init/action.cpp - third_party/android/platform/system/core - Git at Google

 /*
  * Copyright (C) 2015 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.
  */

 #include "action.h"

 #include <android-base/chrono_utils.h>
 #include <android-base/logging.h>
 #include <android-base/properties.h>
 #include <android-base/strings.h>

 #include "util.h"

 using android::base::Join;
 using android::base::StartsWith;

 namespace android {
 namespace init {

 Result<Success> RunBuiltinFunction(const BuiltinFunction& function,
                                    const std::vector<std::string>& args,
                                    const std::string& context) {
     auto builtin_arguments = BuiltinArguments(context);

     builtin_arguments.args.resize(args.size());
     builtin_arguments.args[0] = args[0];
     for (std::size_t i = 1; i < args.size(); ++i) {
         if (!expand_props(args[i], &builtin_arguments.args[i])) {
             return Error() << "cannot expand '" << args[i] << "'";
         }
     }

     return function(builtin_arguments);
 }

 Command::Command(BuiltinFunction f, bool execute_in_subcontext,
                  const std::vector<std::string>& args, int line)
     : func_(std::move(f)), execute_in_subcontext_(execute_in_subcontext), args_(args), line_(line) {}

 Result<Success> Command::InvokeFunc(Subcontext* subcontext) const {
     if (execute_in_subcontext_ && subcontext) {
         return subcontext->Execute(args_);
     } else {
         const std::string& context = subcontext ? subcontext->context() : kInitContext;
         return RunBuiltinFunction(func_, args_, context);
     }
 }

 std::string Command::BuildCommandString() const {
     return Join(args_, ' ');
 }

 Action::Action(bool oneshot, Subcontext* subcontext, const std::string& filename, int line)
     : oneshot_(oneshot), subcontext_(subcontext), filename_(filename), line_(line) {}

 const KeywordFunctionMap* Action::function_map_ = nullptr;

 Result<Success> Action::AddCommand(const std::vector<std::string>& args, int line) {
     if (!function_map_) {
         return Error() << "no function map available";
     }

     auto function = function_map_->FindFunction(args);
     if (!function) return Error() << function.error();

     commands_.emplace_back(function->second, function->first, args, line);
     return Success();
 }

 void Action::AddCommand(BuiltinFunction f, const std::vector<std::string>& args, int line) {
     commands_.emplace_back(f, false, args, line);
 }

 std::size_t Action::NumCommands() const {
     return commands_.size();
 }

 void Action::ExecuteOneCommand(std::size_t command) const {
     // We need a copy here since some Command execution may result in
     // changing commands_ vector by importing .rc files through parser
     Command cmd = commands_[command];
     ExecuteCommand(cmd);
 }

 void Action::ExecuteAllCommands() const {
     for (const auto& c : commands_) {
         ExecuteCommand(c);
     }
 }

 void Action::ExecuteCommand(const Command& command) const {
     android::base::Timer t;
     auto result = command.InvokeFunc(subcontext_);
     auto duration = t.duration();

     // There are many legacy paths in rootdir/init.rc that will virtually never exist on a new
     // device, such as '/sys/class/leds/jogball-backlight/brightness'.  As of this writing, there
     // are 198 such failures on bullhead.  Instead of spamming the log reporting them, we do not
     // report such failures unless we're running at the DEBUG log level.
     bool report_failure = !result.has_value();
     if (report_failure && android::base::GetMinimumLogSeverity() > android::base::DEBUG &&
         result.error_errno() == ENOENT) {
         report_failure = false;
     }

     // Any action longer than 50ms will be warned to user as slow operation
     if (report_failure || duration > 50ms ||
         android::base::GetMinimumLogSeverity() <= android::base::DEBUG) {
         std::string trigger_name = BuildTriggersString();
         std::string cmd_str = command.BuildCommandString();

         LOG(INFO) << "Command '" << cmd_str << "' action=" << trigger_name << " (" << filename_
                   << ":" << command.line() << ") took " << duration.count() << "ms and "
                   << (result ? "succeeded" : "failed: " + result.error_string());
     }
 }

