commit 2f7d9aeb0e44e41cfc965b764672a8955f1b650e
author Alec Mouri <alecmouri@google.com> Mon Nov 30 19:32:33 2020 -0800
committer Alec Mouri <alecmouri@google.com> Thu Dec 03 17:12:48 2020 -0800
tree 12dfc52aa12ac0cd5ba544ac758b363983912301
parent be97cfacd67cc63f840066800663b56b071c3ff5

Store layers with pending frames as smart pointers instead of raw pointers

Layers can be removed in between invalidations, which is problematic
when using raw pointers. Instead, store a set of sp<Layer> with a custom
hash

Bug: 170729573
Test: builds
Change-Id: I87dd48a7767b8c05461cb4e56b3fbcd037d0603e

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 576bd50..f8260c3 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -2110,7 +2110,7 @@
     ALOGV("postComposition");
 
     nsecs_t dequeueReadyTime = systemTime();
-    for (auto layer : mLayersWithQueuedFrames) {
+    for (const auto& layer : mLayersWithQueuedFrames) {
         layer->releasePendingBuffer(dequeueReadyTime);
     }
 
@@ -3055,7 +3055,7 @@
         // writes to Layer current state. See also b/119481871
         Mutex::Autolock lock(mStateLock);
 
-        for (auto& layer : mLayersWithQueuedFrames) {
+        for (const auto& layer : mLayersWithQueuedFrames) {
             if (layer->latchBuffer(visibleRegions, latchTime, expectedPresentTime)) {
                 mLayersPendingRefresh.push_back(layer);
             }

services/surfaceflinger/SurfaceFlinger.h

diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index a909ad8..0509247 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -1091,9 +1091,8 @@
     bool mAnimCompositionPending = false;
 
     // Tracks layers that have pending frames which are candidates for being
-    // latched. Because this contains a set of raw layer pointers, can only be
-    // mutated on the main thread.
-    std::unordered_set<Layer*> mLayersWithQueuedFrames;
+    // latched.
+    std::unordered_set<sp<Layer>, ISurfaceComposer::SpHash<Layer>> mLayersWithQueuedFrames;
     // Tracks layers that need to update a display's dirty region.
     std::vector<sp<Layer>> mLayersPendingRefresh;
     std::array<sp<Fence>, 2> mPreviousPresentFences = {Fence::NO_FENCE, Fence::NO_FENCE};