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This repository has been superceded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.cpp@15:92d7c0b8a0f5, 2016-05-10 (annotated)

Committer:
Christopher Haster
Date:
Tue May 10 09:23:27 2016 -0500
Revision:
15:92d7c0b8a0f5
Parent:
14:5abf2ccf2dbf
Child:
16:ff5d48fcce1b
Abstracted out irq primitives

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Christopher Haster 2:11cda6bead99 1 #include "EventQueue.h"
Christopher Haster 2:11cda6bead99 2 #include "Event.h"
Christopher Haster 10:62767e708bb6 3 #include "mbed.h"
Christopher Haster 0:b1b901ae3696 4
Christopher Haster 9:2b0910397844 5 #ifndef EVENTS_NO_RTOS
Christopher Haster 9:2b0910397844 6 #include "rtos.h"
Christopher Haster 9:2b0910397844 7 #endif
Christopher Haster 9:2b0910397844 8
Christopher Haster 0:b1b901ae3696 9
Christopher Haster 15:92d7c0b8a0f5 10 // Platform specific definitions
Christopher Haster 15:92d7c0b8a0f5 11 static inline unsigned irq_disable() {
Christopher Haster 15:92d7c0b8a0f5 12 unsigned primask = __get_PRIMASK();
Christopher Haster 15:92d7c0b8a0f5 13 __disable_irq();
Christopher Haster 15:92d7c0b8a0f5 14 return primask;
Christopher Haster 15:92d7c0b8a0f5 15 }
Christopher Haster 14:5abf2ccf2dbf 16
Christopher Haster 15:92d7c0b8a0f5 17 static inline void irq_enable(unsigned primask) {
Christopher Haster 15:92d7c0b8a0f5 18 __set_PRIMASK(primask);
Christopher Haster 15:92d7c0b8a0f5 19 }
Christopher Haster 15:92d7c0b8a0f5 20
Christopher Haster 15:92d7c0b8a0f5 21 static inline void irq_wfi() {
Christopher Haster 15:92d7c0b8a0f5 22 #ifndef EVENTS_NO_RTOS
Christopher Haster 15:92d7c0b8a0f5 23 Thread::yield();
Christopher Haster 15:92d7c0b8a0f5 24 #else
Christopher Haster 15:92d7c0b8a0f5 25 __WFI();
Christopher Haster 15:92d7c0b8a0f5 26 #endif
Christopher Haster 15:92d7c0b8a0f5 27 }
Christopher Haster 15:92d7c0b8a0f5 28
Christopher Haster 15:92d7c0b8a0f5 29
Christopher Haster 15:92d7c0b8a0f5 30 // Event queue definitions
Christopher Haster 14:5abf2ccf2dbf 31 EventQueue::EventQueue(unsigned event_count, unsigned event_context) {
Christopher Haster 14:5abf2ccf2dbf 32 _event_context = sizeof(FuncPtr<void()>) + event_context;
Christopher Haster 14:5abf2ccf2dbf 33 unsigned event_size = sizeof(struct event) + _event_context;
Christopher Haster 14:5abf2ccf2dbf 34 _mem = malloc(event_count * event_size);
Christopher Haster 14:5abf2ccf2dbf 35 _free = (struct event*)_mem;
Christopher Haster 14:5abf2ccf2dbf 36
Christopher Haster 14:5abf2ccf2dbf 37 if (_mem) {
Christopher Haster 14:5abf2ccf2dbf 38 for (unsigned i = 0; i < event_count-1; i++) {
Christopher Haster 14:5abf2ccf2dbf 39 ((struct event*)((char*)_mem + i*event_size))->next =
Christopher Haster 14:5abf2ccf2dbf 40 (struct event*)((char*)_mem + (i+1)*event_size);
Christopher Haster 14:5abf2ccf2dbf 41 }
