AAPXS v2: basic host extension now works.

aapxssample now invokes `notify_parameters_changed()` in every `process()`
(which usually should not happen but as a dogfooding).

androidaudioplugin/src/main/cpp/core/aapxs/parameters-aapxs.cpp

@@ -103,7 +103,7 @@ AAPXSExtensionServiceProxy aap::xs::AAPXSDefinition_Parameters::aapxs_parameters
     if (!service->typed_service)
         service->typed_service = std::make_unique<ParametersServiceAAPXS>(aapxsInstance, serialization);
     //*service->typed_service = ParametersServiceAAPXS(aapxsInstance, serialization);
-    service->service_proxy.aapxs_context = &service->typed_service;
+    service->service_proxy.aapxs_context = service->typed_service.get();
     service->service_proxy.as_host_extension = aapxs_parameters_as_host_extension;
     return service->service_proxy;
 }
@@ -196,5 +196,5 @@ int32_t aap::xs::ParametersClientAAPXS::getEnumerationAsync(int32_t index, int32
 }
 
 void aap::xs::ParametersServiceAAPXS::notifyParametersChanged() {
-    callVoidFunctionSynchronously(OPCODE_NOTIFY_PARAMETERS_CHANGED);
+    fireVoidFunctionAndForget(OPCODE_NOTIFY_PARAMETERS_CHANGED);
 }

androidaudioplugin/src/main/cpp/core/hosting/PluginInstance.Local.cpp

@@ -65,13 +65,14 @@ AndroidAudioPluginHost* aap::LocalPluginInstance::getHostFacadeForCompleteInstan
 void *
 aap::LocalPluginInstance::internalGetHostExtension(AndroidAudioPluginHost *host, const char *uri) {
     auto instance = (LocalPluginInstance *) host->context;
+    // FIXME: in the future maybe we want to eliminate this kind of special cases.
     if (strcmp(uri, AAP_PLUGIN_INFO_EXTENSION_URI) == 0) {
         instance->host_plugin_info.get = get_plugin_info;
         return &instance->host_plugin_info;
     }
-    // FIXME: implement more extensions
+    // Look up host extension and get proxy via AAPXSDefinition.
     auto definition = instance->getAAPXSRegistry()->items()->getByUri(uri);
-    if (definition) {
+    if (definition && definition->get_host_extension_proxy) {
         auto aapxsInstance = instance->getAAPXSDispatcher().getHostAAPXSByUri(uri);
         auto proxy = definition->get_host_extension_proxy(definition, aapxsInstance, aapxsInstance->serialization);
         return proxy.as_host_extension(&proxy);
@@ -176,14 +177,10 @@ void aap::LocalPluginInstance::setupAAPXS() {
 }
 
 static inline void staticSendAAPXSReply(AAPXSRecipientInstance* instance, AAPXSRequestContext* context) {
-    ((aap::LocalPluginInstance *) instance->host_context)->sendPluginAAPXSReply(context->uri,
-                                                                                context->opcode,
-                                                                                context->serialization->data,
-                                                                                context->serialization->data_size,
-                                                                                context->request_id);
+    ((aap::LocalPluginInstance *) instance->host_context)->sendPluginAAPXSReply(context);
 }
 static inline bool staticSendAAPXSRequest(AAPXSInitiatorInstance* instance, AAPXSRequestContext* context) {
-    return ((aap::LocalPluginInstance*) instance->host_context)->sendHostAAPXSRequest(context->uri, context->opcode, context->serialization->data, context->serialization->data_size, context->request_id);
+    return ((aap::LocalPluginInstance*) instance->host_context)->sendHostAAPXSRequest(context);
 }
 
 void aap::LocalPluginInstance::setupAAPXSInstances() {
@@ -203,38 +200,34 @@ void aap::LocalPluginInstance::setupAAPXSInstances() {
 }
 
