Revised AIDL for callback API.

Now it does receives `requestProcess()` instead of `notify()` that merely
requests host to call `process()`.

It is part of #73

androidaudioplugin/src/main/aidl/org/androidaudioplugin/AudioPluginInterfaceCallback.aidl

@@ -1,5 +1,5 @@
 package org.androidaudioplugin;
 
 oneway interface AudioPluginInterfaceCallback {
-    void notify(int instanceId, String uri, int size);
+    void requestProcess(int instanceId);
 }

androidaudioplugin/src/main/cpp/android/AudioPluginInterfaceImpl.h

@@ -31,7 +31,10 @@ class AudioPluginInterfaceImpl : public aidl::org::androidaudioplugin::BnAudioPl
 
     AudioPluginInterfaceImpl() {
         plugins = PluginListSnapshot::queryServices();
-        svc.reset(new PluginService(&plugins));
+        svc.reset(new PluginService(&plugins, [&](int32_t instanceId) {
+            if (callback)
+                callback->requestProcess(instanceId);
+        }));
         aap::PluginServiceList::getInstance()->addBoundServiceInProcess(svc.get());
     }
 

androidaudioplugin/src/main/cpp/android/audio-plugin-host-android-internal.h

@@ -43,14 +43,32 @@ class AndroidPluginClientSystem : public PluginClientSystem {
 class AndroidPluginClientConnectionData {
     ndk::SpAIBinder spAIBinder;
     std::shared_ptr<aidl::org::androidaudioplugin::IAudioPluginInterface> proxy;
+    std::shared_ptr<aidl::org::androidaudioplugin::IAudioPluginInterfaceCallback> callback;
+    std::function<::ndk::ScopedAStatus(int32_t)> handle_request_process;
+
+    class AudioPluginCallback : public aidl::org::androidaudioplugin::IAudioPluginInterfaceCallbackDefault {
+        AndroidPluginClientConnectionData* owner;
+
+    public:
+        AudioPluginCallback(AndroidPluginClientConnectionData* owner) : owner(owner) {}
+        ::ndk::ScopedAStatus requestProcess(int32_t in_instanceId) override {
+            return owner->handleRequestProcess(in_instanceId);
+        }
+    };
 
 public:
     AndroidPluginClientConnectionData(AIBinder* aiBinder) {
         spAIBinder.set(aiBinder);
         proxy = aidl::org::androidaudioplugin::BpAudioPluginInterface::fromBinder(spAIBinder);
+        callback = std::make_shared<AudioPluginCallback>(this);
+        proxy->setCallback(callback);
     }
 
     aidl::org::androidaudioplugin::IAudioPluginInterface *getProxy() { return proxy.get(); }
+
+    ::ndk::ScopedAStatus handleRequestProcess(int32_t instanceId) {
+        return handle_request_process(instanceId);
+    }
 };
 
 } // namespace aap

androidaudioplugin/src/main/cpp/android/gen/include/aidl/org/androidaudioplugin/AudioPluginInterfaceCallback.h

@@ -19,20 +19,20 @@ class IAudioPluginInterfaceCallback : public ::ndk::ICInterface {
   IAudioPluginInterfaceCallback();
   virtual ~IAudioPluginInterfaceCallback();
 
-  static constexpr uint32_t TRANSACTION_notify = FIRST_CALL_TRANSACTION + 0;
+  static constexpr uint32_t TRANSACTION_requestProcess = FIRST_CALL_TRANSACTION + 0;
 
   static std::shared_ptr<IAudioPluginInterfaceCallback> fromBinder(const ::ndk::SpAIBinder& binder);
   static binder_status_t writeToParcel(AParcel* parcel, const std::shared_ptr<IAudioPluginInterfaceCallback>& instance);
   static binder_status_t readFromParcel(const AParcel* parcel, std::shared_ptr<IAudioPluginInterfaceCallback>* instance);
   static bool setDefaultImpl(const std::shared_ptr<IAudioPluginInterfaceCallback>& impl);
   static const std::shared_ptr<IAudioPluginInterfaceCallback>& getDefaultImpl();
-  virtual ::ndk::ScopedAStatus notify(int32_t in_instanceId, int32_t in_portId, int32_t in_size) = 0;
+  virtual ::ndk::ScopedAStatus requestProcess(int32_t in_instanceId) = 0;
 private:
   static std::shared_ptr<IAudioPluginInterfaceCallback> default_impl;
 };
 class IAudioPluginInterfaceCallbackDefault : public IAudioPluginInterfaceCallback {
 public:
-  ::ndk::ScopedAStatus notify(int32_t in_instanceId, int32_t in_portId, int32_t in_size) override;
+  ::ndk::ScopedAStatus requestProcess(int32_t in_instanceId) override;
   ::ndk::SpAIBinder asBinder() override;
   bool isRemote() override;
 };

androidaudioplugin/src/main/cpp/android/gen/include/aidl/org/androidaudioplugin/BnAudioPluginInterfaceCallback.h

