Add sdevent C++ wrappers
Add C++ wrappers around select sd-event APIs, for a more C++ like
programming API.
Includes support for core sd_event and timer related sd_event_source
APIs.
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
Change-Id: I10ac5406c9f8831b4efb294d3aef36026469d4a5
diff --git a/src/sdevent/event.hpp b/src/sdevent/event.hpp
new file mode 100644
index 0000000..5462202
--- /dev/null
+++ b/src/sdevent/event.hpp
@@ -0,0 +1,140 @@
+#pragma once
+
+#include <chrono>
+#include <memory>
+#include <sdbusplus/bus.hpp>
+#include <systemd/sd-event.h>
+
+// TODO: openbmc/openbmc#1720 - add error handling for sd_event API failures
+
+namespace sdevent
+{
+namespace event
+{
+namespace timer
+{
+class Timer;
+} // namespace timer
+}
+namespace event
+{
+
+using EventPtr = sd_event*;
+class Event;
+
+/** @brief Get an instance of the 'default' event. */
+Event newDefault();
+
+namespace details
+{
+
+/** @brief unique_ptr functor to release an event reference. */
+struct EventDeleter
+{
+ void operator()(sd_event* ptr) const
+ {
+ deleter(ptr);
+ }
+
+ decltype(&sd_event_unref) deleter = sd_event_unref;
+};
+
+/* @brief Alias 'event' to a unique_ptr type for auto-release. */
+using Event = std::unique_ptr<sd_event, EventDeleter>;
+
+} // namespace details
+
+/** @class Event
+ * @brief Provides C++ bindings to the sd_event_* class functions.
+ */
+class Event
+{
+ public:
+ /* Define all of the basic class operations:
+ * Not allowed:
+ * - Default constructor to avoid nullptrs.
+ * - Copy operations due to internal unique_ptr.
+ * Allowed:
+ * - Move operations.
+ * - Destructor.
+ */
+ Event() = delete;
+ Event(const Event&) = delete;
+ Event& operator=(const Event&) = delete;
+ Event(Event&&) = default;
+ Event& operator=(Event&&) = default;
+ ~Event() = default;
+
+ /** @brief Conversion constructor from 'EventPtr'.
+ *
+ * Increments ref-count of the event-pointer and releases it when
+ * done.
+ */
+ explicit Event(EventPtr e);
+
+ /** @brief Constructor for 'Event'.
+ *
+ * Takes ownership of the event-pointer and releases it when done.
+ */
+ Event(EventPtr e, std::false_type);
+
+ /** @brief Release ownership of the stored event-pointer. */
+ EventPtr release()
+ {
+ return evt.release();
+ }
+
+ /** @brief Wait indefinitely for new event sources. */
+ void loop()
+ {
+ sd_event_loop(evt.get());
+ }
+
+ /** @brief Attach to a DBus loop. */
+ void attach(sdbusplus::bus::bus& bus)
+ {
+ bus.attach_event(evt.get(), SD_EVENT_PRIORITY_NORMAL);
+ }
+
+ /** @brief C++ wrapper for sd_event_now. */
+ auto now()
+ {
+ using namespace std::chrono;
+
+ uint64_t usec;
+ sd_event_now(evt.get(), CLOCK_MONOTONIC, &usec);
+ microseconds d(usec);
+ return steady_clock::time_point(d);
+ }
+
+ friend class timer::Timer;
+
+ private:
+
+ EventPtr get()
+ {
+ return evt.get();
+ }
+
+ details::Event evt;
+};
+
+inline Event::Event(EventPtr l) : evt(sd_event_ref(l))
+{
+
+}
+
+inline Event::Event(EventPtr l, std::false_type) : evt(l)
+{
+
+}
+
+inline Event newDefault()
+{
+ sd_event* e = nullptr;
+ sd_event_default(&e);
+ return Event(e, std::false_type());
+}
+
+} // namespace event
+} // namespace sdevent