thermalservice: add ThermalService interfaces and thermalserviced

Binder interfaces IThermalService and IThermalEventListener are used
by frameworks native and Java code to publish and subscribe to
thermal events, and to detect thermal throttling status.

A following change adds HwBinder interfaces for vendor thermal
management code to send thermal events to this service.

Test: marlin
Bug: 30982366
Change-Id: I246ddd9b386e2388701b73fa0ecf9aff78ce0adb
diff --git a/services/thermalservice/ThermalService.cpp b/services/thermalservice/ThermalService.cpp
new file mode 100644
index 0000000..6e09a83
--- /dev/null
+++ b/services/thermalservice/ThermalService.cpp
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2017 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 "ThermalService.h"
+#include <android/os/IThermalService.h>
+#include <android/os/IThermalEventListener.h>
+#include <android/os/Temperature.h>
+#include <binder/IPCThreadState.h>
+#include <binder/IServiceManager.h>
+#include <utils/Errors.h>
+#include <utils/Mutex.h>
+#include <utils/String16.h>
+
+namespace android {
+namespace os {
+
+/**
+ * Notify registered listeners of a thermal throttling start/stop event.
+ * @param temperature the temperature at which the event was generated
+ */
+binder::Status ThermalService::notifyThrottling(
+    const bool isThrottling, const Temperature& temperature) {
+    Mutex::Autolock _l(mListenersLock);
+
+    mThrottled = isThrottling;
+    mThrottleTemperature = temperature;
+
+    for (size_t i = 0; i < mListeners.size(); i++) {
+      mListeners[i]->notifyThrottling(isThrottling, temperature);
+    }
+    return binder::Status::ok();
+}
+
+/**
+ * Query whether the system is currently thermal throttling.
+ * @return true if currently thermal throttling, else false
+ */
+binder::Status ThermalService::isThrottling(bool* _aidl_return) {
+    Mutex::Autolock _l(mListenersLock);
+    *_aidl_return = mThrottled;
+    return binder::Status::ok();
+}
+
+/**
+ * Register a new thermal event listener.
+ * @param listener the client's IThermalEventListener instance to which
+ *                 notifications are to be sent
+ */
+binder::Status ThermalService::registerThermalEventListener(
+    const sp<IThermalEventListener>& listener) {
+    {
+        if (listener == NULL)
+            return binder::Status::ok();
+        Mutex::Autolock _l(mListenersLock);
+        // check whether this is a duplicate
+        for (size_t i = 0; i < mListeners.size(); i++) {
+            if (IInterface::asBinder(mListeners[i]) ==
+                IInterface::asBinder(listener)) {
+                return binder::Status::ok();
+            }
+        }
+
+        mListeners.add(listener);
+        IInterface::asBinder(listener)->linkToDeath(this);
+    }
+
+    return binder::Status::ok();
+}
+
+/**
+ * Unregister a previously-registered thermal event listener.
+ * @param listener the client's IThermalEventListener instance to which
+ *                 notifications are to no longer be sent
+ */
+binder::Status ThermalService::unregisterThermalEventListener(
+    const sp<IThermalEventListener>& listener) {
+    if (listener == NULL)
+        return binder::Status::ok();
+    Mutex::Autolock _l(mListenersLock);
+    for (size_t i = 0; i < mListeners.size(); i++) {
+        if (IInterface::asBinder(mListeners[i]) ==
+            IInterface::asBinder(listener)) {
+            IInterface::asBinder(mListeners[i])->unlinkToDeath(this);
+            mListeners.removeAt(i);
+            break;
+        }
+    }
+
+    return binder::Status::ok();
+}
+
+void ThermalService::binderDied(const wp<IBinder>& who) {
+    Mutex::Autolock _l(mListenersLock);
+
+    for (size_t i = 0; i < mListeners.size(); i++) {
+        if (IInterface::asBinder(mListeners[i]) == who) {
+            mListeners.removeAt(i);
+            break;
+        }
+    }
+}
+
+/**
+ * Publish the supplied ThermalService to servicemanager.
+ */
+void ThermalService::publish(
+    const sp<ThermalService>& service) {
+    defaultServiceManager()->addService(String16("thermalservice"),
+                                        service);
+}
+
+}  // namespace os
+}  // namespace android