@@ -27,8 +27,8 @@ class IAudioPluginInterfaceCallbackDelegator : public BnAudioPluginInterfaceCall
   explicit IAudioPluginInterfaceCallbackDelegator(const std::shared_ptr<IAudioPluginInterfaceCallback> &impl) : _impl(impl) {
   }
 
-  ::ndk::ScopedAStatus notify(int32_t in_instanceId, int32_t in_portId, int32_t in_size) override {
-    return _impl->notify(in_instanceId, in_portId, in_size);
+  ::ndk::ScopedAStatus requestProcess(int32_t in_instanceId) override {
+    return _impl->requestProcess(in_instanceId);
   }
 protected:
 private:

androidaudioplugin/src/main/cpp/android/gen/include/aidl/org/androidaudioplugin/BpAudioPluginInterfaceCallback.h

@@ -12,7 +12,7 @@ class BpAudioPluginInterfaceCallback : public ::ndk::BpCInterface<IAudioPluginIn
   explicit BpAudioPluginInterfaceCallback(const ::ndk::SpAIBinder& binder);
   virtual ~BpAudioPluginInterfaceCallback();
 
-  ::ndk::ScopedAStatus notify(int32_t in_instanceId, int32_t in_portId, int32_t in_size) override;
+  ::ndk::ScopedAStatus requestProcess(int32_t in_instanceId) override;
 };
 }  // namespace androidaudioplugin
 }  // namespace org

androidaudioplugin/src/main/cpp/android/gen/org/androidaudioplugin/AudioPluginInterfaceCallback.cpp

@@ -13,21 +13,13 @@ static binder_status_t _aidl_org_androidaudioplugin_AudioPluginInterfaceCallback
   binder_status_t _aidl_ret_status = STATUS_UNKNOWN_TRANSACTION;
   std::shared_ptr<BnAudioPluginInterfaceCallback> _aidl_impl = std::static_pointer_cast<BnAudioPluginInterfaceCallback>(::ndk::ICInterface::asInterface(_aidl_binder));
   switch (_aidl_code) {
-    case (FIRST_CALL_TRANSACTION + 0 /*notify*/): {
+    case (FIRST_CALL_TRANSACTION + 0 /*requestProcess*/): {
       int32_t in_instanceId;
-      int32_t in_portId;
-      int32_t in_size;
 
       _aidl_ret_status = ::ndk::AParcel_readData(_aidl_in, &in_instanceId);
       if (_aidl_ret_status != STATUS_OK) break;
 
-      _aidl_ret_status = ::ndk::AParcel_readData(_aidl_in, &in_portId);
-      if (_aidl_ret_status != STATUS_OK) break;
-
-      _aidl_ret_status = ::ndk::AParcel_readData(_aidl_in, &in_size);
-      if (_aidl_ret_status != STATUS_OK) break;
-
-      ::ndk::ScopedAStatus _aidl_status = _aidl_impl->notify(in_instanceId, in_portId, in_size);
+      ::ndk::ScopedAStatus _aidl_status = _aidl_impl->requestProcess(in_instanceId);
       _aidl_ret_status = STATUS_OK;
       break;
     }
@@ -40,7 +32,7 @@ static AIBinder_Class* _g_aidl_org_androidaudioplugin_AudioPluginInterfaceCallba
 BpAudioPluginInterfaceCallback::BpAudioPluginInterfaceCallback(const ::ndk::SpAIBinder& binder) : BpCInterface(binder) {}
 BpAudioPluginInterfaceCallback::~BpAudioPluginInterfaceCallback() {}
 
