Add defaultPassthroughServiceImplementation.

Bug: 32282345
Test: nfc
Change-Id: I1369c291bfb1ce7ca28f4e62825eee1afbc3bea6
diff --git a/include/hidl/LegacySupport.h b/include/hidl/LegacySupport.h
new file mode 100644
index 0000000..5acc1d0
--- /dev/null
+++ b/include/hidl/LegacySupport.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <utils/Log.h>
+
+#include "IServiceManager.h"
+#include <hwbinder/IPCThreadState.h>
+#include <hwbinder/ProcessState.h>
+#include <utils/Errors.h>
+#include <utils/StrongPointer.h>
+
+#ifndef ANDROID_HIDL_LEGACY_SUPPORT_H
+#define ANDROID_HIDL_LEGACY_SUPPORT_H
+
+namespace android {
+namespace hardware {
+
+/**
+ * Creates default passthrough service implementation. This method never returns.
+ *
+ * Return value is exit status.
+ */
+template<class Interface>
+int defaultPassthroughServiceImplementation(std::string name) {
+    sp<Interface> service = Interface::getService(name, true /* getStub */);
+
+    if (service == nullptr) {
+        ALOGE("Could not get passthrough implementation.");
+        return EXIT_FAILURE;
+    }
+
+    LOG_FATAL_IF(service->isRemote(), "Implementation is remote!");
+
+    status_t status = service->registerAsService(name);
+
+    if (status == OK) {
+        ALOGI("Registration complete.");
+    } else {
+        ALOGE("Could not register service (%d).", status);
+    }
+
+    ProcessState::self()->setThreadPoolMaxThreadCount(0);
+    ProcessState::self()->startThreadPool();
+    IPCThreadState::self()->joinThreadPool();
+
+    return 0;
+}
+
+}  // namespace hardware
+}  // namespace android
+
+#endif  // ANDROID_HIDL_LEGACY_SUPPORT_H
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