Read from BufferReleaseChannel in background thread

Bug: 294133380
Flag: com.android.graphics.libgui.flags.buffer_release_channel
Test: BLASTBufferQueueTest
Change-Id: I99c5da3bd99d6893ae24f5d55e7553b02bfc07ab
diff --git a/services/surfaceflinger/TransactionCallbackInvoker.h b/services/surfaceflinger/TransactionCallbackInvoker.h
index 7853a9f..14a7487 100644
--- a/services/surfaceflinger/TransactionCallbackInvoker.h
+++ b/services/surfaceflinger/TransactionCallbackInvoker.h
@@ -16,18 +16,14 @@
 
 #pragma once
 
-#include <condition_variable>
 #include <deque>
-#include <mutex>
 #include <optional>
-#include <queue>
-#include <thread>
 #include <unordered_map>
-#include <unordered_set>
 
 #include <android-base/thread_annotations.h>
 #include <binder/IBinder.h>
 #include <ftl/future.h>
+#include <gui/BufferReleaseChannel.h>
 #include <gui/ITransactionCompletedListener.h>
 #include <ui/Fence.h>
 #include <ui/FenceResult.h>
@@ -59,6 +55,7 @@
     uint64_t frameNumber = 0;
     uint64_t previousFrameNumber = 0;
     ReleaseCallbackId previousReleaseCallbackId = ReleaseCallbackId::INVALID_ID;
+    std::shared_ptr<gui::BufferReleaseChannel::ProducerEndpoint> bufferReleaseChannel;
 };
 
 class TransactionCallbackInvoker {
@@ -86,6 +83,14 @@
     std::unordered_map<sp<IBinder>, std::deque<TransactionStats>, IListenerHash>
         mCompletedTransactions;
 
+    struct BufferRelease {
+        std::shared_ptr<gui::BufferReleaseChannel::ProducerEndpoint> channel;
+        ReleaseCallbackId callbackId;
+        sp<Fence> fence;
+        uint32_t currentMaxAcquiredBufferCount;
+    };
+    std::vector<BufferRelease> mBufferReleases;
+
     sp<Fence> mPresentFence;
 };