Close Transactions explicitly

Ensure one-shot, scheduled Transactions are closed after application.
While individual Transaction instances aren't all that heavy, this
avoids unnecessary GC pressure and churn.

Bug: 216159702
Test: atest WmTests SystemUITests FrameworksCoreTests
Change-Id: Iec053dd8163fb9b300fd1e9eb9f1472a0d0dd782

3 files changed, 24 insertions, 13 deletions

diff --git a/core/java/android/view/InsetsSourceConsumer.java b/core/java/android/view/InsetsSourceConsumer.java
index b1582cf9f023..6aab6359d23e 100644
--- a/core/java/android/view/InsetsSourceConsumer.java
+++ b/core/java/android/view/InsetsSourceConsumer.java
@@ -98,6 +98,13 @@ public class InsetsSourceConsumer {
      */
     private boolean mIsAnimationPending;
 
+    /**
+     * @param type The {@link InternalInsetsType} of the consumed insets.
+     * @param state The current {@link InsetsState} of the consumed insets.
+     * @param transactionSupplier The source of new {@link Transaction} instances. The supplier
+     *         must provide *new* instances, which will be explicitly closed by this class.
+     * @param controller The {@link InsetsController} to use for insets interaction.
+     */
     public InsetsSourceConsumer(@InternalInsetsType int type, InsetsState state,
             Supplier<Transaction> transactionSupplier, InsetsController controller) {
         mType = type;
@@ -390,16 +397,17 @@ public class InsetsSourceConsumer {
             return;
         }
 
-        final Transaction t = mTransactionSupplier.get();
-        if (DEBUG) Log.d(TAG, "applyRequestedVisibilityToControl: " + mRequestedVisible);
-        if (mRequestedVisible) {
-            t.show(mSourceControl.getLeash());
-        } else {
-            t.hide(mSourceControl.getLeash());
+        try (Transaction t = mTransactionSupplier.get()) {
+            if (DEBUG) Log.d(TAG, "applyRequestedVisibilityToControl: " + mRequestedVisible);
+            if (mRequestedVisible) {
+                t.show(mSourceControl.getLeash());
+            } else {
+                t.hide(mSourceControl.getLeash());
+            }
+            // Ensure the alpha value is aligned with the actual requested visibility.
+            t.setAlpha(mSourceControl.getLeash(), mRequestedVisible ? 1 : 0);
+            t.apply();
         }
-        // Ensure the alpha value is aligned with the actual requested visibility.
-        t.setAlpha(mSourceControl.getLeash(), mRequestedVisible ? 1 : 0);
-        t.apply();
         onPerceptible(mRequestedVisible);
     }
 
diff --git a/core/java/android/view/SyncRtSurfaceTransactionApplier.java b/core/java/android/view/SyncRtSurfaceTransactionApplier.java
index 3e2110341693..e9c937cc0f9b 100644
--- a/core/java/android/view/SyncRtSurfaceTransactionApplier.java
+++ b/core/java/android/view/SyncRtSurfaceTransactionApplier.java
@@ -65,10 +65,12 @@ public class SyncRtSurfaceTransactionApplier {
         applyParams(t, params);
 
         mTargetViewRootImpl.registerRtFrameCallback(frame -> {
-            if (mTargetSc == null || !mTargetSc.isValid()) {
-                return;
+            if (mTargetSc != null && mTargetSc.isValid()) {
+                applyTransaction(t, frame);
             }
-            applyTransaction(t, frame);
+            // The transaction was either dropped, successfully applied, or merged with a future
+            // transaction, so we can safely release its resources.
+            t.close();
         });
 
         // Make sure a frame gets scheduled.
diff --git a/core/java/android/view/ViewRootImpl.java b/core/java/android/view/ViewRootImpl.java
index 8bb7e677362c..4edb344e5632 100644
--- a/core/java/android/view/ViewRootImpl.java
+++ b/core/java/android/view/ViewRootImpl.java
@@ -4175,7 +4175,7 @@ public final class ViewRootImpl implements ViewParent,
                         + " didProduceBuffer=" + didProduceBuffer);
             }
 
-            Transaction tmpTransaction = new Transaction();
+            final Transaction tmpTransaction = new Transaction();
             tmpTransaction.merge(mRtBLASTSyncTransaction);
 
             // If frame wasn't drawn, clear out the next transaction so it doesn't affect the next
@@ -4206,6 +4206,7 @@ public final class ViewRootImpl implements ViewParent,
                         blastSyncConsumer.accept(mSurfaceChangedTransaction);
                     }
                 }
+                tmpTransaction.close();
 
                 if (reportNextDraw) {
                     pendingDrawFinished();