JNI Lifecycle Fix: Make Java/Native object relation inherently thread safe by using shared_ptr_ref<T>

8 files changed, 657 insertions, 520 deletions

diff --git a/java/jni/direct_bt/DBGattServer.cxx b/java/jni/direct_bt/DBGattServer.cxx
index 9975cef5..f6719748 100644
--- a/java/jni/direct_bt/DBGattServer.cxx
+++ b/java/jni/direct_bt/DBGattServer.cxx
@@ -51,7 +51,7 @@ using namespace direct_bt;
 static const std::string _dbGattValueClazzName("org/direct_bt/DBGattValue");
 static const std::string _dbGattValueClazzCtorArgs("([BIZ)V");
 
-static jobject _createDBGattValueFromDesc(JNIEnv *env_, jclass clazz, jmethodID clazz_ctor, DBGattDesc* valueHolder) {
+static jobject _createDBGattValueFromDesc(JNIEnv *env_, jclass clazz, jmethodID clazz_ctor, const DBGattDescRef& valueHolder) {
     const jau::POctets& value = valueHolder->getValue();
     jbyteArray jval = env_->NewByteArray(value.size());
     env_->SetByteArrayRegion(jval, 0, value.size(), (const jbyte*)(value.get_ptr()));
@@ -65,7 +65,7 @@ static jobject _createDBGattValueFromDesc(JNIEnv *env_, jclass clazz, jmethodID
     return jDBGattValue;
 };
 
-static jobject _createDBGattValueFromChar(JNIEnv *env_, jclass clazz, jmethodID clazz_ctor, DBGattChar* valueHolder) {
+static jobject _createDBGattValueFromChar(JNIEnv *env_, jclass clazz, jmethodID clazz_ctor, const DBGattCharRef& valueHolder) {
     const jau::POctets& value = valueHolder->getValue();
     jbyteArray jval = env_->NewByteArray(value.size());
     env_->SetByteArrayRegion(jval, 0, value.size(), (const jbyte*)(value.get_ptr()));
@@ -87,9 +87,9 @@ static jobject _createDBGattValueFromChar(JNIEnv *env_, jclass clazz, jmethodID
 
 jobject Java_org_direct_1bt_DBGattDesc_getValue(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<DBGattDesc> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattDesc>>(env, obj);
+        jau::shared_ptr_ref<DBGattDesc> ref(env, obj); // hold until done
         jclass clazz = jau::search_class(env, _dbGattValueClazzName.c_str());
-        return jau::convert_instance_to_jobject<DBGattDesc>(env, clazz, _dbGattValueClazzCtorArgs.c_str(), _createDBGattValueFromDesc, ref_ptr->get());
+        return jau::convert_instance_to_jobject<DBGattDesc>(env, clazz, _dbGattValueClazzCtorArgs.c_str(), _createDBGattValueFromDesc, ref.shared_ptr());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -98,7 +98,7 @@ jobject Java_org_direct_1bt_DBGattDesc_getValue(JNIEnv *env, jobject obj) {
 
 jboolean Java_org_direct_1bt_DBGattDesc_setValue(JNIEnv *env, jobject obj, jbyteArray jsource, jint jsource_pos, jint jsource_len, jint jdest_pos) {
     try {
-        std::shared_ptr<DBGattDesc>& ref = *jau::getInstance<std::shared_ptr<DBGattDesc>>(env, obj);
+        jau::shared_ptr_ref<DBGattDesc> ref(env, obj); // hold until done
 
         if( nullptr == jsource ) {
             return JNI_FALSE;
@@ -154,14 +154,12 @@ jlong Java_org_direct_1bt_DBGattDesc_ctorImpl(JNIEnv *env, jobject obj,
         std::shared_ptr<const jau::uuid_t> type( jau::uuid_t::create(stype) );
 
         // new instance
-        std::shared_ptr<DBGattDesc> ref = std::make_shared<DBGattDesc>(
-                                            type, std::move(value), JNI_TRUE == jvariable_length_);
+        jau::shared_ptr_ref<DBGattDesc> ref( new DBGattDesc(type, std::move(value), JNI_TRUE == jvariable_length_) );
 
         ref->setJavaObject( std::make_shared<jau::JavaGlobalObj>( std::move(global_obj), nullptr ) );
         jau::JavaGlobalObj::check(ref->getJavaObject(), E_FILE_LINE);
 
-        std::shared_ptr<DBGattDesc> * ref_ptr = new std::shared_ptr<DBGattDesc>(std::move(ref));
-        return (jlong)(intptr_t)ref_ptr;
+        return ref.release_to_jlong();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -171,10 +169,15 @@ jlong Java_org_direct_1bt_DBGattDesc_ctorImpl(JNIEnv *env, jobject obj,
 void Java_org_direct_1bt_DBGattDesc_dtorImpl(JNIEnv *env, jclass clazz, jlong nativeInstance) {
     (void)clazz;
     try {
-        if( 0 != nativeInstance ) {
-            std::shared_ptr<DBGattDesc> * ref_ptr = reinterpret_cast<std::shared_ptr<DBGattDesc> *>(nativeInstance);
-            (*ref_ptr)->setJavaObject();
-            delete ref_ptr;
+        jau::shared_ptr_ref<DBGattDesc> sref(nativeInstance, false /* throw_on_nullptr */); // hold copy until done
+        if( nullptr != sref.pointer() ) {
+            if( !sref.is_null() ) {
+                jau::JavaAnonRef sref_java = sref->getJavaObject(); // hold until done!
+                jau::JavaGlobalObj::check(sref_java, E_FILE_LINE);
+                sref->setJavaObject();
+            }
+            std::shared_ptr<DBGattDesc>* sref_ptr = jau::castInstance<DBGattDesc>(nativeInstance);
+            delete sref_ptr;
         }
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -184,8 +187,8 @@ void Java_org_direct_1bt_DBGattDesc_dtorImpl(JNIEnv *env, jclass clazz, jlong na
 jshort Java_org_direct_1bt_DBGattDesc_getHandle(JNIEnv *env, jobject obj)
 {
     try {
-        std::shared_ptr<DBGattDesc> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattDesc>>(env, obj);
-        return (jshort)( (*ref_ptr)->getHandle() );
+        jau::shared_ptr_ref<DBGattDesc> ref(env, obj); // hold until done
+        return (jshort)( ref->getHandle() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -196,8 +199,8 @@ jshort Java_org_direct_1bt_DBGattDesc_getHandle(JNIEnv *env, jobject obj)
 void Java_org_direct_1bt_DBGattDesc_bzero(JNIEnv *env, jobject obj)
 {
     try {
-        std::shared_ptr<DBGattDesc> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattDesc>>(env, obj);
-        (*ref_ptr)->bzero();
+        jau::shared_ptr_ref<DBGattDesc> ref(env, obj); // hold until done
+        ref->bzero();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -205,8 +208,8 @@ void Java_org_direct_1bt_DBGattDesc_bzero(JNIEnv *env, jobject obj)
 
 jstring Java_org_direct_1bt_DBGattDesc_toString(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<DBGattDesc> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattDesc>>(env, obj);
-        return jau::from_string_to_jstring(env, (*ref_ptr)->toString());
+        jau::shared_ptr_ref<DBGattDesc> ref(env, obj); // hold until done
+        return jau::from_string_to_jstring(env, ref->toString());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -222,9 +225,9 @@ jstring Java_org_direct_1bt_DBGattDesc_toString(JNIEnv *env, jobject obj) {
 
 jobject Java_org_direct_1bt_DBGattChar_getValue(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<DBGattChar> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattChar>>(env, obj);
+        jau::shared_ptr_ref<DBGattChar> ref(env, obj); // hold until done
         jclass clazz = jau::search_class(env, _dbGattValueClazzName.c_str());
-        return jau::convert_instance_to_jobject<DBGattChar>(env, clazz, _dbGattValueClazzCtorArgs.c_str(), _createDBGattValueFromChar, ref_ptr->get());
+        return jau::convert_instance_to_jobject<DBGattChar>(env, clazz, _dbGattValueClazzCtorArgs.c_str(), _createDBGattValueFromChar, ref.shared_ptr());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -233,7 +236,7 @@ jobject Java_org_direct_1bt_DBGattChar_getValue(JNIEnv *env, jobject obj) {
 
 jboolean Java_org_direct_1bt_DBGattChar_setValue(JNIEnv *env, jobject obj, jbyteArray jsource, jint jsource_pos, jint jsource_len, jint jdest_pos) {
     try {
-        std::shared_ptr<DBGattChar>& ref = *jau::getInstance<std::shared_ptr<DBGattChar>>(env, obj);
+        jau::shared_ptr_ref<DBGattChar> ref(env, obj); // hold until done
 
         if( nullptr == jsource ) {
             return JNI_FALSE;
@@ -299,8 +302,8 @@ jlong Java_org_direct_1bt_DBGattChar_ctorImpl(JNIEnv *env, jobject obj,
                 throw jau::InternalError("GetPrimitiveArrayCritical(DBGattDesc* array) is null", E_FILE_LINE);
             }
             for(jau::nsize_t i=0; i < count; ++i) {
-                std::shared_ptr<DBGattDesc> *desc_ref = (std::shared_ptr<DBGattDesc> *) (intptr_t) jlong_desc_ref_array[i];
-                descriptors.push_back( *desc_ref );
+                std::shared_ptr<DBGattDesc> desc_ref = *( (std::shared_ptr<DBGattDesc> *) (intptr_t) jlong_desc_ref_array[i] );
+                descriptors.push_back( desc_ref );
             }
         }
 
@@ -312,16 +315,14 @@ jlong Java_org_direct_1bt_DBGattChar_ctorImpl(JNIEnv *env, jobject obj,
         std::shared_ptr<const jau::uuid_t> type( jau::uuid_t::create(stype) );
 
         // new instance
-        std::shared_ptr<DBGattChar> ref = std::make_shared<DBGattChar>(
-                                            type, properties,
-                                            std::move(descriptors),
-                                            std::move(value), JNI_TRUE == jvariable_length_);
+        jau::shared_ptr_ref<DBGattChar> ref( new DBGattChar(type, properties,
+                                             std::move(descriptors),
+                                             std::move(value), JNI_TRUE == jvariable_length_) );
 
         ref->setJavaObject( std::make_shared<jau::JavaGlobalObj>( std::move(global_obj), nullptr ) );
         jau::JavaGlobalObj::check(ref->getJavaObject(), E_FILE_LINE);
 
-        std::shared_ptr<DBGattChar> * ref_ptr = new std::shared_ptr<DBGattChar>(std::move(ref));
-        return (jlong) (intptr_t) ref_ptr;
+        return ref.release_to_jlong();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -331,10 +332,15 @@ jlong Java_org_direct_1bt_DBGattChar_ctorImpl(JNIEnv *env, jobject obj,
 void Java_org_direct_1bt_DBGattChar_dtorImpl(JNIEnv *env, jclass clazz, jlong nativeInstance) {
     (void)clazz;
     try {
-        if( 0 != nativeInstance ) {
-            std::shared_ptr<DBGattChar> * ref_ptr = reinterpret_cast<std::shared_ptr<DBGattChar> *>(nativeInstance);
-            (*ref_ptr)->setJavaObject();
-            delete ref_ptr;
+        jau::shared_ptr_ref<BTGattChar> sref(nativeInstance, false /* throw_on_nullptr */); // hold copy until done
+        if( nullptr != sref.pointer() ) {
+            if( !sref.is_null() ) {
+                jau::JavaAnonRef sref_java = sref->getJavaObject(); // hold until done!
+                jau::JavaGlobalObj::check(sref_java, E_FILE_LINE);
+                sref->setJavaObject();
+            }
+            std::shared_ptr<BTGattChar>* sref_ptr = jau::castInstance<BTGattChar>(nativeInstance);
+            delete sref_ptr;
         }
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -344,8 +350,8 @@ void Java_org_direct_1bt_DBGattChar_dtorImpl(JNIEnv *env, jclass clazz, jlong na
 jshort Java_org_direct_1bt_DBGattChar_getHandle(JNIEnv *env, jobject obj)
 {
     try {
-        std::shared_ptr<DBGattChar> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattChar>>(env, obj);
-        return (jshort)( (*ref_ptr)->getHandle() );
+        jau::shared_ptr_ref<DBGattChar> ref(env, obj); // hold until done
+        return (jshort)( ref->getHandle() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -355,8 +361,8 @@ jshort Java_org_direct_1bt_DBGattChar_getHandle(JNIEnv *env, jobject obj)
 jshort Java_org_direct_1bt_DBGattChar_getEndHandle(JNIEnv *env, jobject obj)
 {
     try {
-        std::shared_ptr<DBGattChar> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattChar>>(env, obj);
-        return (jshort)( (*ref_ptr)->getEndHandle() );
+        jau::shared_ptr_ref<DBGattChar> ref(env, obj); // hold until done
+        return (jshort)( ref->getEndHandle() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -366,8 +372,8 @@ jshort Java_org_direct_1bt_DBGattChar_getEndHandle(JNIEnv *env, jobject obj)
 jshort Java_org_direct_1bt_DBGattChar_getValueHandle(JNIEnv *env, jobject obj)
 {
     try {
-        std::shared_ptr<DBGattChar> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattChar>>(env, obj);
-        return (jshort)( (*ref_ptr)->getValueHandle() );
+        jau::shared_ptr_ref<DBGattChar> ref(env, obj); // hold until done
+        return (jshort)( ref->getValueHandle() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -378,8 +384,8 @@ jshort Java_org_direct_1bt_DBGattChar_getValueHandle(JNIEnv *env, jobject obj)
 void Java_org_direct_1bt_DBGattChar_bzero(JNIEnv *env, jobject obj)
 {
     try {
-        std::shared_ptr<DBGattChar> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattChar>>(env, obj);
-        (*ref_ptr)->bzero();
+        jau::shared_ptr_ref<DBGattChar> ref(env, obj); // hold until done
+        ref->bzero();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -387,8 +393,8 @@ void Java_org_direct_1bt_DBGattChar_bzero(JNIEnv *env, jobject obj)
 
 jstring Java_org_direct_1bt_DBGattChar_toString(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<DBGattChar> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattChar>>(env, obj);
-        return jau::from_string_to_jstring(env, (*ref_ptr)->toString());
+        jau::shared_ptr_ref<DBGattChar> ref(env, obj); // hold until done
+        return jau::from_string_to_jstring(env, ref->toString());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -424,8 +430,8 @@ jlong Java_org_direct_1bt_DBGattService_ctorImpl(JNIEnv *env, jobject obj,
                 throw jau::InternalError("GetPrimitiveArrayCritical(DBGattChar* array) is null", E_FILE_LINE);
             }
             for(jau::nsize_t i=0; i < count; ++i) {
-                std::shared_ptr<DBGattChar> *char_ref = (std::shared_ptr<DBGattChar> *) (intptr_t) jlong_char_ref_array[i];
-                characteristics.push_back( *char_ref );
+                std::shared_ptr<DBGattChar> char_ref = *( (std::shared_ptr<DBGattChar> *) (intptr_t) jlong_char_ref_array[i] );
+                characteristics.push_back( char_ref );
             }
         }
 
@@ -434,15 +440,12 @@ jlong Java_org_direct_1bt_DBGattService_ctorImpl(JNIEnv *env, jobject obj,
         std::shared_ptr<const jau::uuid_t> type( jau::uuid_t::create(stype) );
 
         // new instance
-        std::shared_ptr<DBGattService> ref = std::make_shared<DBGattService>(
-                                            JNI_TRUE == jprimary, type,
-                                            std::move(characteristics));
+        jau::shared_ptr_ref<DBGattService> ref( new DBGattService( JNI_TRUE == jprimary, type, std::move(characteristics) ) );
 
         ref->setJavaObject( std::make_shared<jau::JavaGlobalObj>( std::move(global_obj), nullptr ) );
         jau::JavaGlobalObj::check(ref->getJavaObject(), E_FILE_LINE);
 
