commit acd2258a5492a9e289fd7f4b8ea90543d6843a23
author Patrick Williams <pdwilliams@google.com> Wed Jul 12 13:47:28 2023 -0500
committer Patrick Williams <pdwilliams@google.com> Wed Jul 19 15:30:27 2023 -0500
tree 1c6f2759a47368a791265aed7b12b9aa8098e518
parent de231db01afd598ba675b0bc67aaece30832f7e0

Improve updateInputFlinger performance

This change improves the performance of the WindowInfosListenerInvoker work done on SurfaceFlinger's background executor thread. The primary optimization made is not sending a WindowInfosReportedListener with every call to WindowInfosListener.onWindowInfosChanged. Instead, we send a new interface, WindowInfosPublisher, and a unique listener id to listeners when they're added.  Listeners call WindowInfosPublisher.ackWindowInfosReceived with their id after processing each update.

From traces taken during development, the new code is a major improvement, taking about 15% of the time spent previously on SurfaceFlinger's background thread for sending window infos. Performance with this change seems roughly in line with the performance in T.

Bug: 290377931
Test: atest WindowInfosListenerTest
Test: atest WindowInfosListenerInvokerTest
Test: manually killing system server and checking valid state on restart
Change-Id: Ib39ba935727df0bc1ab4030bcfe8301de7e64805

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index a9a1d80..f8d39cb 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -6347,8 +6347,7 @@
                   ftl::to_underlying(windowInfosDebug.maxSendDelayVsyncId));
     StringAppendF(&result, "  max send delay (ns): %" PRId64 " ns\n",
                   windowInfosDebug.maxSendDelayDuration);
-    StringAppendF(&result, "  unsent messages: %" PRIu32 "\n",
-                  windowInfosDebug.pendingMessageCount);
+    StringAppendF(&result, "  unsent messages: %zu\n", windowInfosDebug.pendingMessageCount);
     result.append("\n");
 }
 
@@ -8214,9 +8213,9 @@
                                    forceApplyPolicy);
 }
 
-status_t SurfaceFlinger::addWindowInfosListener(
-        const sp<IWindowInfosListener>& windowInfosListener) {
-    mWindowInfosListenerInvoker->addWindowInfosListener(windowInfosListener);
+status_t SurfaceFlinger::addWindowInfosListener(const sp<IWindowInfosListener>& windowInfosListener,
+                                                gui::WindowInfosListenerInfo* outInfo) {
+    mWindowInfosListenerInvoker->addWindowInfosListener(windowInfosListener, outInfo);
     setTransactionFlags(eInputInfoUpdateNeeded);
     return NO_ERROR;
 }
@@ -9300,7 +9299,8 @@
 }
 
 binder::Status SurfaceComposerAIDL::addWindowInfosListener(
-        const sp<gui::IWindowInfosListener>& windowInfosListener) {
+        const sp<gui::IWindowInfosListener>& windowInfosListener,
+        gui::WindowInfosListenerInfo* outInfo) {
     status_t status;
     const int pid = IPCThreadState::self()->getCallingPid();
     const int uid = IPCThreadState::self()->getCallingUid();
@@ -9308,7 +9308,7 @@
     // WindowInfosListeners
     if (uid == AID_SYSTEM || uid == AID_GRAPHICS ||
         checkPermission(sAccessSurfaceFlinger, pid, uid)) {
-        status = mFlinger->addWindowInfosListener(windowInfosListener);
+        status = mFlinger->addWindowInfosListener(windowInfosListener, outInfo);
     } else {
         status = PERMISSION_DENIED;
     }