Add a cache to getService with invalidation (b6ed0eb3) · Commits · e / os / android_frameworks_native

libs/binder/BackendUnifiedServiceManager.cpp

+117 −3

Original line number	Diff line number	Diff line
		@@ -24,11 +24,111 @@

		namespace android {

		#ifdef LIBBINDER_CLIENT_CACHE
		constexpr bool kUseCache = true;
		#else
		constexpr bool kUseCache = false;
		#endif

		using AidlServiceManager = android::os::IServiceManager;
		using IAccessor = android::os::IAccessor;

		static const char* kStaticCachableList[] = {
		"activity",
		"android.hardware.thermal.IThermal/default",
		"android.hardware.power.IPower/default",
		"android.frameworks.stats.IStats/default",
		"android.system.suspend.ISystemSuspend/default",
		"appops",
		"audio",
		"batterystats",
		"carrier_config",
		"connectivity",
		"content_capture",
		"device_policy",
		"display",
		"dropbox",
		"econtroller",
		"isub",
		"legacy_permission",
		"location",
		"media.extractor",
		"media.metrics",
		"media.player",
		"media.resource_manager",
		"netd_listener",
		"netstats",
		"network_management",
		"nfc",
		"package_native",
		"performance_hint",
		"permission",
		"permissionmgr",
		"permission_checker",
		"phone",
		"platform_compat",
		"power",
		"role",
		"sensorservice",
		"statscompanion",
		"telephony.registry",
		"thermalservice",
		"time_detector",
		"trust",
		"uimode",
		"virtualdevice",
		"virtualdevice_native",
		"webviewupdate",
		};

		bool BinderCacheWithInvalidation::isClientSideCachingEnabled(const std::string& serviceName) {
		if (ProcessState::self()->getThreadPoolMaxTotalThreadCount() <= 0) {
		ALOGW("Thread Pool max thread count is 0. Cannot cache binder as linkToDeath cannot be "
		"implemented. serviceName: %s",
		serviceName.c_str());
		return false;
		}
		for (const char* name : kStaticCachableList) {
		if (name == serviceName) {
		return true;
		}
		}
		return false;
		}

		binder::Status BackendUnifiedServiceManager::updateCache(const std::string& serviceName,
		const os::Service& service) {
		if (!kUseCache) {
		return binder::Status::ok();
		}
		if (service.getTag() == os::Service::Tag::binder) {
		sp<IBinder> binder = service.get<os::Service::Tag::binder>();
		if (binder && mCacheForGetService->isClientSideCachingEnabled(serviceName) &&
		binder->isBinderAlive()) {
		return mCacheForGetService->setItem(serviceName, binder);
		}
		}
		return binder::Status::ok();
		}

		bool BackendUnifiedServiceManager::returnIfCached(const std::string& serviceName,
		os::Service* _out) {
		if (!kUseCache) {
		return false;
		}
		sp<IBinder> item = mCacheForGetService->getItem(serviceName);
		// TODO(b/363177618): Enable caching for binders which are always null.
		if (item != nullptr && item->isBinderAlive()) {
		*_out = os::Service::make<os::Service::Tag::binder>(item);
		return true;
		}
		return false;
		}

		BackendUnifiedServiceManager::BackendUnifiedServiceManager(const sp<AidlServiceManager>& impl)
		: mTheRealServiceManager(impl) {}
		: mTheRealServiceManager(impl) {
		mCacheForGetService = std::make_shared<BinderCacheWithInvalidation>();
		}

		sp<AidlServiceManager> BackendUnifiedServiceManager::getImpl() {
		return mTheRealServiceManager;
		@@ -44,10 +144,17 @@ binder::Status BackendUnifiedServiceManager::getService(const ::std::string& nam

		binder::Status BackendUnifiedServiceManager::getService2(const ::std::string& name,
		os::Service* _out) {
		if (returnIfCached(name, _out)) {
		return binder::Status::ok();
		}
		os::Service service;
		binder::Status status = mTheRealServiceManager->getService2(name, &service);

		if (status.isOk()) {
		status = toBinderService(name, service, _out);
		if (status.isOk()) {
		return toBinderService(name, service, _out);
		return updateCache(name, service);
		}
		}
		return status;
		}
		@@ -55,9 +162,16 @@ binder::Status BackendUnifiedServiceManager::getService2(const ::std::string& na
		binder::Status BackendUnifiedServiceManager::checkService(const ::std::string& name,
		os::Service* _out) {
		os::Service service;
		if (returnIfCached(name, _out)) {
		return binder::Status::ok();
		}

		binder::Status status = mTheRealServiceManager->checkService(name, &service);
		if (status.isOk()) {
		return toBinderService(name, service, _out);
		status = toBinderService(name, service, _out);
		if (status.isOk()) {
		return updateCache(name, service);
		}
		}
		return status;
		}

libs/binder/BackendUnifiedServiceManager.h

+81 −0

Original line number	Diff line number	Diff line
		@@ -18,9 +18,87 @@
		#include <android/os/BnServiceManager.h>
		#include <android/os/IServiceManager.h>
		#include <binder/IPCThreadState.h>
		#include <map>
		#include <memory>

