Added simple dispatcher task for executing func after specified period.

src/main/fc/fc_dispatch.c

@@ -0,0 +1,81 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Cleanflight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+#include <platform.h>
+
+#include "drivers/system.h"
+#include "fc/fc_dispatch.h"
+
+#define DISPATCH_QUEUE_SIZE     5
+
+typedef struct {
+    dispatchFuncPtr ptr;
+    uint32_t delayedUntil;
+} dispatchItem_t;
+
+static dispatchItem_t queue[DISPATCH_QUEUE_SIZE];
+static int next = 0;
+
+static void dispatchRemove(int index)
+{
+    if (index == (DISPATCH_QUEUE_SIZE-1)) {
+        queue[index].ptr = NULL;
+        next = index;
+        return;
+    }
+
+    for (int i = index; i < DISPATCH_QUEUE_SIZE-1; i++) {
+        queue[i].ptr = queue[i+1].ptr;
+
+        if (queue[i].ptr == NULL) {
+            next = i;
+            break;
+        }
+        queue[i].delayedUntil = queue[i+1].delayedUntil;
+    }
+}
+
+void dispatchProcess(void)
+{
+    if (queue[0].ptr == NULL) {
+        return;
+    }
+
+    for (int i = 0; i < DISPATCH_QUEUE_SIZE; i++) {
+        if (queue[i].ptr == NULL) {
+            break;
+        }
+        if (queue[i].delayedUntil < micros()) {
+            (*queue[i].ptr)();
+            queue[i].ptr = NULL;
+            dispatchRemove(i);
+        }
+    }
+}
+
+void dispatchAdd(dispatchFuncPtr ptr, uint32_t delayUs)
+{
+    if (next < DISPATCH_QUEUE_SIZE) {
+        queue[next].ptr = ptr;
+        queue[next].delayedUntil = micros() + delayUs;
+        next++;
+    }
+}