commit e72481c5c16d401c776e0ba49b84b80223769b91
author Phil Burk <philburk@google.com> Tue Aug 08 13:20:45 2017 -0700
committer Phil Burk <philburk@google.com> Wed Aug 09 14:11:57 2017 -0700
tree 282c04aa82bba9f854b3125fa8edade0b41f5287
parent e88fd530455d39e4c770870c74c1198820f62bfe

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

services/oboeservice/AAudioServiceStreamMMAP.cpp

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;