OboeService: initial commit

This builds a standalone service that is easy to test.

Bug: 33269952
Test: test_oboe_api

Change-Id: I1890b1b974e728c2c0c15e24aa02121c2774bd56
Signed-off-by: Phil Burk <philburk@google.com>
diff --git a/services/oboeservice/SharedRingBuffer.cpp b/services/oboeservice/SharedRingBuffer.cpp
new file mode 100644
index 0000000..c3df5ce
--- /dev/null
+++ b/services/oboeservice/SharedRingBuffer.cpp
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "OboeService"
+//#define LOG_NDEBUG 0
+#include <utils/Log.h>
+
+#include "AudioClock.h"
+#include "AudioEndpointParcelable.h"
+
+//#include "OboeServiceStreamBase.h"
+//#include "OboeServiceStreamFakeHal.h"
+
+#include "SharedRingBuffer.h"
+
+using namespace android;
+using namespace oboe;
+
+SharedRingBuffer::~SharedRingBuffer()
+{
+    if (mSharedMemory != nullptr) {
+        delete mFifoBuffer;
+        munmap(mSharedMemory, mSharedMemorySizeInBytes);
+        close(mFileDescriptor);
+        mSharedMemory = nullptr;
+    }
+}
+
+oboe_result_t SharedRingBuffer::allocate(fifo_frames_t   bytesPerFrame,
+                                         fifo_frames_t   capacityInFrames) {
+    mCapacityInFrames = capacityInFrames;
+
+    // Create shared memory large enough to hold the data and the read and write counters.
+    mDataMemorySizeInBytes = bytesPerFrame * capacityInFrames;
+    mSharedMemorySizeInBytes = mDataMemorySizeInBytes + (2 * (sizeof(fifo_counter_t)));
+    mFileDescriptor = ashmem_create_region("OboeSharedRingBuffer", mSharedMemorySizeInBytes);
+    if (mFileDescriptor < 0) {
+        ALOGE("SharedRingBuffer::allocate() ashmem_create_region() failed %d", errno);
+        return OBOE_ERROR_INTERNAL;
+    }
+    int err = ashmem_set_prot_region(mFileDescriptor, PROT_READ|PROT_WRITE); // TODO error handling?
+    if (err < 0) {
+        ALOGE("SharedRingBuffer::allocate() ashmem_set_prot_region() failed %d", errno);
+        close(mFileDescriptor);
+        return OBOE_ERROR_INTERNAL; // TODO convert errno to a better OBOE_ERROR;
+    }
+
+    // Map the fd to memory addresses.
+    mSharedMemory = (uint8_t *) mmap(0, mSharedMemorySizeInBytes,
+                         PROT_READ|PROT_WRITE,
+                         MAP_SHARED,
+                         mFileDescriptor, 0);
+    if (mSharedMemory == MAP_FAILED) {
+        ALOGE("SharedRingBuffer::allocate() mmap() failed %d", errno);
+        close(mFileDescriptor);
+        return OBOE_ERROR_INTERNAL; // TODO convert errno to a better OBOE_ERROR;
+    }
+
+    // Get addresses for our counters and data from the shared memory.
+    fifo_counter_t *readCounterAddress =
+            (fifo_counter_t *) &mSharedMemory[SHARED_RINGBUFFER_READ_OFFSET];
+    fifo_counter_t *writeCounterAddress =
+            (fifo_counter_t *) &mSharedMemory[SHARED_RINGBUFFER_WRITE_OFFSET];
+    uint8_t *dataAddress = &mSharedMemory[SHARED_RINGBUFFER_DATA_OFFSET];
+
+    mFifoBuffer = new(std::nothrow) FifoBuffer(bytesPerFrame, capacityInFrames,
+                                 readCounterAddress, writeCounterAddress, dataAddress);
+    return (mFifoBuffer == nullptr) ? OBOE_ERROR_NO_MEMORY : OBOE_OK;
+}
+
+void SharedRingBuffer::fillParcelable(AudioEndpointParcelable &endpointParcelable,
+                    RingBufferParcelable &ringBufferParcelable) {
+    int fdIndex = endpointParcelable.addFileDescriptor(mFileDescriptor, mSharedMemorySizeInBytes);
+    ringBufferParcelable.setupMemory(fdIndex,
+                                     SHARED_RINGBUFFER_DATA_OFFSET,
+                                     mDataMemorySizeInBytes,
+                                     SHARED_RINGBUFFER_READ_OFFSET,
+                                     SHARED_RINGBUFFER_WRITE_OFFSET,
+                                     sizeof(fifo_counter_t));
+    ringBufferParcelable.setBytesPerFrame(mFifoBuffer->getBytesPerFrame());
+    ringBufferParcelable.setFramesPerBurst(1);
+    ringBufferParcelable.setCapacityInFrames(mCapacityInFrames);
+}