-        std::shared_ptr<DBGattService> * ref_ptr = new std::shared_ptr<DBGattService>(std::move(ref));
-        return (jlong) (intptr_t) ref_ptr;
+        return ref.release_to_jlong();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -452,10 +455,15 @@ jlong Java_org_direct_1bt_DBGattService_ctorImpl(JNIEnv *env, jobject obj,
 void Java_org_direct_1bt_DBGattService_dtorImpl(JNIEnv *env, jclass clazz, jlong nativeInstance) {
     (void)clazz;
     try {
-        if( 0 != nativeInstance ) {
-            std::shared_ptr<DBGattService> * ref_ptr = reinterpret_cast<std::shared_ptr<DBGattService> *>(nativeInstance);
-            (*ref_ptr)->setJavaObject();
-            delete ref_ptr;
+        jau::shared_ptr_ref<DBGattService> sref(nativeInstance, false /* throw_on_nullptr */); // hold copy until done
+        if( nullptr != sref.pointer() ) {
+            if( !sref.is_null() ) {
+                jau::JavaAnonRef sref_java = sref->getJavaObject(); // hold until done!
+                jau::JavaGlobalObj::check(sref_java, E_FILE_LINE);
+                sref->setJavaObject();
+            }
+            std::shared_ptr<DBGattService>* sref_ptr = jau::castInstance<DBGattService>(nativeInstance);
+            delete sref_ptr;
         }
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -465,8 +473,8 @@ void Java_org_direct_1bt_DBGattService_dtorImpl(JNIEnv *env, jclass clazz, jlong
 jshort Java_org_direct_1bt_DBGattService_getHandle(JNIEnv *env, jobject obj)
 {
     try {
-        std::shared_ptr<DBGattService> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattService>>(env, obj);
-        return (jshort)( (*ref_ptr)->getHandle() );
+        jau::shared_ptr_ref<DBGattService> ref(env, obj); // hold until done
+        return (jshort)( ref->getHandle() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -476,8 +484,8 @@ jshort Java_org_direct_1bt_DBGattService_getHandle(JNIEnv *env, jobject obj)
 jshort Java_org_direct_1bt_DBGattService_getEndHandle(JNIEnv *env, jobject obj)
 {
     try {
-        std::shared_ptr<DBGattService> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattService>>(env, obj);
-        return (jshort)( (*ref_ptr)->getEndHandle() );
+        jau::shared_ptr_ref<DBGattService> ref(env, obj); // hold until done
+        return (jshort)( ref->getEndHandle() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -486,8 +494,8 @@ jshort Java_org_direct_1bt_DBGattService_getEndHandle(JNIEnv *env, jobject obj)
 
 jstring Java_org_direct_1bt_DBGattService_toString(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<DBGattService> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattService>>(env, obj);
-        return jau::from_string_to_jstring(env, (*ref_ptr)->toString());
+        jau::shared_ptr_ref<DBGattService> ref(env, obj); // hold until done
+        return jau::from_string_to_jstring(env, ref->toString());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -522,21 +530,18 @@ jlong Java_org_direct_1bt_DBGattServer_ctorImpl(JNIEnv *env, jobject obj,
                 throw jau::InternalError("GetPrimitiveArrayCritical(DBGattService* array) is null", E_FILE_LINE);
             }
             for(jau::nsize_t i=0; i < count; ++i) {
-                std::shared_ptr<DBGattService> *service_ref = (std::shared_ptr<DBGattService> *) (intptr_t) jlong_service_ref_array[i];
-                services.push_back( *service_ref );
+                std::shared_ptr<DBGattService> service_ref = *( (std::shared_ptr<DBGattService> *) (intptr_t) jlong_service_ref_array[i] );
+                services.push_back( service_ref );
             }
         }
 
         // new instance
-        std::shared_ptr<DBGattServer> ref = std::make_shared<DBGattServer>(
-                                            jmax_att_mtu,
-                                            std::move(services));
+        jau::shared_ptr_ref<DBGattServer> ref( new DBGattServer( jmax_att_mtu, std::move(services) ) );
 
         ref->setJavaObject( std::make_shared<jau::JavaGlobalObj>( std::move(global_obj), nullptr ) );
         jau::JavaGlobalObj::check(ref->getJavaObject(), E_FILE_LINE);
 
-        std::shared_ptr<DBGattServer> * ref_ptr = new std::shared_ptr<DBGattServer>(std::move(ref));
-        return (jlong) (intptr_t) ref_ptr;
+        return ref.release_to_jlong();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -546,10 +551,15 @@ jlong Java_org_direct_1bt_DBGattServer_ctorImpl(JNIEnv *env, jobject obj,
 void Java_org_direct_1bt_DBGattServer_dtorImpl(JNIEnv *env, jclass clazz, jlong nativeInstance) {
     (void)clazz;
     try {
-        if( 0 != nativeInstance ) {
-            std::shared_ptr<DBGattServer> * ref_ptr = reinterpret_cast<std::shared_ptr<DBGattServer> *>(nativeInstance);
-            (*ref_ptr)->setJavaObject();
-            delete ref_ptr;
+        jau::shared_ptr_ref<DBGattServer> sref(nativeInstance, false /* throw_on_nullptr */); // hold copy until done
+        if( nullptr != sref.pointer() ) {
+            if( !sref.is_null() ) {
+                jau::JavaAnonRef sref_java = sref->getJavaObject(); // hold until done!
+                jau::JavaGlobalObj::check(sref_java, E_FILE_LINE);
+                sref->setJavaObject();
+            }
+            std::shared_ptr<DBGattServer>* sref_ptr = jau::castInstance<DBGattServer>(nativeInstance);
+            delete sref_ptr;
         }
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -559,8 +569,8 @@ void Java_org_direct_1bt_DBGattServer_dtorImpl(JNIEnv *env, jclass clazz, jlong
 jint Java_org_direct_1bt_DBGattServer_getMaxAttMTU(JNIEnv *env, jobject obj)
 {
     try {
-        std::shared_ptr<DBGattServer> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattServer>>(env, obj);
-        return (jint)( (*ref_ptr)->getMaxAttMTU() );
+        jau::shared_ptr_ref<DBGattServer> ref(env, obj); // hold until done
+        return (jint)( ref->getMaxAttMTU() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -570,8 +580,8 @@ jint Java_org_direct_1bt_DBGattServer_getMaxAttMTU(JNIEnv *env, jobject obj)
 void Java_org_direct_1bt_DBGattServer_setMaxAttMTU(JNIEnv *env, jobject obj, jint v)
 {
     try {
-        std::shared_ptr<DBGattServer> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattServer>>(env, obj);
-        (*ref_ptr)->setMaxAttMTU(v);
+        jau::shared_ptr_ref<DBGattServer> ref(env, obj); // hold until done
+        ref->setMaxAttMTU(v);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -579,8 +589,8 @@ void Java_org_direct_1bt_DBGattServer_setMaxAttMTU(JNIEnv *env, jobject obj, jin
 
 jstring Java_org_direct_1bt_DBGattServer_toString(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<DBGattServer> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattServer>>(env, obj);
-        return jau::from_string_to_jstring(env, (*ref_ptr)->toString());
+        jau::shared_ptr_ref<DBGattServer> ref(env, obj); // hold until done
+        return jau::from_string_to_jstring(env, ref->toString());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -748,9 +758,9 @@ class JNIDBGattServerListener : public DBGattServer::Listener {
  */
 jboolean Java_org_direct_1bt_DBGattServer_addListenerImpl(JNIEnv *env, jobject obj, jobject jlistener) {
     try {
-        std::shared_ptr<DBGattServer> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattServer>>(env, obj);
-        std::shared_ptr<JNIDBGattServerListener> * listener_ref_ptr = jau::getInstance<std::shared_ptr<JNIDBGattServerListener>>(env, jlistener);
-        bool res = (*ref_ptr)->addListener(*listener_ref_ptr);
+        jau::shared_ptr_ref<DBGattServer> ref(env, obj); // hold until done
+        jau::shared_ptr_ref<JNIDBGattServerListener> listener_ref(env, jlistener); // hold until done
+        bool res = ref->addListener(listener_ref.shared_ptr());
         return res ? JNI_TRUE : JNI_FALSE;
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -765,9 +775,9 @@ jboolean Java_org_direct_1bt_DBGattServer_addListenerImpl(JNIEnv *env, jobject o
  */
 jboolean Java_org_direct_1bt_DBGattServer_removeListenerImpl(JNIEnv *env, jobject obj, jobject jlistener) {
     try {
-        std::shared_ptr<DBGattServer> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattServer>>(env, obj);
-        std::shared_ptr<JNIDBGattServerListener> * listener_ref_ptr = jau::getInstance<std::shared_ptr<JNIDBGattServerListener>>(env, jlistener);
-        bool res = (*ref_ptr)->removeListener(*listener_ref_ptr);
+        jau::shared_ptr_ref<DBGattServer> ref(env, obj); // hold until done
+        jau::shared_ptr_ref<JNIDBGattServerListener> listener_ref(env, jlistener); // hold until done
+        bool res = ref->removeListener(listener_ref.shared_ptr());
         return res ? JNI_TRUE : JNI_FALSE;
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -784,11 +794,10 @@ jboolean Java_org_direct_1bt_DBGattServer_removeListenerImpl(JNIEnv *env, jobjec
 jlong Java_org_direct_1bt_DBGattServer_00024Listener_ctorImpl(JNIEnv *env, jobject obj) {
     try {
         jclass clazz = jau::search_class(env, obj);
-        std::shared_ptr<JNIDBGattServerListener> ref = std::make_shared<JNIDBGattServerListener>(env, clazz, obj);
+        jau::shared_ptr_ref<JNIDBGattServerListener> ref( new JNIDBGattServerListener(env, clazz, obj) );
         env->DeleteLocalRef(clazz);
 
-        std::shared_ptr<JNIDBGattServerListener> * ref_ptr = new std::shared_ptr<JNIDBGattServerListener>(std::move(ref));
-        return (jlong)(intptr_t)ref_ptr;
+        return ref.release_to_jlong();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -803,9 +812,10 @@ jlong Java_org_direct_1bt_DBGattServer_00024Listener_ctorImpl(JNIEnv *env, jobje
 void Java_org_direct_1bt_DBGattServer_00024Listener_dtorImpl(JNIEnv *env, jclass clazz, jlong nativeInstance) {
     (void)clazz;
     try {
-        if( 0 != nativeInstance ) {
-            std::shared_ptr<JNIDBGattServerListener> * ref_ptr = reinterpret_cast<std::shared_ptr<JNIDBGattServerListener> *>(nativeInstance);
-            delete ref_ptr;
+        jau::shared_ptr_ref<JNIDBGattServerListener> sref(nativeInstance, false /* throw_on_nullptr */); // hold copy until done
+        if( nullptr != sref.pointer() ) {
+            std::shared_ptr<JNIDBGattServerListener>* sref_ptr = jau::castInstance<JNIDBGattServerListener>(nativeInstance);
+            delete sref_ptr;
         }
     } catch(...) {
         rethrow_and_raise_java_exception(env);
diff --git a/java/jni/direct_bt/DBTAdapter.cxx b/java/jni/direct_bt/DBTAdapter.cxx
index 461cab35..51023378 100644
--- a/java/jni/direct_bt/DBTAdapter.cxx
+++ b/java/jni/direct_bt/DBTAdapter.cxx
@@ -567,8 +567,9 @@ jint Java_jau_direct_1bt_DBTAdapter_removeAllStatusListenerImpl(JNIEnv *env, job
 
 jboolean Java_jau_direct_1bt_DBTAdapter_isDeviceWhitelisted(JNIEnv *env, jobject obj, jbyteArray jaddress, jbyte jaddressType) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
 
         if( nullptr == jaddress ) {
             throw jau::IllegalArgumentException("address null", E_FILE_LINE);
@@ -596,8 +597,9 @@ jboolean Java_jau_direct_1bt_DBTAdapter_addDeviceToWhitelistImpl1(JNIEnv *env, j
                                                                     jshort min_interval, jshort max_interval,
                                                                     jshort latency, jshort timeout) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
 
         if( nullptr == jaddress ) {
             throw jau::IllegalArgumentException("address null", E_FILE_LINE);
@@ -624,8 +626,9 @@ jboolean Java_jau_direct_1bt_DBTAdapter_addDeviceToWhitelistImpl1(JNIEnv *env, j
 jboolean Java_jau_direct_1bt_DBTAdapter_addDeviceToWhitelistImpl2(JNIEnv *env, jobject obj,
                                                                     jbyteArray jaddress, jbyte jaddressType, int jctype) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
 
         if( nullptr == jaddress ) {
             throw jau::IllegalArgumentException("address null", E_FILE_LINE);
@@ -651,8 +654,9 @@ jboolean Java_jau_direct_1bt_DBTAdapter_addDeviceToWhitelistImpl2(JNIEnv *env, j
 }
 jboolean Java_jau_direct_1bt_DBTAdapter_removeDeviceFromWhitelistImpl(JNIEnv *env, jobject obj, jbyteArray jaddress, jbyte jaddressType) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
 
         if( nullptr == jaddress ) {
             throw jau::IllegalArgumentException("address null", E_FILE_LINE);
@@ -678,33 +682,24 @@ jboolean Java_jau_direct_1bt_DBTAdapter_removeDeviceFromWhitelistImpl(JNIEnv *en
 
 jstring Java_jau_direct_1bt_DBTAdapter_toStringImpl(JNIEnv *env, jobject obj) {
     try {
-        BTAdapter *nativePtr = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(nativePtr->getJavaObject(), E_FILE_LINE);
-        return jau::from_string_to_jstring(env, nativePtr->toString());
-    } catch(...) {
-        rethrow_and_raise_java_exception(env);
-    }
-    return nullptr;
-}
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
 
-void Java_jau_direct_1bt_DBTAdapter_deleteImpl(JNIEnv *env, jobject obj, jlong nativeInstance)
-{
-    (void)obj;
-    try {
-        BTAdapter *adapter = jau::castInstance<BTAdapter>(nativeInstance);
-        DBG_PRINT("Java_jau_direct_1bt_DBTAdapter_deleteImpl (close only) %s", adapter->toString().c_str());
-        adapter->close();
-        // No delete: BTAdapter instance owned by DBTManager
-        // However, adapter->close() cleans up most..
+        return jau::from_string_to_jstring(env, adapter->toString());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
+    return nullptr;
 }
 
 jint Java_jau_direct_1bt_DBTAdapter_getBTMajorVersion(JNIEnv *env, jobject obj)
 {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return (jint) adapter->getBTMajorVersion();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -715,7 +710,10 @@ jint Java_jau_direct_1bt_DBTAdapter_getBTMajorVersion(JNIEnv *env, jobject obj)
 jboolean Java_jau_direct_1bt_DBTAdapter_isPoweredImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return adapter->isPowered();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -726,7 +724,10 @@ jboolean Java_jau_direct_1bt_DBTAdapter_isPoweredImpl(JNIEnv *env, jobject obj)
 jboolean Java_jau_direct_1bt_DBTAdapter_isSuspendedImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return adapter->isSuspended();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -737,7 +738,10 @@ jboolean Java_jau_direct_1bt_DBTAdapter_isSuspendedImpl(JNIEnv *env, jobject obj
 jboolean Java_jau_direct_1bt_DBTAdapter_isValidImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return adapter->isValid();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -748,7 +752,10 @@ jboolean Java_jau_direct_1bt_DBTAdapter_isValidImpl(JNIEnv *env, jobject obj)
 jlong Java_jau_direct_1bt_DBTAdapter_getLEFeaturesImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return (jlong) number( adapter->getLEFeatures() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -762,7 +769,10 @@ jbyte Java_jau_direct_1bt_DBTAdapter_startDiscoveryImpl(JNIEnv *env, jobject obj
                                                         jboolean filter_dup)
 {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return (jbyte) number( adapter->startDiscovery(static_cast<DiscoveryPolicy>(policy), le_scan_active, le_scan_interval, le_scan_window, filter_policy, filter_dup==JNI_TRUE) );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -773,7 +783,10 @@ jbyte Java_jau_direct_1bt_DBTAdapter_startDiscoveryImpl(JNIEnv *env, jobject obj
 jbyte Java_jau_direct_1bt_DBTAdapter_stopDiscoveryImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return (jbyte) number( adapter->stopDiscovery() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -784,7 +797,10 @@ jbyte Java_jau_direct_1bt_DBTAdapter_stopDiscoveryImpl(JNIEnv *env, jobject obj)
 jbyte Java_jau_direct_1bt_DBTAdapter_getCurrentDiscoveryPolicyImpl(JNIEnv *env, jobject obj) {
     DiscoveryPolicy current = DiscoveryPolicy::AUTO_OFF;
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         current = adapter->getCurrentDiscoveryPolicy();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -794,10 +810,13 @@ jbyte Java_jau_direct_1bt_DBTAdapter_getCurrentDiscoveryPolicyImpl(JNIEnv *env,
 
 jboolean Java_jau_direct_1bt_DBTAdapter_removeDevicePausingDiscovery(JNIEnv *env, jobject obj, jobject jdevice) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
 
