7.0 refactor

src/timer.c

@@ -0,0 +1,44 @@
+// Copyright (c) Cesanta Software Limited
+// All rights reserved
+
+#include "timer.h"
+#include "arch.h"
+
+struct mg_timer *g_timers;
+
+void mg_timer_init(struct mg_timer *t, int ms, int flags, void (*fn)(void *),
+                   void *arg) {
+  struct mg_timer tmp = {ms, flags, fn, arg, 0UL, g_timers};
+  *t = tmp;
+  g_timers = t;
+  if (flags & MG_TIMER_RUN_NOW) fn(arg);
+}
+
+void mg_timer_free(struct mg_timer *t) {
+  struct mg_timer **head = &g_timers;
+  while (*head && *head != t) head = &(*head)->next;
+  if (*head) *head = t->next;
+}
+
+void mg_timer_poll(unsigned long now_ms) {
+  // If time goes back (wrapped around), reset timers
+  struct mg_timer *t, *tmp;
+  static unsigned long oldnow;  // Timestamp in a previous invocation
+  if (oldnow > now_ms) {        // If it is wrapped, reset timers
+    for (t = g_timers; t != NULL; t = t->next) t->expire = 0;
+  }
+  oldnow = now_ms;
+
+  for (t = g_timers; t != NULL; t = tmp) {
+    tmp = t->next;
+    if (t->expire == 0) t->expire = now_ms + t->period_ms;
+    if (t->expire > now_ms) continue;
+    t->fn(t->arg);
+    // Try to tick timers with the given period as accurate as possible,
+    // even if this polling function is called with some random period.
+    t->expire = now_ms - t->expire > (unsigned long) t->period_ms
+                    ? now_ms + t->period_ms
+                    : t->expire + t->period_ms;
+    if (!(t->flags & MG_TIMER_REPEAT)) mg_timer_free(t);
+  }
+}