 Result<Success> Action::ParsePropertyTrigger(const std::string& trigger) {
     const static std::string prop_str("property:");
     std::string prop_name(trigger.substr(prop_str.length()));
     size_t equal_pos = prop_name.find('=');
     if (equal_pos == std::string::npos) {
         return Error() << "property trigger found without matching '='";
     }

     std::string prop_value(prop_name.substr(equal_pos + 1));
     prop_name.erase(equal_pos);

     if (auto [it, inserted] = property_triggers_.emplace(prop_name, prop_value); !inserted) {
         return Error() << "multiple property triggers found for same property";
     }
     return Success();
 }

 Result<Success> Action::InitTriggers(const std::vector<std::string>& args) {
     const static std::string prop_str("property:");
     for (std::size_t i = 0; i < args.size(); ++i) {
         if (args[i].empty()) {
             return Error() << "empty trigger is not valid";
         }

         if (i % 2) {
             if (args[i] != "&&") {
                 return Error() << "&& is the only symbol allowed to concatenate actions";
             } else {
                 continue;
             }
         }

         if (!args[i].compare(0, prop_str.length(), prop_str)) {
             if (auto result = ParsePropertyTrigger(args[i]); !result) {
                 return result;
             }
         } else {
             if (!event_trigger_.empty()) {
                 return Error() << "multiple event triggers are not allowed";
             }

             event_trigger_ = args[i];
         }
     }

     return Success();
 }

 Result<Success> Action::InitSingleTrigger(const std::string& trigger) {
     std::vector<std::string> name_vector{trigger};
     if (auto result = InitTriggers(name_vector); !result) {
         return Error() << "InitTriggers() failed: " << result.error();
     }
     return Success();
 }

 // This function checks that all property triggers are satisfied, that is
 // for each (name, value) in property_triggers_, check that the current
 // value of the property 'name' == value.
 //
 // It takes an optional (name, value) pair, which if provided must
 // be present in property_triggers_; it skips the check of the current
 // property value for this pair.
 bool Action::CheckPropertyTriggers(const std::string& name,
                                    const std::string& value) const {
     if (property_triggers_.empty()) {
         return true;
     }

     bool found = name.empty();
     for (const auto& [trigger_name, trigger_value] : property_triggers_) {
         if (trigger_name == name) {
             if (trigger_value != "*" && trigger_value != value) {
                 return false;
             } else {
                 found = true;
             }
         } else {
             std::string prop_val = android::base::GetProperty(trigger_name, "");
             if (prop_val.empty() || (trigger_value != "*" && trigger_value != prop_val)) {
                 return false;
             }
         }
     }
     return found;
 }

 bool Action::CheckEvent(const EventTrigger& event_trigger) const {
     return event_trigger == event_trigger_ && CheckPropertyTriggers();
 }

 bool Action::CheckEvent(const PropertyChange& property_change) const {
     const auto& [name, value] = property_change;
     return event_trigger_.empty() && CheckPropertyTriggers(name, value);
 }

 bool Action::CheckEvent(const BuiltinAction& builtin_action) const {
     return this == builtin_action;
 }

 std::string Action::BuildTriggersString() const {
     std::vector<std::string> triggers;

     for (const auto& [trigger_name, trigger_value] : property_triggers_) {
         triggers.emplace_back(trigger_name + '=' + trigger_value);
     }
     if (!event_trigger_.empty()) {
         triggers.emplace_back(event_trigger_);
     }

     return Join(triggers, " && ");
 }

 void Action::DumpState() const {
     std::string trigger_name = BuildTriggersString();
     LOG(INFO) << "on " << trigger_name;

     for (const auto& c : commands_) {
         std::string cmd_str = c.BuildCommandString();
         LOG(INFO) << "  " << cmd_str;
     }
 }

