Create loader for Power HAL services

Move logic to load underlying Power HAL services to a static class in
services/powermanager, with tests. This can now be reused by
BatteryStatsService and PowerManagerService, removing the dependency
between them.

Bug: 150878220
Test: atest powermanager_test
Change-Id: I52eec130811d49111526f3e152faf4302518c5a8

5 files changed, 262 insertions, 0 deletions

diff --git a/include/powermanager/PowerHalLoader.h b/include/powermanager/PowerHalLoader.h
new file mode 100644
index 0000000000..487b95b298
--- /dev/null
+++ b/include/powermanager/PowerHalLoader.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#ifndef ANDROID_POWERHALLOADER_H
+#define ANDROID_POWERHALLOADER_H
+
+#include <android-base/thread_annotations.h>
+
+#include <android/hardware/power/1.1/IPower.h>
+#include <android/hardware/power/IPower.h>
+
+using IPowerV1_0 = android::hardware::power::V1_0::IPower;
+using IPowerV1_1 = android::hardware::power::V1_1::IPower;
+using IPowerAidl = android::hardware::power::IPower;
+
+namespace android {
+
+// Loads available Power HAL services.
+class PowerHalLoader {
+public:
+    static void unloadAll();
+    static sp<IPowerAidl> loadAidl();
+    static sp<IPowerV1_0> loadHidlV1_0();
+    static sp<IPowerV1_1> loadHidlV1_1();
+
+private:
+    static std::mutex gHalMutex;
+    static sp<IPowerAidl> gHalAidl GUARDED_BY(gHalMutex);
+    static sp<IPowerV1_0> gHalHidlV1_0 GUARDED_BY(gHalMutex);
+    static sp<IPowerV1_1> gHalHidlV1_1 GUARDED_BY(gHalMutex);
+
+    static sp<IPowerV1_0> loadHidlV1_0Locked() EXCLUSIVE_LOCKS_REQUIRED(gHalMutex);
+
+    PowerHalLoader() = default;
+};
+
+} // namespace android
+
+#endif // ANDROID_POWERHALLOADER_H
diff --git a/services/powermanager/Android.bp b/services/powermanager/Android.bp
index cff4a029e6..eaf7fa8253 100644
--- a/services/powermanager/Android.bp
+++ b/services/powermanager/Android.bp
@@ -4,6 +4,7 @@ cc_library_shared {
     srcs: [
         "BatterySaverPolicyConfig.cpp",
         "CoolingDevice.cpp",
+        "PowerHalLoader.cpp",
         "PowerHalWrapper.cpp",
         "PowerSaveState.cpp",
         "Temperature.cpp",
diff --git a/services/powermanager/PowerHalLoader.cpp b/services/powermanager/PowerHalLoader.cpp
new file mode 100644
index 0000000000..3ae538447b
--- /dev/null
+++ b/services/powermanager/PowerHalLoader.cpp
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2020 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 "PowerHalLoader"
+
+#include <android/hardware/power/1.1/IPower.h>
+#include <android/hardware/power/IPower.h>
+#include <binder/IServiceManager.h>
+#include <hardware/power.h>
+#include <hardware_legacy/power.h>
+
+#include <powermanager/PowerHalLoader.h>
+
+using IPowerV1_1 = android::hardware::power::V1_1::IPower;
+using IPowerV1_0 = android::hardware::power::V1_0::IPower;
+using IPowerAidl = android::hardware::power::IPower;
+
+namespace android {
+
+// -------------------------------------------------------------------------------------------------
+
+template <typename T, typename F>
+sp<T> loadHal(bool& exists, sp<T>& hal, F& loadFn, const char* halName) {
+    if (!exists) {
+        return nullptr;
+    }
+    if (hal) {
+        return hal;
+    }
+    hal = loadFn();
+    if (hal) {
+        ALOGV("Successfully connected to Power HAL %s service.", halName);
+    } else {
+        ALOGV("Power HAL %s service not available.", halName);
+        exists = false;
+    }
+    return hal;
+}
+
+// -------------------------------------------------------------------------------------------------
+
+std::mutex PowerHalLoader::gHalMutex;
+sp<IPowerAidl> PowerHalLoader::gHalAidl = nullptr;
+sp<IPowerV1_0> PowerHalLoader::gHalHidlV1_0 = nullptr;
+sp<IPowerV1_1> PowerHalLoader::gHalHidlV1_1 = nullptr;
+
+void PowerHalLoader::unloadAll() {
+    std::lock_guard<std::mutex> lock(gHalMutex);
+    gHalAidl = nullptr;
+    gHalHidlV1_0 = nullptr;
+    gHalHidlV1_1 = nullptr;
+}
+
+sp<IPowerAidl> PowerHalLoader::loadAidl() {
+    std::lock_guard<std::mutex> lock(gHalMutex);
+    static bool gHalExists = true;
+    static auto loadFn = []() { return waitForVintfService<IPowerAidl>(); };
+    return loadHal<IPowerAidl>(gHalExists, gHalAidl, loadFn, "AIDL");
+}
+
+sp<IPowerV1_0> PowerHalLoader::loadHidlV1_0() {
+    std::lock_guard<std::mutex> lock(gHalMutex);