 void
-aap::LocalPluginInstance::sendPluginAAPXSReply(const char* uri, int32_t opcode, void *data, int32_t dataSize, uint32_t requestId) {
+aap::LocalPluginInstance::sendPluginAAPXSReply(AAPXSRequestContext* request) {
     if (instantiation_state == PLUGIN_INSTANTIATION_STATE_ACTIVE) {
-        auto aapxsInstance = getAAPXSDispatcher().getPluginAAPXSByUri(uri);
         aapxs_midi2_processor.addReply(aapxsProcessorAddEventUmpOutput,
                                        this,
-                                       uri,
+                                       request->uri,
                                        // should we support MIDI 2.0 group?
                                        0,
-                                       requestId,
-                                       aapxsInstance->serialization->data,
-                                       dataSize,
-                                       opcode);
+                                       request->request_id,
+                                       request->serialization->data,
+                                       request->serialization->data_size,
+                                       request->opcode);
     } else {
         // it is synchronously handled at Binder IPC, nothing to process here.
     }
 }
 
 bool
-aap::LocalPluginInstance::sendHostAAPXSRequest(const char* uri, int32_t opcode, void *data, int32_t dataSize, uint32_t newRequestId) {
-    auto aapxsInstance = aapxs_dispatcher.getHostAAPXSByUri(uri);
-
+aap::LocalPluginInstance::sendHostAAPXSRequest(AAPXSRequestContext* request) {
     // If it is at ACTIVE state it has to switch to AAPXS SysEx8 MIDI messaging mode,
     // otherwise it goes to the Binder route.
     if (instantiation_state == PLUGIN_INSTANTIATION_STATE_ACTIVE) {
         // aapxsInstance already contains binary data here, so we retrieve data from there.
-        int32_t group = 0; // will we have to give special semantics on it?
         // This is an asynchronous function, so we do not wait for the result.
-        aapxs_host_session.addSession(aapxsSessionAddEventUmpInput, this, group, newRequestId, uri, aapxsInstance->serialization->data, dataSize, opcode);
+        aapxs_host_session.addSession(aapxsSessionAddEventUmpInput, this, request);
         return true;
     } else {
         // the actual implementation is in AudioPluginInterfaceImpl, kicks `hostExtension()` on the callback proxy object.
-        ipc_send_extension_message_func(ipc_send_extension_message_context, uri, getInstanceId(), opcode);
+        ipc_send_extension_message_func(ipc_send_extension_message_context, request->uri, getInstanceId(), request->opcode);
         return false;
     }
 }

include/aap/core/aapxs/typed-aapxs.h

@@ -79,6 +79,14 @@ namespace aap::xs {
             if (aapxs_instance->send_aapxs_request(aapxs_instance, &request))
                 future.wait();
         }
+
+        // "Fire and forget" invocation. Host extensions must be always like this.
+        void fireVoidFunctionAndForget(int32_t opcode) {
+            uint32_t requestId = aapxs_instance->get_new_request_id(aapxs_instance);
+            AAPXSRequestContext request{nullptr, nullptr, serialization, urid, uri, requestId,
+                                        opcode};
+            aapxs_instance->send_aapxs_request(aapxs_instance, &request);
+        }
     };
 
     class AAPXSDefinitionWrapper {

include/aap/core/host/plugin-instance.h

@@ -221,8 +221,12 @@ namespace aap {
         xs::AAPXSDefinitionServiceRegistry* getAAPXSRegistry() { return feature_registry.get(); }
         xs::AAPXSServiceDispatcher& getAAPXSDispatcher() { return aapxs_dispatcher; }
         void setupAAPXSInstances();
-        void sendPluginAAPXSReply(const char *uri, int32_t opcode, void *data, int32_t dataSize, uint32_t newRequestId);
-        bool sendHostAAPXSRequest(const char *uri, int32_t opcode, void *data, int32_t dataSize, uint32_t newRequestId);
+        void sendPluginAAPXSReply(AAPXSRequestContext* request);
+        // returns true if it is asynchronously invoked without waiting for result,
+        // or false if it is synchronously completed.
+        // Note that, however, there should not be synchronous callback in ACTIVE (realtime) mode, because
+        // there will not be any RT-safe return mode across multiple `process()` calls.
+        bool sendHostAAPXSRequest(AAPXSRequestContext* request);
 
         void setIpcExtensionMessageSender(aapxs_host_ipc_sender sender, void* context) {
             ipc_send_extension_message_func = sender;