SF: Do not duplicate fences per layer per frame

Convert the unique_fd of RenderEngineResult (and futures thereof) into
sp<Fence> such that postFramebuffer does not duplicate release/present
fences.

Remove a few copies of shared futures/pointers with std::move.

Bug: 232436803
Test: simpleperf (-33% cycles in sys_dup)
Change-Id: Ia7c6c8333a712441f3612fb5c720ea2932799636

1 files changed, 7 insertions, 6 deletions

diff --git a/services/surfaceflinger/TransactionCallbackInvoker.cpp b/services/surfaceflinger/TransactionCallbackInvoker.cpp
index e1f348fdba..fa8cffc32a 100644
--- a/services/surfaceflinger/TransactionCallbackInvoker.cpp
+++ b/services/surfaceflinger/TransactionCallbackInvoker.cpp
@@ -133,10 +133,10 @@ status_t TransactionCallbackInvoker::addCallbackHandle(const sp<CallbackHandle>&
     if (surfaceControl) {
         sp<Fence> prevFence = nullptr;
 
-        for (const auto& futureStruct : handle->previousReleaseFences) {
-            sp<Fence> currentFence = sp<Fence>::make(dup(futureStruct.get().drawFence));
+        for (const auto& future : handle->previousReleaseFences) {
+            sp<Fence> currentFence = future.get().value_or(Fence::NO_FENCE);
             if (prevFence == nullptr && currentFence->getStatus() != Fence::Status::Invalid) {
-                prevFence = currentFence;
+                prevFence = std::move(currentFence);
                 handle->previousReleaseFence = prevFence;
             } else if (prevFence != nullptr) {
                 // If both fences are signaled or both are unsignaled, we need to merge
@@ -147,7 +147,7 @@ status_t TransactionCallbackInvoker::addCallbackHandle(const sp<CallbackHandle>&
                     snprintf(fenceName, 32, "%.28s", handle->name.c_str());
                     sp<Fence> mergedFence = Fence::merge(fenceName, prevFence, currentFence);
                     if (mergedFence->isValid()) {
-                        handle->previousReleaseFence = mergedFence;
+                        handle->previousReleaseFence = std::move(mergedFence);
                         prevFence = handle->previousReleaseFence;
                     }
                 } else if (currentFence->getStatus() == Fence::Status::Unsignaled) {
@@ -158,11 +158,12 @@ status_t TransactionCallbackInvoker::addCallbackHandle(const sp<CallbackHandle>&
                     // by this point, they will have both signaled and only the timestamp
                     // will be slightly off; any dependencies after this point will
                     // already have been met.
-                    handle->previousReleaseFence = currentFence;
+                    handle->previousReleaseFence = std::move(currentFence);
                 }
             }
         }
-        handle->previousReleaseFences = {};
+        handle->previousReleaseFences.clear();
+
         FrameEventHistoryStats eventStats(handle->frameNumber,
                                           handle->gpuCompositionDoneFence->getSnapshot().fence,
                                           handle->compositorTiming, handle->refreshStartTime,