +440,7 @@ jint Java_direct_1bt_tinyb_DBTAdapter_removeAllStatusListener(JNIEnv *env, jobje
 
 jboolean Java_direct_1bt_tinyb_DBTAdapter_isDeviceWhitelisted(JNIEnv *env, jobject obj, jstring jaddress) {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
 
         std::string saddress = from_jstring_to_string(env, jaddress);
@@ -456,7 +456,7 @@ jboolean Java_direct_1bt_tinyb_DBTAdapter_addDeviceToWhitelist__Ljava_lang_Strin
                                                                jshort min_interval, jshort max_interval,
                                                                jshort latency, jshort timeout) {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
 
         std::string saddress = from_jstring_to_string(env, jaddress);
@@ -472,7 +472,7 @@ jboolean Java_direct_1bt_tinyb_DBTAdapter_addDeviceToWhitelist__Ljava_lang_Strin
 jboolean Java_direct_1bt_tinyb_DBTAdapter_addDeviceToWhitelist__Ljava_lang_String_2II(JNIEnv *env, jobject obj,
                                                                jstring jaddress, int jaddressType, int jctype) {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
 
         std::string saddress = from_jstring_to_string(env, jaddress);
@@ -487,7 +487,7 @@ jboolean Java_direct_1bt_tinyb_DBTAdapter_addDeviceToWhitelist__Ljava_lang_Strin
 }
 jboolean Java_direct_1bt_tinyb_DBTAdapter_removeDeviceFromWhitelist(JNIEnv *env, jobject obj, jstring jaddress, int jaddressType) {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
 
         std::string saddress = from_jstring_to_string(env, jaddress);
@@ -502,7 +502,7 @@ jboolean Java_direct_1bt_tinyb_DBTAdapter_removeDeviceFromWhitelist(JNIEnv *env,
 
 jstring Java_direct_1bt_tinyb_DBTAdapter_toStringImpl(JNIEnv *env, jobject obj) {
     try {
-        DBTAdapter *nativePtr = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *nativePtr = getDBTObject<DBTAdapter>(env, obj);
         JavaGlobalObj::check(nativePtr->getJavaObject(), E_FILE_LINE);
         return from_string_to_jstring(env, nativePtr->toString());
     } catch(...) {
@@ -526,7 +526,7 @@ void Java_direct_1bt_tinyb_DBTAdapter_deleteImpl(JNIEnv *env, jobject obj, jlong
 jboolean Java_direct_1bt_tinyb_DBTAdapter_startDiscoveryImpl(JNIEnv *env, jobject obj, jboolean keepAlive)
 {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         return adapter->startDiscovery(keepAlive);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -537,7 +537,7 @@ jboolean Java_direct_1bt_tinyb_DBTAdapter_startDiscoveryImpl(JNIEnv *env, jobjec
 jboolean Java_direct_1bt_tinyb_DBTAdapter_stopDiscoveryImpl(JNIEnv *env, jobject obj)
 {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         adapter->stopDiscovery();
         return JNI_TRUE;
     } catch(...) {
@@ -549,7 +549,7 @@ jboolean Java_direct_1bt_tinyb_DBTAdapter_stopDiscoveryImpl(JNIEnv *env, jobject
 jobject Java_direct_1bt_tinyb_DBTAdapter_getDiscoveredDevicesImpl(JNIEnv *env, jobject obj)
 {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         std::vector<std::shared_ptr<DBTDevice>> array = adapter->getDiscoveredDevices();
         return convert_vector_sharedptr_to_jarraylist(env, array);
     } catch(...) {
@@ -561,7 +561,7 @@ jobject Java_direct_1bt_tinyb_DBTAdapter_getDiscoveredDevicesImpl(JNIEnv *env, j
 jint Java_direct_1bt_tinyb_DBTAdapter_removeDevicesImpl(JNIEnv *env, jobject obj)
 {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         return adapter->removeDiscoveredDevices();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -575,7 +575,7 @@ jint Java_direct_1bt_tinyb_DBTAdapter_removeDevicesImpl(JNIEnv *env, jobject obj
 
