Introduce release buffer callback for BufferStateLayer

Currently BLAST clients use the TransactionCompleted callbacks to
determine when to release buffers. The TransactionCompleted callback
is overloaded. For transactions without buffers, the callback is
called when the transaction is applied on the server. If the
Transaction contains one or more buffers, the callback is called when
all the buffers are latched and ready to be presented. If we have
multiple buffers on multiple transactions, where one or more buffers
maybe dropped, the pending callbacks are called together. This may
delay signaling the client when a buffer can be released.

To fix this, we introduce a new buffer release callback that is
called as soon as a buffer is dropped by the server or when a new
buffer has been latched and the buffer will no longer be presented.
This new callback provides a graphic bufferid to identify the buffer
that can be released and a release fence to wait on.

BlastBufferQueue has been switched to use this new callback. Other
BLAST users continue to use the existing callback.

Test: go/wm-smoke
Test: atest ReleaseBufferCallbackTest
Bug: 178385281

Change-Id: Idd88e4994e543443198a5a8cfa0e3f5f67d5d482

1 files changed, 2 insertions, 1 deletions

diff --git a/services/surfaceflinger/TransactionCallbackInvoker.cpp b/services/surfaceflinger/TransactionCallbackInvoker.cpp
index a78510e902..3590e76cb9 100644
--- a/services/surfaceflinger/TransactionCallbackInvoker.cpp
+++ b/services/surfaceflinger/TransactionCallbackInvoker.cpp
@@ -201,7 +201,8 @@ status_t TransactionCallbackInvoker::addCallbackHandle(const sp<CallbackHandle>&
                                           handle->dequeueReadyTime);
         transactionStats->surfaceStats.emplace_back(surfaceControl, handle->acquireTime,
                                                     handle->previousReleaseFence,
-                                                    handle->transformHint, eventStats, jankData);
+                                                    handle->transformHint, eventStats, jankData,
+                                                    handle->previousBufferId);
     }
     return NO_ERROR;
 }