aaudio: fix ownership problems with file descriptors

Use unique_fd to track file descriptors.
Fix extra close of file descriptor in SharedMemoryParcelable.cpp.
This bug was causing unrelated file descriptors to be closed!

Bug: 64311216
Test: write_sine.cpp, FD should survive aaudio close
Change-Id: I4f38c83510a49ea22b79b96d970ee48153417249
diff --git a/services/oboeservice/AAudioServiceStreamMMAP.cpp b/services/oboeservice/AAudioServiceStreamMMAP.cpp
index 970d734..68dcaff 100644
--- a/services/oboeservice/AAudioServiceStreamMMAP.cpp
+++ b/services/oboeservice/AAudioServiceStreamMMAP.cpp
@@ -31,6 +31,7 @@
 #include "SharedMemoryProxy.h"
 #include "utility/AAudioUtilities.h"
 
+using android::base::unique_fd;
 using namespace android;
 using namespace aaudio;
 
@@ -69,11 +70,6 @@
         AudioClock::sleepForNanos(100 * AAUDIO_NANOS_PER_MILLISECOND);
     }
 
-    if (mAudioDataFileDescriptor != -1) {
-        ::close(mAudioDataFileDescriptor);
-        mAudioDataFileDescriptor = -1;
-    }
-
     return AAudioServiceStreamBase::close();
 }
 
@@ -193,7 +189,13 @@
                            ? audio_channel_count_from_out_mask(config.channel_mask)
                            : audio_channel_count_from_in_mask(config.channel_mask);
 
-    mAudioDataFileDescriptor = mMmapBufferinfo.shared_memory_fd;
+    // AAudio creates a copy of this FD and retains ownership of the copy.
+    // Assume that AudioFlinger will close the original shared_memory_fd.
+    mAudioDataFileDescriptor.reset(dup(mMmapBufferinfo.shared_memory_fd));
+    if (mAudioDataFileDescriptor.get() == -1) {
+        ALOGE("AAudioServiceStreamMMAP::open() - could not dup shared_memory_fd");
+        return AAUDIO_ERROR_INTERNAL; // TODO review
+    }
     mFramesPerBurst = mMmapBufferinfo.burst_size_frames;
     mAudioFormat = AAudioConvert_androidToAAudioDataFormat(config.format);
     mSampleRate = config.sample_rate;
diff --git a/services/oboeservice/AAudioServiceStreamMMAP.h b/services/oboeservice/AAudioServiceStreamMMAP.h
index e6f8fad..e631fd3 100644
--- a/services/oboeservice/AAudioServiceStreamMMAP.h
+++ b/services/oboeservice/AAudioServiceStreamMMAP.h
@@ -19,6 +19,7 @@
 
 #include <atomic>
 
+#include <android-base/unique_fd.h>
 #include <media/audiohal/StreamHalInterface.h>
 #include <media/MmapStreamCallback.h>
 #include <media/MmapStreamInterface.h>
@@ -33,6 +34,7 @@
 #include "TimestampScheduler.h"
 #include "utility/MonotonicCounter.h"
 
+
 namespace aaudio {
 
     /**
@@ -133,9 +135,9 @@
     MonotonicCounter                    mFramesWritten;
     MonotonicCounter                    mFramesRead;
     int32_t                             mPreviousFrameCounter = 0;   // from HAL
-    int                                 mAudioDataFileDescriptor = -1;
     int64_t                             mHardwareTimeOffsetNanos = 0; // TODO get from HAL
 
+
     // Interface to the AudioFlinger MMAP support.
     android::sp<android::MmapStreamInterface> mMmapStream;
     struct audio_mmap_buffer_info             mMmapBufferinfo;
@@ -143,6 +145,7 @@
     audio_port_handle_t                       mDeviceId = AUDIO_PORT_HANDLE_NONE;
     android::AudioClient                      mServiceClient;
     bool                                      mInService = false;
+    android::base::unique_fd                  mAudioDataFileDescriptor;
 };
 