 void Java_direct_1bt_tinyb_DBTAdapter_setPowered(JNIEnv *env, jobject obj, jboolean value) {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
         adapter->setPowered(JNI_TRUE == value ? true : false);
     } catch(...) {
@@ -585,7 +585,7 @@ void Java_direct_1bt_tinyb_DBTAdapter_setPowered(JNIEnv *env, jobject obj, jbool
 
 jstring Java_direct_1bt_tinyb_DBTAdapter_getAlias(JNIEnv *env, jobject obj) {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
         return from_string_to_jstring(env, adapter->getLocalName().getName());
     } catch(...) {
@@ -596,7 +596,7 @@ jstring Java_direct_1bt_tinyb_DBTAdapter_getAlias(JNIEnv *env, jobject obj) {
 
 void Java_direct_1bt_tinyb_DBTAdapter_setAlias(JNIEnv *env, jobject obj, jstring jnewalias) {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
         std::string newalias = from_jstring_to_string(env, jnewalias);
         adapter->setLocalName(newalias, std::string());
@@ -607,7 +607,7 @@ void Java_direct_1bt_tinyb_DBTAdapter_setAlias(JNIEnv *env, jobject obj, jstring
 
 void Java_direct_1bt_tinyb_DBTAdapter_setDiscoverable(JNIEnv *env, jobject obj, jboolean value) {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
         adapter->setDiscoverable(JNI_TRUE == value ? true : false);
     } catch(...) {
@@ -617,7 +617,7 @@ void Java_direct_1bt_tinyb_DBTAdapter_setDiscoverable(JNIEnv *env, jobject obj,
 
 jobject Java_direct_1bt_tinyb_DBTAdapter_connectDevice(JNIEnv *env, jobject obj, jstring jaddress, jstring jaddressType) {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
         std::string saddress = from_jstring_to_string(env, jaddress);
         EUI48 address(saddress);
@@ -642,7 +642,7 @@ jobject Java_direct_1bt_tinyb_DBTAdapter_connectDevice(JNIEnv *env, jobject obj,
 
 void Java_direct_1bt_tinyb_DBTAdapter_setPairable(JNIEnv *env, jobject obj, jboolean value) {
     try {
-        DBTAdapter *adapter = getInstance<DBTAdapter>(env, obj);
+        DBTAdapter *adapter = getDBTObject<DBTAdapter>(env, obj);
         JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
         adapter->setBondable(JNI_TRUE == value ? true : false);
     } catch(...) {
diff --git a/java/jni/direct_bt/DBTDevice.cxx b/java/jni/direct_bt/DBTDevice.cxx
index ae57644a..d28ac0c2 100644
--- a/java/jni/direct_bt/DBTDevice.cxx
+++ b/java/jni/direct_bt/DBTDevice.cxx
@@ -141,7 +141,7 @@ class JNICharacteristicListener : public GATTCharacteristicListener {
 void Java_direct_1bt_tinyb_DBTDevice_initImpl(JNIEnv *env, jobject obj)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -150,7 +150,7 @@ void Java_direct_1bt_tinyb_DBTDevice_initImpl(JNIEnv *env, jobject obj)
 
 jstring Java_direct_1bt_tinyb_DBTDevice_getNameImpl(JNIEnv *env, jobject obj) {
     try {
-        DBTDevice *nativePtr = getInstance<DBTDevice>(env, obj);
+        DBTDevice *nativePtr = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(nativePtr->getJavaObject(), E_FILE_LINE);
         return from_string_to_jstring(env, nativePtr->getName());
     } catch(...) {
@@ -161,7 +161,7 @@ jstring Java_direct_1bt_tinyb_DBTDevice_getNameImpl(JNIEnv *env, jobject obj) {
 