-        BTDevice *device = jau::getJavaUplinkObject<BTDevice>(env, jdevice);
-        jau::JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTDevice> device(env, jdevice); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return adapter->removeDevicePausingDiscovery(*device) ? JNI_TRUE : JNI_FALSE;
     } catch(...) {
@@ -809,7 +828,10 @@ jboolean Java_jau_direct_1bt_DBTAdapter_removeDevicePausingDiscovery(JNIEnv *env
 jbyte Java_jau_direct_1bt_DBTAdapter_getRoleImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return (jbyte) number( adapter->getRole() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -820,7 +842,10 @@ jbyte Java_jau_direct_1bt_DBTAdapter_getRoleImpl(JNIEnv *env, jobject obj)
 jbyte Java_jau_direct_1bt_DBTAdapter_getBTModeImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return (jbyte) number( adapter->getBTMode() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -831,7 +856,10 @@ jbyte Java_jau_direct_1bt_DBTAdapter_getBTModeImpl(JNIEnv *env, jobject obj)
 jobject Java_jau_direct_1bt_DBTAdapter_getDiscoveredDevicesImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         jau::darray<BTDeviceRef> array = adapter->getDiscoveredDevices();
         return convert_vector_sharedptr_to_jarraylist(env, array);
     } catch(...) {
@@ -843,7 +871,10 @@ jobject Java_jau_direct_1bt_DBTAdapter_getDiscoveredDevicesImpl(JNIEnv *env, job
 jint Java_jau_direct_1bt_DBTAdapter_removeDiscoveredDevicesImpl1(JNIEnv *env, jobject obj)
 {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return adapter->removeDiscoveredDevices();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -854,8 +885,9 @@ jint Java_jau_direct_1bt_DBTAdapter_removeDiscoveredDevicesImpl1(JNIEnv *env, jo
 jboolean Java_jau_direct_1bt_DBTAdapter_removeDiscoveredDeviceImpl1(JNIEnv *env, jobject obj, jbyteArray jaddress, jbyte jaddressType)
 {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
 
         if( nullptr == jaddress ) {
             throw jau::IllegalArgumentException("address null", E_FILE_LINE);
@@ -885,8 +917,10 @@ jboolean Java_jau_direct_1bt_DBTAdapter_removeDiscoveredDeviceImpl1(JNIEnv *env,
 
 jboolean Java_jau_direct_1bt_DBTAdapter_setPowered(JNIEnv *env, jobject obj, jboolean power_on) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return adapter->setPowered(JNI_TRUE == power_on ? true : false) ? JNI_TRUE : JNI_FALSE;
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -896,8 +930,10 @@ jboolean Java_jau_direct_1bt_DBTAdapter_setPowered(JNIEnv *env, jobject obj, jbo
 
 jboolean Java_jau_direct_1bt_DBTAdapter_getSecureConnectionsEnabled(JNIEnv *env, jobject obj) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return adapter->getSecureConnectionsEnabled() ? JNI_TRUE : JNI_FALSE;
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -907,8 +943,10 @@ jboolean Java_jau_direct_1bt_DBTAdapter_getSecureConnectionsEnabled(JNIEnv *env,
 
 jbyte Java_jau_direct_1bt_DBTAdapter_setSecureConnectionsImpl(JNIEnv *env, jobject obj, jboolean enable) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         HCIStatusCode res = adapter->setSecureConnections(JNI_TRUE == enable ? true : false);
         return (jbyte) number(res);
     } catch(...) {
@@ -921,8 +959,10 @@ jbyte Java_jau_direct_1bt_DBTAdapter_setDefaultConnParamImpl(JNIEnv *env, jobjec
                                                              jshort conn_interval_min, jshort conn_interval_max,
                                                              jshort conn_latency, jshort supervision_timeout) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         HCIStatusCode res = adapter->setDefaultConnParam(static_cast<uint16_t>(conn_interval_min),
                                                          static_cast<uint16_t>(conn_interval_max),
                                                          static_cast<uint16_t>(conn_latency),
@@ -936,8 +976,9 @@ jbyte Java_jau_direct_1bt_DBTAdapter_setDefaultConnParamImpl(JNIEnv *env, jobjec
 
 void Java_jau_direct_1bt_DBTAdapter_setServerConnSecurityImpl(JNIEnv *env, jobject obj, jbyte jsec_level, jbyte jio_cap) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
 
         adapter->setServerConnSecurity( to_BTSecurityLevel( static_cast<uint8_t>(jsec_level) ),
                                         to_SMPIOCapability( static_cast<uint8_t>(jio_cap) ) );
@@ -948,8 +989,10 @@ void Java_jau_direct_1bt_DBTAdapter_setServerConnSecurityImpl(JNIEnv *env, jobje
 
 void Java_jau_direct_1bt_DBTAdapter_setSMPKeyPath(JNIEnv *env, jobject obj, jstring jpath) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         std::string path = jau::from_jstring_to_string(env, jpath);
         adapter->setSMPKeyPath(path);
     } catch(...) {
@@ -959,8 +1002,10 @@ void Java_jau_direct_1bt_DBTAdapter_setSMPKeyPath(JNIEnv *env, jobject obj, jstr
 
 jbyte Java_jau_direct_1bt_DBTAdapter_initializeImpl(JNIEnv *env, jobject obj, jbyte jbtMode) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         const BTMode btMode = static_cast<BTMode>(jbtMode);
         HCIStatusCode res = adapter->initialize(btMode);
         return (jbyte) number(res);
@@ -972,8 +1017,10 @@ jbyte Java_jau_direct_1bt_DBTAdapter_initializeImpl(JNIEnv *env, jobject obj, jb
 
 jboolean Java_jau_direct_1bt_DBTAdapter_isInitialized(JNIEnv *env, jobject obj) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return adapter->isInitialized();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -983,8 +1030,10 @@ jboolean Java_jau_direct_1bt_DBTAdapter_isInitialized(JNIEnv *env, jobject obj)
 
 jbyte Java_jau_direct_1bt_DBTAdapter_resetImpl(JNIEnv *env, jobject obj) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         HCIStatusCode res = adapter->reset();
         return (jbyte) number(res);
     } catch(...) {
@@ -996,8 +1045,9 @@ jbyte Java_jau_direct_1bt_DBTAdapter_resetImpl(JNIEnv *env, jobject obj) {
 jbyte Java_jau_direct_1bt_DBTAdapter_setDefaultLE_1PHYImpl(JNIEnv *env, jobject obj,
                                                            jbyte jTx, jbyte jRx) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
 
         const LE_PHYs Tx = static_cast<LE_PHYs>(jTx);
         const LE_PHYs Rx = static_cast<LE_PHYs>(jRx);
@@ -1011,8 +1061,10 @@ jbyte Java_jau_direct_1bt_DBTAdapter_setDefaultLE_1PHYImpl(JNIEnv *env, jobject
 
 jstring Java_jau_direct_1bt_DBTAdapter_getNameImpl(JNIEnv *env, jobject obj) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return jau::from_string_to_jstring(env, adapter->getName());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -1022,8 +1074,10 @@ jstring Java_jau_direct_1bt_DBTAdapter_getNameImpl(JNIEnv *env, jobject obj) {
 
 jstring Java_jau_direct_1bt_DBTAdapter_getShortNameImpl(JNIEnv *env, jobject obj) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return jau::from_string_to_jstring(env, adapter->getShortName());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -1033,8 +1087,10 @@ jstring Java_jau_direct_1bt_DBTAdapter_getShortNameImpl(JNIEnv *env, jobject obj
 
 jbyte Java_jau_direct_1bt_DBTAdapter_setNameImpl(JNIEnv *env, jobject obj, jstring jname, jstring jshort_name) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         std::string name = jau::from_jstring_to_string(env, jname);
         std::string short_name = jau::from_jstring_to_string(env, jshort_name);
         return (jbyte) number( adapter->setName(name, short_name) );
@@ -1046,8 +1102,9 @@ jbyte Java_jau_direct_1bt_DBTAdapter_setNameImpl(JNIEnv *env, jobject obj, jstri
 
 jobject Java_jau_direct_1bt_DBTAdapter_connectDeviceImpl(JNIEnv *env, jobject obj, jbyteArray jaddress, jbyte jaddressType) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
 
         if( nullptr == jaddress ) {
             throw jau::IllegalArgumentException("address null", E_FILE_LINE);
@@ -1073,7 +1130,7 @@ jobject Java_jau_direct_1bt_DBTAdapter_connectDeviceImpl(JNIEnv *env, jobject ob
             if( !hci.isOpen() ) {
                 throw BTException("Adapter's HCI closed "+adapter->toString(), E_FILE_LINE);
             }
-            std::shared_ptr<jau::JavaAnon> jDeviceRef = device->getJavaObject();
+            jau::JavaAnonRef jDeviceRef = device->getJavaObject();
             jau::JavaGlobalObj::check(jDeviceRef, E_FILE_LINE);
 
             device->connectDefault();
@@ -1087,8 +1144,10 @@ jobject Java_jau_direct_1bt_DBTAdapter_connectDeviceImpl(JNIEnv *env, jobject ob
 
 void Java_jau_direct_1bt_DBTAdapter_printDeviceListsImpl(JNIEnv *env, jobject obj) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         adapter->printDeviceLists();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -1103,22 +1162,18 @@ jbyte Java_jau_direct_1bt_DBTAdapter_startAdvertising1Impl(JNIEnv *env, jobject
                                                            jshort adv_interval_min, jshort adv_interval_max,
                                                            jbyte jadv_type, jbyte adv_chan_map, jbyte filter_policy) {
     try {
-        DBGattServerRef gattServerRef; // nullptr
-        if( nullptr != jgattServerData ) {
-            std::shared_ptr<DBGattServer> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattServer>>(env, jgattServerData);
-            gattServerRef = *ref_ptr;
-        }
-        if( nullptr == jeir ) {
-            throw jau::IllegalArgumentException("eir null", E_FILE_LINE);
-        }
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, jeir);
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
+        jau::shared_ptr_ref<DBGattServer> gatt_server_ref(env, jgattServerData, false /** throw_on_null */); // hold until done
+        gatt_server_ref.null_check1();
+        jau::shared_ptr_ref<EInfoReport> eir_ref(env, jeir); // hold until done
 
         const EIRDataType adv_mask = static_cast<EIRDataType>(jadv_mask);
         const EIRDataType scanrsp_mask = static_cast<EIRDataType>(jscanrsp_mask);
         const AD_PDU_Type adv_type = static_cast<AD_PDU_Type>(jadv_type);
-        HCIStatusCode res = adapter->startAdvertising(gattServerRef, *eir_ptr, adv_mask, scanrsp_mask, adv_interval_min, adv_interval_max, adv_type, adv_chan_map, filter_policy);
+        HCIStatusCode res = adapter->startAdvertising(gatt_server_ref.shared_ptr(), *eir_ref, adv_mask, scanrsp_mask, adv_interval_min, adv_interval_max, adv_type, adv_chan_map, filter_policy);
         return (jbyte) number(res);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -1131,15 +1186,15 @@ jbyte Java_jau_direct_1bt_DBTAdapter_startAdvertising2Impl(JNIEnv *env, jobject
                                                            jshort adv_interval_min, jshort adv_interval_max, jbyte jadv_type, jbyte adv_chan_map,
                                                            jbyte filter_policy) {
     try {
-        DBGattServerRef gattServerRef; // nullptr
-        if( nullptr != jgattServerData ) {
-            std::shared_ptr<DBGattServer> * ref_ptr = jau::getInstance<std::shared_ptr<DBGattServer>>(env, jgattServerData);
-            gattServerRef = *ref_ptr;
-        }
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
+        jau::shared_ptr_ref<DBGattServer> gatt_server_ref(env, jgattServerData, false /** throw_on_null */); // hold until done
+        gatt_server_ref.null_check1();
+
         const AD_PDU_Type adv_type = static_cast<AD_PDU_Type>(jadv_type);
-        HCIStatusCode res = adapter->startAdvertising(gattServerRef, adv_interval_min, adv_interval_max, adv_type, adv_chan_map, filter_policy);
+        HCIStatusCode res = adapter->startAdvertising(gatt_server_ref.shared_ptr(), adv_interval_min, adv_interval_max, adv_type, adv_chan_map, filter_policy);
         return (jbyte) number(res);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -1149,8 +1204,10 @@ jbyte Java_jau_direct_1bt_DBTAdapter_startAdvertising2Impl(JNIEnv *env, jobject
 
 jbyte Java_jau_direct_1bt_DBTAdapter_stopAdvertisingImpl(JNIEnv *env, jobject obj) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         HCIStatusCode res = adapter->stopAdvertising();
         return (jbyte) number(res);
     } catch(...) {
@@ -1161,8 +1218,10 @@ jbyte Java_jau_direct_1bt_DBTAdapter_stopAdvertisingImpl(JNIEnv *env, jobject ob
 
 jboolean Java_jau_direct_1bt_DBTAdapter_isAdvertising(JNIEnv *env, jobject obj) {
     try {
-        BTAdapter *adapter = jau::getJavaUplinkObject<BTAdapter>(env, obj);
-        jau::JavaGlobalObj::check(adapter->getJavaObject(), E_FILE_LINE);
+        jau::shared_ptr_ref<BTAdapter> adapter(env, obj); // hold until done
+        jau::JavaAnonRef adapter_java = adapter->getJavaObject(); // hold until done!
+        jau::JavaGlobalObj::check(adapter_java, E_FILE_LINE);
+
         return adapter->isAdvertising() ? JNI_TRUE : JNI_FALSE;
     } catch(...) {
         rethrow_and_raise_java_exception(env);
diff --git a/java/jni/direct_bt/DBTDevice.cxx b/java/jni/direct_bt/DBTDevice.cxx
index d28e50db..86d940f9 100644
--- a/java/jni/direct_bt/DBTDevice.cxx
+++ b/java/jni/direct_bt/DBTDevice.cxx
@@ -59,7 +59,7 @@ class JNIGattCharListener : public BTGattCharListener {
 
         };
     */
-    const BTGattChar * associatedCharacteristicRef;
+    std::shared_ptr<BTGattChar> associatedCharacteristicRef;
     JNIGlobalRef listenerObj; // keep listener instance alive
     JNIGlobalRef associatedCharacteristicObj; // keeps associated characteristic alive, if not null
     jmethodID  mNotificationReceived = nullptr;
@@ -67,7 +67,7 @@ class JNIGattCharListener : public BTGattCharListener {
 
   public:
 