-::ndk::ScopedAStatus BpAudioPluginInterfaceCallback::notify(int32_t in_instanceId, int32_t in_portId, int32_t in_size) {
+::ndk::ScopedAStatus BpAudioPluginInterfaceCallback::requestProcess(int32_t in_instanceId) {
   binder_status_t _aidl_ret_status = STATUS_OK;
   ::ndk::ScopedAStatus _aidl_status;
   ::ndk::ScopedAParcel _aidl_in;
@@ -52,15 +44,9 @@ ::ndk::ScopedAStatus BpAudioPluginInterfaceCallback::notify(int32_t in_instanceI
   _aidl_ret_status = ::ndk::AParcel_writeData(_aidl_in.get(), in_instanceId);
   if (_aidl_ret_status != STATUS_OK) goto _aidl_error;
 
-  _aidl_ret_status = ::ndk::AParcel_writeData(_aidl_in.get(), in_portId);
-  if (_aidl_ret_status != STATUS_OK) goto _aidl_error;
-
-  _aidl_ret_status = ::ndk::AParcel_writeData(_aidl_in.get(), in_size);
-  if (_aidl_ret_status != STATUS_OK) goto _aidl_error;
-
   _aidl_ret_status = AIBinder_transact(
     asBinder().get(),
-    (FIRST_CALL_TRANSACTION + 0 /*notify*/),
+    (FIRST_CALL_TRANSACTION + 0 /*requestProcess*/),
     _aidl_in.getR(),
     _aidl_out.getR(),
     FLAG_ONEWAY
@@ -69,7 +55,7 @@ ::ndk::ScopedAStatus BpAudioPluginInterfaceCallback::notify(int32_t in_instanceI
     #endif  // BINDER_STABILITY_SUPPORT
     );
   if (_aidl_ret_status == STATUS_UNKNOWN_TRANSACTION && IAudioPluginInterfaceCallback::getDefaultImpl()) {
-    _aidl_status = IAudioPluginInterfaceCallback::getDefaultImpl()->notify(in_instanceId, in_portId, in_size);
+    _aidl_status = IAudioPluginInterfaceCallback::getDefaultImpl()->requestProcess(in_instanceId);
     goto _aidl_status_return;
   }
   if (_aidl_ret_status != STATUS_OK) goto _aidl_error;
@@ -129,7 +115,7 @@ const std::shared_ptr<IAudioPluginInterfaceCallback>& IAudioPluginInterfaceCallb
   return IAudioPluginInterfaceCallback::default_impl;
 }
 std::shared_ptr<IAudioPluginInterfaceCallback> IAudioPluginInterfaceCallback::default_impl = nullptr;
-::ndk::ScopedAStatus IAudioPluginInterfaceCallbackDefault::notify(int32_t /*in_instanceId*/, int32_t /*in_portId*/, int32_t /*in_size*/) {
+::ndk::ScopedAStatus IAudioPluginInterfaceCallbackDefault::requestProcess(int32_t /*in_instanceId*/) {
   ::ndk::ScopedAStatus _aidl_status;
   _aidl_status.set(AStatus_fromStatus(STATUS_UNKNOWN_TRANSACTION));
   return _aidl_status;

androidaudioplugin/src/main/cpp/core/hosting/audio-plugin-host.cpp

@@ -15,6 +15,8 @@
 #include "../extensions/midi-service.h"
 #include "../extensions/port-config-service.h"
 #include "../extensions/gui-service.h"
+#include "aap/core/host/plugin-instance.h"
+
 
 #define AAP_HOST_TAG "AAP_HOST"
 
@@ -242,7 +244,7 @@ PluginInstance* PluginHost::instantiateLocalPlugin(const PluginInformation *desc
 		aap::a_log_f(AAP_LOG_LEVEL_ERROR, AAP_HOST_TAG, "aap::PluginHost: AAP factory entrypoint function %s could not instantiate a plugin.", entrypoint.c_str());
 		return nullptr;
 	}
-	auto instance = new LocalPluginInstance(aapxs_registry.get(), localInstanceIdSerial++, descriptor, pluginFactory, sampleRate);
+	auto instance = new LocalPluginInstance(this, aapxs_registry.get(), localInstanceIdSerial++, descriptor, pluginFactory, sampleRate);
 	instances.emplace_back(instance);
 	return instance;
 }
@@ -463,7 +465,7 @@ void PluginInstance::scanParametersAndBuildList() {
 
 AndroidAudioPluginHost* RemotePluginInstance::getHostFacadeForCompleteInstantiation() {
     plugin_host_facade.context = this;
-    plugin_host_facade.get_extension_data = nullptr; // we shouldn't need it.
+    plugin_host_facade.get_extension = nullptr; // we shouldn't need it.
     return &plugin_host_facade;
 }
 
