hpx simple component docs

[mariomulansky]

add a descriptive example on how to use a simple_component. For example there: http://stellar.cct.lsu.edu/files/hpx_master/docs/html/hpx/manual/applying_actions/action_invocation/apply.html describe how to get the global address of an instance, how to create such an instance in the first place. One is completely lost at that point. A short walk-through for simple components (maybe also managed components) would be very helpful in the docs.

[hkaiser]

Have you seen this: http://stellar.cct.lsu.edu/files/hpx_master/docs/html/hpx/tutorial/examples/accumulator.html?

[mariomulansky]

Yes, but is this the simplest way of using components? In the action invocations it sounds like one just has to register a member function, while the allocator consists of server, stubs and client.

[hkaiser]

The docs need updating here and there, but essentially that's it, yes. Note that the stub/client classes are just thin wrappers around a hpx::id_type, making the calls more type safe. The plain (and simplest) way to work with components is:

hpx::id_type target_locality = hpx::find_here();
hpx::id_type acc = hpx::components::new_<accumulator_component_type>(target_locality).get();

accumulator_component_type::add_action add;
add(acc, 5);    // adds 5 to the accumulator instance referred to by acc;

[mariomulansky]

ok i got a trivial example running, based on the quickstart/component_in_executable.cpp example. In your code above I think new_ returns a future, so it should be

hpx::lcos::future<hpx::id_type> acc = hpx::components::new_<accumulator_component_type>(target_locality);

and then

add(acc.get(), 5);

It took me way more time than it should, the docs in http://stellar.cct.lsu.edu/files/hpx_master/docs/html/hpx/manual/applying_actions/action_type_definition.html are very misleading, e.g. why is there the macro HPX_COMPONENT_EXPORT that never appears in the examples? Then it even says a note on the second argument for the HPX_REGISTER_ACTION_DECLARATION, but the line below doesn't have a second argument?

[hkaiser]

Yes, I added the .get() in my example above to compensate for that.

Could you provide a patch for the docs based on your experience? You will know best what you missed and what's wrong there.

[hkaiser]

Can this be closed now?