diff --git a/libs/binder/RpcServer.cpp b/libs/binder/RpcServer.cpp
index 3c63789..dc10d1c 100644
--- a/libs/binder/RpcServer.cpp
+++ b/libs/binder/RpcServer.cpp
@@ -134,7 +134,7 @@
 
 bool RpcServer::acceptOne() {
     LOG_ALWAYS_FATAL_IF(!mAgreedExperimental, "no!");
-    LOG_ALWAYS_FATAL_IF(mServer.get() == -1, "RpcServer must be setup to join.");
+    LOG_ALWAYS_FATAL_IF(!hasServer(), "RpcServer must be setup to join.");
 
     unique_fd clientFd(
             TEMP_FAILURE_RETRY(accept4(mServer.get(), nullptr, nullptr /*length*/, SOCK_CLOEXEC)));
@@ -232,11 +232,7 @@
 
 bool RpcServer::setupSocketServer(const RpcSocketAddress& addr) {
     LOG_RPC_DETAIL("Setting up socket server %s", addr.toString().c_str());
-
-    {
-        std::lock_guard<std::mutex> _l(mLock);
-        LOG_ALWAYS_FATAL_IF(mServer.get() != -1, "Each RpcServer can only have one server.");
-    }
+    LOG_ALWAYS_FATAL_IF(hasServer(), "Each RpcServer can only have one server.");
 
     unique_fd serverFd(
             TEMP_FAILURE_RETRY(socket(addr.addr()->sa_family, SOCK_STREAM | SOCK_CLOEXEC, 0)));
@@ -275,4 +271,9 @@
     (void)mSessions.erase(it);
 }
 
+bool RpcServer::hasServer() {
+    std::lock_guard<std::mutex> _l(mLock);
+    return mServer.ok();
+}
+
 } // namespace android
diff --git a/libs/binder/include/binder/RpcServer.h b/libs/binder/include/binder/RpcServer.h
index 6e27540..771bbe6 100644
--- a/libs/binder/include/binder/RpcServer.h
+++ b/libs/binder/include/binder/RpcServer.h
@@ -74,6 +74,11 @@
      */
     [[nodiscard]] bool setupInetServer(unsigned int port, unsigned int* assignedPort);
 
+    /**
+     * If setup*Server has been successful, return true. Otherwise return false.
+     */
+    [[nodiscard]] bool hasServer();
+
     void iUnderstandThisCodeIsExperimentalAndIWillNotUseItInProduction();
 
     /**
diff --git a/libs/binder/ndk/include_platform/android/binder_manager.h b/libs/binder/ndk/include_platform/android/binder_manager.h
index db72067..2a66941 100644
--- a/libs/binder/ndk/include_platform/android/binder_manager.h
+++ b/libs/binder/ndk/include_platform/android/binder_manager.h
@@ -35,7 +35,7 @@
  * \return EX_NONE on success.
  */
 __attribute__((warn_unused_result)) binder_exception_t AServiceManager_addService(
-        AIBinder* binder, const char* instance);
+        AIBinder* binder, const char* instance) __INTRODUCED_IN(29);
 
 /**
  * Gets a binder object with this specific instance name. Will return nullptr immediately if the
@@ -47,7 +47,8 @@
  *
  * \param instance identifier of the service used to lookup the service.
  */
-__attribute__((warn_unused_result)) AIBinder* AServiceManager_checkService(const char* instance);
+__attribute__((warn_unused_result)) AIBinder* AServiceManager_checkService(const char* instance)
+        __INTRODUCED_IN(29);
 
 /**
  * Gets a binder object with this specific instance name. Blocks for a couple of seconds waiting on
@@ -59,7 +60,8 @@
  *
  * \param instance identifier of the service used to lookup the service.
  */
-__attribute__((warn_unused_result)) AIBinder* AServiceManager_getService(const char* instance);
+__attribute__((warn_unused_result)) AIBinder* AServiceManager_getService(const char* instance)
+        __INTRODUCED_IN(29);
 
 /**
  * Registers a lazy service with the default service manager under the 'instance' name.