commit ec0ab384811cd1172c63c91dfde526e3717cc167
author Vishnu Nair <vishnun@google.com> Wed Feb 13 15:32:56 2019 -0800
committer Vishnu Nair <vishnun@google.com> Wed Feb 13 15:32:56 2019 -0800
tree ab0c9c4a7d1371cc94d0f4d599bead699250fa9e
parent 101843de76cfd5a5b2c4cd8ffaf6f973f96c8c04

SF: Lock access to InputWindowCommands

Fixes regression caused by ag/6260282.
Create a pending list of InputWindowCommands so that we can apply the commands without
holding on to the mStateLock to better align with the current and drawing state locking
strategy.

Bug: 124061013
Test: go/wm-smoke
Change-Id: I9ccec72da0d2139ca546e34df8e62c58c178d292

libs/gui/SurfaceComposerClient.cpp

diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index 46b9128..bf2a03d 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -383,6 +383,7 @@
     other.mListenerCallbacks.clear();
 
     mInputWindowCommands.merge(other.mInputWindowCommands);
+    other.mInputWindowCommands.clear();
 
     return *this;
 }

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index c98220d..dc3409b 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -3098,6 +3098,7 @@
         });
     }
 
+    commitInputWindowCommands();
     commitTransaction();
 }
 
@@ -3128,6 +3129,11 @@
     mInputFlinger->setInputWindows(inputHandles);
 }
 
+void SurfaceFlinger::commitInputWindowCommands() {
+    mInputWindowCommands.merge(mPendingInputWindowCommands);
+    mPendingInputWindowCommands.clear();
+}
+
 void SurfaceFlinger::executeInputWindowCommands() {
     for (const auto& transferTouchFocusCommand : mInputWindowCommands.transferTouchFocusCommands) {
         if (transferTouchFocusCommand.fromToken != nullptr &&
@@ -3706,7 +3712,7 @@
             if (!transactionIsReadyToBeApplied(desiredPresentTime, states)) {
                 break;
             }
-            applyTransactionState(states, displays, flags, mInputWindowCommands);
+            applyTransactionState(states, displays, flags, mPendingInputWindowCommands);
             transactionQueue.pop();
         }
 
@@ -4174,7 +4180,7 @@
         flags |= eTraversalNeeded;
     }
 
-    mInputWindowCommands.merge(inputWindowCommands);
+    mPendingInputWindowCommands.merge(inputWindowCommands);
     return flags;
 }
 
@@ -4390,7 +4396,7 @@
     d.width = 0;
     d.height = 0;
     displays.add(d);
-    setTransactionState(state, displays, 0, nullptr, mInputWindowCommands, -1);
+    setTransactionState(state, displays, 0, nullptr, mPendingInputWindowCommands, -1);
 
     setPowerModeInternal(display, HWC_POWER_MODE_NORMAL);
 

services/surfaceflinger/SurfaceFlinger.h

diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index a0f83a2..ea7a32d 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -538,6 +538,7 @@
 
     void updateInputFlinger();
     void updateInputWindowInfo();
+    void commitInputWindowCommands();
     void executeInputWindowCommands();
     void updateCursorAsync();
 
@@ -1144,6 +1145,9 @@
     /* ------------------------------------------------------------------------ */
     sp<IInputFlinger> mInputFlinger;
 
+    // Access must be protected by mStateLock.
+    InputWindowCommands mPendingInputWindowCommands;
+    // Should only be accessed by the drawing thread.
     InputWindowCommands mInputWindowCommands;
 
     ui::DisplayPrimaries mInternalDisplayPrimaries;