Christopher Haster / events

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

Dependents:   SimpleHTTPExample

This repository has been superceded

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@16:ff5d48fcce1b, 2016-04-18 (annotated)

Committer:
Christopher Haster
Date:
Mon Apr 18 09:47:21 2016 -0500
Revision:
16:ff5d48fcce1b
Parent:
15:92d7c0b8a0f5
Child:
17:6d564266850e
Make rtos requirement



Move to yield over wfi

Remove problematic timeout logic as optimization

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Christopher Haster 0:b1b901ae3696 1 /* EventQueue
Christopher Haster 0:b1b901ae3696 2 *
Christopher Haster 0:b1b901ae3696 3 * Flexible queue for managing events
Christopher Haster 0:b1b901ae3696 4 */
Christopher Haster 0:b1b901ae3696 5 #ifndef EVENT_QUEUE_H
Christopher Haster 0:b1b901ae3696 6 #define EVENT_QUEUE_H
Christopher Haster 0:b1b901ae3696 7
Christopher Haster 10:62767e708bb6 8 #include "Timer.h"
Christopher Haster 10:62767e708bb6 9 #include "Ticker.h"
Christopher Haster 14:5abf2ccf2dbf 10 #include "FuncPtr.h"
Christopher Haster 14:5abf2ccf2dbf 11 #include "Binder.h"
Christopher Haster 2:11cda6bead99 12
Christopher Haster 0:b1b901ae3696 13
Christopher Haster 0:b1b901ae3696 14 /** Flexible queue for managing events
Christopher Haster 0:b1b901ae3696 15 */
Christopher Haster 0:b1b901ae3696 16 class EventQueue {
Christopher Haster 0:b1b901ae3696 17 public:
Christopher Haster 2:11cda6bead99 18 /** Create an event queue
Christopher Haster 14:5abf2ccf2dbf 19 * @param event_count Number of events to allow enqueueing at once
Christopher Haster 14:5abf2ccf2dbf 20 * @param event_context Max size of arguments passed with an event
Christopher Haster 2:11cda6bead99 21 */
Christopher Haster 14:5abf2ccf2dbf 22 EventQueue(unsigned event_count=32,
Christopher Haster 14:5abf2ccf2dbf 23 unsigned event_context=0);
Christopher Haster 16:ff5d48fcce1b 24
Christopher Haster 16:ff5d48fcce1b 25 /** Clean up event queue
Christopher Haster 16:ff5d48fcce1b 26 */
Christopher Haster 16:ff5d48fcce1b 27 ~EventQueue();
Christopher Haster 2:11cda6bead99 28
Christopher Haster 0:b1b901ae3696 29 /** Dispatch pending events
Christopher Haster 1:2202c19570e5 30 * @param ms Time to wait for events in milliseconds,
Christopher Haster 0:b1b901ae3696 31 * 0 indicates to return immediately if no events are pending
Christopher Haster 0:b1b901ae3696 32 */
Christopher Haster 1:2202c19570e5 33 void dispatch(int ms=-1);
Christopher Haster 0:b1b901ae3696 34
Christopher Haster 2:11cda6bead99 35 /** Get current tick of the event queue
Christopher Haster 2:11cda6bead99 36 * @return Number of milliseconds since the queue was instantiated,
Christopher Haster 2:11cda6bead99 37 * this count intentionally overflows to 0 after 2^32-1
Christopher Haster 2:11cda6bead99 38 */
Christopher Haster 2:11cda6bead99 39 unsigned get_tick();
Christopher Haster 2:11cda6bead99 40
Christopher Haster 16:ff5d48fcce1b 41 /** Determine if tick has been passed
Christopher Haster 16:ff5d48fcce1b 42 * @param Tick to check
Christopher Haster 16:ff5d48fcce1b 43 * @param True if tick has been passed
Christopher Haster 16:ff5d48fcce1b 44 */
Christopher Haster 16:ff5d48fcce1b 45 bool past_tick(unsigned tick);
Christopher Haster 16:ff5d48fcce1b 46
Christopher Haster 0:b1b901ae3696 47 private:
Christopher Haster 0:b1b901ae3696 48 struct event {
Christopher Haster 1:2202c19570e5 49 struct event *volatile next;
Christopher Haster 2:11cda6bead99 50 unsigned target;
Christopher Haster 2:11cda6bead99 51 int period;
Christopher Haster 2:11cda6bead99 52
Christopher Haster 14:5abf2ccf2dbf 53 void (*dispatch)(void *p);
Christopher Haster 14:5abf2ccf2dbf 54 // data follows
Christopher Haster 0:b1b901ae3696 55 };
Christopher Haster 0:b1b901ae3696 56
Christopher Haster 14:5abf2ccf2dbf 57 struct event *alloc(unsigned size, int ms=-1);
Christopher Haster 14:5abf2ccf2dbf 58 void dealloc(struct event *);
Christopher Haster 14:5abf2ccf2dbf 59
Christopher Haster 14:5abf2ccf2dbf 60 void trigger(struct event *e, int delay);
Christopher Haster 14:5abf2ccf2dbf 61
Christopher Haster 14:5abf2ccf2dbf 62 template <typename F>
Christopher Haster 14:5abf2ccf2dbf 63 bool trigger(F func, int delay, int period, int tolerance, int ms=-1) {
Christopher Haster 14:5abf2ccf2dbf 64 struct event *e = alloc(sizeof(F), ms);
Christopher Haster 14:5abf2ccf2dbf 65 if (!e) {
Christopher Haster 14:5abf2ccf2dbf 66 return false;
Christopher Haster 14:5abf2ccf2dbf 67 }
Christopher Haster 14:5abf2ccf2dbf 68
Christopher Haster 14:5abf2ccf2dbf 69 e->period = period;
Christopher Haster 14:5abf2ccf2dbf 70 (void)tolerance; // unused
Christopher Haster 14:5abf2ccf2dbf 71 e->dispatch = &F::thunk;
Christopher Haster 14:5abf2ccf2dbf 72 *reinterpret_cast<F*>(e+1) = func;
Christopher Haster 14:5abf2ccf2dbf 73
Christopher Haster 14:5abf2ccf2dbf 74 trigger(e, delay);
Christopher Haster 14:5abf2ccf2dbf 75 return true;
Christopher Haster 14:5abf2ccf2dbf 76 }
Christopher Haster 0:b1b901ae3696 77
Christopher Haster 2:11cda6bead99 78 void tick();
Christopher Haster 2:11cda6bead99 79
Christopher Haster 14:5abf2ccf2dbf 80 unsigned _event_context;
Christopher Haster 16:ff5d48fcce1b 81 void *_mem;
Christopher Haster 16:ff5d48fcce1b 82 struct event *volatile _free;
Christopher Haster 2:11cda6bead99 83 struct event *volatile _queue;
Christopher Haster 14:5abf2ccf2dbf 84
Christopher Haster 2:11cda6bead99 85 unsigned _tick;
Christopher Haster 2:11cda6bead99 86 mbed::Ticker _ticker;
Christopher Haster 2:11cda6bead99 87 mbed::Timer _timer;
Christopher Haster 2:11cda6bead99 88
Christopher Haster 0:b1b901ae3696 89 template <typename F>
Christopher Haster 0:b1b901ae3696 90 friend class Event;
Christopher Haster 0:b1b901ae3696 91 };
Christopher Haster 0:b1b901ae3696 92
Christopher Haster 0:b1b901ae3696 93
Christopher Haster 0:b1b901ae3696 94 #endif