Christopher Haster 14:5abf2ccf2dbf 42 ((struct event*)((char*)_mem + (event_count-1)*event_size))->next = 0;
Christopher Haster 14:5abf2ccf2dbf 43 }
Christopher Haster 14:5abf2ccf2dbf 44
Christopher Haster 5:9963a617f952 45 _queue = 0;
Christopher Haster 2:11cda6bead99 46 _tick = 0;
Christopher Haster 2:11cda6bead99 47 _timer.start();
Christopher Haster 2:11cda6bead99 48 _ticker.attach_us(this, &EventQueue::tick, (1 << 16) * 1000);
Christopher Haster 2:11cda6bead99 49 }
Christopher Haster 2:11cda6bead99 50
Christopher Haster 14:5abf2ccf2dbf 51 EventQueue::~EventQueue() {
Christopher Haster 14:5abf2ccf2dbf 52 free(_mem);
Christopher Haster 14:5abf2ccf2dbf 53 }
Christopher Haster 14:5abf2ccf2dbf 54
Christopher Haster 2:11cda6bead99 55 unsigned EventQueue::get_tick() {
Christopher Haster 2:11cda6bead99 56 return _tick + (unsigned)_timer.read_ms();
Christopher Haster 2:11cda6bead99 57 }
Christopher Haster 2:11cda6bead99 58
Christopher Haster 2:11cda6bead99 59 void EventQueue::tick() {
Christopher Haster 2:11cda6bead99 60 _timer.reset();
Christopher Haster 2:11cda6bead99 61 _tick += 1 << 16;
Christopher Haster 2:11cda6bead99 62 }
Christopher Haster 2:11cda6bead99 63
Christopher Haster 2:11cda6bead99 64 void EventQueue::wakeup() {
Christopher Haster 2:11cda6bead99 65
Christopher Haster 2:11cda6bead99 66 }
Christopher Haster 0:b1b901ae3696 67
Christopher Haster 15:92d7c0b8a0f5 68 void EventQueue::exit(volatile bool *exit) {
Christopher Haster 15:92d7c0b8a0f5 69 *exit = true;
Christopher Haster 15:92d7c0b8a0f5 70 }
Christopher Haster 15:92d7c0b8a0f5 71
Christopher Haster 1:2202c19570e5 72 void EventQueue::dispatch(int ms) {
Christopher Haster 10:62767e708bb6 73 Timeout timeout;
Christopher Haster 15:92d7c0b8a0f5 74 volatile bool exit = false;
Christopher Haster 2:11cda6bead99 75
Christopher Haster 2:11cda6bead99 76 if (ms >= 0) {
Christopher Haster 15:92d7c0b8a0f5 77 Event<void(volatile bool*)> e(this, this, &EventQueue::exit);
Christopher Haster 15:92d7c0b8a0f5 78 e.delay(ms);
Christopher Haster 15:92d7c0b8a0f5 79 e.trigger(&exit);
Christopher Haster 2:11cda6bead99 80 }
Christopher Haster 0:b1b901ae3696 81
Christopher Haster 0:b1b901ae3696 82 while (true) {
Christopher Haster 0:b1b901ae3696 83 while (_queue) {
Christopher Haster 2:11cda6bead99 84 int diff = (int)(_queue->target - get_tick());
Christopher Haster 2:11cda6bead99 85 if (diff > 0) {
Christopher Haster 2:11cda6bead99 86 timeout.attach_us(this, &EventQueue::wakeup, diff * 1000);
Christopher Haster 2:11cda6bead99 87 break;
Christopher Haster 2:11cda6bead99 88 }
Christopher Haster 2:11cda6bead99 89
Christopher Haster 2:11cda6bead99 90 struct event *volatile e = _queue;
Christopher Haster 0:b1b901ae3696 91 _queue = _queue->next;
Christopher Haster 2:11cda6bead99 92
Christopher Haster 14:5abf2ccf2dbf 93 e->dispatch(reinterpret_cast<void *>(e + 1));
