implemented port buffer and shared memory preparation part.

There was a lot of cumbersome androidaudioplugin API that needs to be
addressed and cleaned up... logged as atsushieno/aap-core#79

aap-midi-device-service/src/main/cpp/AAPMidiProcessor.cpp

@@ -1,3 +1,5 @@
+#include <sys/mman.h>
+#include <android/sharedmem.h>
 #include <aap/logging.h>
 #include <aap/audio-plugin-host-android.h>
 #include "AAPMidiProcessor.h"
@@ -23,10 +25,11 @@ namespace aapmidideviceservice {
         return oboe::DataCallbackResult::Continue;
     }
 
-    void AAPMidiProcessor::initialize(int32_t sampleRate) {
+    void AAPMidiProcessor::initialize(int32_t sampleRate, int32_t pluginFrameSize) {
         // AAP settings
         host = std::make_unique<aap::PluginHost>(&host_manager);
         sample_rate = sampleRate;
+        plugin_frame_size = pluginFrameSize;
 
         // Oboe configuration
         builder.setDirection(oboe::Direction::Output);
@@ -39,6 +42,20 @@ namespace aapmidideviceservice {
     }
 
     void AAPMidiProcessor::terminate() {
+
+        // free shared memory buffers and close FDs for the instances.
+        // FIXME: shouldn't androidaudioplugin implement this functionality so that we don't have
+        //  to manage it everywhere? It is also super error prone.
+        for (auto& data : instance_data_list) {
+            int numBuffers = data->plugin_buffer->num_buffers;
+            for (int n = 0; n < numBuffers; n++) {
+                munmap(data->buffer_pointers[n], data->plugin_buffer->num_frames * sizeof(float));
+                int fd = data->portSharedMemoryFDs[n];
+                if (fd != 0)
+                    close(fd);
+            }
+        }
+
         host.reset();
     }
 
@@ -71,11 +88,44 @@ namespace aapmidideviceservice {
             return;
         }
 
+        auto pluginInfo = host_manager.getPluginInformation(pluginId);
+        int32_t numPorts = pluginInfo->getNumPorts();
+
         auto instanceId = host->createInstance(pluginId, sample_rate);
-        instance_ids.emplace_back(instanceId);
+        auto instance = host->getInstance(instanceId);
+
+        auto data = std::make_unique<PluginInstanceData>(instanceId, numPorts);
+
+        instance->completeInstantiation();
+
+        auto sharedMemoryExtension = (aap::SharedMemoryExtension*) instance->getExtension(aap::SharedMemoryExtension::URI);
+
+        auto buffer = std::make_unique<AndroidAudioPluginBuffer>();
+        buffer->num_buffers = numPorts;
+        buffer->num_frames = plugin_frame_size;
+
+        size_t memSize = buffer->num_frames * sizeof(float);
+
+        data->instance_id = instanceId;
+        data->plugin_buffer = std::move(buffer);
+        data->plugin_buffer->buffers = data->buffer_pointers.get();
+
+
+        for (int i = 0; i < numPorts; i++) {
+            int fd = ASharedMemory_create(nullptr, memSize);
+            data->portSharedMemoryFDs.emplace_back(fd);
+            sharedMemoryExtension->getPortBufferFDs().emplace_back(fd);
+            data->plugin_buffer->buffers[i] = mmap(nullptr, memSize,
+                                                         PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+        }
+
+        instance->prepare(plugin_frame_size, data->plugin_buffer.get());
+
+        instance_data_list.emplace_back(std::move(data));
     }
 
     void AAPMidiProcessor::activate() {
+        // start Oboe stream.
         if (state != AAP_MIDI_PROCESSOR_STATE_CREATED) {
             aap::aprintf("Unexpected call to start() at %s state.",
                          convertStateToText(state).c_str());
@@ -92,10 +142,20 @@ namespace aapmidideviceservice {
 
         stream->requestStart();
 