-    JNIGattCharListener(JNIEnv *env, BTDevice *device, jobject listener, BTGattChar * associatedCharacteristicRef_)
+    JNIGattCharListener(JNIEnv *env, const std::shared_ptr<BTDevice>& device, jobject listener, const std::shared_ptr<BTGattChar>& associatedCharacteristicRef_)
     : associatedCharacteristicRef(associatedCharacteristicRef_),
       listenerObj(listener)
     {
@@ -103,7 +103,7 @@ class JNIGattCharListener : public BTGattCharListener {
 
     void notificationReceived(BTGattCharRef charDecl,
                               const TROOctets& charValue, const uint64_t timestamp) override {
-        std::shared_ptr<jau::JavaAnon> jCharDeclRef = charDecl->getJavaObject();
+        jau::JavaAnonRef jCharDeclRef = charDecl->getJavaObject();
         if( !jau::JavaGlobalObj::isValid(jCharDeclRef) ) {
             return; // java object has been pulled
         }
@@ -124,7 +124,7 @@ class JNIGattCharListener : public BTGattCharListener {
     void indicationReceived(BTGattCharRef charDecl,
                             const TROOctets& charValue, const uint64_t timestamp,
                             const bool confirmationSent) override {
-        std::shared_ptr<jau::JavaAnon> jCharDeclRef = charDecl->getJavaObject();
+        jau::JavaAnonRef jCharDeclRef = charDecl->getJavaObject();
         if( !jau::JavaGlobalObj::isValid(jCharDeclRef) ) {
             return; // java object has been pulled
         }
@@ -144,11 +144,34 @@ class JNIGattCharListener : public BTGattCharListener {
 };
 
 
+void Java_jau_direct_1bt_DBTDevice_deleteImpl(JNIEnv *env, jobject obj, jlong nativeInstance)
+{
+    (void)obj;
+    try {
+        jau::shared_ptr_ref<BTDevice> sref(nativeInstance, false /* throw_on_nullptr */); // hold copy until done
+        if( nullptr != sref.pointer() ) {
+            if( !sref.is_null() ) {
+                DBG_PRINT("Java_jau_direct_1bt_DBTDevice_deleteImpl (w/ remove) %s", sref->toString().c_str());
+                sref->remove();
+            } else {
+                DBG_PRINT("Java_jau_direct_1bt_DBTDevice_deleteImpl null reference");
+            }
+            std::shared_ptr<BTDevice>* sref_ptr = jau::castInstance<BTDevice>(nativeInstance);
+            delete sref_ptr;
+        } else {
+            DBG_PRINT("Java_jau_direct_1bt_DBTDevice_deleteImpl null reference store");
+        }
+    } catch(...) {
+        rethrow_and_raise_java_exception(env);
+    }
+}
+
 void Java_jau_direct_1bt_DBTDevice_initImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -156,9 +179,10 @@ void Java_jau_direct_1bt_DBTDevice_initImpl(JNIEnv *env, jobject obj)
 
 jstring Java_jau_direct_1bt_DBTDevice_getNameImpl(JNIEnv *env, jobject obj) {
     try {
-        BTDevice *nativePtr = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(nativePtr->getJavaObject(), E_FILE_LINE);
-        return from_string_to_jstring(env, nativePtr->getName());
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
+        return from_string_to_jstring(env, device->getName());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -167,9 +191,10 @@ jstring Java_jau_direct_1bt_DBTDevice_getNameImpl(JNIEnv *env, jobject obj) {
 
 jstring Java_jau_direct_1bt_DBTDevice_toStringImpl(JNIEnv *env, jobject obj) {
     try {
-        BTDevice *nativePtr = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(nativePtr->getJavaObject(), E_FILE_LINE);
-        return from_string_to_jstring(env, nativePtr->toString());
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
+        return from_string_to_jstring(env, device->toString());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -178,34 +203,31 @@ jstring Java_jau_direct_1bt_DBTDevice_toStringImpl(JNIEnv *env, jobject obj) {
 
 jboolean Java_jau_direct_1bt_DBTDevice_addCharListener(JNIEnv *env, jobject obj, jobject listener, jobject jAssociatedCharacteristic) {
     try {
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
+
         if( nullptr == listener ) {
             throw IllegalArgumentException("BTGattCharListener argument is null", E_FILE_LINE);
         }
         {
-            JNIGattCharListener * pre =
-                    getObjectRef<JNIGattCharListener>(env, listener, "nativeInstance");
-            if( nullptr != pre ) {
+            std::shared_ptr<JNIGattCharListener>* pre_orig = jau::getInstance<JNIGattCharListener>(env, listener, false /* throw_on_nullptr */);
+            if( !( nullptr == pre_orig || nullptr == *pre_orig ) ) {
                 throw IllegalStateException("BTGattCharListener's nativeInstance not null, already in use", E_FILE_LINE);
                 return false;
             }
         }
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         std::shared_ptr<BTGattHandler> gatt = device->getGattHandler();
         if( nullptr == gatt ) {
             throw IllegalStateException("BTGattChar's device GATTHandle not connected: "+ device->toString(), E_FILE_LINE);
         }
 
-        BTGattChar * associatedCharacteristicRef = nullptr;
-        if( nullptr != jAssociatedCharacteristic ) {
-            associatedCharacteristicRef = getJavaUplinkObject<BTGattChar>(env, jAssociatedCharacteristic);
-        }
-
-        std::shared_ptr<BTGattCharListener> l =
-                std::shared_ptr<BTGattCharListener>( new JNIGattCharListener(env, device, listener, associatedCharacteristicRef) );
+        jau::shared_ptr_ref<BTGattChar> associatedCharacteristicRef(env, jAssociatedCharacteristic, false /* throw_on_nullptr */);
 
-        if( gatt->addCharListener(l) ) {
-            setInstance(env, listener, l.get());
+        shared_ptr_ref<JNIGattCharListener> l(
+                        new JNIGattCharListener(env, device.shared_ptr(), listener, associatedCharacteristicRef.shared_ptr()) );
+        if( gatt->addCharListener( l.shared_ptr() ) ) {
+            l.release_into_object(env, listener);
             return JNI_TRUE;
         }
     } catch(...) {
@@ -216,23 +238,24 @@ jboolean Java_jau_direct_1bt_DBTDevice_addCharListener(JNIEnv *env, jobject obj,
 
 jboolean Java_jau_direct_1bt_DBTDevice_removeCharListener(JNIEnv *env, jobject obj, jobject jlistener) {
     try {
+        shared_ptr_ref<BTDevice> device(env, obj, false /* throw_on_nullptr */); // hold until done
+        if( device.is_null() ) {
+            // OK to have device being deleted already @ shutdown
+            return JNI_FALSE;
+        }
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
+
         if( nullptr == jlistener ) {
             throw IllegalArgumentException("BTGattCharListener argument is null", E_FILE_LINE);
         }
-        JNIGattCharListener * pre =
-                getObjectRef<JNIGattCharListener>(env, jlistener, "nativeInstance");
-        if( nullptr == pre ) {
+        shared_ptr_ref<JNIGattCharListener> pre( env, jlistener, false /* throw_on_nullptr */ ); // hold until done
+        if( pre.is_null() ) {
             WARN_PRINT("BTGattCharListener's nativeInstance is null, not in use");
             return false;
         }
-        setObjectRef<JNIGattCharListener>(env, jlistener, nullptr, "nativeInstance");
+        jau::clearInstance<JNIGattCharListener>(env, jlistener);
 
-        BTDevice *device = getJavaUplinkObjectUnchecked<BTDevice>(env, obj);
-        if( nullptr == device ) {
-            // OK to have device being deleted already @ shutdown
-            return 0;
-        }
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
         std::shared_ptr<BTGattHandler> gatt = device->getGattHandler();
         if( nullptr == gatt ) {
             // OK to have BTGattHandler being shutdown @ disable
@@ -240,8 +263,8 @@ jboolean Java_jau_direct_1bt_DBTDevice_removeCharListener(JNIEnv *env, jobject o
             return false;
         }
 
-        if( ! gatt->removeCharListener(pre) ) {
-            WARN_PRINT("Failed to remove BTGattCharListener with nativeInstance: %p at %s", pre, device->toString().c_str());
+        if( ! gatt->removeCharListener(pre.shared_ptr()) ) {
+            WARN_PRINT("Failed to remove BTGattCharListener with nativeInstance: %p at %s", pre.shared_ptr().get(), device->toString().c_str());
             return false;
         }
         return true;
@@ -253,15 +276,18 @@ jboolean Java_jau_direct_1bt_DBTDevice_removeCharListener(JNIEnv *env, jobject o
 
 jint Java_jau_direct_1bt_DBTDevice_removeAllAssociatedCharListener(JNIEnv *env, jobject obj, jobject jAssociatedCharacteristic) {
     try {
-        if( nullptr == jAssociatedCharacteristic ) {
-            throw IllegalArgumentException("associatedCharacteristic argument is null", E_FILE_LINE);
-        }
-        BTDevice *device = getJavaUplinkObjectUnchecked<BTDevice>(env, obj);
-        if( nullptr == device ) {
+        shared_ptr_ref<BTDevice> device(env, obj, false /* throw_on_nullptr */); // hold until done
+        if( device.is_null() ) {
             // OK to have device being deleted already @ shutdown
             return 0;
         }
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
+
+        shared_ptr_ref<BTGattChar> associatedCharacteristicRef(env, jAssociatedCharacteristic);
+        jau::JavaAnonRef device_gattchar = associatedCharacteristicRef->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_gattchar, E_FILE_LINE);
+
         std::shared_ptr<BTGattHandler> gatt = device->getGattHandler();
         if( nullptr == gatt ) {
             // OK to have BTGattHandler being shutdown @ disable
@@ -269,10 +295,7 @@ jint Java_jau_direct_1bt_DBTDevice_removeAllAssociatedCharListener(JNIEnv *env,
             return 0;
         }
 
-        BTGattChar * associatedCharacteristicRef = getJavaUplinkObject<BTGattChar>(env, jAssociatedCharacteristic);
-        JavaGlobalObj::check(associatedCharacteristicRef->getJavaObject(), E_FILE_LINE);
-
-        return gatt->removeAllAssociatedCharListener(associatedCharacteristicRef);
+        return gatt->removeAllAssociatedCharListener(associatedCharacteristicRef.shared_ptr());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -281,12 +304,14 @@ jint Java_jau_direct_1bt_DBTDevice_removeAllAssociatedCharListener(JNIEnv *env,
 
 jint Java_jau_direct_1bt_DBTDevice_removeAllCharListener(JNIEnv *env, jobject obj) {
     try {
-        BTDevice *device = getJavaUplinkObjectUnchecked<BTDevice>(env, obj);
-        if( nullptr == device ) {
+        shared_ptr_ref<BTDevice> device(env, obj, false /* throw_on_nullptr */); // hold until done
+        if( device.is_null() ) {
             // OK to have device being deleted already @ shutdown
             return 0;
         }
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
+
         std::shared_ptr<BTGattHandler> gatt = device->getGattHandler();
         if( nullptr == gatt ) {
             // OK to have BTGattHandler being shutdown @ disable
@@ -300,24 +325,12 @@ jint Java_jau_direct_1bt_DBTDevice_removeAllCharListener(JNIEnv *env, jobject ob
     return 0;
 }
 
-void Java_jau_direct_1bt_DBTDevice_deleteImpl(JNIEnv *env, jobject obj, jlong nativeInstance)
-{
-    (void)obj;
-    try {
-        BTDevice *device = castInstance<BTDevice>(nativeInstance);
-        DBG_PRINT("Java_jau_direct_1bt_DBTDevice_deleteImpl (remove only) %s", device->toString().c_str());
-        device->remove();
-        // No delete: BTDevice instance owned by BTAdapter
-        // However, device->remove() might issue destruction
-    } catch(...) {
-        rethrow_and_raise_java_exception(env);
-    }
-}
-
 jbyte Java_jau_direct_1bt_DBTDevice_getRoleImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
         return (jbyte) number( device->getRole() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -328,8 +341,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_getRoleImpl(JNIEnv *env, jobject obj)
 jbyte Java_jau_direct_1bt_DBTDevice_getConnectedLE_1PHYImpl(JNIEnv *env, jobject obj,
                                                             jbyteArray jresTx, jbyteArray jresRx) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         if( nullptr == jresTx ) {
             throw IllegalArgumentException("resTx byte array null", E_FILE_LINE);
@@ -371,8 +385,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_getConnectedLE_1PHYImpl(JNIEnv *env, jobject
 jbyte Java_jau_direct_1bt_DBTDevice_setConnectedLE_1PHYImpl(JNIEnv *env, jobject obj,
                                                             jbyte jTx, jbyte jRx) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         const LE_PHYs Tx = static_cast<LE_PHYs>(jTx);
         const LE_PHYs Rx = static_cast<LE_PHYs>(jRx);
@@ -386,8 +401,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_setConnectedLE_1PHYImpl(JNIEnv *env, jobject
 
 jbyte Java_jau_direct_1bt_DBTDevice_getTxPhysImpl(JNIEnv *env, jobject obj) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return number( device->getTxPhys() );
     } catch(...) {
@@ -398,8 +414,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_getTxPhysImpl(JNIEnv *env, jobject obj) {
 
 jbyte Java_jau_direct_1bt_DBTDevice_getRxPhysImpl(JNIEnv *env, jobject obj) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return number( device->getRxPhys() );
     } catch(...) {
@@ -411,8 +428,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_getRxPhysImpl(JNIEnv *env, jobject obj) {
 jbyte Java_jau_direct_1bt_DBTDevice_disconnectImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
         return (jint) number( device->disconnect() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -423,8 +441,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_disconnectImpl(JNIEnv *env, jobject obj)
 jboolean Java_jau_direct_1bt_DBTDevice_removeImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
         device->remove();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -435,8 +454,9 @@ jboolean Java_jau_direct_1bt_DBTDevice_removeImpl(JNIEnv *env, jobject obj)
 jbyte Java_jau_direct_1bt_DBTDevice_connectDefaultImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
         return (jbyte) number( device->connectDefault() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -447,8 +467,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_connectDefaultImpl(JNIEnv *env, jobject obj)
 jbyte Java_jau_direct_1bt_DBTDevice_connectLEImpl0(JNIEnv *env, jobject obj)
 {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
         HCIStatusCode res = device->connectLE();
         return (jbyte) number(res);
     } catch(...) {
@@ -463,8 +484,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_connectLEImpl1(JNIEnv *env, jobject obj,
                                                      jshort latency, jshort timeout)
 {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
         HCIStatusCode res = device->connectLE(interval, window, min_interval, max_interval, latency, timeout);
         return (jbyte) number(res);
     } catch(...) {
@@ -475,8 +497,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_connectLEImpl1(JNIEnv *env, jobject obj,
 
 jbyte Java_jau_direct_1bt_DBTDevice_getAvailableSMPKeysImpl(JNIEnv *env, jobject obj, jboolean responder) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return number( device->getAvailableSMPKeys(JNI_TRUE == responder) );
     } catch(...) {
@@ -487,8 +510,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_getAvailableSMPKeysImpl(JNIEnv *env, jobject
 
 jbyte Java_jau_direct_1bt_DBTDevice_uploadKeysImpl(JNIEnv *env, jobject obj) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return number( device->uploadKeys() );
     } catch(...) {
@@ -499,8 +523,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_uploadKeysImpl(JNIEnv *env, jobject obj) {
 
 void Java_jau_direct_1bt_DBTDevice_getLongTermKeyImpl(JNIEnv *env, jobject obj, jboolean responder, jbyteArray jsink) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         if( nullptr == jsink ) {
             throw IllegalArgumentException("byte array null", E_FILE_LINE);
@@ -523,8 +548,9 @@ void Java_jau_direct_1bt_DBTDevice_getLongTermKeyImpl(JNIEnv *env, jobject obj,
 
