A class to manage a loose queue of isolated tasks, which can be performed either synchronously (in the foreground thread) or asynchronously (by a background thread).
The AsyncTaskManager is actually a collection of
AsyncTaskChains, each of which maintains a list of tasks. Each chain can be either foreground or background (it may run only in the main thread, or it may be serviced by one or more background threads). See
AsyncTaskChainfor more information.
If you do not require background processing, it is perfectly acceptable to create only one
AsyncTaskChain, which runs in the main thread. This is a common configuration.
explicit AsyncTaskManager(std::string const &name)
void add(AsyncTask *task)
Adds the indicated task to the active queue. It is an error if the task is already added to this or any other active queue.
Stops all threads and messily empties the task list. This is intended to be called on destruction only.
AsyncTask *find_task(std::string const &name) const
Returns the first task found with the indicated name, or NULL if there is no task with the indicated name.
If there are multiple tasks with the same name, returns one of them arbitrarily.
AsyncTaskChain *find_task_chain(std::string const &name)
Searches a new
AsyncTaskChainof the indicated name and returns it if it exists, or NULL otherwise.
AsyncTaskCollection find_tasks(std::string const &name) const
Returns the list of tasks found with the indicated name.
AsyncTaskCollection find_tasks_matching(GlobPattern const &pattern) const
Returns the list of tasks found whose name matches the indicated glob pattern, e.g. “my_task_*”.
AsyncTaskCollection get_active_tasks(void) const
Returns the set of tasks that are active (and not sleeping) on the task manager, at the time of the call.
double get_next_wake_time(void) const
Returns the scheduled time (on the manager’s clock) of the next sleeping task, on any task chain, to awaken. Returns -1 if there are no sleeping tasks.
int get_num_task_chains(void) const
Returns the number of different task chains.
std::size_t get_num_tasks(void) const
Returns the number of tasks that are currently active or sleeping within the task manager.
AsyncTaskCollection get_sleeping_tasks(void) const
Returns the set of tasks that are sleeping (and not active) on the task manager, at the time of the call.
AsyncTaskCollection get_tasks(void) const
Returns the set of tasks that are active or sleeping on the task manager, at the time of the call.
bool has_task(AsyncTask *task) const
Returns true if the indicated task has been added to this
AsyncTaskManager, false otherwise.
AsyncTaskChain *make_task_chain(std::string const &name)
virtual void output(std::ostream &out) const
Runs through all the tasks in the task list, once, if the task manager is running in single-threaded mode (no threads available). This method does nothing in threaded mode, so it may safely be called in either case.
std::size_t remove(AsyncTaskCollection const &tasks)
Removes the indicated task from the active queue. Returns true if the task is successfully removed, or false if it wasn’t there.
Removes all of the tasks in the
AsyncTaskCollection. Returns the number of tasks removed.
bool remove_task_chain(std::string const &name)
AsyncTaskChainof the indicated name. If the chain still has tasks, this will block until all tasks are finished.
Returns true if successful, or false if the chain did not exist.
void set_clock(ClockObject *clock)
Replaces the clock pointer used within the
AsyncTaskManager. This is used to control when tasks with a set_delay() specified will be scheduled. It can also be ticked automatically each epoch, if set_tick_clock() is true.
The default is the global clock pointer.
Starts any requested threads to service the tasks on the queue. This is normally not necessary, since adding a task will start the threads automatically.
Blocks until the task list is empty.
virtual void write(std::ostream &out, int indent_level = 0) const
- explicit AsyncTaskManager(std::string const &name)