A high-level executive that dispatches tasks based on the contents of the database. More...

#include <dbTaskDispatcher.h>

Public Types
enum	Status { READY, NO_TASK, ERROR, RUNNING, DONE }
Public Member Functions
void	checkCurrentTask ()
	Checks the status of the current task; cleans up after it if done.
	DBTaskDispatcher ()
Status	getStatus () const
	Returns the status of the Dispatcher.
int	init (int argc, char **argv)
	Calls the database connection function.
int	mainLoop ()
	Main operation loop, called periodically.
void	registerTaskCreator (std::string task_name, DBTaskCreator *creator)
	Register a new task creator for a task with the given name.
void	startNewTask ()
	Attempts to read a task from the dbase and start it.
	~DBTaskDispatcher ()
Private Member Functions
int	connect (std::string host, int port, std::string username, std::string password, std::string database)
	Connects to the database. Returns 0 on success.
Private Attributes
std::vector< std::string >	mAcceptedTaskTypes
	A list of accepted task types. Empty if all task types are accepted.
int	mCompletedTasks
	The number of tasks completed so far.
DBTask *	mCurrentTask
	The task currently being executed.
db_planner::DatabaseManager *	mDBMgr
	The db mgr used to connect to the dbase.
int	mMaxTasks
	Max number of tasks to be completed. -1 means no max limit.
Status	mStatus
	The status of the Dispatcher.
std::map< std::string, DBTaskCreator * >	mTaskCreators
	Map from task name in database to task creators.

Detailed Description

A high-level executive that dispatches tasks based on the contents of the database.

The DBTaskDispatcher is in charge of reading the list of tasks to be executed from the database, creating and startinng the appropriate instances of the DBTask class and then monitoring them.

It can run either one-shot tasks (that do something and they're done) or event-based tasks which have their own callback system.

On exit, the Dispatcher will exit GraspIt's main loop, thus terminating the application. Before doing that, it will set its own status to inform the main app of the outcome of the tasks. It can exit because:

it has performed a pre-set maximum number of tasks

no more tasks to be executed are listed in the database

there was an error communicating with the database

Note that if a DBTask itself finishes with an error, the Dispatcher will mark that in the database, then proceed to the next task.

The DBTaskDispatcher is a GraspIt! Plugin.

Definition at line 84 of file dbTaskDispatcher.h.

Member Enumeration Documentation

enum graspit_dbase_tasks::DBTaskDispatcher::Status

Enumerator:

READY
NO_TASK
ERROR
RUNNING
DONE

Definition at line 87 of file dbTaskDispatcher.h.

Constructor & Destructor Documentation

graspit_dbase_tasks::DBTaskDispatcher::DBTaskDispatcher ( )

Definition at line 49 of file dbTaskDispatcher.cpp.

graspit_dbase_tasks::DBTaskDispatcher::~DBTaskDispatcher ( )

Definition at line 56 of file dbTaskDispatcher.cpp.

Member Function Documentation

void graspit_dbase_tasks::DBTaskDispatcher::checkCurrentTask ( )

Checks the status of the current task; cleans up after it if done.

Checks on the current task; if it is finished, cleans up after it and marks the result in the database.

If task is finished, sets status to READY, unless there is an error marking the finished task in the database, in which case status is set to ERROR.

Nore that even if the task finishes with an error, the dispatcher will be READY for the next task (not abort altogether). The task that had an error is marked as such in the database. However, if there is an error in communicating with the database, the dispatcher will abort altogether.

Definition at line 151 of file dbTaskDispatcher.cpp.

int graspit_dbase_tasks::DBTaskDispatcher::connect	(	std::string	host,
		int	port,
		std::string	username,
		std::string	password,
		std::string	database
	)		`[private]`

Connects to the database. Returns 0 on success.

Definition at line 66 of file dbTaskDispatcher.cpp.

Status graspit_dbase_tasks::DBTaskDispatcher::getStatus ( ) const [inline]

Returns the status of the Dispatcher.

Definition at line 138 of file dbTaskDispatcher.h.

int graspit_dbase_tasks::DBTaskDispatcher::init	(	int	argc,
		char **	argv
	)

Calls the database connection function.

Definition at line 87 of file dbTaskDispatcher.cpp.

int graspit_dbase_tasks::DBTaskDispatcher::mainLoop ( )

Main operation loop, called periodically.

Will start tasks as long as there are tasks to be run. If the tasks are of the one-shot type, it just loops in here as long as it has tasks. If the task is event-based and needs us to surrender control, it will surrender control but schedule the timer to come back here and check on the task later.

Definition at line 190 of file dbTaskDispatcher.cpp.