 void Java_jau_direct_1bt_DBTDevice_setLongTermKeyImpl(JNIEnv *env, jobject obj, jbyteArray jsource) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         if( nullptr == jsource ) {
             throw IllegalArgumentException("byte array null", E_FILE_LINE);
@@ -548,8 +574,9 @@ void Java_jau_direct_1bt_DBTDevice_setLongTermKeyImpl(JNIEnv *env, jobject obj,
 
 void Java_jau_direct_1bt_DBTDevice_getIdentityResolvingKeyImpl(JNIEnv *env, jobject obj, jboolean responder, jbyteArray jsink) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         if( nullptr == jsink ) {
             throw IllegalArgumentException("byte array null", E_FILE_LINE);
@@ -572,8 +599,9 @@ void Java_jau_direct_1bt_DBTDevice_getIdentityResolvingKeyImpl(JNIEnv *env, jobj
 
 void Java_jau_direct_1bt_DBTDevice_setIdentityResolvingKeyImpl(JNIEnv *env, jobject obj, jbyteArray jsource) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         if( nullptr == jsource ) {
             throw IllegalArgumentException("byte array null", E_FILE_LINE);
@@ -597,8 +625,9 @@ void Java_jau_direct_1bt_DBTDevice_setIdentityResolvingKeyImpl(JNIEnv *env, jobj
 
 void Java_jau_direct_1bt_DBTDevice_getSignatureResolvingKeyImpl(JNIEnv *env, jobject obj, jboolean responder, jbyteArray jsink) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         if( nullptr == jsink ) {
             throw IllegalArgumentException("byte array null", E_FILE_LINE);
@@ -621,8 +650,9 @@ void Java_jau_direct_1bt_DBTDevice_getSignatureResolvingKeyImpl(JNIEnv *env, job
 
 void Java_jau_direct_1bt_DBTDevice_setSignatureResolvingKeyImpl(JNIEnv *env, jobject obj, jbyteArray jsource) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         if( nullptr == jsource ) {
             throw IllegalArgumentException("byte array null", E_FILE_LINE);
@@ -646,8 +676,9 @@ void Java_jau_direct_1bt_DBTDevice_setSignatureResolvingKeyImpl(JNIEnv *env, job
 
 void Java_jau_direct_1bt_DBTDevice_getLinkKeyImpl(JNIEnv *env, jobject obj, jboolean responder, jbyteArray jsink) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         if( nullptr == jsink ) {
             throw IllegalArgumentException("byte array null", E_FILE_LINE);
@@ -670,8 +701,9 @@ void Java_jau_direct_1bt_DBTDevice_getLinkKeyImpl(JNIEnv *env, jobject obj, jboo
 
 void Java_jau_direct_1bt_DBTDevice_setLinkKeyImpl(JNIEnv *env, jobject obj, jbyteArray jsource) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         if( nullptr == jsource ) {
             throw IllegalArgumentException("byte array null", E_FILE_LINE);
@@ -695,8 +727,9 @@ void Java_jau_direct_1bt_DBTDevice_setLinkKeyImpl(JNIEnv *env, jobject obj, jbyt
 
 jbyte Java_jau_direct_1bt_DBTDevice_unpairImpl(JNIEnv *env, jobject obj) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
         HCIStatusCode res = device->unpair();
         return (jbyte) number(res);
     } catch(...) {
@@ -707,8 +740,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_unpairImpl(JNIEnv *env, jobject obj) {
 
 jbyte Java_jau_direct_1bt_DBTDevice_getConnSecurityLevelImpl(JNIEnv *env, jobject obj) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return number( device->getConnSecurityLevel() );
     } catch(...) {
@@ -719,8 +753,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_getConnSecurityLevelImpl(JNIEnv *env, jobjec
 
 jbyte Java_jau_direct_1bt_DBTDevice_getConnIOCapabilityImpl(JNIEnv *env, jobject obj) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return number( device->getConnIOCapability() );
     } catch(...) {
@@ -731,8 +766,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_getConnIOCapabilityImpl(JNIEnv *env, jobject
 
 jboolean Java_jau_direct_1bt_DBTDevice_setConnSecurityImpl(JNIEnv *env, jobject obj, jbyte jsec_level, jbyte jio_cap) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return device->setConnSecurity( to_BTSecurityLevel( static_cast<uint8_t>(jsec_level) ),
                                         to_SMPIOCapability( static_cast<uint8_t>(jio_cap) ) );
@@ -744,8 +780,9 @@ jboolean Java_jau_direct_1bt_DBTDevice_setConnSecurityImpl(JNIEnv *env, jobject
 
 jboolean Java_jau_direct_1bt_DBTDevice_setConnSecurityAutoImpl(JNIEnv *env, jobject obj, jbyte jio_cap) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return device->setConnSecurityAuto( to_SMPIOCapability( static_cast<uint8_t>(jio_cap) ) );
     } catch(...) {
@@ -756,8 +793,9 @@ jboolean Java_jau_direct_1bt_DBTDevice_setConnSecurityAutoImpl(JNIEnv *env, jobj
 
 jboolean Java_jau_direct_1bt_DBTDevice_isConnSecurityAutoEnabled(JNIEnv *env, jobject obj) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return device->isConnSecurityAutoEnabled();
     } catch(...) {
@@ -768,8 +806,9 @@ jboolean Java_jau_direct_1bt_DBTDevice_isConnSecurityAutoEnabled(JNIEnv *env, jo
 
 jbyte Java_jau_direct_1bt_DBTDevice_getPairingModeImpl(JNIEnv *env, jobject obj) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return number( device->getPairingMode() );
     } catch(...) {
@@ -780,8 +819,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_getPairingModeImpl(JNIEnv *env, jobject obj)
 
 jbyte Java_jau_direct_1bt_DBTDevice_getPairingStateImpl(JNIEnv *env, jobject obj) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return static_cast<uint8_t>( device->getPairingState() );
     } catch(...) {
@@ -792,8 +832,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_getPairingStateImpl(JNIEnv *env, jobject obj
 
 jbyte Java_jau_direct_1bt_DBTDevice_setPairingPasskeyImpl(JNIEnv *env, jobject obj, jint jpasskey) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return number( device->setPairingPasskey( static_cast<uint32_t>(jpasskey) ) );
     } catch(...) {
@@ -804,8 +845,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_setPairingPasskeyImpl(JNIEnv *env, jobject o
 
 jbyte Java_jau_direct_1bt_DBTDevice_setPairingPasskeyNegativeImpl(JNIEnv *env, jobject obj) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return number( device->setPairingPasskeyNegative() );
     } catch(...) {
@@ -816,8 +858,9 @@ jbyte Java_jau_direct_1bt_DBTDevice_setPairingPasskeyNegativeImpl(JNIEnv *env, j
 
 jbyte Java_jau_direct_1bt_DBTDevice_setPairingNumericComparisonImpl(JNIEnv *env, jobject obj, jboolean jequal) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return number( device->setPairingNumericComparison( JNI_TRUE == jequal ? true : false ) );
     } catch(...) {
@@ -834,8 +877,8 @@ static const std::string _serviceClazzCtorArgs("(JLjau/direct_bt/DBTDevice;ZLjav
 
 jobject Java_jau_direct_1bt_DBTDevice_getGattServicesImpl(JNIEnv *env, jobject obj) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        std::shared_ptr<JavaAnon> device_java = device->getJavaObject(); // hold until done!
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
         JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         jau::darray<BTGattServiceRef> services = device->getGattServices(); // implicit GATT connect and discovery if required incl GenericAccess retrieval
@@ -846,14 +889,14 @@ jobject Java_jau_direct_1bt_DBTDevice_getGattServicesImpl(JNIEnv *env, jobject o
         // BTGattService(final long nativeInstance, final BTDevice device, final boolean isPrimary,
         //                final String type_uuid, final short handleStart, final short handleEnd)
 
-        std::function<jobject(JNIEnv*, jclass, jmethodID, BTGattService*)> ctor_service =
-                [](JNIEnv *env_, jclass clazz, jmethodID clazz_ctor, BTGattService *service)->jobject {
+        std::function<jobject(JNIEnv*, jclass, jmethodID, const BTGattServiceRef&)> ctor_service =
+                [](JNIEnv *env_, jclass clazz, jmethodID clazz_ctor, const BTGattServiceRef& service)->jobject {
                     // prepare adapter ctor
                     std::shared_ptr<BTDevice> _device = service->getDeviceUnchecked();
                     if( nullptr == _device ) {
                         throw jau::RuntimeException("Service's device null: "+service->toString(), E_FILE_LINE);
                     }
-                    std::shared_ptr<JavaAnon> _device_java = _device->getJavaObject(); // hold until done!
+                    jau::JavaAnonRef _device_java = _device->getJavaObject(); // hold until done!
                     JavaGlobalObj::check(_device_java, E_FILE_LINE);
                     jobject jdevice = JavaGlobalObj::GetObject(_device_java);
 
@@ -861,11 +904,12 @@ jobject Java_jau_direct_1bt_DBTDevice_getGattServicesImpl(JNIEnv *env, jobject o
                     const jstring juuid = from_string_to_jstring(env_, service->type->toUUID128String());
                     java_exception_check_and_throw(env_, E_FILE_LINE);
 
-                    jobject jservice = env_->NewObject(clazz, clazz_ctor, (jlong)service, jdevice, isPrimary,
+                    shared_ptr_ref<BTGattService> service_sref(service); // new instance to be released into new jobject
+                    jobject jservice = env_->NewObject(clazz, clazz_ctor, service_sref.release_to_jlong(), jdevice, isPrimary,
                             juuid, service->handle, service->end_handle);
                     java_exception_check_and_throw(env_, E_FILE_LINE);
                     JNIGlobalRef::check(jservice, E_FILE_LINE);
-                    std::shared_ptr<JavaAnon> jServiceRef = service->getJavaObject(); // GlobalRef
+                    jau::JavaAnonRef jServiceRef = service->getJavaObject(); // GlobalRef
                     JavaGlobalObj::check(jServiceRef, E_FILE_LINE);
                     env_->DeleteLocalRef(juuid);
                     env_->DeleteLocalRef(jservice);
@@ -881,8 +925,9 @@ jobject Java_jau_direct_1bt_DBTDevice_getGattServicesImpl(JNIEnv *env, jobject o
 
 jboolean Java_jau_direct_1bt_DBTDevice_sendNotification(JNIEnv *env, jobject obj, jshort char_value_handle, jbyteArray jval) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         if( nullptr == jval ) {
             throw IllegalArgumentException("byte array null", E_FILE_LINE);
@@ -907,8 +952,9 @@ jboolean Java_jau_direct_1bt_DBTDevice_sendNotification(JNIEnv *env, jobject obj
 
 jboolean Java_jau_direct_1bt_DBTDevice_sendIndication(JNIEnv *env, jobject obj, jshort char_value_handle, jbyteArray jval) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         if( nullptr == jval ) {
             throw IllegalArgumentException("byte array null", E_FILE_LINE);
@@ -934,8 +980,9 @@ jboolean Java_jau_direct_1bt_DBTDevice_sendIndication(JNIEnv *env, jobject obj,
 jboolean Java_jau_direct_1bt_DBTDevice_pingGATTImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
         return device->pingGATT() ? JNI_TRUE : JNI_FALSE;
     } catch(...) {
@@ -947,8 +994,9 @@ jboolean Java_jau_direct_1bt_DBTDevice_pingGATTImpl(JNIEnv *env, jobject obj)
 jshort Java_jau_direct_1bt_DBTDevice_getRSSI(JNIEnv *env, jobject obj)
 {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
         return (jshort) device->getRSSI();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -958,14 +1006,15 @@ jshort Java_jau_direct_1bt_DBTDevice_getRSSI(JNIEnv *env, jobject obj)
 
 void Java_jau_direct_1bt_DBTDevice_getEIRImpl(JNIEnv *env, jobject obj, jobject jeir_sink) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        std::shared_ptr<EInfoReport>* eir_sink_ptr_ref = jau::getInstance<std::shared_ptr<EInfoReport>>(env, jeir_sink);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
-        std::shared_ptr<EInfoReport> eir = device->getEIR();
+        shared_ptr_ref<EInfoReport> eir_sink(env, jeir_sink);
 
         // replace the shared managed object
-        *eir_sink_ptr_ref = eir;
-
+        eir_sink = device->getEIR();
+        eir_sink.release_into_object(env, jeir_sink);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -973,14 +1022,15 @@ void Java_jau_direct_1bt_DBTDevice_getEIRImpl(JNIEnv *env, jobject obj, jobject
 
 void Java_jau_direct_1bt_DBTDevice_getEIRIndImpl(JNIEnv *env, jobject obj, jobject jeir_sink) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        std::shared_ptr<EInfoReport>* eir_sink_ptr_ref = jau::getInstance<std::shared_ptr<EInfoReport>>(env, jeir_sink);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
-        std::shared_ptr<EInfoReport> eir = device->getEIRInd();
+        shared_ptr_ref<EInfoReport> eir_sink(env, jeir_sink);
 
         // replace the shared managed object
-        *eir_sink_ptr_ref = eir;
-
+        eir_sink = device->getEIRInd();
+        eir_sink.release_into_object(env, jeir_sink);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -988,14 +1038,15 @@ void Java_jau_direct_1bt_DBTDevice_getEIRIndImpl(JNIEnv *env, jobject obj, jobje
 
 void Java_jau_direct_1bt_DBTDevice_getEIRScanRspImpl(JNIEnv *env, jobject obj, jobject jeir_sink) {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        std::shared_ptr<EInfoReport>* eir_sink_ptr_ref = jau::getInstance<std::shared_ptr<EInfoReport>>(env, jeir_sink);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
 
-        std::shared_ptr<EInfoReport> eir = device->getEIRScanRsp();
+        shared_ptr_ref<EInfoReport> eir_sink(env, jeir_sink);
 
         // replace the shared managed object
-        *eir_sink_ptr_ref = eir;
-
+        eir_sink = device->getEIRScanRsp();
+        eir_sink.release_into_object(env, jeir_sink);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -1004,8 +1055,9 @@ void Java_jau_direct_1bt_DBTDevice_getEIRScanRspImpl(JNIEnv *env, jobject obj, j
 jshort Java_jau_direct_1bt_DBTDevice_getTxPower(JNIEnv *env, jobject obj)
 {
     try {
-        BTDevice *device = getJavaUplinkObject<BTDevice>(env, obj);
-        JavaGlobalObj::check(device->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTDevice> device(env, obj); // hold until done
+        jau::JavaAnonRef device_java = device->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(device_java, E_FILE_LINE);
         return (jshort) device->getTxPower();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
diff --git a/java/jni/direct_bt/DBTGattChar.cxx b/java/jni/direct_bt/DBTGattChar.cxx
index f99c5b0f..c438851a 100644
--- a/java/jni/direct_bt/DBTGattChar.cxx
+++ b/java/jni/direct_bt/DBTGattChar.cxx
@@ -36,34 +36,37 @@
 using namespace direct_bt;
 using namespace jau;
 
-jstring Java_jau_direct_1bt_DBTGattChar_toStringImpl(JNIEnv *env, jobject obj) {
+void Java_jau_direct_1bt_DBTGattChar_deleteImpl(JNIEnv *env, jobject obj, jlong nativeInstance) {
+    (void)obj;
     try {
-        BTGattChar *nativePtr = getJavaUplinkObject<BTGattChar>(env, obj);
-        JavaGlobalObj::check(nativePtr->getJavaObject(), E_FILE_LINE);
-        return from_string_to_jstring(env, nativePtr->toString());
+        jau::shared_ptr_ref<BTGattChar> sref(nativeInstance, false /* throw_on_nullptr */); // hold copy until done
+        if( nullptr != sref.pointer() ) {
+            std::shared_ptr<BTGattChar>* sref_ptr = jau::castInstance<BTGattChar>(nativeInstance);
+            delete sref_ptr;
+        }
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
-    return nullptr;
 }
 
