Add sdevent io source C++ wrappers

Change-Id: Ifadee2bb8788be87e759d1f0be875f7047a2f37e
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>

1 files changed, 104 insertions, 0 deletions

diff --git a/sdevent/io.hpp b/sdevent/io.hpp
new file mode 100644
index 0000000..93625a0
--- /dev/null
+++ b/sdevent/io.hpp
@@ -0,0 +1,104 @@
+#pragma once
+
+#include <functional>
+#include <memory>
+#include <phosphor-logging/elog.hpp>
+#include <phosphor-logging/elog-errors.hpp>
+#include <systemd/sd-event.h>
+#include <xyz/openbmc_project/Common/error.hpp>
+
+#include "sdevent/source.hpp"
+#include "sdevent/event.hpp"
+
+namespace sdevent
+{
+namespace event
+{
+namespace io
+{
+
+/** @class IO
+ *  @brief Provides C++ bindings to the sd_event_source* io functions.
+ */
+class IO
+{
+    private:
+        using InternalFailure = sdbusplus::xyz::openbmc_project::Common::
+            Error::InternalFailure;
+
+    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.
+         */
+        IO() = delete;
+        IO(const IO&) = delete;
+        IO& operator=(const IO&) = delete;
+        IO(IO&&) = default;
+        IO& operator=(IO&&) = default;
+        ~IO() = default;
+
+        using Callback = std::function<void(source::Source&)>;
+
+        /** @brief Register an io callback.
+         *
+         *  @param[in] event - The event to register on.
+         *  @param[in] fd - The file descriptor to poll.
+         *  @param[in] callback - The callback method.
+         */
+        IO(
+            sdevent::event::Event& event,
+            int fd,
+            Callback callback)
+            : src(nullptr),
+              cb(std::make_unique<Callback>(std::move(callback)))
+        {
+            sd_event_source* source = nullptr;
+            auto rc = sd_event_add_io(
+                event.get(),
+                &source,
+                fd,
+                EPOLLIN,
+                callCallback,
+                cb.get());
+            if (rc < 0)
+            {
+                phosphor::logging::elog<InternalFailure>();
+            }
+
+            src = decltype(src){source, std::false_type()};
+        }
+
+        /** @brief Set the IO source enable state. */
+        void enable(int enable)
+        {
+            src.enable(enable);
+        }
+
+        /** @brief Query the IO enable state. */
+        auto enabled()
+        {
+            return src.enabled();
+        }
+
+    private:
+        source::Source src;
+        std::unique_ptr<Callback> cb = nullptr;
+
+        static int callCallback(sd_event_source* s, int fd, uint32_t events,
+                                void* context)
+        {
+            source::Source source(s);
+            auto c = static_cast<Callback*>(context);
+            (*c)(source);
+
+            return 0;
+        }
+};
+} // namespace io
+} // namespace event
+} // namespace sdevent