class Poco::TaskManager

Overview

The TaskManager manages a collection of tasks and monitors their lifetime. More…

#include <TaskManager.h>

class TaskManager
{
public:
    // typedefs

    typedef AutoPtr<Task> TaskPtr;
    typedef std::list<TaskPtr> TaskList;

    // fields

    static const int MIN_PROGRESS_NOTIFICATION_INTERVAL;

    // construction

    TaskManager();
    TaskManager(ThreadPool& pool);

    // methods

    void
    start(Task* pTask);

    void
    cancelAll();

    void
    joinAll();

    TaskList
    taskList() const;

    int
    count() const;

    void
    addObserver(const AbstractObserver& observer);

    void
    removeObserver(const AbstractObserver& observer);

protected:
    // methods

    void
    postNotification(const Notification::Ptr& pNf);

    void
    taskStarted(Task* pTask);

    void
    taskProgress(
        Task* pTask,
        float progress
        );

    void
    taskCancelled(Task* pTask);

    void
    taskFinished(Task* pTask);

    void
    taskFailed(
        Task* pTask,
        const Exception& exc
        );
};

Detailed Documentation

The TaskManager manages a collection of tasks and monitors their lifetime.

A TaskManager has a built-in NotificationCenter that is used to send out notifications on task progress and task states. See the TaskNotification class and its subclasses for the various events that result in a notification. To keep the number of notifications small, a TaskProgressNotification will only be sent out once in 100 milliseconds.

Construction

TaskManager()

Creates the TaskManager, using the default ThreadPool.

TaskManager(ThreadPool& pool)

Creates the TaskManager, using the given ThreadPool.

Methods

void
start(Task* pTask)

Starts the given task in a thread obtained from the thread pool.

The TaskManager takes ownership of the Task object and deletes it when it it finished.

void
cancelAll()

Requests cancellation of all tasks.

void
joinAll()

Waits for the completion of all the threads in the TaskManager ‘s thread pool.

Note: joinAll() will wait for ALL tasks in the TaskManager ‘s ThreadPool to complete. If the ThreadPool has threads created by other facilities, these threads must also complete before joinAll() can return.

TaskList
taskList() const

Returns a copy of the internal task list.

int
count() const

Returns the number of tasks in the internal task list.

void
addObserver(const AbstractObserver& observer)

Registers an observer with the NotificationCenter.

Usage:

Observer<MyClass, MyNotification> obs(*this, &MyClass::handleNotification);
notificationCenter.addObserver(obs);

void
removeObserver(const AbstractObserver& observer)

Unregisters an observer with the NotificationCenter.

void
postNotification(const Notification::Ptr& pNf)

Posts a notification to the task manager’s notification center.