Christopher Haster 2:11cda6bead99 94
Christopher Haster 2:11cda6bead99 95 if (e->period >= 0) {
Christopher Haster 14:5abf2ccf2dbf 96 trigger(e, e->period);
Christopher Haster 14:5abf2ccf2dbf 97 } else {
Christopher Haster 14:5abf2ccf2dbf 98 dealloc(e);
Christopher Haster 2:11cda6bead99 99 }
Christopher Haster 0:b1b901ae3696 100 }
Christopher Haster 0:b1b901ae3696 101
Christopher Haster 15:92d7c0b8a0f5 102 if (exit) {
Christopher Haster 15:92d7c0b8a0f5 103 break;
Christopher Haster 15:92d7c0b8a0f5 104 }
Christopher Haster 15:92d7c0b8a0f5 105
Christopher Haster 15:92d7c0b8a0f5 106 irq_wfi();
Christopher Haster 0:b1b901ae3696 107 }
Christopher Haster 0:b1b901ae3696 108 }
Christopher Haster 0:b1b901ae3696 109
Christopher Haster 14:5abf2ccf2dbf 110 void EventQueue::trigger(struct event *e, int delay) {
Christopher Haster 14:5abf2ccf2dbf 111 e->target = get_tick() + (unsigned)delay;
Christopher Haster 2:11cda6bead99 112
Christopher Haster 15:92d7c0b8a0f5 113 unsigned primask = irq_disable();
Christopher Haster 2:11cda6bead99 114 struct event *volatile *p = &_queue;
Christopher Haster 14:5abf2ccf2dbf 115 while (*p && (*p)->target < e->target) {
Christopher Haster 2:11cda6bead99 116 p = &(*p)->next;
Christopher Haster 0:b1b901ae3696 117 }
Christopher Haster 2:11cda6bead99 118
Christopher Haster 14:5abf2ccf2dbf 119 e->next = *p;
Christopher Haster 14:5abf2ccf2dbf 120 *p = e;
Christopher Haster 15:92d7c0b8a0f5 121 irq_enable(primask);
Christopher Haster 0:b1b901ae3696 122 }
Christopher Haster 0:b1b901ae3696 123
Christopher Haster 14:5abf2ccf2dbf 124 EventQueue::event *EventQueue::alloc(unsigned size, int ms) {
Christopher Haster 14:5abf2ccf2dbf 125 if (size > _event_context) {
Christopher Haster 14:5abf2ccf2dbf 126 return 0;
Christopher Haster 14:5abf2ccf2dbf 127 }
Christopher Haster 14:5abf2ccf2dbf 128
Christopher Haster 14:5abf2ccf2dbf 129 struct event *e;
Christopher Haster 14:5abf2ccf2dbf 130
Christopher Haster 15:92d7c0b8a0f5 131 unsigned primask = irq_disable();
Christopher Haster 14:5abf2ccf2dbf 132 e = _free;
Christopher Haster 14:5abf2ccf2dbf 133 if (e) {
Christopher Haster 14:5abf2ccf2dbf 134 _free = e->next;
Christopher Haster 0:b1b901ae3696 135 }
Christopher Haster 15:92d7c0b8a0f5 136 irq_enable(primask);
Christopher Haster 14:5abf2ccf2dbf 137
Christopher Haster 14:5abf2ccf2dbf 138 return e;
Christopher Haster 0:b1b901ae3696 139 }
Christopher Haster 0:b1b901ae3696 140
Christopher Haster 14:5abf2ccf2dbf 141 void EventQueue::dealloc(struct event *e) {
Christopher Haster 15:92d7c0b8a0f5 142 unsigned primask = irq_disable();
Christopher Haster 14:5abf2ccf2dbf 143 e->next = _free;
Christopher Haster 14:5abf2ccf2dbf 144 _free = e;
Christopher Haster 15:92d7c0b8a0f5 145 irq_enable(primask);
Christopher Haster 14:5abf2ccf2dbf 146 }
Christopher Haster 14:5abf2ccf2dbf 147