-void Java_jau_direct_1bt_DBTGattChar_deleteImpl(JNIEnv *env, jobject obj, jlong nativeInstance) {
-    (void)obj;
+jstring Java_jau_direct_1bt_DBTGattChar_toStringImpl(JNIEnv *env, jobject obj) {
     try {
-        BTGattChar *characteristic = castInstance<BTGattChar>(nativeInstance);
-        (void)characteristic;
-        // No delete: Service instance owned by BTGattService -> BTDevice
+        shared_ptr_ref<BTGattChar> characteristic(env, obj); // hold until done
+        jau::JavaAnonRef characteristic_java = characteristic->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(characteristic_java, E_FILE_LINE);
+        return from_string_to_jstring(env, characteristic->toString());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
+    return nullptr;
 }
 
 static const std::string _descriptorClazzCtorArgs("(JLjau/direct_bt/DBTGattChar;Ljava/lang/String;S[B)V");
 
 jobject Java_jau_direct_1bt_DBTGattChar_getDescriptorsImpl(JNIEnv *env, jobject obj) {
     try {
-        BTGattChar *characteristic = getJavaUplinkObject<BTGattChar>(env, obj);
-        std::shared_ptr<JavaAnon> characteristic_java = characteristic->getJavaObject(); // hold until done!
+        shared_ptr_ref<BTGattChar> characteristic(env, obj); // hold until done
+        jau::JavaAnonRef characteristic_java = characteristic->getJavaObject(); // hold until done!
         JavaGlobalObj::check(characteristic_java, E_FILE_LINE);
 
         jau::darray<BTGattDescRef> & descriptorList = characteristic->descriptorList;
@@ -74,14 +77,14 @@ jobject Java_jau_direct_1bt_DBTGattChar_getDescriptorsImpl(JNIEnv *env, jobject
         // BTGattDesc(final long nativeInstance, final BTGattChar characteristic,
         //                   final String type_uuid, final short handle, final byte[] value)
 
-        std::function<jobject(JNIEnv*, jclass, jmethodID, BTGattDesc *)> ctor_desc =
-                [](JNIEnv *env_, jclass clazz, jmethodID clazz_ctor, BTGattDesc *descriptor)->jobject {
+        std::function<jobject(JNIEnv*, jclass, jmethodID, const BTGattDescRef&)> ctor_desc =
+                [](JNIEnv *env_, jclass clazz, jmethodID clazz_ctor, const BTGattDescRef& descriptor)->jobject {
                     // prepare adapter ctor
                     std::shared_ptr<BTGattChar> _characteristic = descriptor->getGattCharUnchecked();
                     if( nullptr == _characteristic ) {
                         throw jau::RuntimeException("Descriptor's characteristic null: "+descriptor->toString(), E_FILE_LINE);
                     }
-                    std::shared_ptr<JavaAnon> _characteristic_java = _characteristic->getJavaObject(); // hold until done!
+                    jau::JavaAnonRef _characteristic_java = _characteristic->getJavaObject(); // hold until done!
                     JavaGlobalObj::check(_characteristic_java, E_FILE_LINE);
                     jobject jcharacteristic = JavaGlobalObj::GetObject(_characteristic_java);
 
@@ -93,11 +96,12 @@ jobject Java_jau_direct_1bt_DBTGattChar_getDescriptorsImpl(JNIEnv *env, jobject
                     env_->SetByteArrayRegion(jval, 0, (jsize)value_size, (const jbyte *)descriptor->value.get_ptr());
                     java_exception_check_and_throw(env_, E_FILE_LINE);
 
-                    jobject jdesc = env_->NewObject(clazz, clazz_ctor, (jlong)descriptor, jcharacteristic,
+                    shared_ptr_ref<BTGattDesc> descriptor_sref(descriptor); // new instance to be released into new jobject
+                    jobject jdesc = env_->NewObject(clazz, clazz_ctor, descriptor_sref.release_to_jlong(), jcharacteristic,
                             juuid, (jshort)descriptor->handle, jval);
                     java_exception_check_and_throw(env_, E_FILE_LINE);
                     JNIGlobalRef::check(jdesc, E_FILE_LINE);
-                    std::shared_ptr<JavaAnon> jDescRef = descriptor->getJavaObject(); // GlobalRef
+                    jau::JavaAnonRef jDescRef = descriptor->getJavaObject(); // GlobalRef
                     JavaGlobalObj::check(jDescRef, E_FILE_LINE);
                     env_->DeleteLocalRef(juuid);
                     env_->DeleteLocalRef(jval);
@@ -114,8 +118,9 @@ jobject Java_jau_direct_1bt_DBTGattChar_getDescriptorsImpl(JNIEnv *env, jobject
 
 jbyteArray Java_jau_direct_1bt_DBTGattChar_readValueImpl(JNIEnv *env, jobject obj) {
     try {
-        BTGattChar *characteristic = getJavaUplinkObject<BTGattChar>(env, obj);
-        JavaGlobalObj::check(characteristic->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTGattChar> characteristic(env, obj); // hold until done
+        jau::JavaAnonRef characteristic_java = characteristic->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(characteristic_java, E_FILE_LINE);
 
         POctets res(BTGattHandler::number(BTGattHandler::Defaults::MAX_ATT_MTU), 0, jau::endian::little);
         if( !characteristic->readValue(res) ) {
@@ -137,6 +142,10 @@ jbyteArray Java_jau_direct_1bt_DBTGattChar_readValueImpl(JNIEnv *env, jobject ob
 
 jboolean Java_jau_direct_1bt_DBTGattChar_writeValueImpl(JNIEnv *env, jobject obj, jbyteArray jval, jboolean withResponse) {
     try {
+        shared_ptr_ref<BTGattChar> characteristic(env, obj); // hold until done
+        jau::JavaAnonRef characteristic_java = characteristic->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(characteristic_java, E_FILE_LINE);
+
         if( nullptr == jval ) {
             throw IllegalArgumentException("byte array null", E_FILE_LINE);
         }
@@ -144,8 +153,6 @@ jboolean Java_jau_direct_1bt_DBTGattChar_writeValueImpl(JNIEnv *env, jobject obj
         if( 0 == value_size ) {
             return JNI_TRUE;
         }
-        BTGattChar *characteristic = getJavaUplinkObject<BTGattChar>(env, obj);
-        JavaGlobalObj::check(characteristic->getJavaObject(), E_FILE_LINE);
 
         JNICriticalArray<uint8_t, jbyteArray> criticalArray(env); // RAII - release
         uint8_t * value_ptr = criticalArray.get(jval, criticalArray.Mode::NO_UPDATE_AND_RELEASE);
@@ -174,8 +181,8 @@ jboolean Java_jau_direct_1bt_DBTGattChar_writeValueImpl(JNIEnv *env, jobject obj
 jboolean Java_jau_direct_1bt_DBTGattChar_configNotificationIndicationImpl(JNIEnv *env, jobject obj,
                         jboolean enableNotification, jboolean enableIndication, jbooleanArray jEnabledState) {
     try {
-        BTGattChar *characteristic = getJavaUplinkObjectUnchecked<BTGattChar>(env, obj);
-        if( nullptr == characteristic ) {
+        shared_ptr_ref<BTGattChar> characteristic(env, obj, false /* throw_on_nullptr */); // hold until done
+        if( characteristic.is_null() ) {
             if( !enableNotification && !enableIndication ) {
                 // OK to have native characteristic being shutdown @ disable
                 DBG_PRINT("Characteristic's native instance has been deleted");
@@ -183,7 +190,8 @@ jboolean Java_jau_direct_1bt_DBTGattChar_configNotificationIndicationImpl(JNIEnv
             }
             throw IllegalStateException("Characteristic's native instance deleted", E_FILE_LINE);
         }
-        JavaGlobalObj::check(characteristic->getJavaObject(), E_FILE_LINE);
+        jau::JavaAnonRef characteristic_java = characteristic->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(characteristic_java, E_FILE_LINE);
 
         if( nullptr == jEnabledState ) {
             throw IllegalArgumentException("boolean array null", E_FILE_LINE);
diff --git a/java/jni/direct_bt/DBTGattDesc.cxx b/java/jni/direct_bt/DBTGattDesc.cxx
index d144aa17..ad12259c 100644
--- a/java/jni/direct_bt/DBTGattDesc.cxx
+++ b/java/jni/direct_bt/DBTGattDesc.cxx
@@ -37,11 +37,14 @@
 using namespace direct_bt;
 using namespace jau;
 
-void Java_jau_direct_1bt_DBTGattDesc_deleteImpl(JNIEnv *env, jobject obj) {
+void Java_jau_direct_1bt_DBTGattDesc_deleteImpl(JNIEnv *env, jobject obj, jlong nativeInstance) {
+    (void)obj;
     try {
-        BTGattDesc *descriptor = getJavaUplinkObject<BTGattDesc>(env, obj);
-        (void)descriptor;
-        // No delete: Service instance owned by GATTService -> BTDevice
+        jau::shared_ptr_ref<BTGattDesc> sref(nativeInstance, false /* throw_on_nullptr */); // hold copy until done
+        if( nullptr != sref.pointer() ) {
+            std::shared_ptr<BTGattDesc>* sref_ptr = jau::castInstance<BTGattDesc>(nativeInstance);
+            delete sref_ptr;
+        }
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -50,8 +53,9 @@ void Java_jau_direct_1bt_DBTGattDesc_deleteImpl(JNIEnv *env, jobject obj) {
 jstring Java_jau_direct_1bt_DBTGattDesc_toStringImpl(JNIEnv *env, jobject obj) {
     (void)obj;
     try {
-        BTGattDesc *descriptor = getJavaUplinkObject<BTGattDesc>(env, obj);
-        JavaGlobalObj::check(descriptor->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTGattDesc> descriptor(env, obj); // hold until done
+        jau::JavaAnonRef descriptor_java = descriptor->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(descriptor_java, E_FILE_LINE);
         return from_string_to_jstring(env, descriptor->toString());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -61,8 +65,9 @@ jstring Java_jau_direct_1bt_DBTGattDesc_toStringImpl(JNIEnv *env, jobject obj) {
 
 jbyteArray Java_jau_direct_1bt_DBTGattDesc_readValueImpl(JNIEnv *env, jobject obj) {
     try {
-        BTGattDesc *descriptor = getJavaUplinkObject<BTGattDesc>(env, obj);
-        JavaGlobalObj::check(descriptor->getJavaObject(), E_FILE_LINE);
+        shared_ptr_ref<BTGattDesc> descriptor(env, obj); // hold until done
+        jau::JavaAnonRef descriptor_java = descriptor->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(descriptor_java, E_FILE_LINE);
 
         if( !descriptor->readValue() ) {
             ERR_PRINT("Characteristic readValue failed: %s", descriptor->toString().c_str());
@@ -82,6 +87,10 @@ jbyteArray Java_jau_direct_1bt_DBTGattDesc_readValueImpl(JNIEnv *env, jobject ob
 
 jboolean Java_jau_direct_1bt_DBTGattDesc_writeValueImpl(JNIEnv *env, jobject obj, jbyteArray jval) {
     try {
+        shared_ptr_ref<BTGattDesc> descriptor(env, obj); // hold until done
+        jau::JavaAnonRef descriptor_java = descriptor->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(descriptor_java, E_FILE_LINE);
+
         if( nullptr == jval ) {
             throw IllegalArgumentException("byte array null", E_FILE_LINE);
         }
@@ -89,9 +98,6 @@ jboolean Java_jau_direct_1bt_DBTGattDesc_writeValueImpl(JNIEnv *env, jobject obj
         if( 0 == value_size ) {
             return JNI_TRUE;
         }
-        BTGattDesc *descriptor = getJavaUplinkObject<BTGattDesc>(env, obj);
-        JavaGlobalObj::check(descriptor->getJavaObject(), E_FILE_LINE);
-
         JNICriticalArray<uint8_t, jbyteArray> criticalArray(env); // RAII - release
         uint8_t * value_ptr = criticalArray.get(jval, criticalArray.Mode::NO_UPDATE_AND_RELEASE);
         if( NULL == value_ptr ) {
diff --git a/java/jni/direct_bt/DBTGattService.cxx b/java/jni/direct_bt/DBTGattService.cxx
index b3c9c793..0873626f 100644
--- a/java/jni/direct_bt/DBTGattService.cxx
+++ b/java/jni/direct_bt/DBTGattService.cxx
@@ -38,37 +38,40 @@
 using namespace direct_bt;
 using namespace jau;
 
-jstring Java_jau_direct_1bt_DBTGattService_toStringImpl(JNIEnv *env, jobject obj) {
+void Java_jau_direct_1bt_DBTGattService_deleteImpl(JNIEnv *env, jobject obj, jlong nativeInstance) {
+    (void)obj;
     try {
-        BTGattService *nativePtr = getJavaUplinkObject<BTGattService>(env, obj);
-        JavaGlobalObj::check(nativePtr->getJavaObject(), E_FILE_LINE);
-        return from_string_to_jstring(env, nativePtr->toString());
+        jau::shared_ptr_ref<BTGattService> sref(nativeInstance, false /* throw_on_nullptr */); // hold copy until done
+        if( nullptr != sref.pointer() ) {
+            std::shared_ptr<BTGattService>* sref_ptr = jau::castInstance<BTGattService>(nativeInstance);
+            delete sref_ptr;
+        }
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
-    return nullptr;
 }
 
-
-void Java_jau_direct_1bt_DBTGattService_deleteImpl(JNIEnv *env, jobject obj, jlong nativeInstance) {
-    (void)obj;
+jstring Java_jau_direct_1bt_DBTGattService_toStringImpl(JNIEnv *env, jobject obj) {
     try {
-        BTGattService *service = castInstance<BTGattService>(nativeInstance);
-        (void)service;
-        // No delete: Service instance owned by BTDevice
+        shared_ptr_ref<BTGattService> service(env, obj); // hold until done
+        jau::JavaAnonRef service_java = service->getJavaObject(); // hold until done!
+        JavaGlobalObj::check(service_java, E_FILE_LINE);
+        return from_string_to_jstring(env, service->toString());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
+    return nullptr;
 }
 
+
 static const std::string _characteristicClazzCtorArgs("(JLjau/direct_bt/DBTGattService;SLorg/direct_bt/GattCharPropertySet;Ljava/lang/String;SII)V");
 static const std::string _gattCharPropSetClassName("org/direct_bt/GattCharPropertySet");
 static const std::string _gattCharPropSetClazzCtorArgs("(B)V");
 
 jobject Java_jau_direct_1bt_DBTGattService_getCharsImpl(JNIEnv *env, jobject obj) {
     try {
-        BTGattService *service = getJavaUplinkObject<BTGattService>(env, obj);
-        std::shared_ptr<JavaAnon> service_java = service->getJavaObject(); // hold until done!
+        shared_ptr_ref<BTGattService> service(env, obj); // hold until done
+        jau::JavaAnonRef service_java = service->getJavaObject(); // hold until done!
         JavaGlobalObj::check(service_java, E_FILE_LINE);
 
         jau::darray<std::shared_ptr<BTGattChar>> & characteristics = service->characteristicList;
@@ -96,14 +99,14 @@ jobject Java_jau_direct_1bt_DBTGattService_getCharsImpl(JNIEnv *env, jobject obj
                         final int clientCharacteristicsConfigIndex,
                         final int userDescriptionIndex)
         */
-        std::function<jobject(JNIEnv*, jclass, jmethodID, BTGattChar *)> ctor_char =
-                [&gattCharPropSetClazz, &gattCharPropSetClazzCtor](JNIEnv *env_, jclass clazz, jmethodID clazz_ctor, BTGattChar *characteristic)->jobject {
+        std::function<jobject(JNIEnv*, jclass, jmethodID, const BTGattCharRef&)> ctor_char =
+                [&gattCharPropSetClazz, &gattCharPropSetClazzCtor](JNIEnv *env_, jclass clazz, jmethodID clazz_ctor, const BTGattCharRef& characteristic)->jobject {
                     // prepare adapter ctor
                     std::shared_ptr<BTGattService> _service = characteristic->getServiceUnchecked();
                     if( nullptr == _service ) {
                         throw jau::RuntimeException("Characteristic's service null: "+characteristic->toString(), E_FILE_LINE);
                     }
-                    std::shared_ptr<JavaAnon> _service_java = _service->getJavaObject(); // hold until done!
+                    jau::JavaAnonRef _service_java = _service->getJavaObject(); // hold until done!
                     JavaGlobalObj::check(_service_java, E_FILE_LINE);
 
                     jobject jservice = JavaGlobalObj::GetObject(_service_java);
@@ -116,14 +119,15 @@ jobject Java_jau_direct_1bt_DBTGattService_getCharsImpl(JNIEnv *env, jobject obj
                     const jstring uuid = from_string_to_jstring(env_, characteristic->value_type->toUUID128String());
                     java_exception_check_and_throw(env_, E_FILE_LINE);
 