 jstring Java_direct_1bt_tinyb_DBTDevice_toStringImpl(JNIEnv *env, jobject obj) {
     try {
-        DBTDevice *nativePtr = getInstance<DBTDevice>(env, obj);
+        DBTDevice *nativePtr = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(nativePtr->getJavaObject(), E_FILE_LINE);
         return from_string_to_jstring(env, nativePtr->toString());
     } catch(...) {
@@ -183,7 +183,7 @@ jboolean Java_direct_1bt_tinyb_DBTDevice_addCharacteristicListener(JNIEnv *env,
                 return false;
             }
         }
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         std::shared_ptr<GATTHandler> gatt = device->getGATTHandler();
         if( nullptr == gatt ) {
@@ -192,7 +192,7 @@ jboolean Java_direct_1bt_tinyb_DBTDevice_addCharacteristicListener(JNIEnv *env,
 
         GATTCharacteristic * associatedCharacteristicRef = nullptr;
         if( nullptr != jAssociatedCharacteristic ) {
-            associatedCharacteristicRef = getInstance<GATTCharacteristic>(env, jAssociatedCharacteristic);
+            associatedCharacteristicRef = getDBTObject<GATTCharacteristic>(env, jAssociatedCharacteristic);
         }
 
         std::shared_ptr<GATTCharacteristicListener> l =
@@ -221,7 +221,7 @@ jboolean Java_direct_1bt_tinyb_DBTDevice_removeCharacteristicListener(JNIEnv *en
         }
         setObjectRef<JNICharacteristicListener>(env, jlistener, nullptr, "nativeInstance");
 
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         std::shared_ptr<GATTHandler> gatt = device->getGATTHandler();
         if( nullptr == gatt ) {
@@ -246,7 +246,7 @@ jint Java_direct_1bt_tinyb_DBTDevice_removeAllAssociatedCharacteristicListener(J
         if( nullptr == jAssociatedCharacteristic ) {
             throw IllegalArgumentException("associatedCharacteristic argument is null", E_FILE_LINE);
         }
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         std::shared_ptr<GATTHandler> gatt = device->getGATTHandler();
         if( nullptr == gatt ) {
@@ -255,7 +255,7 @@ jint Java_direct_1bt_tinyb_DBTDevice_removeAllAssociatedCharacteristicListener(J
             return 0;
         }
 
-        GATTCharacteristic * associatedCharacteristicRef = getInstance<GATTCharacteristic>(env, jAssociatedCharacteristic);
+        GATTCharacteristic * associatedCharacteristicRef = getDBTObject<GATTCharacteristic>(env, jAssociatedCharacteristic);
         JavaGlobalObj::check(associatedCharacteristicRef->getJavaObject(), E_FILE_LINE);
 
         return gatt->removeAllAssociatedCharacteristicListener(associatedCharacteristicRef);
@@ -267,7 +267,7 @@ jint Java_direct_1bt_tinyb_DBTDevice_removeAllAssociatedCharacteristicListener(J
 
 jint Java_direct_1bt_tinyb_DBTDevice_removeAllCharacteristicListener(JNIEnv *env, jobject obj) {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         std::shared_ptr<GATTHandler> gatt = device->getGATTHandler();
         if( nullptr == gatt ) {
@@ -298,7 +298,7 @@ void Java_direct_1bt_tinyb_DBTDevice_deleteImpl(JNIEnv *env, jobject obj, jlong
 jboolean Java_direct_1bt_tinyb_DBTDevice_disconnectImpl(JNIEnv *env, jobject obj)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         return device->disconnect() ? JNI_TRUE : JNI_FALSE;
     } catch(...) {
@@ -310,7 +310,7 @@ jboolean Java_direct_1bt_tinyb_DBTDevice_disconnectImpl(JNIEnv *env, jobject obj
 jboolean Java_direct_1bt_tinyb_DBTDevice_removeImpl(JNIEnv *env, jobject obj)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         device->remove();
     } catch(...) {
@@ -322,7 +322,7 @@ jboolean Java_direct_1bt_tinyb_DBTDevice_removeImpl(JNIEnv *env, jobject obj)
 jboolean Java_direct_1bt_tinyb_DBTDevice_connectImpl__(JNIEnv *env, jobject obj)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         bool res = device->connectDefault();
         return res ? JNI_TRUE : JNI_FALSE;
@@ -338,7 +338,7 @@ jboolean Java_direct_1bt_tinyb_DBTDevice_connectImpl__SSSSSS(JNIEnv *env, jobjec
                                                              jshort latency, jshort timeout)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         bool res;
         switch( device->addressType ) {
@@ -366,7 +366,7 @@ static const std::string _serviceClazzCtorArgs("(JLdirect_bt/tinyb/DBTDevice;ZLj
 
