diff --git a/libs/binder/Binder.cpp b/libs/binder/Binder.cpp
index 4965386..53750c9 100644
--- a/libs/binder/Binder.cpp
+++ b/libs/binder/Binder.cpp
@@ -179,6 +179,17 @@
     return transact(SET_RPC_CLIENT_TRANSACTION, data, &reply);
 }
 
+void IBinder::withLock(const std::function<void()>& doWithLock) {
+    BBinder* local = localBinder();
+    if (local) {
+        local->withLock(doWithLock);
+        return;
+    }
+    BpBinder* proxy = this->remoteBinder();
+    LOG_ALWAYS_FATAL_IF(proxy == nullptr, "binder object must be either local or remote");
+    proxy->withLock(doWithLock);
+}
+
 // ---------------------------------------------------------------------------
 
 class BBinder::RpcServerLink : public IBinder::DeathRecipient {
@@ -337,6 +348,14 @@
     return e->mObjects.detach(objectID);
 }
 
+void BBinder::withLock(const std::function<void()>& doWithLock) {
+    Extras* e = getOrCreateExtras();
+    LOG_ALWAYS_FATAL_IF(!e, "no memory");
+
+    AutoMutex _l(e->mLock);
+    doWithLock();
+}
+
 BBinder* BBinder::localBinder()
 {
     return this;