diff --git a/libs/binderthreadstate/IPCThreadStateBase.cpp b/libs/binderthreadstate/IPCThreadStateBase.cpp
new file mode 100644
index 0000000..fede151
--- /dev/null
+++ b/libs/binderthreadstate/IPCThreadStateBase.cpp
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#define LOG_TAG "IPCThreadStateBase"
+
+#include <binderthreadstate/IPCThreadStateBase.h>
+#include <android-base/macros.h>
+
+#include <utils/Log.h>
+
+#include <errno.h>
+#include <inttypes.h>
+#include <pthread.h>
+
+namespace android {
+
+static pthread_mutex_t gTLSMutex = PTHREAD_MUTEX_INITIALIZER;
+static bool gHaveTLS = false;
+static pthread_key_t gTLS = 0;
+
+IPCThreadStateBase::IPCThreadStateBase() {
+    pthread_setspecific(gTLS, this);
+}
+
+IPCThreadStateBase* IPCThreadStateBase::self()
+{
+    if (gHaveTLS) {
+restart:
+        const pthread_key_t k = gTLS;
+        IPCThreadStateBase* st = (IPCThreadStateBase*)pthread_getspecific(k);
+        if (st) return st;
+        return new IPCThreadStateBase;
+    }
+
+    pthread_mutex_lock(&gTLSMutex);
+    if (!gHaveTLS) {
+        int key_create_value = pthread_key_create(&gTLS, threadDestructor);
+        if (key_create_value != 0) {
+            pthread_mutex_unlock(&gTLSMutex);
+            ALOGW("IPCThreadStateBase::self() unable to create TLS key, expect a crash: %s\n",
+                    strerror(key_create_value));
+            return nullptr;
+        }
+        gHaveTLS = true;
+    }
+    pthread_mutex_unlock(&gTLSMutex);
+    goto restart;
+}
+
+void IPCThreadStateBase::pushCurrentState(CallState callState) {
+    mCallStateStack.emplace(callState);
+}
+
+IPCThreadStateBase::CallState IPCThreadStateBase::popCurrentState() {
+    ALOG_ASSERT(mCallStateStack.size > 0);
+    CallState val = mCallStateStack.top();
+    mCallStateStack.pop();
+    return val;
+}
+
+IPCThreadStateBase::CallState IPCThreadStateBase::getCurrentBinderCallState() {
+    if (mCallStateStack.size() > 0) {
+        return mCallStateStack.top();
+    }
+    return CallState::NONE;
+}
+
+void IPCThreadStateBase::threadDestructor(void *st)
+{
+    IPCThreadStateBase* const self = static_cast<IPCThreadStateBase*>(st);
+    if (self) {
+        delete self;
+    }
+}
+
+}; // namespace android