@@ -498,8 +500,9 @@ void RemotePluginInstance::prepare(int frameCount) {
 
 //----
 
-LocalPluginInstance::LocalPluginInstance(AAPXSRegistry *aapxsRegistry, int32_t instanceId, const PluginInformation* pluginInformation, AndroidAudioPluginFactory* loadedPluginFactory, int sampleRate)
+LocalPluginInstance::LocalPluginInstance(PluginHost *host, AAPXSRegistry *aapxsRegistry, int32_t instanceId, const PluginInformation* pluginInformation, AndroidAudioPluginFactory* loadedPluginFactory, int sampleRate)
         : PluginInstance(pluginInformation, loadedPluginFactory, sampleRate),
+		  host(host),
           aapxs_registry(aapxsRegistry),
           aapxsServiceInstances([&]() { return getPlugin(); }),
           standards(this) {
@@ -509,7 +512,8 @@ LocalPluginInstance::LocalPluginInstance(AAPXSRegistry *aapxsRegistry, int32_t i
 
 AndroidAudioPluginHost* LocalPluginInstance::getHostFacadeForCompleteInstantiation() {
     plugin_host_facade.context = this;
-    plugin_host_facade.get_extension_data = internalGetExtensionData;
+    plugin_host_facade.get_extension = internalGetExtension;
+	plugin_host_facade.request_process = internalRequestProcess;
     return &plugin_host_facade;
 }
 
@@ -578,6 +582,10 @@ void LocalPluginInstance::notify_parameters_changed(AndroidAudioPluginHost *host
     assert(false); // FIXME: implement
 }
 
+void LocalPluginInstance::requestProcessToHost() {
+	((PluginService*) host)->requestProcessToHost(instance_id);
+}
+
 //----
 
 AAPXSClientInstance* RemoteAAPXSManager::setupAAPXSInstance(AAPXSFeature *feature, int32_t dataSize) {

androidaudioplugin/src/main/update-binder.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-ANDROID_HOME=~/Android/Sdk
+ANDROID_HOME=~/Android/sdk
 BUILD_TOOLS_VERSION=33.0.2
 THIS_DIR=`dirname $(readlink -f $0)`
 AIDL_DIR=$THIS_DIR

include/aap/android-audio-plugin.h

@@ -55,7 +55,8 @@ struct AndroidAudioPlugin;
 
 struct AndroidAudioPluginHost;
 
-typedef void* (*aap_host_get_extension_data_t) (struct AndroidAudioPluginHost* host, const char *uri);
+typedef void* (*aap_host_get_extension_func_t) (struct AndroidAudioPluginHost* host, const char *uri);
+typedef void (*aap_host_request_process_func_t) (struct AndroidAudioPluginHost* host);
 
 /**
  * Represents a host from plugin's perspective.
@@ -65,8 +66,10 @@ typedef void* (*aap_host_get_extension_data_t) (struct AndroidAudioPluginHost* h
  */
 typedef struct AndroidAudioPluginHost {
     void *context;
-    /** returns the shared data space that the host provides. */
-    aap_host_get_extension_data_t get_extension_data;
+    /** returns the host extension that the host provides. */
+    aap_host_get_extension_func_t get_extension;
+    /** notify host that it should send process() request at inactive state. */
+    aap_host_request_process_func_t request_process;
 } AndroidAudioPluginHost;
 
 /* function types */

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

@@ -37,6 +37,7 @@ namespace aap {
     {
     protected:
         PluginListSnapshot* plugin_list{nullptr};
+
         std::vector<PluginInstance*> instances{};
         PluginInstance* instantiateLocalPlugin(const PluginInformation *pluginInfo, int sampleRate);
 
@@ -59,9 +60,10 @@ namespace aap {
 
 
     class PluginService : public PluginHost {
+        std::function<void(int32_t)> plugin_callback;
     public:
-        PluginService(PluginListSnapshot* contextPluginList)
-                : PluginHost(contextPluginList)
+        PluginService(PluginListSnapshot* contextPluginList, std::function<void(int32_t)> pluginCallback)
+                : PluginHost(contextPluginList), plugin_callback(pluginCallback)
         {
         }
 
