Merge "Fix deadlock caused by two-threaded property controls" into udc-dev am:... (56630091) · Commits · e / os / android_system_core

init/property_service.cpp

+27 −23

Original line number	Diff line number	Diff line
		@@ -117,7 +117,6 @@ static bool accept_messages = false;
		static std::mutex accept_messages_lock;
		static std::thread property_service_thread;
		static std::thread property_service_for_system_thread;
		static std::mutex set_property_lock;

		static std::unique_ptr<PersistWriteThread> persist_write_thread;

		@@ -395,7 +394,11 @@ static std::optional<uint32_t> PropertySet(const std::string& name, const std::s
		return {PROP_ERROR_INVALID_VALUE};
		}

		auto lock = std::lock_guard{set_property_lock};
		if (name == "sys.powerctl") {
		// No action here - NotifyPropertyChange will trigger the appropriate action, and since this
		// can come to the second thread, we mustn't call out to the __system_property_* functions
		// which support multiple readers but only one mutator.
		} else {
		prop_info* pi = (prop_info*)__system_property_find(name.c_str());
		if (pi != nullptr) {
		// ro.* properties are actually "write-once".
		@@ -422,6 +425,7 @@ static std::optional<uint32_t> PropertySet(const std::string& name, const std::s
		}
		WritePersistentProperty(name, value);
		}
		}

		NotifyPropertyChange(name, value);
		return {PROP_SUCCESS};