 ActionManager::ActionManager() : current_command_(0) {
 }

 ActionManager& ActionManager::GetInstance() {
     static ActionManager instance;
     return instance;
 }

 void ActionManager::AddAction(std::unique_ptr<Action> action) {
     actions_.emplace_back(std::move(action));
 }

 void ActionManager::QueueEventTrigger(const std::string& trigger) {
     event_queue_.emplace(trigger);
 }

 void ActionManager::QueuePropertyChange(const std::string& name, const std::string& value) {
     event_queue_.emplace(std::make_pair(name, value));
 }

 void ActionManager::QueueAllPropertyActions() {
     QueuePropertyChange("", "");
 }

 void ActionManager::QueueBuiltinAction(BuiltinFunction func, const std::string& name) {
     auto action = std::make_unique<Action>(true, nullptr, "<Builtin Action>", 0);
     std::vector<std::string> name_vector{name};

     if (auto result = action->InitSingleTrigger(name); !result) {
         LOG(ERROR) << "Cannot queue BuiltinAction for " << name << ": " << result.error();
         return;
     }

     action->AddCommand(func, name_vector, 0);

     event_queue_.emplace(action.get());
     actions_.emplace_back(std::move(action));
 }

 void ActionManager::ExecuteOneCommand() {
     // Loop through the event queue until we have an action to execute
     while (current_executing_actions_.empty() && !event_queue_.empty()) {
         for (const auto& action : actions_) {
             if (std::visit([&action](const auto& event) { return action->CheckEvent(event); },
                            event_queue_.front())) {
                 current_executing_actions_.emplace(action.get());
             }
         }
         event_queue_.pop();
     }

     if (current_executing_actions_.empty()) {
         return;
     }

     auto action = current_executing_actions_.front();

     if (current_command_ == 0) {
         std::string trigger_name = action->BuildTriggersString();
         LOG(INFO) << "processing action (" << trigger_name << ") from (" << action->filename()
                   << ":" << action->line() << ")";
     }

     action->ExecuteOneCommand(current_command_);

     // If this was the last command in the current action, then remove
     // the action from the executing list.
     // If this action was oneshot, then also remove it from actions_.
     ++current_command_;
     if (current_command_ == action->NumCommands()) {
         current_executing_actions_.pop();
         current_command_ = 0;
         if (action->oneshot()) {
             auto eraser = [&action] (std::unique_ptr<Action>& a) {
                 return a.get() == action;
             };
             actions_.erase(std::remove_if(actions_.begin(), actions_.end(), eraser));
         }
     }
 }

 bool ActionManager::HasMoreCommands() const {
     return !current_executing_actions_.empty() || !event_queue_.empty();
 }

 void ActionManager::DumpState() const {
     for (const auto& a : actions_) {
         a->DumpState();
     }
 }

 void ActionManager::ClearQueue() {
     // We are shutting down so don't claim the oneshot builtin actions back
     current_executing_actions_ = {};
     event_queue_ = {};
     current_command_ = 0;
 }

 Result<Success> ActionParser::ParseSection(std::vector<std::string>&& args,
                                            const std::string& filename, int line) {
     std::vector<std::string> triggers(args.begin() + 1, args.end());
     if (triggers.size() < 1) {
         return Error() << "Actions must have a trigger";
     }

     Subcontext* action_subcontext = nullptr;
     if (subcontexts_) {
         for (auto& subcontext : *subcontexts_) {
             if (StartsWith(filename, subcontext.path_prefix().c_str())) {
                 action_subcontext = &subcontext;
                 break;
             }
         }
     }

     auto action = std::make_unique<Action>(false, action_subcontext, filename, line);

     if (auto result = action->InitTriggers(triggers); !result) {
         return Error() << "InitTriggers() failed: " << result.error();
     }

     action_ = std::move(action);
     return Success();
 }

 Result<Success> ActionParser::ParseLineSection(std::vector<std::string>&& args, int line) {
     return action_ ? action_->AddCommand(std::move(args), line) : Success();
 }

 Result<Success> ActionParser::EndSection() {
     if (action_ && action_->NumCommands() > 0) {
         action_manager_->AddAction(std::move(action_));
     }

     return Success();
 }

 }  // namespace init
 }  // namespace android
	/*
	* Copyright (C) 2015 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.
	*/