-                    jobject jcharVal = env_->NewObject(clazz, clazz_ctor, (jlong)characteristic, jservice,
+                    shared_ptr_ref<BTGattChar> characteristic_sref(characteristic); // new instance to be released into new jobject
+                    jobject jcharVal = env_->NewObject(clazz, clazz_ctor, characteristic_sref.release_to_jlong(), jservice,
                             characteristic->handle, jGattCharPropSet,
                             uuid, characteristic->value_handle,
                             characteristic->clientCharConfigIndex,
                             characteristic->userDescriptionIndex);
                     java_exception_check_and_throw(env_, E_FILE_LINE);
                     JNIGlobalRef::check(jcharVal, E_FILE_LINE);
-                    std::shared_ptr<JavaAnon> jCharRef = characteristic->getJavaObject(); // GlobalRef
+                    jau::JavaAnonRef jCharRef = characteristic->getJavaObject(); // GlobalRef
                     JavaGlobalObj::check(jCharRef, E_FILE_LINE);
                     env_->DeleteLocalRef(jGattCharPropSet);
                     env_->DeleteLocalRef(jcharVal);
diff --git a/java/jni/direct_bt/DBTManager.cxx b/java/jni/direct_bt/DBTManager.cxx
index a8fa2f72..6d7f9137 100644
--- a/java/jni/direct_bt/DBTManager.cxx
+++ b/java/jni/direct_bt/DBTManager.cxx
@@ -109,12 +109,18 @@ static void _addMgmtCBOnce(JNIEnv *env, BTManager & mgmt, JNIGlobalRef jmgmtRef,
     }
 }
 
+// special NOP deleted for shared_ptr<BTManager>: static singleton
+static void nodelete_BTManager(BTManager* p) { (void)p; }
+
 void Java_jau_direct_1bt_DBTManager_initImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTManager *manager = &BTManager::get(); // special: static singleton
+        std::shared_ptr<BTManager> manager( &BTManager::get(), nodelete_BTManager ); // special: static singleton
         jau::JNIGlobalRef global_obj(obj); // lock instance first (global reference), inserted below
-        setInstance<BTManager>(env, global_obj.getObject(), manager);
+        {
+            jau::shared_ptr_ref<BTManager> ref( manager );
+            ref.release_into_object(env, global_obj.getObject());
+        }
         java_exception_check_and_throw(env, E_FILE_LINE);
         manager->setJavaObject( std::make_shared<jau::JavaGlobalObj>( std::move(global_obj), nullptr ) );
         JavaGlobalObj::check(manager->getJavaObject(), E_FILE_LINE);
@@ -133,17 +139,23 @@ void Java_jau_direct_1bt_DBTManager_deleteImpl(JNIEnv *env, jobject obj, jlong n
 {
     (void)obj;
     try {
-        BTManager *manager = castInstance<BTManager>(nativeInstance); // special: static singleton
-        manager->close();
-        manager->setJavaObject();
-        (void) manager;
+        jau::shared_ptr_ref<BTManager> manager(nativeInstance, false /* throw_on_nullptr */); // hold copy until done
+        if( nullptr != manager.pointer() ) {
+            if( !manager.is_null() ) {
+                jau::JavaAnonRef manager_java = manager->getJavaObject(); // hold until done!
+                jau::JavaGlobalObj::check(manager_java, E_FILE_LINE);
+                manager->setJavaObject();
+            }
+            std::shared_ptr<BTManager>* ref_ptr = jau::castInstance<BTManager>(nativeInstance); // special: static singleton
+            delete ref_ptr; // will leave singleton BTManager instance untouched -> nodelete_BTManager()
+        }
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
 }
 
 static const std::string _adapterClazzCtorArgs("(J[BBLjava/lang/String;I)V");
-static jobject _createJavaAdapter(JNIEnv *env_, jclass clazz, jmethodID clazz_ctor, BTAdapter* adapter) {
+static jobject _createJavaAdapter(JNIEnv *env_, jclass clazz, jmethodID clazz_ctor, const std::shared_ptr<BTAdapter>& adapter) {
     // prepare adapter ctor
     const EUI48 addr = adapter->getAddressAndType().address;
     jbyteArray jaddr = env_->NewByteArray(sizeof(addr));
@@ -151,26 +163,27 @@ static jobject _createJavaAdapter(JNIEnv *env_, jclass clazz, jmethodID clazz_ct
     jau::java_exception_check_and_throw(env_, E_FILE_LINE);
     const jstring name = from_string_to_jstring(env_, adapter->getName());
     java_exception_check_and_throw(env_, E_FILE_LINE);
-    jobject jAdapter = env_->NewObject(clazz, clazz_ctor, (jlong)adapter, jaddr, adapter->getAddressAndType().type, name, adapter->dev_id);
+    jau::shared_ptr_ref<BTAdapter> adapter_ref( adapter );
+    jobject jAdapter = env_->NewObject(clazz, clazz_ctor, adapter_ref.release_to_jlong(), jaddr, adapter->getAddressAndType().type, name, adapter->dev_id);
     java_exception_check_and_throw(env_, E_FILE_LINE);
     JNIGlobalRef::check(jAdapter, E_FILE_LINE);
-    std::shared_ptr<JavaAnon> jAdapterRef = adapter->getJavaObject(); // GlobalRef
+    jau::JavaAnonRef jAdapterRef = adapter->getJavaObject(); // GlobalRef
     JavaGlobalObj::check(jAdapterRef, E_FILE_LINE);
     env_->DeleteLocalRef(jaddr);
     env_->DeleteLocalRef(name);
     env_->DeleteLocalRef(jAdapter);
 
-    DBG_PRINT("Java_jau_direct_1bt_DBTManager_createJavaAdapter: New Adapter %p %s", adapter, adapter->toString().c_str());
+    DBG_PRINT("Java_jau_direct_1bt_DBTManager_createJavaAdapter: New Adapter %p %s", adapter.get(), adapter->toString().c_str());
     return JavaGlobalObj::GetObject(jAdapterRef);
 };
 
 jobject Java_jau_direct_1bt_DBTManager_getAdapterListImpl(JNIEnv *env, jobject obj)
 {
     try {
-        BTManager *manager = getInstance<BTManager>(env, obj);
-        DBG_PRINT("Java_jau_direct_1bt_DBTManager_getAdapterListImpl: Manager %s", manager->toString().c_str());
+        jau::shared_ptr_ref<BTManager> ref(env, obj); // hold until done
+        DBG_PRINT("Java_jau_direct_1bt_DBTManager_getAdapterListImpl: Manager %s", ref->toString().c_str());
 
-        jau::darray<std::shared_ptr<BTAdapter>> adapters = manager->getAdapters();
+        jau::darray<std::shared_ptr<BTAdapter>> adapters = ref->getAdapters();
         return convert_vector_sharedptr_to_jarraylist<jau::darray<std::shared_ptr<BTAdapter>>, BTAdapter>(
                 env, adapters, _adapterClazzCtorArgs.c_str(), _createJavaAdapter);
     } catch(...) {
@@ -182,16 +195,16 @@ jobject Java_jau_direct_1bt_DBTManager_getAdapterListImpl(JNIEnv *env, jobject o
 jobject Java_jau_direct_1bt_DBTManager_getAdapterImpl(JNIEnv *env, jobject obj, jint dev_id)
 {
     try {
-        BTManager *manager = getInstance<BTManager>(env, obj);
+        jau::shared_ptr_ref<BTManager> ref(env, obj); // hold until done
 
-        std::shared_ptr<BTAdapter> adapter = manager->getAdapter(dev_id);
+        std::shared_ptr<BTAdapter> adapter = ref->getAdapter(dev_id);
         if( nullptr == adapter ) {
             ERR_PRINT("BTManager::getAdapterImpl: Adapter dev_id %d: Not found", dev_id);
             return nullptr;
         }
         DBG_PRINT("BTManager::getAdapterImpl: Adapter dev_id %d: %s", dev_id, adapter->toString().c_str());
 
-        return jau::convert_instance_to_jobject<BTAdapter>(env, adapter.get(),  _adapterClazzCtorArgs.c_str(), _createJavaAdapter);
+        return jau::convert_instance_to_jobject<BTAdapter>(env, adapter,  _adapterClazzCtorArgs.c_str(), _createJavaAdapter);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
diff --git a/java/jni/direct_bt/EInfoReport.cxx b/java/jni/direct_bt/EInfoReport.cxx
index 75dd5965..47a69981 100644
--- a/java/jni/direct_bt/EInfoReport.cxx
+++ b/java/jni/direct_bt/EInfoReport.cxx
@@ -44,10 +44,9 @@ jlong Java_org_direct_1bt_EInfoReport_ctorImpl1(JNIEnv *env, jobject obj) {
     try {
         (void)obj;
         // new instance
-        std::shared_ptr<EInfoReport> ref = std::make_shared<EInfoReport>();
+        jau::shared_ptr_ref<EInfoReport> ref( new EInfoReport() );
 
-        std::shared_ptr<EInfoReport> * ref_ptr = new std::shared_ptr<EInfoReport>(std::move(ref));
-        return (jlong)(intptr_t)ref_ptr;
+        return ref.release_to_jlong();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -62,18 +61,8 @@ jlong Java_org_direct_1bt_EInfoReport_ctorImpl1(JNIEnv *env, jobject obj) {
 jlong Java_org_direct_1bt_EInfoReport_ctorImpl2(JNIEnv *env, jobject obj, jlong nativeInstanceOther) {
     try {
         (void)obj;
-        std::shared_ptr<EInfoReport> * ref_ptr_other = reinterpret_cast<std::shared_ptr<EInfoReport> *>(nativeInstanceOther);
-        if (ref_ptr_other == nullptr) {
-            throw jau::RuntimeException("Given std::shared_ptr<EInfoReport> * nullptr", E_FILE_LINE);
-        }
-        if (*ref_ptr_other == nullptr) {
-            throw jau::RuntimeException("Given std::shared_ptr<EInfoReport> nullptr", E_FILE_LINE);
-        }
-        // shared instance with other
-        std::shared_ptr<EInfoReport> ref( *ref_ptr_other );
-
-        std::shared_ptr<EInfoReport> * ref_ptr = new std::shared_ptr<EInfoReport>(std::move(ref));
-        return (jlong)(intptr_t)ref_ptr;
+        jau::shared_ptr_ref<EInfoReport> ref_other_cpy(nativeInstanceOther);
+        return ref_other_cpy.release_to_jlong();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -82,17 +71,12 @@ jlong Java_org_direct_1bt_EInfoReport_ctorImpl2(JNIEnv *env, jobject obj, jlong
 
 void Java_org_direct_1bt_EInfoReport_replace_nativeImpl(JNIEnv *env, jobject obj, jlong nativeInstanceOther) {
     try {
-        std::shared_ptr<EInfoReport> * ref_ptr_other = reinterpret_cast<std::shared_ptr<EInfoReport> *>(nativeInstanceOther);
-        if (ref_ptr_other == nullptr) {
-            throw jau::RuntimeException("Given std::shared_ptr<EInfoReport> * nullptr", E_FILE_LINE);
-        }
-        if (*ref_ptr_other == nullptr) {
-            throw jau::RuntimeException("Given std::shared_ptr<EInfoReport> nullptr", E_FILE_LINE);
-        }
-        std::shared_ptr<EInfoReport>* eir_ptr_ref = jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
+        jau::shared_ptr_ref<EInfoReport> ref_other(nativeInstanceOther);
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj);
 
         // replace the shared managed object
-        *eir_ptr_ref = *ref_ptr_other;
+        ref = ref_other.shared_ptr();
+        ref.release_into_object(env, obj);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -106,9 +90,10 @@ void Java_org_direct_1bt_EInfoReport_replace_nativeImpl(JNIEnv *env, jobject obj
 void Java_org_direct_1bt_EInfoReport_dtorImpl(JNIEnv *env, jclass clazz, jlong nativeInstance) {
     (void)clazz;
     try {
-        if( 0 != nativeInstance ) {
-            std::shared_ptr<EInfoReport> * ref_ptr = reinterpret_cast<std::shared_ptr<EInfoReport> *>(nativeInstance);
-            delete ref_ptr;
+        jau::shared_ptr_ref<EInfoReport> sref(nativeInstance, false /* throw_on_nullptr */); // hold copy until done
+        if( nullptr != sref.pointer() ) {
+            std::shared_ptr<EInfoReport>* sref_ptr = jau::castInstance<EInfoReport>(nativeInstance);
+            delete sref_ptr;
         }
     } catch(...) {
         rethrow_and_raise_java_exception(env);
@@ -117,8 +102,8 @@ void Java_org_direct_1bt_EInfoReport_dtorImpl(JNIEnv *env, jclass clazz, jlong n
 
 void Java_org_direct_1bt_EInfoReport_clear(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        eir_ptr->clear();
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        ref->clear();
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -126,9 +111,9 @@ void Java_org_direct_1bt_EInfoReport_clear(JNIEnv *env, jobject obj) {
 
 jint Java_org_direct_1bt_EInfoReport_setImpl(JNIEnv *env, jobject obj, jobject jeir_other) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        std::shared_ptr<EInfoReport>& eir_other_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, jeir_other);
-        return static_cast<jint>( number( eir_ptr->set(*eir_other_ptr) ) );
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        jau::shared_ptr_ref<EInfoReport> ref_other(env, jeir_other); // hold until done
+        return static_cast<jint>( number( ref->set(*ref_other) ) );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -142,8 +127,8 @@ jint Java_org_direct_1bt_EInfoReport_setImpl(JNIEnv *env, jobject obj, jobject j
  */
 void Java_org_direct_1bt_EInfoReport_setAddressTypeImpl(JNIEnv *env, jobject obj, jbyte jat) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        eir_ptr->setAddressType(static_cast<BDAddressType>(jat));
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        ref->setAddressType(static_cast<BDAddressType>(jat));
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -156,7 +141,7 @@ void Java_org_direct_1bt_EInfoReport_setAddressTypeImpl(JNIEnv *env, jobject obj
  */
 void Java_org_direct_1bt_EInfoReport_setAddressImpl(JNIEnv *env, jobject obj, jbyteArray jaddress) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
 
         if( nullptr == jaddress ) {
             throw jau::IllegalArgumentException("address null", E_FILE_LINE);
@@ -172,7 +157,7 @@ void Java_org_direct_1bt_EInfoReport_setAddressImpl(JNIEnv *env, jobject obj, jb
         }
         const EUI48& address = *reinterpret_cast<EUI48 *>(address_ptr);
 