@@ -70,6 +72,10 @@ namespace aap {
         inline LocalPluginInstance* getLocalInstance(int32_t instanceId) {
             return (LocalPluginInstance*) getInstanceById(instanceId);
         }
+
+        void requestProcessToHost(int32_t instanceId) {
+            plugin_callback(instanceId);
+        }
     };
 
     class PluginClient : public PluginHost {

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

@@ -10,6 +10,7 @@
 namespace aap {
 
     class PluginSharedMemoryStore;
+    class PluginHost;
 
 /**
  * The common basis for client RemotePluginInstance and service LocalPluginInstance.
@@ -174,6 +175,7 @@ namespace aap {
             AndroidAudioPlugin *getPlugin() override { return owner->getPlugin(); }
         };
 
+        PluginHost *host;
         AAPXSRegistry *aapxs_registry;
         AndroidAudioPluginHost plugin_host_facade{};
         AAPXSInstanceMap <AAPXSServiceInstance> aapxsServiceInstances;
@@ -187,7 +189,7 @@ namespace aap {
         static void notify_parameters_changed(AndroidAudioPluginHost *host, AndroidAudioPlugin *plugin);
 
         inline static void *
-        internalGetExtensionData(AndroidAudioPluginHost *host, const char *uri) {
+        internalGetExtension(AndroidAudioPluginHost *host, const char *uri) {
             if (strcmp(uri, AAP_PLUGIN_INFO_EXTENSION_URI) == 0) {
                 auto instance = (LocalPluginInstance *) host->context;
                 instance->host_plugin_info.get = get_plugin_info;
@@ -201,11 +203,16 @@ namespace aap {
             return nullptr;
         }
 
+        inline static void internalRequestProcess(AndroidAudioPluginHost *host) {
+            auto instance = (LocalPluginInstance *) host->context;
+            instance->requestProcessToHost();
+        }
+
     protected:
         AndroidAudioPluginHost *getHostFacadeForCompleteInstantiation() override;
 
     public:
-        LocalPluginInstance(AAPXSRegistry *aapxsRegistry, int32_t instanceId,
+        LocalPluginInstance(PluginHost *host, AAPXSRegistry *aapxsRegistry, int32_t instanceId,
                             const PluginInformation *pluginInformation,
                             AndroidAudioPluginFactory *loadedPluginFactory, int sampleRate);
 
@@ -261,6 +268,8 @@ namespace aap {
             plugin->prepare(plugin, getAudioPluginBuffer());
             instantiation_state = PLUGIN_INSTANTIATION_STATE_INACTIVE;
         }
+
+        void requestProcessToHost();
     };
 
     class RemotePluginInstance : public PluginInstance {

samples/aapbarebonepluginsample/src/main/cpp/aapbarebonepluginsample.cpp

@@ -51,7 +51,7 @@ void sample_plugin_delete(
 
 void sample_plugin_prepare(AndroidAudioPlugin *plugin, aap_buffer_t *buffer) {
     auto ctx = (SamplePluginSpecific*) plugin->plugin_specific;
-    auto ext = (aap_host_plugin_info_extension_t*) ctx->host.get_extension_data(&ctx->host, AAP_PLUGIN_INFO_EXTENSION_URI);
+    auto ext = (aap_host_plugin_info_extension_t*) ctx->host.get_extension(&ctx->host, AAP_PLUGIN_INFO_EXTENSION_URI);
     assert(ext);
     auto pluginInfo = ext->get(&ctx->host, PLUGIN_URI);
     auto numPorts = pluginInfo.get_port_count(&pluginInfo);

samples/aapinstrumentsample/src/main/cpp/aapinstrumentsample.cpp

@@ -454,7 +454,7 @@ AndroidAudioPlugin *sample_plugin_new(
     handle->midi_protocol = 2; // this is for testing MIDI2 in port.
 #endif
 
-    auto pluginInfoExt = (aap_host_plugin_info_extension_t*) host->get_extension_data(host, AAP_PLUGIN_INFO_EXTENSION_URI);
+    auto pluginInfoExt = (aap_host_plugin_info_extension_t*) host->get_extension(host, AAP_PLUGIN_INFO_EXTENSION_URI);
     if (pluginInfoExt != nullptr) {
         auto info = pluginInfoExt->get(host, pluginUniqueId);
         aap::a_log_f(AAP_LOG_LEVEL_INFO, AAP_APP_LOG_TAG, "plugin-info test: displayName: %s", info.display_name(&info));