 jobject Java_direct_1bt_tinyb_DBTDevice_getServicesImpl(JNIEnv *env, jobject obj) {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
 
         std::vector<GATTServiceRef> services = device->getGATTServices(); // implicit GATT connect and discovery if required incl GenericAccess retrieval
@@ -387,10 +387,7 @@ jobject Java_direct_1bt_tinyb_DBTDevice_getServicesImpl(JNIEnv *env, jobject obj
         std::function<jobject(JNIEnv*, jclass, jmethodID, GATTService*)> ctor_service =
                 [](JNIEnv *env, jclass clazz, jmethodID clazz_ctor, GATTService *service)->jobject {
                     // prepare adapter ctor
-                    std::shared_ptr<DBTDevice> device = service->getDevice();
-                    if( nullptr == device ) {
-                        throw IllegalStateException("Service's DBTDevice destructed: "+service->toString(), E_FILE_LINE);
-                    }
+                    std::shared_ptr<DBTDevice> device = service->getDeviceChecked();
                     JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
                     jobject jdevice = JavaGlobalObj::GetObject(device->getJavaObject());
                     const jboolean isPrimary = service->isPrimary;
@@ -418,7 +415,7 @@ jobject Java_direct_1bt_tinyb_DBTDevice_getServicesImpl(JNIEnv *env, jobject obj
 jboolean Java_direct_1bt_tinyb_DBTDevice_pingGATTImpl(JNIEnv *env, jobject obj)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
 
         return device->pingGATT() ? JNI_TRUE : JNI_FALSE;
@@ -431,7 +428,7 @@ jboolean Java_direct_1bt_tinyb_DBTDevice_pingGATTImpl(JNIEnv *env, jobject obj)
 jstring Java_direct_1bt_tinyb_DBTDevice_getIcon(JNIEnv *env, jobject obj)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         return nullptr; // FIXME
     } catch(...) {
@@ -443,7 +440,7 @@ jstring Java_direct_1bt_tinyb_DBTDevice_getIcon(JNIEnv *env, jobject obj)
 void Java_direct_1bt_tinyb_DBTDevice_setTrustedImpl(JNIEnv *env, jobject obj, jboolean value)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         (void)value;
         // FIXME
@@ -455,7 +452,7 @@ void Java_direct_1bt_tinyb_DBTDevice_setTrustedImpl(JNIEnv *env, jobject obj, jb
 void Java_direct_1bt_tinyb_DBTDevice_setBlockedImpl(JNIEnv *env, jobject obj, jboolean value)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         (void)value;
         // FIXME
@@ -467,7 +464,7 @@ void Java_direct_1bt_tinyb_DBTDevice_setBlockedImpl(JNIEnv *env, jobject obj, jb
 jboolean JNICALL Java_direct_1bt_tinyb_DBTDevice_getLegacyPairing(JNIEnv *env, jobject obj)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         return JNI_FALSE; // FIXME
     } catch(...) {
@@ -479,7 +476,7 @@ jboolean JNICALL Java_direct_1bt_tinyb_DBTDevice_getLegacyPairing(JNIEnv *env, j
 jshort Java_direct_1bt_tinyb_DBTDevice_getRSSI(JNIEnv *env, jobject obj)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         return (jshort) device->getRSSI();
     } catch(...) {
@@ -492,7 +489,7 @@ jshort Java_direct_1bt_tinyb_DBTDevice_getRSSI(JNIEnv *env, jobject obj)
 jobjectArray Java_direct_1bt_tinyb_DBTDevice_getUUIDs(JNIEnv *env, jobject obj)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         return nullptr; // FIXME
     } catch(...) {
@@ -504,7 +501,7 @@ jobjectArray Java_direct_1bt_tinyb_DBTDevice_getUUIDs(JNIEnv *env, jobject obj)
 jstring Java_direct_1bt_tinyb_DBTDevice_getModalias(JNIEnv *env, jobject obj)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         return nullptr; // FIXME
     } catch(...) {
@@ -516,7 +513,7 @@ jstring Java_direct_1bt_tinyb_DBTDevice_getModalias(JNIEnv *env, jobject obj)
 jobject Java_direct_1bt_tinyb_DBTDevice_getManufacturerData(JNIEnv *env, jobject obj)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         std::shared_ptr<ManufactureSpecificData> mdata = device->getManufactureSpecificData();
 