+        // activate instances
+        for (int i = 0; i < host->getInstanceCount(); i++)
+            host->getInstance(i)->activate();
+
         state = AAP_MIDI_PROCESSOR_STATE_STARTED;
     }
 
     void AAPMidiProcessor::deactivate() {
+
+        // deactivate instances
+        for (int i = 0; i < host->getInstanceCount(); i++)
+            host->getInstance(i)->deactivate();
+
+        // close Oboe stream.
         stream->stop();
         stream->close();
         stream.reset();

aap-midi-device-service/src/main/cpp/AAPMidiProcessor.h

@@ -19,14 +19,26 @@ namespace aapmidideviceservice {
         AAP_MIDI_PROCESSOR_STATE_ERROR
     };
 
+    struct PluginInstanceData {
+        PluginInstanceData(int instanceId, size_t numPorts) : instance_id(instanceId) {
+            buffer_pointers.reset((void**) calloc(sizeof(void*), numPorts));
+        }
+
+        int instance_id;
+        std::vector<int> portSharedMemoryFDs{};
+        std::unique_ptr<AndroidAudioPluginBuffer> plugin_buffer;
+        std::unique_ptr<void*> buffer_pointers{nullptr};
+    };
+
     class AAPMidiProcessor {
         static std::string convertStateToText(AAPMidiProcessorState state);
 
         // AAP
         aap::PluginHostManager host_manager{};
         std::unique_ptr<aap::PluginHost> host{nullptr};
         int sample_rate{0};
-        std::vector<int32_t> instance_ids{};
+        int plugin_frame_size{1024};
+        std::vector<std::unique_ptr<PluginInstanceData>> instance_data_list{};
 
         // Oboe
         oboe::AudioStreamBuilder builder;
@@ -37,7 +49,7 @@ namespace aapmidideviceservice {
     public:
         static AAPMidiProcessor* getInstance();
 
-        void initialize(int32_t sampleRate);
+        void initialize(int32_t sampleRate, int32_t frameSize);
 
         static void registerPluginService(const aap::AudioPluginServiceConnection service);
 

aap-midi-device-service/src/main/cpp/aapmidideviceservice-jni.cpp

@@ -28,8 +28,8 @@ extern "C" {
 #define AAPMIDIDEVICE_INSTANCE aapmidideviceservice::AAPMidiProcessor::getInstance()
 
 JNIEXPORT void JNICALL Java_org_androidaudioplugin_midideviceservice_AudioPluginMidiReceiver_initializeReceiverNative(
-        JNIEnv *env, jobject midiReceiver, jobject applicationContext, jint sampleRate) {
-    AAPMIDIDEVICE_INSTANCE->initialize(sampleRate);
+        JNIEnv *env, jobject midiReceiver, jobject applicationContext, jint sampleRate, jint frameSize) {
+    AAPMIDIDEVICE_INSTANCE->initialize(sampleRate, frameSize);
 }
 
 JNIEXPORT void JNICALL Java_org_androidaudioplugin_midideviceservice_AudioPluginMidiReceiver_registerPluginService(

aap-midi-device-service/src/main/java/org/androidaudioplugin/midideviceservice/AudioPluginMidiDeviceService.kt

@@ -43,6 +43,7 @@ class AudioPluginMidiReceiver(private val service: AudioPluginMidiDeviceService)
     // time as it must be instantiated at MidiDeviceService instantiation time when ApplicationContext
     // is not assigned yet (as onCreate() was not invoked yet!).
     private var sampleRate: Int? = null
+    private var frameSize: Int = 4096
 
     fun initialize() {
         val audioManager = service.getSystemService(Context.AUDIO_SERVICE) as AudioManager
@@ -62,7 +63,7 @@ class AudioPluginMidiReceiver(private val service: AudioPluginMidiDeviceService)
 
             activate()
         }
-        initializeReceiverNative(service.applicationContext, sampleRate!!)
+        initializeReceiverNative(service.applicationContext, sampleRate!!, frameSize)
 
         setupDefaultPlugins()
     }
@@ -95,7 +96,7 @@ class AudioPluginMidiReceiver(private val service: AudioPluginMidiDeviceService)
         processMessage(msg, offset, count, timestamp)
 
     // Initialize basic native parts, without any plugin information.
-    private external fun initializeReceiverNative(applicationContext: Context, sampleRate: Int)
+    private external fun initializeReceiverNative(applicationContext: Context, sampleRate: Int, frameSize: Int)
     private external fun terminateReceiverNative()
     // register Binder instance to native host
     private external fun registerPluginService(binder: IBinder, packageName: String, className: String)