async: add client-object proxy
Add a class which acts as a client-side proxy to a object. The
proxy holds the object address (service, path, interface) and
creates Senders for standard dbus operations: method-call,
get-property, set-property, get-all-properties. These Senders
can also be used in co-routine contexts (via co_await).
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I4b2e50a8b55d10975984ac4244bb075db8746fbf
diff --git a/example/coroutine-example.cpp b/example/coroutine-example.cpp
new file mode 100644
index 0000000..8cfa0f4
--- /dev/null
+++ b/example/coroutine-example.cpp
@@ -0,0 +1,81 @@
+#include <sdbusplus/async.hpp>
+
+#include <iostream>
+#include <string>
+#include <variant>
+#include <vector>
+
+auto runner(sdbusplus::async::context& ctx) -> sdbusplus::async::task<>
+{
+ // Create a proxy to the systemd manager object.
+ constexpr auto systemd = sdbusplus::async::proxy()
+ .service("org.freedesktop.systemd1")
+ .path("/org/freedesktop/systemd1")
+ .interface("org.freedesktop.systemd1.Manager");
+
+ // Call ListUnitFiles method.
+ using ret_type = std::vector<std::tuple<std::string, std::string>>;
+ for (auto& [file, status] :
+ co_await systemd.call<ret_type>(ctx, "ListUnitFiles"))
+ {
+ std::cout << file << " " << status << std::endl;
+ }
+
+ // Get the Architecture property.
+ std::cout << co_await systemd.get_property<std::string>(ctx, "Architecture")
+ << std::endl;
+
+ // Get all the properties.
+ using variant_type =
+ std::variant<bool, std::string, std::vector<std::string>, uint64_t,
+ int32_t, uint32_t, double>;
+ for (auto& [property, value] :
+ co_await systemd.get_all_properties<variant_type>(ctx))
+ {
+ std::cout
+ << property << " is "
+ << std::visit(
+ // Convert the variant member to a string for printing.
+ [](auto v) {
+ if constexpr (std::is_same_v<
+ std::remove_cvref_t<decltype(v)>,
+ std::vector<std::string>>)
+ {
+ return std::string{"Array"};
+ }
+ else if constexpr (std::is_same_v<
+ std::remove_cvref_t<decltype(v)>,
+ std::string>)
+ {
+ return v;
+ }
+ else
+ {
+ return std::to_string(v);
+ }
+ },
+ value)
+ << std::endl;
+ }
+
+ // Try to set the Architecture property (which won't work).
+ try
+ {
+ co_await systemd.set_property(ctx, "Architecture", "arm64");
+ }
+ catch (const std::exception& e)
+ {
+ std::cout << "Caught exception because you cannot set Architecture: "
+ << e.what() << std::endl;
+ }
+
+ co_return;
+}
+
+int main()
+{
+ sdbusplus::async::context ctx;
+ ctx.run(runner(ctx));
+
+ return 0;
+}
diff --git a/example/meson.build b/example/meson.build
index 17fd569..1850596 100644
--- a/example/meson.build
+++ b/example/meson.build
@@ -33,6 +33,12 @@
)
executable(
+ 'coroutine-example',
+ 'coroutine-example.cpp',
+ dependencies: [ sdbusplus_dep ],
+)
+
+executable(
'register-property',
'register-property.cpp',
dependencies: asio_dep,