fixes

src/concurrency/Periodic.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include "PeriodicTask.h"
+
+namespace concurrency {
+
+/**
+ * @brief Periodically invoke a callback. This just provides C-style callback conventions 
+ *        rather than a virtual function - FIXME, remove?
+ */
+class Periodic : public PeriodicTask
+{
+    uint32_t (*callback)();
+
+  public:
+    // callback returns the period for the next callback invocation (or 0 if we should no longer be called)
+    Periodic(uint32_t (*_callback)()) : callback(_callback) {}
+
+  protected:
+    void doTask() {
+        uint32_t p = callback();
+        setPeriod(p);
+    }
+};
+
+} // namespace concurrency