commit 0bb6a47f5264571690d57c609f0e945086dba9b1
author Ady Abraham <adyabr@google.com> Mon Oct 12 10:22:13 2020 -0700
committer Ady Abraham <adyabr@google.com> Tue Nov 03 10:19:21 2020 -0800
tree f9ab6720e867e1f133360a4515036e15e4f1694f
parent 9febda8e05bbd924d14682454fdc7a846c38f954

SurfaceFlinger: throttle applications based on uid

Add the ability for SurfaceFlinger to be able to throttle down to
a divider of the refresh rate (i.e. for 30/45 for 90Hz)

Change-Id: I6bfd6f43ee1f30e771a136c558d8ae9a6d7fbe0f
Test: Manually via 1039 SF backdoor
Bug: 170502573
Bug: 169270763
Bug: 169271059

services/surfaceflinger/BufferLayer.cpp

diff --git a/services/surfaceflinger/BufferLayer.cpp b/services/surfaceflinger/BufferLayer.cpp
index d302f98..fa75ffa 100644
--- a/services/surfaceflinger/BufferLayer.cpp
+++ b/services/surfaceflinger/BufferLayer.cpp
@@ -393,6 +393,15 @@
                               nsecs_t expectedPresentTime) {
     ATRACE_CALL();
 
+    // If this is not a valid vsync for the layer's uid, return and try again later
+    const bool isVsyncValidForUid =
+            mFlinger->mScheduler->isVsyncValid(expectedPresentTime, mOwnerUid);
+    if (!isVsyncValidForUid) {
+        ATRACE_NAME("!isVsyncValidForUid");
+        mFlinger->setTransactionFlags(eTraversalNeeded);
+        return false;
+    }
+
     bool refreshRequired = latchSidebandStream(recomputeVisibleRegions);
 
     if (refreshRequired) {