Add the timer class
Usage would be instantiate the timer with the call back
and start the timer with the time.
callback will be called once the timer expires.
Change-Id: I09394264ba18bd90a1c101fc77bc45f7268c5db0
Signed-off-by: Ratan Gupta <ratagupt@in.ibm.com>
diff --git a/timer.hpp b/timer.hpp
new file mode 100644
index 0000000..408ded4
--- /dev/null
+++ b/timer.hpp
@@ -0,0 +1,99 @@
+#pragma once
+
+#include <chrono>
+#include <functional>
+#include <systemd/sd-event.h>
+
+namespace phosphor
+{
+namespace network
+{
+
+/** @class Timer
+ * @brief Usage would be,instantiate the timer with the call back
+ * and start the timer for the given time.
+ */
+class Timer
+{
+ public:
+ /** @brief Only need the default Timer */
+ Timer() = delete;
+ Timer(const Timer&) = delete;
+ Timer& operator=(const Timer&) = delete;
+ Timer(Timer&&) = delete;
+ Timer& operator=(Timer&&) = delete;
+
+ /** @brief Constructs timer object
+ *
+ * @param[in] funcCallBack - optional function callback for timer
+ * expirations
+ */
+ Timer(std::function<void()> userCallBack = nullptr):
+ userCallBack(userCallBack)
+ {
+ // Initialize the timer
+ initialize();
+ }
+
+ ~Timer()
+ {
+ if (eventSource)
+ {
+ eventSource = sd_event_source_unref(eventSource);
+ }
+ if(timeEvent)
+ {
+ timeEvent = sd_event_unref(timeEvent);
+ }
+ }
+
+ inline auto isExpired() const
+ {
+ return expired;
+ }
+
+ /** @brief Starts the timer with specified expiration value.
+ * input is an offset from the current steady_clock
+ */
+ int startTimer(std::chrono::microseconds usec);
+
+ /** @brief Enables / disables the timer */
+ int setTimer(int action);
+
+ private:
+ /** @brief the sd_event structure */
+ sd_event* timeEvent = nullptr;
+
+ /** @brief Source of events */
+ sd_event_source* eventSource = nullptr;
+
+ bool expired = true;
+
+ /** @brief Initializes the timer object with infinite
+ * expiration time and sets up the callback handler
+ *
+ * @return None.
+ *
+ * @error std::runtime exception thrown
+ */
+ void initialize();
+
+ /** @brief Callback function when timer goes off
+ *
+ * @param[in] eventSource - Source of the event
+ * @param[in] usec - time in micro seconds
+ * @param[in] userData - User data pointer
+ *
+ */
+ static int timeoutHandler(sd_event_source* eventSource,
+ uint64_t usec, void* userData);
+
+ /** @brief Gets the current time from steady clock */
+ static std::chrono::microseconds getTime();
+
+ /** @brief Optional function to call on timer expiration */
+ std::function<void()> userCallBack;
+};
+
+} // namespace network
+} // namespace phosphor