@@ -553,7 +550,7 @@ jobject Java_direct_1bt_tinyb_DBTDevice_getManufacturerData(JNIEnv *env, jobject
 jshort Java_direct_1bt_tinyb_DBTDevice_getTxPower(JNIEnv *env, jobject obj)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         return (jshort) device->getTxPower();
     } catch(...) {
@@ -613,7 +610,7 @@ static void disableBlockedNotifications(JNIEnv *env, jobject obj, DBTManager &mg
 void Java_direct_1bt_tinyb_DBTDevice_disableBlockedNotificationsImpl(JNIEnv *env, jobject obj)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         DBTManager & mgmt = device->getAdapter().getManager();
 
@@ -625,7 +622,7 @@ void Java_direct_1bt_tinyb_DBTDevice_disableBlockedNotificationsImpl(JNIEnv *env
 void Java_direct_1bt_tinyb_DBTDevice_enableBlockedNotificationsImpl(JNIEnv *env, jobject obj, jobject javaCallback)
 {
     try {
-        DBTDevice *device= getInstance<DBTDevice>(env, obj);
+        DBTDevice *device= getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         DBTAdapter & adapter = device->getAdapter();
         DBTManager & mgmt = adapter.getManager();
@@ -700,7 +697,7 @@ static void disablePairedNotifications(JNIEnv *env, jobject obj, DBTManager &mgm
 void Java_direct_1bt_tinyb_DBTDevice_disablePairedNotificationsImpl(JNIEnv *env, jobject obj)
 {
     try {
-        DBTDevice *device = getInstance<DBTDevice>(env, obj);
+        DBTDevice *device = getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         DBTManager & mgmt = device->getAdapter().getManager();
 
@@ -712,7 +709,7 @@ void Java_direct_1bt_tinyb_DBTDevice_disablePairedNotificationsImpl(JNIEnv *env,
 void Java_direct_1bt_tinyb_DBTDevice_enablePairedNotificationsImpl(JNIEnv *env, jobject obj, jobject javaCallback)
 {
     try {
-        DBTDevice *device= getInstance<DBTDevice>(env, obj);
+        DBTDevice *device= getDBTObject<DBTDevice>(env, obj);
         JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         DBTAdapter & adapter = device->getAdapter();
         DBTManager & mgmt = adapter.getManager();
diff --git a/java/jni/direct_bt/DBTGattCharacteristic.cxx b/java/jni/direct_bt/DBTGattCharacteristic.cxx
index 84483d6a..6260818a 100644
--- a/java/jni/direct_bt/DBTGattCharacteristic.cxx
+++ b/java/jni/direct_bt/DBTGattCharacteristic.cxx
@@ -39,7 +39,7 @@ using namespace direct_bt;
 
 jstring Java_direct_1bt_tinyb_DBTGattCharacteristic_toStringImpl(JNIEnv *env, jobject obj) {
     try {
-        GATTCharacteristic *nativePtr = getInstance<GATTCharacteristic>(env, obj);
+        GATTCharacteristic *nativePtr = getDBTObject<GATTCharacteristic>(env, obj);
         JavaGlobalObj::check(nativePtr->getJavaObject(), E_FILE_LINE);
         return from_string_to_jstring(env, nativePtr->toString());
     } catch(...) {
@@ -63,7 +63,7 @@ static const std::string _descriptorClazzCtorArgs("(JLdirect_bt/tinyb/DBTGattCha
 
