A high-level executive that dispatches tasks based on the contents of the database. More...
#include <taskDispatcher.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. | |
| int | connect (std::string host, int port, std::string username, std::string password, std::string database) |
| Connects to the database. Returns 0 on success. | |
| Status | getStatus () const |
| Returns the status of the Dispatcher. | |
| void | mainLoop () |
| Main operation loop, called periodically. | |
| void | startNewTask () |
| Attempts to read a task from the dbase and start it. | |
| TaskDispatcher () | |
| ~TaskDispatcher () | |
Static Public Member Functions | |
| static void | sensorCB (void *data, SoSensor *) |
| Static sensor callback, just calls mainLoop(). | |
Private Attributes | |
| int | mCompletedTasks |
| The number of tasks completed so far. | |
| Task * | mCurrentTask |
| The task currently being executed. | |
| db_planner::DatabaseManager * | mDBMgr |
| The db mgr used to connect to the dbase. | |
| TaskFactory | mFactory |
| A factory for instantiating the right type of task. | |
| int | mMaxTasks |
| Max number of tasks to be completed. -1 means no max limit. | |
| SoTimerSensor * | mSensor |
| The timer sensor used to wake up periodically. | |
| Status | mStatus |
| The status of the Dispatcher. | |
A high-level executive that dispatches tasks based on the contents of the database.
The TaskDispatcher is in charge of reading the list of tasks to be executed from the database, creating and startinng the appropriate instances of the Task class and then monitoring them.
It can run either one-shot tasks (that do something and they're done) or even-based tasks which have their own callback system. In the latter case, the Dispatcher uses a callback timer of its own to wake up periodically and check on the currently running task.
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:
Note that if a Task itself finishes with an error, the Dispacther will mark that in the database, then proceed to the next task.
Definition at line 128 of file taskDispatcher.h.
Definition at line 131 of file taskDispatcher.h.
| TaskDispatcher::TaskDispatcher | ( | ) |
Definition at line 47 of file taskDispatcher.cpp.
| TaskDispatcher::~TaskDispatcher | ( | ) |
Definition at line 58 of file taskDispatcher.cpp.
| void TaskDispatcher::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 164 of file taskDispatcher.cpp.
| int TaskDispatcher::connect | ( | std::string | host, | |
| int | port, | |||
| std::string | username, | |||
| std::string | password, | |||
| std::string | database | |||
| ) |
Connects to the database. Returns 0 on success.
Definition at line 69 of file taskDispatcher.cpp.
| Status TaskDispatcher::getStatus | ( | ) | const [inline] |
Returns the status of the Dispatcher.
Definition at line 164 of file taskDispatcher.h.
| void TaskDispatcher::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 198 of file taskDispatcher.cpp.
| void TaskDispatcher::sensorCB | ( | void * | data, | |
| SoSensor * | ||||
| ) | [static] |
Static sensor callback, just calls mainLoop().
Definition at line 229 of file taskDispatcher.cpp.
| void TaskDispatcher::startNewTask | ( | ) |
Attempts to read a task from the dbase and start it.
Gets a new task from the database and starts it. Possible outcomes:
Definition at line 103 of file taskDispatcher.cpp.
int TaskDispatcher::mCompletedTasks [private] |
The number of tasks completed so far.
Definition at line 143 of file taskDispatcher.h.
Task* TaskDispatcher::mCurrentTask [private] |
The task currently being executed.
Definition at line 138 of file taskDispatcher.h.
The db mgr used to connect to the dbase.
Definition at line 136 of file taskDispatcher.h.
TaskFactory TaskDispatcher::mFactory [private] |
A factory for instantiating the right type of task.
Definition at line 134 of file taskDispatcher.h.
int TaskDispatcher::mMaxTasks [private] |
Max number of tasks to be completed. -1 means no max limit.
Definition at line 145 of file taskDispatcher.h.
SoTimerSensor* TaskDispatcher::mSensor [private] |
The timer sensor used to wake up periodically.
Definition at line 147 of file taskDispatcher.h.
Status TaskDispatcher::mStatus [private] |
The status of the Dispatcher.
Definition at line 141 of file taskDispatcher.h.
