#include "pico/cyw43_arch.h"
#include "pico/stdlib.h"
+#include "pico/util/pheap.h"
#include "pico/util/queue.h"
#include "blink.h"
#include "config.h"
#include "net.h"
+typedef struct {
+ uint32_t timestamp;
+ u16_t seq;
+ u8_t send_count;
+} send_t;
+
+uint32_t next_send(send_t *s) {
+ return s->timestamp + (1 << s->send_count) - 1;
+}
+
+bool next_send_less_than(void *user_data, pheap_node_id_t a,
+ pheap_node_id_t b) {
+ send_t *sends = (send_t *)user_data;
+ return next_send(&sends[a]) < next_send(&sends[b]);
+}
+
+enum event_type { BUTTONPRESS, SEND };
+typedef struct {
+ enum event_type type;
+ union {
+ struct {
+ uint32_t timestamp;
+ } buttonpress;
+ };
+} event_t;
+
queue_t queue;
uint32_t time_s() { return time_us_64() / 1000000ul; }
+/* Often we don't bother checking for failure (full queue) because
+ * 1. The best thing to do in this unfortunate situation is to blithely
+ * continue, dropping some events; continuing is better than stopping.
+ * 2. Neither interrupt context nor queue-processing context can block
+ * until space is available, or even sit around & blink the LED to
+ * signal a problem.
+ * (We also get a bit of type safety by taking event_t* rather than void*.) */
+static void queue_try_add_ignoring_errors(queue_t *q, event_t *e) {
+ queue_try_add(q, e);
+}
+
static void button_pressed() {
/* This runs in interrupt context; don't linger. */
static uint64_t last_button_press_time = 0;
uint32_t now = time_s();
uint32_t time_since_last_press = now - last_button_press_time;
- if (time_since_last_press >= minimum_seconds_between_button_presses) {
+ if (time_since_last_press >= config_minimum_seconds_between_button_presses) {
last_button_press_time = now;
- /* We don't check for failure (full queue) here because there's not much to
- * be done about it. */
- queue_try_add(&queue, &now);
+ event_t e;
+ e.type = BUTTONPRESS;
+ e.buttonpress.timestamp = now;
+ queue_try_add_ignoring_errors(&queue, &e);
+ }
+}
+
+static void time_to_send(uint _) {
+ /* This runs in interrupt context; don't linger. */
+ event_t e;
+ e.type = SEND;
+ queue_try_add_ignoring_errors(&queue, &e);
+}
+
+void service_sleeps(int alarm, send_t *sleeping_sends, pheap_t *sleeps_heap) {
+ hardware_alarm_cancel(alarm);
+
+ while (1) {
+ uint32_t now = time_s();
+ pheap_node_id_t i = ph_peek_head(sleeps_heap);
+ if (i == 0)
+ return;
+ send_t *send = &sleeping_sends[i];
+ if (next_send(send) > now) {
+ uint32_t sleep_duration = next_send(send) - now;
+ if (hardware_alarm_set_target(
+ alarm, make_timeout_time_ms(sleep_duration * 1000)))
+ signal_error_by_blinking();
+ return;
+ }
+ if (ph_remove_head(sleeps_heap, false) != i)
+ signal_error_by_blinking();
+ uint32_t ago = now - send->timestamp;
+ send_report(send->seq, ago);
+ send->send_count++;
+ if (send->send_count < config_resend_count)
+ ph_insert_node(sleeps_heap, i);
+ else
+ ph_free_node(sleeps_heap, i);
+ }
+}
+
+void service_queue() {
+ int alarm = hardware_alarm_claim_unused(true);
+ if (alarm == -1)
+ signal_error_by_blinking();
+ hardware_alarm_set_callback(alarm, time_to_send);
+
+ send_t sleeping_sends[PICO_PHEAP_MAX_ENTRIES];
+ pheap_t *sleeps_heap =
+ ph_create(PICO_PHEAP_MAX_ENTRIES, next_send_less_than, sleeping_sends);
+ u16_t seq = 0;
+ while (1) {
+ service_sleeps(alarm, sleeping_sends, sleeps_heap);
+
+ event_t e;
+ queue_remove_blocking(&queue, &e);
+ switch (e.type) {
+ case BUTTONPRESS: {
+ pheap_node_id_t i = ph_new_node(sleeps_heap);
+ if (i == 0) {
+ /* TODO: Don't drop new presses just because sleeps_heap is full of old
+ * presses. */
+ break;
+ }
+ sleeping_sends[i].timestamp = e.buttonpress.timestamp;
+ sleeping_sends[i].seq = seq++;
+ sleeping_sends[i].send_count = 0;
+ ph_insert_node(sleeps_heap, i);
+ } break;
+ case SEND: {
+ /* OK, we're awake. Cool. Thanks! (We actually do the sends in the
+ * service_sleeps() call at the top of the loop.) */
+ } break;
+ default:
+ signal_error_by_blinking();
+ }
}
}
signal_error_by_blinking();
cyw43_arch_enable_sta_mode();
signal(3, 100);
- if (cyw43_arch_wifi_connect_timeout_ms(wifi_ssid, wifi_pass,
+ if (cyw43_arch_wifi_connect_timeout_ms(config_wifi_ssid, config_wifi_pass,
CYW43_AUTH_WPA2_AES_PSK, 90000))
signal_error_by_blinking();
signal(2, 300);
- queue_init(&queue, sizeof(uint32_t), 99);
+ queue_init(&queue, sizeof(event_t), 99);
begin_listening_for_button_press(button_pressed);
- u16_t seq = 0;
- while (1) {
- uint32_t t;
- queue_remove_blocking(&queue, &t);
- seq++;
- for (int i = 0; i < resend_count; i++) {
- uint32_t now = time_s();
- uint32_t ago = now - t;
- send_report(seq, ago);
- signal(i == 0 ? 2 : 1, 100);
- sleep_ms(resend_interval_ms);
- }
- }
+ service_queue();
}
projects / tattlekey / blobdiff