commit 43cb3cb3f14afed11d91db2091fbffecaf7a88e6
author chaviw <chaviw@google.com> Fri May 31 15:23:41 2019 -0700
committer chaviw <chaviw@google.com> Fri May 31 17:12:43 2019 -0700
tree 96d395a410ffc2b4a5fe7dedf0c4fd19725016be
parent 6107273cef6cbd0c5a93f15867667321647775c3

Clear remoteSyncPoints for detached layers.

When a layer gets detached, the remote sync points should get removed so
the buffer layer isn't waiting for that transaction to get applied.
Detached layers can never apply transactions so the buffer layer will
wait forever for the transaction to get applied.

Test: Steps from bug
Test: ChildLayerTest.DetachChildrenWithDeferredTransaction
Fixes: 132125338
Change-Id: I333855a70a40152457f39e953bc7300d696c7c62

services/surfaceflinger/Layer.cpp

diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 379b004..3ca6ef5 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -144,6 +144,20 @@
  */
 void Layer::onLayerDisplayed(const sp<Fence>& /*releaseFence*/) {}
 
+void Layer::removeRemoteSyncPoints() {
+    for (auto& point : mRemoteSyncPoints) {
+        point->setTransactionApplied();
+    }
+    mRemoteSyncPoints.clear();
+
+    {
+        Mutex::Autolock pendingStateLock(mPendingStateMutex);
+        for (State pendingState : mPendingStates) {
+            pendingState.barrierLayer_legacy = nullptr;
+        }
+    }
+}
+
 void Layer::onRemovedFromCurrentState() {
     mRemovedFromCurrentState = true;
 
@@ -162,10 +176,7 @@
     // never finish applying transactions. We signal the sync point
     // now so that another layer will not become indefinitely
     // blocked.
-    for (auto& point: mRemoteSyncPoints) {
-        point->setTransactionApplied();
-    }
-    mRemoteSyncPoints.clear();
+    removeRemoteSyncPoints();
 
     {
     Mutex::Autolock syncLock(mLocalSyncPointMutex);
@@ -667,7 +678,7 @@
             // to be applied as per normal (no synchronization).
             mCurrentState.barrierLayer_legacy = nullptr;
         } else {
-            auto syncPoint = std::make_shared<SyncPoint>(mCurrentState.frameNumber_legacy);
+            auto syncPoint = std::make_shared<SyncPoint>(mCurrentState.frameNumber_legacy, this);
             if (barrierLayer->addSyncPoint(syncPoint)) {
                 mRemoteSyncPoints.push_back(std::move(syncPoint));
             } else {
@@ -1510,6 +1521,7 @@
         if (client != nullptr && parentClient != client) {
             child->mLayerDetached = true;
             child->detachChildren();
+            child->removeRemoteSyncPoints();
         }
     }