	#include "action.h"

	#include <android-base/chrono_utils.h>
	#include <android-base/logging.h>
	#include <android-base/properties.h>
	#include <android-base/strings.h>

	#include "util.h"

	using android::base::Join;
	using android::base::StartsWith;

	namespace android {
	namespace init {

	Result<Success> RunBuiltinFunction(const BuiltinFunction& function,
	const std::vector<std::string>& args,
	const std::string& context) {
	auto builtin_arguments = BuiltinArguments(context);

	builtin_arguments.args.resize(args.size());
	builtin_arguments.args[0] = args[0];
	for (std::size_t i = 1; i < args.size(); ++i) {
	if (!expand_props(args[i], &builtin_arguments.args[i])) {
	return Error() << "cannot expand '" << args[i] << "'";
	}
	}

	return function(builtin_arguments);
	}

	Command::Command(BuiltinFunction f, bool execute_in_subcontext,
	const std::vector<std::string>& args, int line)
	: func_(std::move(f)), execute_in_subcontext_(execute_in_subcontext), args_(args), line_(line) {}

	Result<Success> Command::InvokeFunc(Subcontext* subcontext) const {
	if (execute_in_subcontext_ && subcontext) {
	return subcontext->Execute(args_);
	} else {
	const std::string& context = subcontext ? subcontext->context() : kInitContext;
	return RunBuiltinFunction(func_, args_, context);
	}
	}

	std::string Command::BuildCommandString() const {
	return Join(args_, ' ');
	}

	Action::Action(bool oneshot, Subcontext* subcontext, const std::string& filename, int line)
	: oneshot_(oneshot), subcontext_(subcontext), filename_(filename), line_(line) {}

	const KeywordFunctionMap* Action::function_map_ = nullptr;

	Result<Success> Action::AddCommand(const std::vector<std::string>& args, int line) {
	if (!function_map_) {
	return Error() << "no function map available";
	}

	auto function = function_map_->FindFunction(args);
	if (!function) return Error() << function.error();

	commands_.emplace_back(function->second, function->first, args, line);
	return Success();
	}

	void Action::AddCommand(BuiltinFunction f, const std::vector<std::string>& args, int line) {
	commands_.emplace_back(f, false, args, line);
	}

	std::size_t Action::NumCommands() const {
	return commands_.size();
	}

	void Action::ExecuteOneCommand(std::size_t command) const {
	// We need a copy here since some Command execution may result in
	// changing commands_ vector by importing .rc files through parser
	Command cmd = commands_[command];
	ExecuteCommand(cmd);
	}

	void Action::ExecuteAllCommands() const {
	for (const auto& c : commands_) {
	ExecuteCommand(c);
	}
	}

	void Action::ExecuteCommand(const Command& command) const {
	android::base::Timer t;
	auto result = command.InvokeFunc(subcontext_);
	auto duration = t.duration();

	// There are many legacy paths in rootdir/init.rc that will virtually never exist on a new
	// device, such as '/sys/class/leds/jogball-backlight/brightness'. As of this writing, there
	// are 198 such failures on bullhead. Instead of spamming the log reporting them, we do not
	// report such failures unless we're running at the DEBUG log level.
	bool report_failure = !result.has_value();
	if (report_failure && android::base::GetMinimumLogSeverity() > android::base::DEBUG &&
	result.error_errno() == ENOENT) {
	report_failure = false;
	}

	// Any action longer than 50ms will be warned to user as slow operation
	if (report_failure \|\| duration > 50ms \|\|
	android::base::GetMinimumLogSeverity() <= android::base::DEBUG) {
	std::string trigger_name = BuildTriggersString();
	std::string cmd_str = command.BuildCommandString();

	LOG(INFO) << "Command '" << cmd_str << "' action=" << trigger_name << " (" << filename_
	<< ":" << command.line() << ") took " << duration.count() << "ms and "
	<< (result ? "succeeded" : "failed: " + result.error_string());
	}
	}

