Merge "init: add wait_for_prop builtin command" (d25e4c58) · Commits · e / os / android_system_core

init/README.md

+7 −1

Original line number	Diff line number	Diff line
		@@ -298,7 +298,8 @@ Commands
		> Fork and execute command with the given arguments. The command starts
		after "--" so that an optional security context, user, and supplementary
		groups can be provided. No other commands will be run until this one
		finishes. _seclabel_ can be a - to denote default.
		finishes. _seclabel_ can be a - to denote default. Properties are expanded
		within _argument_.

		`export <name> <value>`
		> Set the environment variable _name_ equal to _value_ in the
		@@ -412,6 +413,11 @@ Commands
		or the timeout has been reached. If timeout is not specified it
		currently defaults to five seconds.

		`wait_for_prop <name> <value>`
		> Wait for system property _name_ to be _value_. Properties are expanded
		within _value_. If property _name_ is already set to _value_, continue
		immediately.

		`write <path> <content>`
		> Open the file at _path_ and write a string to it with write(2).
		If the file does not exist, it will be created. If it does exist,

+24 −0

Original line number	Diff line number	Diff line
		@@ -1003,6 +1003,29 @@ static int do_wait(const std::vector<std::string>& args) {
		return -1;
		}

		static int do_wait_for_prop(const std::vector<std::string>& args) {
		const char* name = args[1].c_str();
		const char* value = args[2].c_str();
		size_t value_len = strlen(value);

		if (!is_legal_property_name(name)) {
		LOG(ERROR) << "do_wait_for_prop(\"" << name << "\", \"" << value
		<< "\") failed: bad name";
		return -1;
		}
		if (value_len >= PROP_VALUE_MAX) {
		LOG(ERROR) << "do_wait_for_prop(\"" << name << "\", \"" << value
		<< "\") failed: value too long";
		return -1;
		}
		if (!wait_property(name, value)) {
		LOG(ERROR) << "do_wait_for_prop(\"" << name << "\", \"" << value
		<< "\") failed: init already in waiting";
		return -1;
		}
		return 0;
		}

		/*
		* Callback to make a directory from the ext4 code
		*/
		@@ -1074,6 +1097,7 @@ BuiltinFunctionMap::Map& BuiltinFunctionMap::map() const {
		{"verity_load_state", {0, 0, do_verity_load_state}},
		{"verity_update_state", {0, 0, do_verity_update_state}},
		{"wait", {1, 2, do_wait}},
		{"wait_for_prop", {2, 2, do_wait_for_prop}},
		{"write", {2, 2, do_write}},
		};
		return builtin_functions;

+29 −1

Original line number	Diff line number	Diff line
		@@ -87,6 +87,10 @@ bool waiting_for_exec = false;

		static int epoll_fd = -1;

		static std::unique_ptr<Timer> waiting_for_prop(nullptr);
		static std::string wait_prop_name;
		static std::string wait_prop_value;

		void register_epoll_handler(int fd, void (*fn)()) {
		epoll_event ev;
		ev.events = EPOLLIN;
		@@ -128,10 +132,34 @@ int add_environment(const char key, const char val)
		return -1;
		}

		bool wait_property(const char name, const char value)
		{
		if (waiting_for_prop) {
		return false;
		}
		if (property_get(name) != value) {
		// Current property value is not equal to expected value
		wait_prop_name = name;
		wait_prop_value = value;
		waiting_for_prop.reset(new Timer());
		} else {
		LOG(INFO) << "wait_property(\"" << name << "\", \"" << value << "\"): already set";
		}
		return true;
		}

		void property_changed(const char name, const char value)
		{
		if (property_triggers_enabled)
		ActionManager::GetInstance().QueuePropertyTrigger(name, value);
		if (waiting_for_prop) {
		if (wait_prop_name == name && wait_prop_value == value) {
		wait_prop_name.clear();
		wait_prop_value.clear();
		LOG(INFO) << "Wait for property took " << *waiting_for_prop;
		waiting_for_prop.reset();
		}
		}
		}

		static void restart_processes()
		@@ -876,7 +904,7 @@ int main(int argc, char** argv) {
		am.QueueBuiltinAction(queue_property_triggers_action, "queue_property_triggers");

		while (true) {
		if (!waiting_for_exec) {
		if (!(waiting_for_exec \|\| waiting_for_prop)) {
		am.ExecuteOneCommand();
		restart_processes();
		}

+2 −0

Original line number	Diff line number	Diff line
		@@ -36,4 +36,6 @@ void register_epoll_handler(int fd, void (*fn)());

		int add_environment(const char* key, const char* val);

		bool wait_property(const char name, const char value);

		#endif /* _INIT_INIT_H */