[wpinet] Move network portions of wpiutil into new wpinet library (#4077)

wpinet/src/main/native/cpp/uv/Check.cpp

@@ -0,0 +1,29 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include "wpinet/uv/Check.h"
+
+#include "wpinet/uv/Loop.h"
+
+namespace wpi::uv {
+
+std::shared_ptr<Check> Check::Create(Loop& loop) {
+  auto h = std::make_shared<Check>(private_init{});
+  int err = uv_check_init(loop.GetRaw(), h->GetRaw());
+  if (err < 0) {
+    loop.ReportError(err);
+    return nullptr;
+  }
+  h->Keep();
+  return h;
+}
+
+void Check::Start() {
+  Invoke(&uv_check_start, GetRaw(), [](uv_check_t* handle) {
+    Check& h = *static_cast<Check*>(handle->data);
+    h.check();
+  });
+}
+
+}  // namespace wpi::uv