	Result<Success> Action::ParsePropertyTrigger(const std::string& trigger) {
	const static std::string prop_str("property:");
	std::string prop_name(trigger.substr(prop_str.length()));
	size_t equal_pos = prop_name.find('=');
	if (equal_pos == std::string::npos) {
	return Error() << "property trigger found without matching '='";
	}

	std::string prop_value(prop_name.substr(equal_pos + 1));
	prop_name.erase(equal_pos);

	if (auto [it, inserted] = property_triggers_.emplace(prop_name, prop_value); !inserted) {
	return Error() << "multiple property triggers found for same property";
	}
	return Success();
	}

	Result<Success> Action::InitTriggers(const std::vector<std::string>& args) {
	const static std::string prop_str("property:");
	for (std::size_t i = 0; i < args.size(); ++i) {
	if (args[i].empty()) {
	return Error() << "empty trigger is not valid";
	}

	if (i % 2) {
	if (args[i] != "&&") {
	return Error() << "&& is the only symbol allowed to concatenate actions";
	} else {
	continue;
	}
	}

	if (!args[i].compare(0, prop_str.length(), prop_str)) {
	if (auto result = ParsePropertyTrigger(args[i]); !result) {
	return result;
	}
	} else {
	if (!event_trigger_.empty()) {
	return Error() << "multiple event triggers are not allowed";
	}

	event_trigger_ = args[i];
	}
	}

	return Success();
	}

	Result<Success> Action::InitSingleTrigger(const std::string& trigger) {
	std::vector<std::string> name_vector{trigger};
	if (auto result = InitTriggers(name_vector); !result) {
	return Error() << "InitTriggers() failed: " << result.error();
	}
	return Success();
	}

	// This function checks that all property triggers are satisfied, that is
	// for each (name, value) in property_triggers_, check that the current
	// value of the property 'name' == value.
	//
	// It takes an optional (name, value) pair, which if provided must
	// be present in property_triggers_; it skips the check of the current
	// property value for this pair.
	bool Action::CheckPropertyTriggers(const std::string& name,
	const std::string& value) const {
	if (property_triggers_.empty()) {
	return true;
	}

	bool found = name.empty();
	for (const auto& [trigger_name, trigger_value] : property_triggers_) {
	if (trigger_name == name) {
	if (trigger_value != "*" && trigger_value != value) {
	return false;
	} else {
	found = true;
	}
	} else {
	std::string prop_val = android::base::GetProperty(trigger_name, "");
	if (prop_val.empty() \|\| (trigger_value != "*" && trigger_value != prop_val)) {
	return false;
	}
	}
	}
	return found;
	}

	bool Action::CheckEvent(const EventTrigger& event_trigger) const {
	return event_trigger == event_trigger_ && CheckPropertyTriggers();
	}

	bool Action::CheckEvent(const PropertyChange& property_change) const {
	const auto& [name, value] = property_change;
	return event_trigger_.empty() && CheckPropertyTriggers(name, value);
	}

	bool Action::CheckEvent(const BuiltinAction& builtin_action) const {
	return this == builtin_action;
	}

	std::string Action::BuildTriggersString() const {
	std::vector<std::string> triggers;

	for (const auto& [trigger_name, trigger_value] : property_triggers_) {
	triggers.emplace_back(trigger_name + '=' + trigger_value);
	}
	if (!event_trigger_.empty()) {
	triggers.emplace_back(event_trigger_);
	}

	return Join(triggers, " && ");
	}

	void Action::DumpState() const {
	std::string trigger_name = BuildTriggersString();
	LOG(INFO) << "on " << trigger_name;

	for (const auto& c : commands_) {
	std::string cmd_str = c.BuildCommandString();
	LOG(INFO) << " " << cmd_str;
	}
	}