 jobject Java_direct_1bt_tinyb_DBTGattCharacteristic_getDescriptorsImpl(JNIEnv *env, jobject obj) {
     try {
-        GATTCharacteristic *characteristic = getInstance<GATTCharacteristic>(env, obj);
+        GATTCharacteristic *characteristic = getDBTObject<GATTCharacteristic>(env, obj);
         JavaGlobalObj::check(characteristic->getJavaObject(), E_FILE_LINE);
 
         std::vector<GATTDescriptorRef> & descriptorList = characteristic->descriptorList;
@@ -112,7 +112,7 @@ jobject Java_direct_1bt_tinyb_DBTGattCharacteristic_getDescriptorsImpl(JNIEnv *e
 
 jbyteArray Java_direct_1bt_tinyb_DBTGattCharacteristic_readValueImpl(JNIEnv *env, jobject obj) {
     try {
-        GATTCharacteristic *characteristic = getInstance<GATTCharacteristic>(env, obj);
+        GATTCharacteristic *characteristic = getDBTObject<GATTCharacteristic>(env, obj);
         JavaGlobalObj::check(characteristic->getJavaObject(), E_FILE_LINE);
 
         POctets res(GATTHandler::number(GATTHandler::Defaults::MAX_ATT_MTU), 0);
@@ -142,7 +142,7 @@ jboolean Java_direct_1bt_tinyb_DBTGattCharacteristic_writeValueImpl(JNIEnv *env,
         if( 0 == value_size ) {
             return JNI_TRUE;
         }
-        GATTCharacteristic *characteristic = getInstance<GATTCharacteristic>(env, obj);
+        GATTCharacteristic *characteristic = getDBTObject<GATTCharacteristic>(env, obj);
         JavaGlobalObj::check(characteristic->getJavaObject(), E_FILE_LINE);
 
         JNICriticalArray<uint8_t, jbyteArray> criticalArray(env); // RAII - release
@@ -165,7 +165,7 @@ jboolean Java_direct_1bt_tinyb_DBTGattCharacteristic_writeValueImpl(JNIEnv *env,
 jboolean Java_direct_1bt_tinyb_DBTGattCharacteristic_configNotificationIndicationImpl(JNIEnv *env, jobject obj,
                         jboolean enableNotification, jboolean enableIndication, jbooleanArray jEnabledState) {
     try {
-        GATTCharacteristic *characteristic = getInstanceUnchecked<GATTCharacteristic>(env, obj);
+        GATTCharacteristic *characteristic = getDBTObjectUnchecked<GATTCharacteristic>(env, obj);
         if( nullptr == characteristic ) {
             if( !enableNotification && !enableIndication ) {
                 // OK to have native characteristic being shutdown @ disable
diff --git a/java/jni/direct_bt/DBTGattDescriptor.cxx b/java/jni/direct_bt/DBTGattDescriptor.cxx
index 066e9f5f..d1462825 100644
--- a/java/jni/direct_bt/DBTGattDescriptor.cxx
+++ b/java/jni/direct_bt/DBTGattDescriptor.cxx
@@ -39,7 +39,7 @@ using namespace direct_bt;
 
 void Java_direct_1bt_tinyb_DBTGattDescriptor_deleteImpl(JNIEnv *env, jobject obj) {
     try {
-        GATTDescriptor *descriptor = getInstance<GATTDescriptor>(env, obj);
+        GATTDescriptor *descriptor = getDBTObject<GATTDescriptor>(env, obj);
         (void)descriptor;
         // No delete: Service instance owned by GATTService -> DBTDevice
     } catch(...) {
@@ -61,7 +61,7 @@ jstring Java_direct_1bt_tinyb_DBTGattDescriptor_toStringImpl(JNIEnv *env, jobjec
 
