Merge "IServiceManager: add registerForNotifications."

6 files changed, 144 insertions, 0 deletions

diff --git a/cmds/dumpsys/tests/dumpsys_test.cpp b/cmds/dumpsys/tests/dumpsys_test.cpp
index 677d6c78ea..49c1318945 100644
--- a/cmds/dumpsys/tests/dumpsys_test.cpp
+++ b/cmds/dumpsys/tests/dumpsys_test.cpp
@@ -61,6 +61,10 @@ class ServiceManagerMock : public IServiceManager {
     MOCK_METHOD1(getDeclaredInstances, Vector<String16>(const String16&));
     MOCK_METHOD1(updatableViaApex, std::optional<String16>(const String16&));
     MOCK_METHOD1(getConnectionInfo, std::optional<ConnectionInfo>(const String16&));
+    MOCK_METHOD2(registerForNotifications, status_t(const String16&,
+                                             const sp<LocalRegistrationCallback>&));
+    MOCK_METHOD2(unregisterForNotifications, status_t(const String16&,
+                                             const sp<LocalRegistrationCallback>&));
   protected:
     MOCK_METHOD0(onAsBinder, IBinder*());
 };
diff --git a/libs/binder/IServiceManager.cpp b/libs/binder/IServiceManager.cpp
index 81e61daae1..ea2f8d2274 100644
--- a/libs/binder/IServiceManager.cpp
+++ b/libs/binder/IServiceManager.cpp
@@ -43,6 +43,8 @@
 
 namespace android {
 
+using AidlRegistrationCallback = IServiceManager::LocalRegistrationCallback;
+
 using AidlServiceManager = android::os::IServiceManager;
 using android::binder::Status;
 
@@ -79,7 +81,24 @@ public:
     Vector<String16> getDeclaredInstances(const String16& interface) override;
     std::optional<String16> updatableViaApex(const String16& name) override;
     std::optional<IServiceManager::ConnectionInfo> getConnectionInfo(const String16& name) override;
+    class RegistrationWaiter : public android::os::BnServiceCallback {
+    public:
+        explicit RegistrationWaiter(const sp<AidlRegistrationCallback>& callback)
+              : mImpl(callback) {}
+        Status onRegistration(const std::string& name, const sp<IBinder>& binder) override {
+            mImpl->onServiceRegistration(String16(name.c_str()), binder);
+            return Status::ok();
+        }
+
+    private:
+        sp<AidlRegistrationCallback> mImpl;
+    };
+
+    status_t registerForNotifications(const String16& service,
+                                      const sp<AidlRegistrationCallback>& cb) override;
 
+    status_t unregisterForNotifications(const String16& service,
+                                        const sp<AidlRegistrationCallback>& cb) override;
     // for legacy ABI
     const String16& getInterfaceDescriptor() const override {
         return mTheRealServiceManager->getInterfaceDescriptor();
@@ -90,6 +109,17 @@ public:
 
 protected:
     sp<AidlServiceManager> mTheRealServiceManager;
+    // AidlRegistrationCallback -> services that its been registered for
+    // notifications.
+    using LocalRegistrationAndWaiter =
+            std::pair<sp<LocalRegistrationCallback>, sp<RegistrationWaiter>>;
+    using ServiceCallbackMap = std::map<std::string, std::vector<LocalRegistrationAndWaiter>>;
+    ServiceCallbackMap mNameToRegistrationCallback;
+    std::mutex mNameToRegistrationLock;
+
+    void removeRegistrationCallbackLocked(const sp<AidlRegistrationCallback>& cb,
+                                          ServiceCallbackMap::iterator* it,
+                                          sp<RegistrationWaiter>* waiter);
 
     // Directly get the service in a way that, for lazy services, requests the service to be started
     // if it is not currently started. This way, calls directly to ServiceManagerShim::getService
@@ -442,6 +472,77 @@ std::optional<IServiceManager::ConnectionInfo> ServiceManagerShim::getConnection
             : std::nullopt;
 }
 