		namespace android {

		class BinderCacheWithInvalidation
		: public std::enable_shared_from_this<BinderCacheWithInvalidation> {
		class BinderInvalidation : public IBinder::DeathRecipient {
		public:
		BinderInvalidation(std::weak_ptr<BinderCacheWithInvalidation> cache, const std::string& key)
		: mCache(cache), mKey(key) {}

		void binderDied(const wp<IBinder>& who) override {
		sp<IBinder> binder = who.promote();
		if (std::shared_ptr<BinderCacheWithInvalidation> cache = mCache.lock()) {
		cache->removeItem(mKey, binder);
		} else {
		ALOGI("Binder Cache pointer expired: %s", mKey.c_str());
		}
		}

		private:
		std::weak_ptr<BinderCacheWithInvalidation> mCache;
		std::string mKey;
		};
		struct Entry {
		sp<IBinder> service;
		sp<BinderInvalidation> deathRecipient;
		};

		public:
		sp<IBinder> getItem(const std::string& key) const {
		std::lock_guard<std::mutex> lock(mCacheMutex);

		if (auto it = mCache.find(key); it != mCache.end()) {
		return it->second.service;
		}
		return nullptr;
		}

		bool removeItem(const std::string& key, const sp<IBinder>& who) {
		std::lock_guard<std::mutex> lock(mCacheMutex);
		if (auto it = mCache.find(key); it != mCache.end()) {
		if (it->second.service == who) {
		status_t result = who->unlinkToDeath(it->second.deathRecipient);
		if (result != DEAD_OBJECT) {
		ALOGW("Unlinking to dead binder resulted in: %d", result);
		}
		mCache.erase(key);
		return true;
		}
		}
		return false;
		}

		binder::Status setItem(const std::string& key, const sp<IBinder>& item) {
		sp<BinderInvalidation> deathRecipient =
		sp<BinderInvalidation>::make(shared_from_this(), key);

		// linkToDeath if binder is a remote binder.
		if (item->localBinder() == nullptr) {
		status_t status = item->linkToDeath(deathRecipient);
		if (status != android::OK) {
		ALOGE("Failed to linkToDeath binder for service %s. Error: %d", key.c_str(),
		status);
		return binder::Status::fromStatusT(status);
		}
		}
		std::lock_guard<std::mutex> lock(mCacheMutex);
		Entry entry = {.service = item, .deathRecipient = deathRecipient};
		mCache[key] = entry;
		return binder::Status::ok();
		}

		bool isClientSideCachingEnabled(const std::string& serviceName);

		private:
		std::map<std::string, Entry> mCache;
		mutable std::mutex mCacheMutex;
		};

		class BackendUnifiedServiceManager : public android::os::BnServiceManager {
		public:
		explicit BackendUnifiedServiceManager(const sp<os::IServiceManager>& impl);
		@@ -58,9 +136,12 @@ public:
		}

		private:
		std::shared_ptr<BinderCacheWithInvalidation> mCacheForGetService;
		sp<os::IServiceManager> mTheRealServiceManager;
		binder::Status toBinderService(const ::std::string& name, const os::Service& in,
		os::Service* _out);
		binder::Status updateCache(const std::string& serviceName, const os::Service& service);
		bool returnIfCached(const std::string& serviceName, os::Service* _out);
		};

		sp<BackendUnifiedServiceManager> getBackendUnifiedServiceManager();

libs/binder/IServiceManager.cpp

+6 −0

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@
		#define LOG_TAG "ServiceManagerCppClient"

		#include <binder/IServiceManager.h>
		#include <binder/IServiceManagerUnitTestHelper.h>
		#include "BackendUnifiedServiceManager.h"

		#include <inttypes.h>
		@@ -311,6 +312,11 @@ void setDefaultServiceManager(const sp<IServiceManager>& sm) {
		}
		}

		sp<IServiceManager> getServiceManagerShimFromAidlServiceManagerForTests(
		const sp<AidlServiceManager>& sm) {
		return sp<CppBackendShim>::make(sp<BackendUnifiedServiceManager>::make(sm));
		}

		std::weak_ptr<AccessorProvider> addAccessorProvider(RpcAccessorProvider&& providerCallback) {
		std::lock_guard<std::mutex> lock(gAccessorProvidersMutex);
		std::shared_ptr<AccessorProvider> provider =

libs/binder/TEST_MAPPING

+3 −0

Original line number	Diff line number	Diff line
		@@ -133,6 +133,9 @@
		{
		"name": "binder_sdk_test",
		"host": true
		},
		{
		"name": "binderCacheUnitTest"
		}
		],
		"imports": [

libs/binder/include/binder/IServiceManagerUnitTestHelper.h

0 → 100644

+29 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2024 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.
		*/

		#pragma once

		#include <android/os/IServiceManager.h>
		#include "IServiceManager.h"
		namespace android {

		/**
		* Encapsulate an AidlServiceManager in a CppBackendShim. Only used for testing.
		*/
		LIBBINDER_EXPORTED sp<IServiceManager> getServiceManagerShimFromAidlServiceManagerForTests(
		const sp<os::IServiceManager>& sm);

		} // namespace android
		No newline at end of file