Christopher Haster / events

Note! This project has moved to github.com/armmbed/mbed-events

Dependents:   SimpleHTTPExample

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This project has moved to mbed-events

Composable event loops combine the cheap synchronicity of event loops with the composability of preempted threads.

Two modular event queue classes are provided:

  • EventLoop - for loops coupled with a c++ managed thread
  • EventQueue - for manually managed event queues

The Event class takes advantage of the extensibility of FuncPtr to allow an event to be passed through APIs as a normal function.

More information on composable event loops.

EventQueue.h

Committer:
Christopher Haster
Date:
2016-04-20
Revision:
2:11cda6bead99
Parent:
1:2202c19570e5
Child:
10:62767e708bb6

File content as of revision 2:11cda6bead99:

/*  EventQueue
 *
 *  Flexible queue for managing events
 */
#ifndef EVENT_QUEUE_H
#define EVENT_QUEUE_H

#include "mbed.h"


/** Flexible queue for managing events
 */
class EventQueue {
public:
    /** Create an event queue
     */
    EventQueue();

    /** Dispatch pending events
     *  @param ms       Time to wait for events in milliseconds,
     *                  0 indicates to return immediately if no events are pending
     */
    void dispatch(int ms=-1);

    /** Get current tick of the event queue
     *  @return         Number of milliseconds since the queue was instantiated,
     *                  this count intentionally overflows to 0 after 2^32-1
     */
    unsigned get_tick();

private:
    struct event {
        struct event *volatile next;
        unsigned target;
        bool registered;

        int delay;
        int period;

        void (*callback)(void *);
        void *data;
    };

    void event_register(struct event *event, int ms);
    void event_unregister(struct event *event);

    void tick();
    void wakeup();

    struct event *volatile _queue;
    unsigned _tick;
    mbed::Ticker _ticker;
    mbed::Timer _timer;

    template <typename F>
    friend class Event;
};


#endif