 } // namespace aaudio
diff --git a/services/oboeservice/SharedRingBuffer.cpp b/services/oboeservice/SharedRingBuffer.cpp
index 6b3fb4c..83b25b3 100644
--- a/services/oboeservice/SharedRingBuffer.cpp
+++ b/services/oboeservice/SharedRingBuffer.cpp
@@ -35,11 +35,6 @@
         munmap(mSharedMemory, mSharedMemorySizeInBytes);
         mSharedMemory = nullptr;
     }
-    if (mFileDescriptor != -1) {
-        ALOGV("SharedRingBuffer: LEAK? close(mFileDescriptor = %d)\n", mFileDescriptor);
-        close(mFileDescriptor);
-        mFileDescriptor = -1;
-    }
 }
 
 aaudio_result_t SharedRingBuffer::allocate(fifo_frames_t   bytesPerFrame,
@@ -49,17 +44,17 @@
     // 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("AAudioSharedRingBuffer", mSharedMemorySizeInBytes);
-    ALOGV("SharedRingBuffer::allocate() LEAK? mFileDescriptor = %d\n", mFileDescriptor);
-    if (mFileDescriptor < 0) {
+    mFileDescriptor.reset(ashmem_create_region("AAudioSharedRingBuffer", mSharedMemorySizeInBytes));
+    if (mFileDescriptor.get() == -1) {
         ALOGE("SharedRingBuffer::allocate() ashmem_create_region() failed %d", errno);
         return AAUDIO_ERROR_INTERNAL;
     }
+    ALOGV("SharedRingBuffer::allocate() mFileDescriptor = %d\n", mFileDescriptor.get());
 
-    int err = ashmem_set_prot_region(mFileDescriptor, PROT_READ|PROT_WRITE); // TODO error handling?
+    int err = ashmem_set_prot_region(mFileDescriptor.get(), PROT_READ|PROT_WRITE); // TODO error handling?
     if (err < 0) {
         ALOGE("SharedRingBuffer::allocate() ashmem_set_prot_region() failed %d", errno);
-        close(mFileDescriptor);
+        mFileDescriptor.reset();
         return AAUDIO_ERROR_INTERNAL; // TODO convert errno to a better AAUDIO_ERROR;
     }
 
@@ -67,10 +62,10 @@
     mSharedMemory = (uint8_t *) mmap(0, mSharedMemorySizeInBytes,
                          PROT_READ|PROT_WRITE,
                          MAP_SHARED,
-                         mFileDescriptor, 0);
+                         mFileDescriptor.get(), 0);
     if (mSharedMemory == MAP_FAILED) {
         ALOGE("SharedRingBuffer::allocate() mmap() failed %d", errno);
-        close(mFileDescriptor);
+        mFileDescriptor.reset();
         return AAUDIO_ERROR_INTERNAL; // TODO convert errno to a better AAUDIO_ERROR;
     }
 
diff --git a/services/oboeservice/SharedRingBuffer.h b/services/oboeservice/SharedRingBuffer.h
index a2c3766..79169bc 100644
--- a/services/oboeservice/SharedRingBuffer.h
+++ b/services/oboeservice/SharedRingBuffer.h
@@ -17,6 +17,7 @@
 #ifndef AAUDIO_SHARED_RINGBUFFER_H
 #define AAUDIO_SHARED_RINGBUFFER_H
 
+#include <android-base/unique_fd.h>
 #include <stdint.h>
 #include <cutils/ashmem.h>
 #include <sys/mman.h>
@@ -51,12 +52,12 @@
     }
 
 private:
-    int                    mFileDescriptor = -1;
-    android::FifoBuffer   *mFifoBuffer = nullptr;
-    uint8_t               *mSharedMemory = nullptr;
-    int32_t                mSharedMemorySizeInBytes = 0;
-    int32_t                mDataMemorySizeInBytes = 0;
-    android::fifo_frames_t mCapacityInFrames = 0;
+    android::base::unique_fd  mFileDescriptor;
+    android::FifoBuffer      *mFifoBuffer = nullptr;
+    uint8_t                  *mSharedMemory = nullptr;
+    int32_t                   mSharedMemorySizeInBytes = 0;
+    int32_t                   mDataMemorySizeInBytes = 0;
+    android::fifo_frames_t    mCapacityInFrames = 0;
 };
 
 } /* namespace aaudio */