+status_t ServiceManagerShim::registerForNotifications(const String16& name,
+                                                      const sp<AidlRegistrationCallback>& cb) {
+    if (cb == nullptr) {
+        ALOGE("%s: null cb passed", __FUNCTION__);
+        return BAD_VALUE;
+    }
+    std::string nameStr = String8(name).c_str();
+    sp<RegistrationWaiter> registrationWaiter = sp<RegistrationWaiter>::make(cb);
+    std::lock_guard<std::mutex> lock(mNameToRegistrationLock);
+    if (Status status =
+                mTheRealServiceManager->registerForNotifications(nameStr, registrationWaiter);
+        !status.isOk()) {
+        ALOGW("Failed to registerForNotifications for %s: %s", nameStr.c_str(),
+              status.toString8().c_str());
+        return UNKNOWN_ERROR;
+    }
+    mNameToRegistrationCallback[nameStr].push_back(std::make_pair(cb, registrationWaiter));
+    return OK;
+}
+
+void ServiceManagerShim::removeRegistrationCallbackLocked(const sp<AidlRegistrationCallback>& cb,
+                                                          ServiceCallbackMap::iterator* it,
+                                                          sp<RegistrationWaiter>* waiter) {
+    std::vector<LocalRegistrationAndWaiter>& localRegistrationAndWaiters = (*it)->second;
+    for (auto lit = localRegistrationAndWaiters.begin();
+         lit != localRegistrationAndWaiters.end();) {
+        if (lit->first == cb) {
+            if (waiter) {
+                *waiter = lit->second;
+            }
+            lit = localRegistrationAndWaiters.erase(lit);
+        } else {
+            ++lit;
+        }
+    }
+
+    if (localRegistrationAndWaiters.empty()) {
+        mNameToRegistrationCallback.erase(*it);
+    }
+}
+
+status_t ServiceManagerShim::unregisterForNotifications(const String16& name,
+                                                        const sp<AidlRegistrationCallback>& cb) {
+    if (cb == nullptr) {
+        ALOGE("%s: null cb passed", __FUNCTION__);
+        return BAD_VALUE;
+    }
+    std::string nameStr = String8(name).c_str();
+    std::lock_guard<std::mutex> lock(mNameToRegistrationLock);
+    auto it = mNameToRegistrationCallback.find(nameStr);
+    sp<RegistrationWaiter> registrationWaiter;
+    if (it != mNameToRegistrationCallback.end()) {
+        removeRegistrationCallbackLocked(cb, &it, &registrationWaiter);
+    } else {
+        ALOGE("%s no callback registered for notifications on %s", __FUNCTION__, nameStr.c_str());
+        return BAD_VALUE;
+    }
+    if (registrationWaiter == nullptr) {
+        ALOGE("%s Callback passed wasn't used to register for notifications", __FUNCTION__);
+        return BAD_VALUE;
+    }
+    if (Status status = mTheRealServiceManager->unregisterForNotifications(String8(name).c_str(),
+                                                                           registrationWaiter);
+        !status.isOk()) {
+        ALOGW("Failed to get service manager to unregisterForNotifications for %s: %s",
+              String8(name).c_str(), status.toString8().c_str());
+        return UNKNOWN_ERROR;
+    }
+    return OK;
+}
+
 #ifndef __ANDROID__
 // ServiceManagerShim for host. Implements the old libbinder android::IServiceManager API.
 // The internal implementation of the AIDL interface android::os::IServiceManager calls into
diff --git a/libs/binder/include/binder/IServiceManager.h b/libs/binder/include/binder/IServiceManager.h
index 240e3c2b26..ea40db8ffa 100644
--- a/libs/binder/include/binder/IServiceManager.h
+++ b/libs/binder/include/binder/IServiceManager.h
@@ -115,6 +115,17 @@ public:
         unsigned int port;
     };
     virtual std::optional<ConnectionInfo> getConnectionInfo(const String16& name) = 0;
+
+    struct LocalRegistrationCallback : public virtual RefBase {
+        virtual void onServiceRegistration(const String16& instance, const sp<IBinder>& binder) = 0;
+        virtual ~LocalRegistrationCallback() {}
+    };
+
+    virtual status_t registerForNotifications(const String16& name,
+                                              const sp<LocalRegistrationCallback>& callback) = 0;
+
+    virtual status_t unregisterForNotifications(const String16& name,
+                                                const sp<LocalRegistrationCallback>& callback) = 0;
 };
 
 sp<IServiceManager> defaultServiceManager();
diff --git a/libs/binder/tests/binderLibTest.cpp b/libs/binder/tests/binderLibTest.cpp
index 63a4b2cc68..700940a529 100644
--- a/libs/binder/tests/binderLibTest.cpp
+++ b/libs/binder/tests/binderLibTest.cpp
@@ -1220,6 +1220,19 @@ TEST_F(BinderLibTest, GotSid) {
     EXPECT_THAT(server->transact(BINDER_LIB_TEST_CAN_GET_SID, data, nullptr), StatusEq(OK));
 }
 
+TEST(ServiceNotifications, Unregister) {
+    auto sm = defaultServiceManager();
+    using LocalRegistrationCallback = IServiceManager::LocalRegistrationCallback;
+    class LocalRegistrationCallbackImpl : public virtual LocalRegistrationCallback {
+        void onServiceRegistration(const String16 &, const sp<IBinder> &) override {}
+        virtual ~LocalRegistrationCallbackImpl() {}
+    };
+    sp<LocalRegistrationCallback> cb = sp<LocalRegistrationCallbackImpl>::make();
+
+    EXPECT_EQ(sm->registerForNotifications(String16("RogerRafa"), cb), OK);
+    EXPECT_EQ(sm->unregisterForNotifications(String16("RogerRafa"), cb), OK);
+}
+
 class BinderLibRpcTestBase : public BinderLibTest {
 public:
     void SetUp() override {
diff --git a/libs/fakeservicemanager/ServiceManager.cpp b/libs/fakeservicemanager/ServiceManager.cpp
index 9f0754b891..61e4a98846 100644
--- a/libs/fakeservicemanager/ServiceManager.cpp
+++ b/libs/fakeservicemanager/ServiceManager.cpp
@@ -84,4 +84,14 @@ std::optional<IServiceManager::ConnectionInfo> ServiceManager::getConnectionInfo
     return std::nullopt;
 }
 
+status_t ServiceManager::registerForNotifications(const String16&,
+                                                  const sp<LocalRegistrationCallback>&) {
+    return INVALID_OPERATION;
+}
+
+status_t ServiceManager::unregisterForNotifications(const String16&,
+                                                const sp<LocalRegistrationCallback>&) {
+    return INVALID_OPERATION;
+}
+
 }  // namespace android
diff --git a/libs/fakeservicemanager/ServiceManager.h b/libs/fakeservicemanager/ServiceManager.h
index b1496ba50b..6d6e008c4f 100644
--- a/libs/fakeservicemanager/ServiceManager.h
+++ b/libs/fakeservicemanager/ServiceManager.h
@@ -53,6 +53,11 @@ public:
 
     std::optional<IServiceManager::ConnectionInfo> getConnectionInfo(const String16& name) override;
 
+    status_t registerForNotifications(const String16& name,
+                                      const sp<LocalRegistrationCallback>& callback) override;
+
+    status_t unregisterForNotifications(const String16& name,
+                                        const sp<LocalRegistrationCallback>& callback) override;
 private:
     std::map<String16, sp<IBinder>> mNameToService;
 };