Merge "Add support for updatable services" (a07d2959) · Commits · e / os / android_system_core

init/README.md

+7 −0

Original line number	Diff line number	Diff line
		@@ -332,6 +332,13 @@ runs the service.
		This is particularly useful for creating a periodic service combined with the restart_period
		option described above.

		`updatable`
		> Mark that the service can be overridden (via the 'override' option) later in
		the boot sequence by APEXes. When a service with updatable option is started
		before APEXes are all activated, the execution is delayed until the activation
		is finished. A service that is not marked as updatable cannot be overridden by
		APEXes.

		`user <username>`
		> Change to 'username' before exec'ing this service.
		Currently defaults to root. (??? probably should default to nobody)

init/builtins.cpp

+1 −0

Original line number	Diff line number	Diff line
		@@ -1079,6 +1079,7 @@ static Result<Success> do_parse_apex_configs(const BuiltinArguments& args) {
		}
		success &= parser.ParseConfigFile(c);
		}
		ServiceList::GetInstance().MarkServicesUpdate();
		if (success) {
		return Success();
		} else {

init/service.cpp

+53 −0

Original line number	Diff line number	Diff line
		@@ -765,6 +765,11 @@ Result<Success> Service::ParseWritepid(std::vector<std::string>&& args) {
		return Success();
		}

		Result<Success> Service::ParseUpdatable(std::vector<std::string>&& args) {
		updatable_ = true;
		return Success();
		}

		class Service::OptionParserMap : public KeywordMap<OptionParser> {
		public:
		OptionParserMap() {}
		@@ -817,6 +822,7 @@ const Service::OptionParserMap::Map& Service::OptionParserMap::map() const {
		{"socket", {3, 6, &Service::ParseSocket}},
		{"timeout_period",
		{1, 1, &Service::ParseTimeoutPeriod}},
		{"updatable", {0, 0, &Service::ParseUpdatable}},
		{"user", {1, 1, &Service::ParseUser}},
		{"writepid", {1, kMax, &Service::ParseWritepid}},
		};
		@@ -834,6 +840,13 @@ Result<Success> Service::ParseLine(std::vector<std::string>&& args) {
		}

		Result<Success> Service::ExecStart() {
		if (is_updatable() && !ServiceList::GetInstance().IsServicesUpdated()) {
		// Don't delay the service for ExecStart() as the semantic is that
		// the caller might depend on the side effect of the execution.
		return Error() << "Cannot start an updatable service '" << name_
		<< "' before configs from APEXes are all loaded";
		}

		flags_ \|= SVC_ONESHOT;

		if (auto result = Start(); !result) {
		@@ -851,6 +864,13 @@ Result<Success> Service::ExecStart() {
		}

		Result<Success> Service::Start() {
		if (is_updatable() && !ServiceList::GetInstance().IsServicesUpdated()) {
		ServiceList::GetInstance().DelayService(*this);
		return Error() << "Cannot start an updatable service '" << name_
		<< "' before configs from APEXes are all loaded. "
		<< "Queued for execution.";
		}

		bool disabled = (flags_ & (SVC_DISABLED \| SVC_RESET));
		// Starting a service removes it from the disabled or reset state and
		// immediately takes it out of the restarting state if it was in there.
		@@ -1280,6 +1300,32 @@ void ServiceList::DumpState() const {
		}
		}

		void ServiceList::MarkServicesUpdate() {
		services_update_finished_ = true;

		// start the delayed services
		for (const auto& name : delayed_service_names_) {
		Service* service = FindService(name);
		if (service == nullptr) {
		LOG(ERROR) << "delayed service '" << name << "' could not be found.";
		continue;
		}
		if (auto result = service->Start(); !result) {
		LOG(ERROR) << result.error_string();
		}
		}
		delayed_service_names_.clear();
		}

		void ServiceList::DelayService(const Service& service) {
		if (services_update_finished_) {
		LOG(ERROR) << "Cannot delay the start of service '" << service.name()
		<< "' because all services are already updated. Ignoring.";
		return;
		}
		delayed_service_names_.emplace_back(service.name());
		}

		Result<Success> ServiceParser::ParseSection(std::vector<std::string>&& args,
		const std::string& filename, int line) {
		if (args.size() < 3) {
		@@ -1291,6 +1337,8 @@ Result<Success> ServiceParser::ParseSection(std::vector<std::string>&& args,
		return Error() << "invalid service name '" << name << "'";
		}

		filename_ = filename;

		Subcontext* restart_action_subcontext = nullptr;
		if (subcontexts_) {
		for (auto& subcontext : *subcontexts_) {
		@@ -1326,6 +1374,11 @@ Result<Success> ServiceParser::EndSection() {
		<< "'";
		}

		if (StartsWith(filename_, "/apex/") && !old_service->is_updatable()) {
		return Error() << "cannot update a non-updatable service '" << service_->name()
		<< "' with a config in APEX";
		}

		service_list_->RemoveService(*old_service);
		old_service = nullptr;
		}

init/service.h

+13 −0

Original line number	Diff line number	Diff line
		@@ -123,6 +123,7 @@ class Service {
		std::chrono::seconds restart_period() const { return restart_period_; }
		std::optional<std::chrono::seconds> timeout_period() const { return timeout_period_; }
		const std::vector<std::string>& args() const { return args_; }
		bool is_updatable() const { return updatable_; }

		private:
		using OptionParser = Result<Success> (Service::*)(std::vector<std::string>&& args);
		@@ -170,6 +171,7 @@ class Service {
		Result<Success> ParseFile(std::vector<std::string>&& args);
		Result<Success> ParseUser(std::vector<std::string>&& args);
		Result<Success> ParseWritepid(std::vector<std::string>&& args);
		Result<Success> ParseUpdatable(std::vector<std::string>&& args);

		template <typename T>
		Result<Success> AddDescriptor(std::vector<std::string>&& args);
		@@ -235,6 +237,8 @@ class Service {
		std::chrono::seconds restart_period_ = 5s;
		std::optional<std::chrono::seconds> timeout_period_;

		bool updatable_ = false;

		std::vector<std::string> args_;

		std::vector<std::function<void(const siginfo_t& siginfo)>> reap_callbacks_;
		@@ -279,8 +283,15 @@ class ServiceList {
		const std::vector<std::unique_ptr<Service>>& services() const { return services_; }
		const std::vector<Service*> services_in_shutdown_order() const;

		void MarkServicesUpdate();
		bool IsServicesUpdated() const { return services_update_finished_; }
		void DelayService(const Service& service);

		private:
		std::vector<std::unique_ptr<Service>> services_;

		bool services_update_finished_ = false;
		std::vector<std::string> delayed_service_names_;
		};

		class ServiceParser : public SectionParser {
		@@ -291,6 +302,7 @@ class ServiceParser : public SectionParser {
		int line) override;
		Result<Success> ParseLineSection(std::vector<std::string>&& args, int line) override;
		Result<Success> EndSection() override;
		void EndFile() override { filename_ = ""; }

		private:
		bool IsValidName(const std::string& name) const;
		@@ -298,6 +310,7 @@ class ServiceParser : public SectionParser {
		ServiceList* service_list_;
		std::vector<Subcontext>* subcontexts_;
		std::unique_ptr<Service> service_;
		std::string filename_;
		};

		} // namespace init