aaudio: refactor references to shared FIFO

Reduce passing of raw pointers.
Use shared_ptrs and unique_ptrs.
Simplify memory management.

Refactor FifoBuffer into two subclasses so that
the internal memory management is simpler.

Bug: 151650670
Test: OboeTester "TEST OUTPUT"
Test: disable EXCLUSIVE mode
Test: OboeTester "ECHO INPUT TO OUTPUT"
Test: disable INPUT EXCLUSIVE mode
Change-Id: I10981767f8719f3cc3525df211285c53219a7979
diff --git a/services/oboeservice/SharedRingBuffer.cpp b/services/oboeservice/SharedRingBuffer.cpp
index 2454446..0a9196a 100644
--- a/services/oboeservice/SharedRingBuffer.cpp
+++ b/services/oboeservice/SharedRingBuffer.cpp
@@ -18,6 +18,8 @@
 //#define LOG_NDEBUG 0
 #include <utils/Log.h>
 
+#include <iomanip>
+#include <iostream>
 #include <sys/mman.h>
 
 #include "binding/RingBufferParcelable.h"
@@ -30,8 +32,8 @@
 
 SharedRingBuffer::~SharedRingBuffer()
 {
+    mFifoBuffer.reset(); // uses mSharedMemory
     if (mSharedMemory != nullptr) {
-        delete mFifoBuffer;
         munmap(mSharedMemory, mSharedMemorySizeInBytes);
         mSharedMemory = nullptr;
     }
@@ -76,7 +78,7 @@
             (fifo_counter_t *) &mSharedMemory[SHARED_RINGBUFFER_WRITE_OFFSET];
     uint8_t *dataAddress = &mSharedMemory[SHARED_RINGBUFFER_DATA_OFFSET];
 
-    mFifoBuffer = new FifoBuffer(bytesPerFrame, capacityInFrames,
+    mFifoBuffer = std::make_shared<FifoBufferIndirect>(bytesPerFrame, capacityInFrames,
                                  readCounterAddress, writeCounterAddress, dataAddress);
     return AAUDIO_OK;
 }
@@ -94,3 +96,19 @@
     ringBufferParcelable.setFramesPerBurst(1);
     ringBufferParcelable.setCapacityInFrames(mCapacityInFrames);
 }
+
+double SharedRingBuffer::getFractionalFullness() const {
+  int32_t framesAvailable = mFifoBuffer->getFullFramesAvailable();
+  int32_t capacity = mFifoBuffer->getBufferCapacityInFrames();
+  return framesAvailable / (double) capacity;
+}
+
+std::string SharedRingBuffer::dump() const {
+    std::stringstream result;
+    int32_t readCounter = mFifoBuffer->getReadCounter();
+    int32_t writeCounter = mFifoBuffer->getWriteCounter();
+    result << std::setw(10) << writeCounter;
+    result << std::setw(10) << readCounter;
+    result << std::setw(8) << (writeCounter - readCounter);
+    return result.str();
+}