	ActionManager::ActionManager() : current_command_(0) {
	}

	ActionManager& ActionManager::GetInstance() {
	static ActionManager instance;
	return instance;
	}

	void ActionManager::AddAction(std::unique_ptr<Action> action) {
	actions_.emplace_back(std::move(action));
	}

	void ActionManager::QueueEventTrigger(const std::string& trigger) {
	event_queue_.emplace(trigger);
	}

	void ActionManager::QueuePropertyChange(const std::string& name, const std::string& value) {
	event_queue_.emplace(std::make_pair(name, value));
	}

	void ActionManager::QueueAllPropertyActions() {
	QueuePropertyChange("", "");
	}

	void ActionManager::QueueBuiltinAction(BuiltinFunction func, const std::string& name) {
	auto action = std::make_unique<Action>(true, nullptr, "<Builtin Action>", 0);
	std::vector<std::string> name_vector{name};

	if (auto result = action->InitSingleTrigger(name); !result) {
	LOG(ERROR) << "Cannot queue BuiltinAction for " << name << ": " << result.error();
	return;
	}

	action->AddCommand(func, name_vector, 0);

	event_queue_.emplace(action.get());
	actions_.emplace_back(std::move(action));
	}

	void ActionManager::ExecuteOneCommand() {
	// Loop through the event queue until we have an action to execute
	while (current_executing_actions_.empty() && !event_queue_.empty()) {
	for (const auto& action : actions_) {
	if (std::visit([&action](const auto& event) { return action->CheckEvent(event); },
	event_queue_.front())) {
	current_executing_actions_.emplace(action.get());
	}
	}
	event_queue_.pop();
	}

	if (current_executing_actions_.empty()) {
	return;
	}

	auto action = current_executing_actions_.front();

	if (current_command_ == 0) {
	std::string trigger_name = action->BuildTriggersString();
	LOG(INFO) << "processing action (" << trigger_name << ") from (" << action->filename()
	<< ":" << action->line() << ")";
	}

	action->ExecuteOneCommand(current_command_);

	// If this was the last command in the current action, then remove
	// the action from the executing list.
	// If this action was oneshot, then also remove it from actions_.
	++current_command_;
	if (current_command_ == action->NumCommands()) {
	current_executing_actions_.pop();
	current_command_ = 0;
	if (action->oneshot()) {
	auto eraser = [&action] (std::unique_ptr<Action>& a) {
	return a.get() == action;
	};
	actions_.erase(std::remove_if(actions_.begin(), actions_.end(), eraser));
	}
	}
	}

	bool ActionManager::HasMoreCommands() const {
	return !current_executing_actions_.empty() \|\| !event_queue_.empty();
	}

	void ActionManager::DumpState() const {
	for (const auto& a : actions_) {
	a->DumpState();
	}
	}

	void ActionManager::ClearQueue() {
	// We are shutting down so don't claim the oneshot builtin actions back
	current_executing_actions_ = {};
	event_queue_ = {};
	current_command_ = 0;
	}

	Result<Success> ActionParser::ParseSection(std::vector<std::string>&& args,
	const std::string& filename, int line) {
	std::vector<std::string> triggers(args.begin() + 1, args.end());
	if (triggers.size() < 1) {
	return Error() << "Actions must have a trigger";
	}

	Subcontext* action_subcontext = nullptr;
	if (subcontexts_) {
	for (auto& subcontext : *subcontexts_) {
	if (StartsWith(filename, subcontext.path_prefix().c_str())) {
	action_subcontext = &subcontext;
	break;
	}
	}
	}

	auto action = std::make_unique<Action>(false, action_subcontext, filename, line);

	if (auto result = action->InitTriggers(triggers); !result) {
	return Error() << "InitTriggers() failed: " << result.error();
	}

	action_ = std::move(action);
	return Success();
	}

	Result<Success> ActionParser::ParseLineSection(std::vector<std::string>&& args, int line) {
	return action_ ? action_->AddCommand(std::move(args), line) : Success();
	}

	Result<Success> ActionParser::EndSection() {
	if (action_ && action_->NumCommands() > 0) {
	action_manager_->AddAction(std::move(action_));
	}

	return Success();
	}

	} // namespace init
	} // namespace android