 jbyteArray Java_direct_1bt_tinyb_DBTGattDescriptor_readValueImpl(JNIEnv *env, jobject obj) {
     try {
-        GATTDescriptor *descriptor = getInstance<GATTDescriptor>(env, obj);
+        GATTDescriptor *descriptor = getDBTObject<GATTDescriptor>(env, obj);
         JavaGlobalObj::check(descriptor->getJavaObject(), E_FILE_LINE);
 
         if( !descriptor->readValue() ) {
@@ -89,7 +89,7 @@ jboolean Java_direct_1bt_tinyb_DBTGattDescriptor_writeValueImpl(JNIEnv *env, job
         if( 0 == value_size ) {
             return JNI_TRUE;
         }
-        GATTDescriptor *descriptor = getInstance<GATTDescriptor>(env, obj);
+        GATTDescriptor *descriptor = getDBTObject<GATTDescriptor>(env, obj);
         JavaGlobalObj::check(descriptor->getJavaObject(), E_FILE_LINE);
 
         JNICriticalArray<uint8_t, jbyteArray> criticalArray(env); // RAII - release
diff --git a/java/jni/direct_bt/DBTGattService.cxx b/java/jni/direct_bt/DBTGattService.cxx
index 7023d755..ef25f486 100644
--- a/java/jni/direct_bt/DBTGattService.cxx
+++ b/java/jni/direct_bt/DBTGattService.cxx
@@ -39,7 +39,7 @@ using namespace direct_bt;
 
 jstring Java_direct_1bt_tinyb_DBTGattService_toStringImpl(JNIEnv *env, jobject obj) {
     try {
-        GATTService *nativePtr = getInstance<GATTService>(env, obj);
+        GATTService *nativePtr = getDBTObject<GATTService>(env, obj);
         JavaGlobalObj::check(nativePtr->getJavaObject(), E_FILE_LINE);
         return from_string_to_jstring(env, nativePtr->toString());
     } catch(...) {
@@ -64,7 +64,7 @@ static const std::string _characteristicClazzCtorArgs("(JLdirect_bt/tinyb/DBTGat
 
 jobject Java_direct_1bt_tinyb_DBTGattService_getCharacteristicsImpl(JNIEnv *env, jobject obj) {
     try {
-        GATTService *service = getInstance<GATTService>(env, obj);
+        GATTService *service = getDBTObject<GATTService>(env, obj);
         JavaGlobalObj::check(service->getJavaObject(), E_FILE_LINE);
 
         std::vector<std::shared_ptr<GATTCharacteristic>> & characteristics = service->characteristicList;
diff --git a/java/jni/direct_bt/helper_dbt.hpp b/java/jni/direct_bt/helper_dbt.hpp
index abd78b50..f644d58c 100644
--- a/java/jni/direct_bt/helper_dbt.hpp
+++ b/java/jni/direct_bt/helper_dbt.hpp
@@ -149,6 +149,37 @@ namespace direct_bt {
     BDAddressType fromJavaAdressTypeToBDAddressType(JNIEnv *env, jstring jAddressType);
     jstring fromBDAddressTypeToJavaAddressType(JNIEnv *env, BDAddressType bdAddressType);
 
+    template <typename T>
+    T *getDBTObject(JNIEnv *env, jobject obj)
+    {
+        jlong instance = env->GetLongField(obj, getInstanceField(env, obj));
+        T *t = reinterpret_cast<T *>(instance);
+        if (t == nullptr) {
+            throw std::runtime_error("Trying to acquire null DBTObject");
+        }
+        t->checkValid();
+        return t;
+    }
+
+    template <typename T>
+    T *getDBTObjectUnchecked(JNIEnv *env, jobject obj)
+    {
+        jlong instance = env->GetLongField(obj, getInstanceField(env, obj));
+        return reinterpret_cast<T *>(instance);
+    }
+
+    template <typename T>
+    void setDBTObject(JNIEnv *env, jobject obj, T *t)
+    {
+        if (t == nullptr) {
+            throw std::runtime_error("Trying to create null DBTObject");
+        }
+        jlong instance = reinterpret_cast<jlong>(t);
+        env->SetLongField(obj, getInstanceField(env, obj), instance);
+    }
+
+
+
 } // namespace direct_bt
 
