From f558ab782c566e995fa6b4ad546feaea46a207bd Mon Sep 17 00:00:00 2001
From: Ady Abraham <adyabr@google.com>
Date: Tue, 18 May 2021 14:00:07 -0700
Subject: [PATCH] Remove the extra buffer allocation from hwui

SurfaceFlinger will set the maxAcquiredBufferCount on the buffer queue
to account for the extra buffers needed, depends on the refresh rate
and app/sf durations, and there is no needed for any addional buffer
allocation is hwui.

Test: TBD
Bug: 188553729
Change-Id: Ic441a6feb15f6b084d45c9e538b11b7b24e36a0e
---
 libs/hwui/renderthread/CanvasContext.cpp   | 4 ----
 libs/hwui/renderthread/ReliableSurface.cpp | 1 -
 libs/hwui/renderthread/ReliableSurface.h   | 6 ------
 3 files changed, 11 deletions(-)

diff --git a/libs/hwui/renderthread/CanvasContext.cpp b/libs/hwui/renderthread/CanvasContext.cpp
index a0d93e928876c..a55aff1b9e671 100644
--- a/libs/hwui/renderthread/CanvasContext.cpp
+++ b/libs/hwui/renderthread/CanvasContext.cpp
@@ -174,16 +174,12 @@ void CanvasContext::setSurface(ANativeWindow* window, bool enableTimeout) {
     ATRACE_CALL();
 
     if (window) {
-        int extraBuffers = 0;
-        native_window_get_extra_buffer_count(window, &extraBuffers);
-
         mNativeSurface = std::make_unique<ReliableSurface>(window);
         mNativeSurface->init();
         if (enableTimeout) {
             // TODO: Fix error handling & re-shorten timeout
             ANativeWindow_setDequeueTimeout(window, 4000_ms);
         }
-        mNativeSurface->setExtraBufferCount(extraBuffers);
     } else {
         mNativeSurface = nullptr;
     }
diff --git a/libs/hwui/renderthread/ReliableSurface.cpp b/libs/hwui/renderthread/ReliableSurface.cpp
index c29cc11fa7ea4..6df34bee22241 100644
--- a/libs/hwui/renderthread/ReliableSurface.cpp
+++ b/libs/hwui/renderthread/ReliableSurface.cpp
@@ -278,7 +278,6 @@ int ReliableSurface::hook_query(const ANativeWindow *window, ANativeWindow_query
     int result = query(window, what, value);
     if (what == ANATIVEWINDOW_QUERY_MIN_UNDEQUEUED_BUFFERS && result == OK) {
         std::lock_guard _lock{rs->mMutex};
-        *value += rs->mExtraBuffers;
         rs->mExpectedBufferCount = *value + 2;
     }
     return result;
diff --git a/libs/hwui/renderthread/ReliableSurface.h b/libs/hwui/renderthread/ReliableSurface.h
index 41969e776fc80..5959647410490 100644
--- a/libs/hwui/renderthread/ReliableSurface.h
+++ b/libs/hwui/renderthread/ReliableSurface.h
@@ -51,11 +51,6 @@ public:
         return ret;
     }
 
-    void setExtraBufferCount(size_t extraBuffers) {
-        std::lock_guard _lock{mMutex};
-        mExtraBuffers = extraBuffers;
-    }
-
     bool didSetExtraBuffers() const {
         std::lock_guard _lock{mMutex};
         return mDidSetExtraBuffers;
@@ -73,7 +68,6 @@ private:
     base::unique_fd mReservedFenceFd;
     bool mHasDequeuedBuffer = false;
     int mBufferQueueState = OK;
-    size_t mExtraBuffers = 0;
     size_t mExpectedBufferCount = 0;
     bool mDidSetExtraBuffers = false;