+    return loadHidlV1_0Locked();
+}
+
+sp<IPowerV1_1> PowerHalLoader::loadHidlV1_1() {
+    std::lock_guard<std::mutex> lock(gHalMutex);
+    static bool gHalExists = true;
+    static auto loadFn = []() { return IPowerV1_1::castFrom(loadHidlV1_0Locked()); };
+    return loadHal<IPowerV1_1>(gHalExists, gHalHidlV1_1, loadFn, "HIDL v1.1");
+}
+
+sp<IPowerV1_0> PowerHalLoader::loadHidlV1_0Locked() {
+    static bool gHalExists = true;
+    static auto loadFn = []() { return IPowerV1_0::getService(); };
+    return loadHal<IPowerV1_0>(gHalExists, gHalHidlV1_0, loadFn, "HIDL v1.0");
+}
+
+// -------------------------------------------------------------------------------------------------
+
+} // namespace android
diff --git a/services/powermanager/tests/Android.bp b/services/powermanager/tests/Android.bp
index 65cde03070..1cf170e059 100644
--- a/services/powermanager/tests/Android.bp
+++ b/services/powermanager/tests/Android.bp
@@ -12,10 +12,12 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+
 cc_test {
     name: "powermanager_test",
     test_suites: ["device-tests"],
     srcs: [
+        "PowerHalLoaderTest.cpp",
         "PowerHalWrapperAidlTest.cpp",
         "PowerHalWrapperHidlV1_0Test.cpp",
         "PowerHalWrapperHidlV1_1Test.cpp",
diff --git a/services/powermanager/tests/PowerHalLoaderTest.cpp b/services/powermanager/tests/PowerHalLoaderTest.cpp
new file mode 100644
index 0000000000..2310a72318
--- /dev/null
+++ b/services/powermanager/tests/PowerHalLoaderTest.cpp
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2020 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 "PowerHalLoaderTest"
+
+#include <android-base/logging.h>
+#include <android/hardware/power/1.1/IPower.h>
+#include <android/hardware/power/IPower.h>
+
+#include <future>
+#include <gtest/gtest.h>
+
+#include <powermanager/PowerHalLoader.h>
+
+using IPowerV1_0 = android::hardware::power::V1_0::IPower;
+using IPowerV1_1 = android::hardware::power::V1_1::IPower;
+using IPowerAidl = android::hardware::power::IPower;
+
+using namespace android;
+
+// -------------------------------------------------------------------------------------------------
+
+template <typename T>
+sp<T> loadHal();
+
+template <>
+sp<IPowerAidl> loadHal<IPowerAidl>() {
+    return PowerHalLoader::loadAidl();
+}
+
+template <>
+sp<IPowerV1_0> loadHal<IPowerV1_0>() {
+    return PowerHalLoader::loadHidlV1_0();
+}
+
+template <>
+sp<IPowerV1_1> loadHal<IPowerV1_1>() {
+    return PowerHalLoader::loadHidlV1_1();
+}
+
+// -------------------------------------------------------------------------------------------------
+
+template <typename T>
+class PowerHalLoaderTest : public testing::Test {
+public:
+    sp<T> load() {
+        return ::loadHal<T>();
+    }
+    void unload() {
+        PowerHalLoader::unloadAll();
+    }
+};
+
+// -------------------------------------------------------------------------------------------------
+
+typedef ::testing::Types<IPowerAidl, IPowerV1_0, IPowerV1_1> PowerHalTypes;
+TYPED_TEST_SUITE(PowerHalLoaderTest, PowerHalTypes);
+
+TYPED_TEST(PowerHalLoaderTest, TestLoadsOnlyOnce) {
+    sp<TypeParam> firstHal = this->load();
+    if (firstHal == nullptr) {
+        ALOGE("Power HAL not available. Skipping test.");
+        return;
+    }
+    sp<TypeParam> secondHal = this->load();
+    ASSERT_EQ(firstHal, secondHal);
+}
+
+TYPED_TEST(PowerHalLoaderTest, TestUnload) {
+    sp<TypeParam> firstHal = this->load();
+    if (firstHal == nullptr) {
+        ALOGE("Power HAL not available. Skipping test.");
+        return;
+    }
+    this->unload();
+    sp<TypeParam> secondHal = this->load();
+    ASSERT_NE(secondHal, nullptr);
+    ASSERT_NE(firstHal, secondHal);
+}
+
+TYPED_TEST(PowerHalLoaderTest, TestLoadMultiThreadLoadsOnlyOnce) {
+    std::vector<std::future<sp<TypeParam>>> futures;
+    for (int i = 0; i < 10; i++) {
+        futures.push_back(
+            std::async(std::launch::async, &PowerHalLoaderTest<TypeParam>::load, this));
+    }
+
+    futures[0].wait();
+    sp<TypeParam> firstHal = futures[0].get();
+    if (firstHal == nullptr) {
+        ALOGE("Power HAL not available. Skipping test.");
+        return;
+    }
+
+    for (int i = 1; i < 10; i++) {
+        futures[i].wait();
+        sp<TypeParam> currentHal = futures[i].get();
+        ASSERT_EQ(firstHal, currentHal);
+    }
+}