Enclose all operations using obtained Parcels in try-finally blocks that will recycle the Parcel in the case that any exception is thrown. (#8733)

binder/src/main/java/io/grpc/binder/internal/BinderTransport.java

@@ -323,18 +323,19 @@ public abstract class BinderTransport
   @GuardedBy("this")
   final void sendSetupTransaction(IBinder iBinder) {
     Parcel parcel = Parcel.obtain();
+    try {
       parcel.writeInt(WIRE_FORMAT_VERSION);
       parcel.writeStrongBinder(incomingBinder);
-    try {
       if (!iBinder.transact(SETUP_TRANSPORT, parcel, null, IBinder.FLAG_ONEWAY)) {
         shutdownInternal(
             Status.UNAVAILABLE.withDescription("Failed sending SETUP_TRANSPORT transaction"), true);
       }
     } catch (RemoteException re) {
       shutdownInternal(statusFromRemoteException(re), true);
-    }
+    } finally {
       parcel.recycle();
     }
+  }
 
   @GuardedBy("this")
   private final void sendShutdownTransaction() {
@@ -345,16 +346,17 @@ public abstract class BinderTransport
         // Ignore.
       }
       Parcel parcel = Parcel.obtain();
+      try {
         // Send empty flags to avoid a memory leak linked to empty parcels (b/207778694).
         parcel.writeInt(0);
-      try {
         outgoingBinder.transact(SHUTDOWN_TRANSPORT, parcel, null, IBinder.FLAG_ONEWAY);
       } catch (RemoteException re) {
         // Ignore.
-      }
+      } finally {
         parcel.recycle();
       }
     }
+  }
 
   protected synchronized void sendPing(int id) throws StatusException {
     if (inState(TransportState.SHUTDOWN_TERMINATED)) {
@@ -363,8 +365,8 @@ public abstract class BinderTransport
       throw Status.FAILED_PRECONDITION.withDescription("Transport not ready.").asException();
     } else {
       Parcel parcel = Parcel.obtain();
-      parcel.writeInt(id);
       try {
+        parcel.writeInt(id);
         outgoingBinder.transact(PING, parcel, null, IBinder.FLAG_ONEWAY);
       } catch (RemoteException re) {
         throw statusFromRemoteException(re).asException();
@@ -410,16 +412,17 @@ public abstract class BinderTransport
 
   final void sendOutOfBandClose(int callId, Status status) {
     Parcel parcel = Parcel.obtain();
+    try {
       parcel.writeInt(0); // Placeholder for flags. Will be filled in below.
       int flags = TransactionUtils.writeStatus(parcel, status);
       TransactionUtils.fillInFlags(parcel, flags | TransactionUtils.FLAG_OUT_OF_BAND_CLOSE);
-    try {
       sendTransaction(callId, parcel);
     } catch (StatusException e) {
       logger.log(Level.WARNING, "Failed sending oob close transaction", e);
-    }
+    } finally {
       parcel.recycle();
     }
+  }
 
   @Override
   public final boolean handleTransaction(int code, Parcel parcel) {
@@ -507,17 +510,18 @@ public abstract class BinderTransport
     long n = numIncomingBytes.get();
     acknowledgedIncomingBytes = n;
     Parcel parcel = Parcel.obtain();
-    parcel.writeLong(n);
     try {
+      parcel.writeLong(n);
       if (!iBinder.transact(ACKNOWLEDGE_BYTES, parcel, null, IBinder.FLAG_ONEWAY)) {
         shutdownInternal(
             Status.UNAVAILABLE.withDescription("Failed sending ack bytes transaction"), true);
       }
     } catch (RemoteException re) {
       shutdownInternal(statusFromRemoteException(re), true);
-    }
+    } finally {
       parcel.recycle();
     }
+  }
 
   @GuardedBy("this")
   final void handleAcknowledgedBytes(long numBytes) {
@@ -909,3 +913,4 @@ public abstract class BinderTransport
     return Status.INTERNAL.withCause(e);
   }
 }
+