 #endif /* HELPER_DBT_HPP_ */
diff --git a/src/direct_bt/DBTAdapter.cpp b/src/direct_bt/DBTAdapter.cpp
index 8e2b858e..ef64e2dc 100644
--- a/src/direct_bt/DBTAdapter.cpp
+++ b/src/direct_bt/DBTAdapter.cpp
@@ -32,7 +32,7 @@
 
 #include <algorithm>
 
-// #define VERBOSE_ON 1
+#define VERBOSE_ON 1
 #include <dbt_debug.hpp>
 
 #include "BasicAlgos.hpp"
@@ -262,7 +262,7 @@ bool DBTAdapter::isDeviceWhitelisted(const EUI48 &address) {
 bool DBTAdapter::addDeviceToWhitelist(const EUI48 &address, const BDAddressType address_type, const HCIWhitelistConnectType ctype,
                                       const uint16_t conn_interval_min, const uint16_t conn_interval_max,
                                       const uint16_t conn_latency, const uint16_t timeout) {
-    checkValid();
+    checkValidAdapter();
     if( mgmt.isDeviceWhitelisted(dev_id, address) ) {
         ERR_PRINT("DBTAdapter::addDeviceToWhitelist: device already listed: dev_id %d, address %s", dev_id, address.toString().c_str());
         return true;
@@ -276,12 +276,12 @@ bool DBTAdapter::addDeviceToWhitelist(const EUI48 &address, const BDAddressType
 }
 
 bool DBTAdapter::removeDeviceFromWhitelist(const EUI48 &address, const BDAddressType address_type) {
-    checkValid();
+    checkValidAdapter();
     return mgmt.removeDeviceFromWhitelist(dev_id, address, address_type);
 }
 
 bool DBTAdapter::addStatusListener(std::shared_ptr<AdapterStatusListener> l) {
-    checkValid();
+    checkValidAdapter();
     if( nullptr == l ) {
         throw IllegalArgumentException("DBTAdapterStatusListener ref is null", E_FILE_LINE);
     }
@@ -298,7 +298,7 @@ bool DBTAdapter::addStatusListener(std::shared_ptr<AdapterStatusListener> l) {
 }
 
 bool DBTAdapter::removeStatusListener(std::shared_ptr<AdapterStatusListener> l) {
-    checkValid();
+    checkValidAdapter();
     if( nullptr == l ) {
         throw IllegalArgumentException("DBTAdapterStatusListener ref is null", E_FILE_LINE);
     }
@@ -315,7 +315,7 @@ bool DBTAdapter::removeStatusListener(std::shared_ptr<AdapterStatusListener> l)
 }
 
 bool DBTAdapter::removeStatusListener(const AdapterStatusListener * l) {
-    checkValid();
+    checkValidAdapter();
     if( nullptr == l ) {
         throw IllegalArgumentException("DBTAdapterStatusListener ref is null", E_FILE_LINE);
     }
@@ -332,7 +332,7 @@ bool DBTAdapter::removeStatusListener(const AdapterStatusListener * l) {
 }
 
 int DBTAdapter::removeAllStatusListener() {
-    checkValid();
+    checkValidAdapter();
     const std::lock_guard<std::recursive_mutex> lock(mtx_statusListenerList); // RAII-style acquire and relinquish via destructor
     int count = statusListenerList.size();
     statusListenerList.clear();
@@ -342,7 +342,7 @@ int DBTAdapter::removeAllStatusListener() {
 bool DBTAdapter::startDiscovery(const bool keepAlive, const HCILEOwnAddressType own_mac_type,
                                 const uint16_t le_scan_interval, const uint16_t le_scan_window)
 {
-    checkValid();
+    checkValidAdapter();
     const std::lock_guard<std::recursive_mutex> lock(mtx_discovery); // RAII-style acquire and relinquish via destructor
     if( ScanType::SCAN_TYPE_NONE != currentScanType ) {
         removeDiscoveredDevices();