commit 2a52ca6274f3ca8b9aea8d22c49ca8fcae4b8455
author Vishnu Nair <vishnun@google.com> Thu Jun 24 13:08:53 2021 -0700
committer Vishnu Nair <vishnun@google.com> Thu Jun 24 13:09:54 2021 -0700
tree 1e9ee0f1e9999e41cd804f8f8a025b11acfc0a61
parent 504a4d8f648b6c2e0ed6971c9666a69dbdeedb45

BlastBufferQueue: Fix acquire counts when holding buffers

Update the acquire count when ever we release a buffer otherwise
when going from 120hz to 60hz we may release multiple buffers
and only decrement the acquire count once. This will prevent the
adapter from acquiring all the possible buffers.

Also make sure we process the shadow queue every time we release
a buffer.

Bug: 188553729
Test: Run backpressure based game on 60Hz and 90hz and collect traces
Change-Id: I23517ee0fe840a9215f368bd85713ba19dbeb2a3

libs/gui/BLASTBufferQueue.cpp

diff --git a/libs/gui/BLASTBufferQueue.cpp b/libs/gui/BLASTBufferQueue.cpp
index 364c939..e15e11c 100644
--- a/libs/gui/BLASTBufferQueue.cpp
+++ b/libs/gui/BLASTBufferQueue.cpp
@@ -151,7 +151,7 @@
                                                       1, false);
     static int32_t id = 0;
     auto consumerName = mName + "(BLAST Consumer)" + std::to_string(id);
-    mPendingBufferTrace = "PendingBuffer - " + mName + "BLAST#" + std::to_string(id);
+    mQueuedBufferTrace = "QueuedBuffer - " + mName + "BLAST#" + std::to_string(id);
     id++;
     mBufferItemConsumer->setName(String8(consumerName.c_str()));
     mBufferItemConsumer->setFrameAvailableListener(this);
@@ -361,16 +361,15 @@
                      graphicBufferId);
             return;
         }
-
+        mNumAcquired--;
         mBufferItemConsumer->releaseBuffer(it->second, releaseBuffer.releaseFence);
         mSubmitted.erase(it);
+        processNextBufferLocked(false /* useNextTransaction */);
     }
 
     ATRACE_INT("PendingRelease", mPendingRelease.size());
-
-    mNumAcquired--;
-    ATRACE_INT(mPendingBufferTrace.c_str(), mNumFrameAvailable + mNumAcquired);
-    processNextBufferLocked(false /* useNextTransaction */);
+    ATRACE_INT(mQueuedBufferTrace.c_str(),
+               mNumFrameAvailable + mNumAcquired - mPendingRelease.size());
     mCallbackCV.notify_all();
 }
 
@@ -538,7 +537,8 @@
     }
     // add to shadow queue
     mNumFrameAvailable++;
-    ATRACE_INT(mPendingBufferTrace.c_str(), mNumFrameAvailable + mNumAcquired);
+    ATRACE_INT(mQueuedBufferTrace.c_str(),
+               mNumFrameAvailable + mNumAcquired - mPendingRelease.size());
 
     BQA_LOGV("onFrameAvailable framenumber=%" PRIu64 " nextTransactionSet=%s", item.mFrameNumber,
              toString(nextTransactionSet));