-        eir_ptr->setAddress(address);
+        ref->setAddress(address);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -185,8 +170,8 @@ void Java_org_direct_1bt_EInfoReport_setAddressImpl(JNIEnv *env, jobject obj, jb
  */
 void Java_org_direct_1bt_EInfoReport_setRSSI(JNIEnv *env, jobject obj, jbyte jrssi) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        eir_ptr->setRSSI(static_cast<int8_t>(jrssi));
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        ref->setRSSI(static_cast<int8_t>(jrssi));
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -199,8 +184,8 @@ void Java_org_direct_1bt_EInfoReport_setRSSI(JNIEnv *env, jobject obj, jbyte jrs
  */
 void Java_org_direct_1bt_EInfoReport_setTxPower(JNIEnv *env, jobject obj, jbyte jtxp) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        eir_ptr->setTxPower(static_cast<int8_t>(jtxp));
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        ref->setTxPower(static_cast<int8_t>(jtxp));
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -213,8 +198,8 @@ void Java_org_direct_1bt_EInfoReport_setTxPower(JNIEnv *env, jobject obj, jbyte
  */
 void Java_org_direct_1bt_EInfoReport_setFlagsImpl(JNIEnv *env, jobject obj, jbyte jf) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        eir_ptr->setFlags(static_cast<GAPFlags>(jf));
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        ref->setFlags(static_cast<GAPFlags>(jf));
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -227,8 +212,8 @@ void Java_org_direct_1bt_EInfoReport_setFlagsImpl(JNIEnv *env, jobject obj, jbyt
  */
 void Java_org_direct_1bt_EInfoReport_addFlagImpl(JNIEnv *env, jobject obj, jbyte jf) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        eir_ptr->addFlags(static_cast<GAPFlags>(jf));
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        ref->addFlags(static_cast<GAPFlags>(jf));
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -241,9 +226,9 @@ void Java_org_direct_1bt_EInfoReport_addFlagImpl(JNIEnv *env, jobject obj, jbyte
  */
 void Java_org_direct_1bt_EInfoReport_setName(JNIEnv *env, jobject obj, jstring jname) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
         std::string name = jau::from_jstring_to_string(env, jname);
-        eir_ptr->setName(name);
+        ref->setName(name);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -256,9 +241,9 @@ void Java_org_direct_1bt_EInfoReport_setName(JNIEnv *env, jobject obj, jstring j
  */
 void Java_org_direct_1bt_EInfoReport_setShortName(JNIEnv *env, jobject obj, jstring jsname) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
         std::string sname = jau::from_jstring_to_string(env, jsname);
-        eir_ptr->setShortName(sname);
+        ref->setShortName(sname);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -271,10 +256,10 @@ void Java_org_direct_1bt_EInfoReport_setShortName(JNIEnv *env, jobject obj, jstr
  */
 void Java_org_direct_1bt_EInfoReport_addService(JNIEnv *env, jobject obj, jstring juuid) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
         std::string uuid_s = jau::from_jstring_to_string(env, juuid);
         std::shared_ptr<const jau::uuid_t> uuid = jau::uuid_t::create(uuid_s);
-        eir_ptr->addService(uuid);
+        ref->addService(uuid);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -287,8 +272,8 @@ void Java_org_direct_1bt_EInfoReport_addService(JNIEnv *env, jobject obj, jstrin
  */
 void Java_org_direct_1bt_EInfoReport_setServicesComplete(JNIEnv *env, jobject obj, jboolean jv) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        eir_ptr->setServicesComplete(JNI_TRUE==jv);
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        ref->setServicesComplete(JNI_TRUE==jv);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -301,8 +286,8 @@ void Java_org_direct_1bt_EInfoReport_setServicesComplete(JNIEnv *env, jobject ob
  */
 void Java_org_direct_1bt_EInfoReport_setDeviceClass(JNIEnv *env, jobject obj, jint jv) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        eir_ptr->setDeviceClass(static_cast<uint32_t>(jv));
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        ref->setDeviceClass(static_cast<uint32_t>(jv));
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -315,8 +300,8 @@ void Java_org_direct_1bt_EInfoReport_setDeviceClass(JNIEnv *env, jobject obj, ji
  */
 void Java_org_direct_1bt_EInfoReport_setDeviceID(JNIEnv *env, jobject obj, jshort jsource, jshort jvendor, jshort jproduct, jshort jversion) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        eir_ptr->setDeviceID(static_cast<uint16_t>(jsource), static_cast<uint16_t>(jvendor), static_cast<uint16_t>(jproduct), static_cast<uint16_t>(jversion));
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        ref->setDeviceID(static_cast<uint16_t>(jsource), static_cast<uint16_t>(jvendor), static_cast<uint16_t>(jproduct), static_cast<uint16_t>(jversion));
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -329,8 +314,8 @@ void Java_org_direct_1bt_EInfoReport_setDeviceID(JNIEnv *env, jobject obj, jshor
  */
 void Java_org_direct_1bt_EInfoReport_setConnInterval(JNIEnv *env, jobject obj, jshort jmin, jshort jmax) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        eir_ptr->setConnInterval(static_cast<uint16_t>(jmin), static_cast<uint16_t>(jmax));
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        ref->setConnInterval(static_cast<uint16_t>(jmin), static_cast<uint16_t>(jmax));
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -343,8 +328,8 @@ void Java_org_direct_1bt_EInfoReport_setConnInterval(JNIEnv *env, jobject obj, j
  */
 jlong Java_org_direct_1bt_EInfoReport_getTimestamp(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return static_cast<jlong>( eir_ptr->getTimestamp() );
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return static_cast<jlong>( ref->getTimestamp() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -358,8 +343,8 @@ jlong Java_org_direct_1bt_EInfoReport_getTimestamp(JNIEnv *env, jobject obj) {
  */
 jint Java_org_direct_1bt_EInfoReport_getEIRDataMaskImpl(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return static_cast<jint>( number( eir_ptr->getEIRDataMask() ) );
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return static_cast<jint>( number( ref->getEIRDataMask() ) );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -368,8 +353,8 @@ jint Java_org_direct_1bt_EInfoReport_getEIRDataMaskImpl(JNIEnv *env, jobject obj
 
 jint Java_org_direct_1bt_EInfoReport_getSourceImpl(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return static_cast<jint>( EInfoReport::number( eir_ptr->getSource() ) );
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return static_cast<jint>( EInfoReport::number( ref->getSource() ) );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -383,8 +368,8 @@ jint Java_org_direct_1bt_EInfoReport_getSourceImpl(JNIEnv *env, jobject obj) {
  */
 jbyte Java_org_direct_1bt_EInfoReport_getFlagsImpl(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return static_cast<jbyte>( number( eir_ptr->getFlags() ) );
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return static_cast<jbyte>( number( ref->getFlags() ) );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -398,8 +383,8 @@ jbyte Java_org_direct_1bt_EInfoReport_getFlagsImpl(JNIEnv *env, jobject obj) {
  */
 jbyte Java_org_direct_1bt_EInfoReport_getADAddressType(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return static_cast<jbyte>( eir_ptr->getADAddressType() );
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return static_cast<jbyte>( ref->getADAddressType() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -413,8 +398,8 @@ jbyte Java_org_direct_1bt_EInfoReport_getADAddressType(JNIEnv *env, jobject obj)
  */
 jbyte Java_org_direct_1bt_EInfoReport_getAddressTypeImpl(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return static_cast<jbyte>( number( eir_ptr->getAddressType() ) );
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return static_cast<jbyte>( number( ref->getAddressType() ) );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -428,8 +413,8 @@ jbyte Java_org_direct_1bt_EInfoReport_getAddressTypeImpl(JNIEnv *env, jobject ob
  */
 jbyteArray Java_org_direct_1bt_EInfoReport_getAddressImpl(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        const EUI48 & addr = eir_ptr->getAddress();
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        const EUI48 & addr = ref->getAddress();
         jbyteArray jaddr = env->NewByteArray(sizeof(addr));
         env->SetByteArrayRegion(jaddr, 0, sizeof(addr), (const jbyte*)(addr.b));
         return jaddr;
@@ -446,8 +431,8 @@ jbyteArray Java_org_direct_1bt_EInfoReport_getAddressImpl(JNIEnv *env, jobject o
  */
 jstring Java_org_direct_1bt_EInfoReport_getName(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return jau::from_string_to_jstring(env, eir_ptr->getName());
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return jau::from_string_to_jstring(env, ref->getName());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -461,8 +446,8 @@ jstring Java_org_direct_1bt_EInfoReport_getName(JNIEnv *env, jobject obj) {
  */
 jstring Java_org_direct_1bt_EInfoReport_getShortName(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return jau::from_string_to_jstring(env, eir_ptr->getShortName());
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return jau::from_string_to_jstring(env, ref->getShortName());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -476,8 +461,8 @@ jstring Java_org_direct_1bt_EInfoReport_getShortName(JNIEnv *env, jobject obj) {
  */
 jbyte Java_org_direct_1bt_EInfoReport_getRSSI(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return static_cast<jbyte>( eir_ptr->getRSSI() );
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return static_cast<jbyte>( ref->getRSSI() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -491,8 +476,8 @@ jbyte Java_org_direct_1bt_EInfoReport_getRSSI(JNIEnv *env, jobject obj) {
  */
 jbyte Java_org_direct_1bt_EInfoReport_getTxPower(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return static_cast<jbyte>( eir_ptr->getTxPower() );
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return static_cast<jbyte>( ref->getTxPower() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -502,8 +487,8 @@ jbyte Java_org_direct_1bt_EInfoReport_getTxPower(JNIEnv *env, jobject obj) {
 jobject Java_org_direct_1bt_EInfoReport_getManufacturerData(JNIEnv *env, jobject obj)
 {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        std::shared_ptr<ManufactureSpecificData> mdata = eir_ptr->getManufactureSpecificData();
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        std::shared_ptr<ManufactureSpecificData> mdata = ref->getManufactureSpecificData();
 
         jclass map_cls = jau::search_class(env, "java/util/HashMap");
         jmethodID map_ctor = jau::search_method(env, map_cls, "<init>", "(I)V", false);
@@ -542,10 +527,10 @@ jobject Java_org_direct_1bt_EInfoReport_getManufacturerData(JNIEnv *env, jobject
  */
 jobject Java_org_direct_1bt_EInfoReport_getServices(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        jau::darray<std::shared_ptr<const jau::uuid_t>> service_uuids = eir_ptr->getServices();
-        std::function<jobject(JNIEnv*, const jau::uuid_t*)> ctor_uuid2string =
-                [](JNIEnv *env_, const jau::uuid_t* uuid_ptr)->jobject {
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        jau::darray<std::shared_ptr<const jau::uuid_t>> service_uuids = ref->getServices();
+        std::function<jobject(JNIEnv*, const std::shared_ptr<const jau::uuid_t>&)> ctor_uuid2string =
+                [](JNIEnv *env_, const std::shared_ptr<const jau::uuid_t>& uuid_ptr)->jobject {
                     return jau::from_string_to_jstring(env_, uuid_ptr->toUUID128String());
                 };
         return jau::convert_vector_sharedptr_to_jarraylist<jau::darray<std::shared_ptr<const jau::uuid_t>>, const jau::uuid_t>(env, service_uuids, ctor_uuid2string);
@@ -562,8 +547,8 @@ jobject Java_org_direct_1bt_EInfoReport_getServices(JNIEnv *env, jobject obj) {
  */
 jboolean Java_org_direct_1bt_EInfoReport_getServicesComplete(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return eir_ptr->getServicesComplete() ? JNI_TRUE : JNI_FALSE;
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return ref->getServicesComplete() ? JNI_TRUE : JNI_FALSE;
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -577,8 +562,8 @@ jboolean Java_org_direct_1bt_EInfoReport_getServicesComplete(JNIEnv *env, jobjec
  */
 jint Java_org_direct_1bt_EInfoReport_getDeviceClass(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return static_cast<jint>( eir_ptr->getDeviceClass() );
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return static_cast<jint>( ref->getDeviceClass() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -592,8 +577,8 @@ jint Java_org_direct_1bt_EInfoReport_getDeviceClass(JNIEnv *env, jobject obj) {
  */
 jshort Java_org_direct_1bt_EInfoReport_getDeviceIDSource(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return static_cast<jshort>( eir_ptr->getDeviceIDSource() );
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return static_cast<jshort>( ref->getDeviceIDSource() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -607,8 +592,8 @@ jshort Java_org_direct_1bt_EInfoReport_getDeviceIDSource(JNIEnv *env, jobject ob
  */
 jshort Java_org_direct_1bt_EInfoReport_getDeviceIDVendor(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return static_cast<jshort>( eir_ptr->getDeviceIDVendor() );
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return static_cast<jshort>( ref->getDeviceIDVendor() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -622,8 +607,8 @@ jshort Java_org_direct_1bt_EInfoReport_getDeviceIDVendor(JNIEnv *env, jobject ob
  */
 jshort Java_org_direct_1bt_EInfoReport_getDeviceIDProduct(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return static_cast<jshort>( eir_ptr->getDeviceIDProduct() );
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return static_cast<jshort>( ref->getDeviceIDProduct() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -637,8 +622,8 @@ jshort Java_org_direct_1bt_EInfoReport_getDeviceIDProduct(JNIEnv *env, jobject o
  */
 jshort Java_org_direct_1bt_EInfoReport_getDeviceIDVersion(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return static_cast<jshort>( eir_ptr->getDeviceIDVersion() );
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return static_cast<jshort>( ref->getDeviceIDVersion() );
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -652,7 +637,7 @@ jshort Java_org_direct_1bt_EInfoReport_getDeviceIDVersion(JNIEnv *env, jobject o
  */
 void Java_org_direct_1bt_EInfoReport_getConnInterval(JNIEnv *env, jobject obj, jshortArray jminmax) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
 
         if( nullptr == jminmax ) {
             throw jau::IllegalArgumentException("address null", E_FILE_LINE);
@@ -666,7 +651,7 @@ void Java_org_direct_1bt_EInfoReport_getConnInterval(JNIEnv *env, jobject obj, j
         if( NULL == array_ptr ) {
             throw jau::InternalError("GetPrimitiveArrayCritical(short array) is null", E_FILE_LINE);
         }
-        eir_ptr->getConnInterval(array_ptr[0], array_ptr[1]);
+        ref->getConnInterval(array_ptr[0], array_ptr[1]);
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -679,8 +664,8 @@ void Java_org_direct_1bt_EInfoReport_getConnInterval(JNIEnv *env, jobject obj, j
  */
 jstring Java_org_direct_1bt_EInfoReport_getDeviceIDModalias(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return jau::from_string_to_jstring(env, eir_ptr->getDeviceIDModalias());
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return jau::from_string_to_jstring(env, ref->getDeviceIDModalias());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -694,8 +679,8 @@ jstring Java_org_direct_1bt_EInfoReport_getDeviceIDModalias(JNIEnv *env, jobject
  */
 jstring Java_org_direct_1bt_EInfoReport_eirDataMaskToString(JNIEnv *env, jobject obj) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return jau::from_string_to_jstring(env, eir_ptr->eirDataMaskToString());
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return jau::from_string_to_jstring(env, ref->eirDataMaskToString());
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }
@@ -709,8 +694,8 @@ jstring Java_org_direct_1bt_EInfoReport_eirDataMaskToString(JNIEnv *env, jobject
  */
 jstring Java_org_direct_1bt_EInfoReport_toString(JNIEnv *env, jobject obj, jboolean includeServices) {
     try {
-        std::shared_ptr<EInfoReport>& eir_ptr = *jau::getInstance<std::shared_ptr<EInfoReport>>(env, obj);
-        return jau::from_string_to_jstring(env, eir_ptr->toString(JNI_TRUE==includeServices));
+        jau::shared_ptr_ref<EInfoReport> ref(env, obj); // hold until done
+        return jau::from_string_to_jstring(env, ref->toString(JNI_TRUE==includeServices));
     } catch(...) {
         rethrow_and_raise_java_exception(env);
     }