Allow track buffer "allocation" to be from pipe

Change-Id: Ib9ac170f8e8b7746b3588157a56cbee3b753a1cb

3 files changed, 27 insertions, 6 deletions

diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index cc2b246..4683a13 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -301,6 +301,8 @@ public:
                 // If a thread does not have such a heap, this method returns 0.
                 virtual sp<MemoryDealer>    readOnlyHeap() const { return 0; }
 
+                virtual sp<IMemory> pipeMemory() const { return 0; }
+
     mutable     Mutex                   mLock;
 
 protected:
diff --git a/services/audioflinger/TrackBase.h b/services/audioflinger/TrackBase.h
index 5f13be3..4cba3fd 100644
--- a/services/audioflinger/TrackBase.h
+++ b/services/audioflinger/TrackBase.h
@@ -39,6 +39,13 @@ public:
         STARTING_2,     // for RecordTrack only
     };
 
+    // where to allocate the data buffer
+    enum alloc_type {
+        ALLOC_CBLK,     // allocate immediately after control block
+        ALLOC_READONLY, // allocate from a separate read-only heap per thread
+        ALLOC_PIPE,     // do not allocate; use the pipe buffer
+    };
+
                         TrackBase(ThreadBase *thread,
                                 const sp<Client>& client,
                                 uint32_t sampleRate,
@@ -50,7 +57,7 @@ public:
                                 int uid,
                                 IAudioFlinger::track_flags_t flags,
                                 bool isOut,
-                                bool useReadOnlyHeap = false);
+                                alloc_type alloc = ALLOC_CBLK);
     virtual             ~TrackBase();
     virtual status_t    initCheck() const { return getCblk() != 0 ? NO_ERROR : NO_MEMORY; }
 
diff --git a/services/audioflinger/Tracks.cpp b/services/audioflinger/Tracks.cpp
index f698fa2..1c55ac7 100644
--- a/services/audioflinger/Tracks.cpp
+++ b/services/audioflinger/Tracks.cpp
@@ -73,7 +73,7 @@ AudioFlinger::ThreadBase::TrackBase::TrackBase(
             int clientUid,
             IAudioFlinger::track_flags_t flags,
             bool isOut,
-            bool useReadOnlyHeap)
+            alloc_type alloc)
     :   RefBase(),
         mThread(thread),
         mClient(client),
@@ -117,7 +117,7 @@ AudioFlinger::ThreadBase::TrackBase::TrackBase(
     // ALOGD("Creating track with %d buffers @ %d bytes", bufferCount, bufferSize);
     size_t size = sizeof(audio_track_cblk_t);
     size_t bufferSize = (sharedBuffer == 0 ? roundup(frameCount) : frameCount) * mFrameSize;
-    if (sharedBuffer == 0 && !useReadOnlyHeap) {
+    if (sharedBuffer == 0 && alloc == ALLOC_CBLK) {
         size += bufferSize;
     }
 
@@ -139,7 +139,8 @@ AudioFlinger::ThreadBase::TrackBase::TrackBase(
     // construct the shared structure in-place.
     if (mCblk != NULL) {
         new(mCblk) audio_track_cblk_t();
-        if (useReadOnlyHeap) {
+        switch (alloc) {
+        case ALLOC_READONLY: {
             const sp<MemoryDealer> roHeap(thread->readOnlyHeap());
             if (roHeap == 0 ||
                     (mBufferMemory = roHeap->allocate(bufferSize)) == 0 ||
@@ -153,7 +154,17 @@ AudioFlinger::ThreadBase::TrackBase::TrackBase(
                 return;
             }
             memset(mBuffer, 0, bufferSize);
-        } else {
+            } break;
+        case ALLOC_PIPE:
+            mBufferMemory = thread->pipeMemory();
+            // mBuffer is the virtual address as seen from current process (mediaserver),
+            // and should normally be coming from mBufferMemory->pointer().
+            // However in this case the TrackBase does not reference the buffer directly.
+            // It should references the buffer via the pipe.
+            // Therefore, to detect incorrect usage of the buffer, we set mBuffer to NULL.
+            mBuffer = NULL;
+            break;
+        case ALLOC_CBLK:
             // clear all buffers
             if (sharedBuffer == 0) {
                 mBuffer = (char*)mCblk + sizeof(audio_track_cblk_t);
@@ -164,6 +175,7 @@ AudioFlinger::ThreadBase::TrackBase::TrackBase(
                 mCblk->mFlags = CBLK_FORCEREADY;    // FIXME hack, need to fix the track ready logic
 #endif
             }
+            break;
         }
 
 #ifdef TEE_SINK
@@ -1842,7 +1854,7 @@ AudioFlinger::RecordThread::RecordTrack::RecordTrack(
     :   TrackBase(thread, client, sampleRate, format,
                   channelMask, frameCount, 0 /*sharedBuffer*/, sessionId, uid,
                   flags, false /*isOut*/,
-                  (flags & IAudioFlinger::TRACK_FAST) != 0 /*useReadOnlyHeap*/),
+                  (flags & IAudioFlinger::TRACK_FAST) != 0 ? ALLOC_READONLY : ALLOC_CBLK),
         mOverflow(false), mResampler(NULL), mRsmpOutBuffer(NULL), mRsmpOutFrameCount(0),
         // See real initialization of mRsmpInFront at RecordThread::start()
         mRsmpInUnrel(0), mRsmpInFront(0), mFramesToDrop(0), mResamplerBufferProvider(NULL)