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/Scheduler/Scheduler.cpp

diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index 7b8448f..a14019e 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -212,13 +212,26 @@
                                                        readyDuration, traceVsync, name);
 }
 
+bool Scheduler::isVsyncValid(nsecs_t expectedVsyncTimestamp, uid_t uid) const {
+    const auto divider = mRefreshRateConfigs.getRefreshRateDividerForUid(uid);
+    if (divider <= 1) {
+        return true;
+    }
+
+    return mVsyncSchedule.tracker->isVSyncInPhase(expectedVsyncTimestamp, divider);
+}
+
 Scheduler::ConnectionHandle Scheduler::createConnection(
         const char* connectionName, frametimeline::TokenManager* tokenManager,
         std::chrono::nanoseconds workDuration, std::chrono::nanoseconds readyDuration,
         impl::EventThread::InterceptVSyncsCallback interceptCallback) {
     auto vsyncSource = makePrimaryDispSyncSource(connectionName, workDuration, readyDuration);
+    auto throttleVsync = [this](nsecs_t expectedVsyncTimestamp, uid_t uid) {
+        return !isVsyncValid(expectedVsyncTimestamp, uid);
+    };
     auto eventThread = std::make_unique<impl::EventThread>(std::move(vsyncSource), tokenManager,
-                                                           std::move(interceptCallback));
+                                                           std::move(interceptCallback),
+                                                           std::move(throttleVsync));
     return createConnection(std::move(eventThread));
 }
 
@@ -379,7 +392,8 @@
         auto eventThread =
                 std::make_unique<impl::EventThread>(std::move(vsyncSource),
                                                     /*tokenManager=*/nullptr,
-                                                    impl::EventThread::InterceptVSyncsCallback());
+                                                    impl::EventThread::InterceptVSyncsCallback(),
+                                                    impl::EventThread::ThrottleVsyncCallback());
 
         mInjectorConnectionHandle = createConnection(std::move(eventThread));
     }