From 14b1aa5b1e45866bf8d147fdc317867ad75756be Mon Sep 17 00:00:00 2001 From: Johannes Schanda Date: Fri, 13 Sep 2013 15:38:06 +0200 Subject: Move tutorial to CommonAPI-Tools --- Tutorial | 412 --------------------------------------------------------------- 1 file changed, 412 deletions(-) delete mode 100644 Tutorial diff --git a/Tutorial b/Tutorial deleted file mode 100644 index 9a1e41f..0000000 --- a/Tutorial +++ /dev/null @@ -1,412 +0,0 @@ -GENIVI_CommonAPI -================ -:Author: Juergen Gehring - juergen.gehring@bmw.de, Manfred Bathelt - manfred.bathelt@bmw.de -:doctitle: GENIVI_CommonAPI_Tutorial - -Copyright ---------- -Copyright (C) 2013, GENIVI Alliance, Inc. -Copyright (C) 2013, BMW AG - -This file is part of GENIVI Project IPC Common API. - -Contributions are licensed to the GENIVI Alliance under one or more -Contribution License Agreements or MPL 2.0 . - -(C) Copyright -This Source Code Form is subject to the terms of the -Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with -this file, You can obtain one at http://mozilla.org/MPL/2.0/. - -For further information see https://collab.genivi.org/wiki/display/genivi/SysInfraEGCommonIDLCommon APIGuide - -== License -This project is licensed under MPL 2.0 - -Contribution is done under GENIVI CLA or MPL2.0. - -== Version -The current version can be taken from the git. - -== Common API Overview - -Common API and its mechanism specific bindings (e.g. Common API D-Bus) provide a set of libraries and tools to work with -RMI communication in a way independent of wich mechanism is used. The main intention is to ease porting your project to -new communication mechanisms and to enable testing of your application way before setting it up on the precise environment -and the communication mechanism it is meant to use. - -Common API consists of two main parts: -* The Common API runtime, which is the basic library required to enable Common API functionality. -* The Common API generator Eclipse plugin, which allows the generation of Common API proxy and stub code out of Franca IDL files. - -The application will use both the Common API runtime and the generated code to implement client and/or service. - -In order to enable communication via a specific communication mechanism, the corresponding Common API middleware library -and middleware generator plugin is required in addition. However, both the middleware specific library and the middleware -specific generated code will NEVER be seen or used by the application code. It is solely the responsibility of the basic -Common API library to enable communication by using this specific middleware library and code. - - -== Getting started with Common API - -The following subsections are meant as a step by step tutorial on how to set up Common API on your system. Additionally, -the Common API middleware library for D-Bus will be installed and an example application will be created that will -communicate via D-Bus. - -Note that you later can switch D-Bus for any other communication layer (provided it has Common API support) -_without the need to touch your code or your binary at all!_. - -Further information on Common API and Common API D-Bus is provided in the individual README files accompanying both packages. - - -=== Setting up the Environment - -==== Requirements - -First, make sure all requirements to build the CommonAPI runtime are installed and in the correct version. -CommonAPI was developed using gcc 4.6 and gcc 4.7, but is feature compatible to gcc 4.5 and compiler compatible to gcc 4.4. - - -==== Setting up Common API - -Download the Common API runtime via git from the download site of http://projects.genivi.org/commonapi/, then compile and install the library on your computer: ----- -$ git clone git://git.projects.genivi.org/ipc/common-api-runtime.git -$ cd common-api-runtime -$ autoreconf -i -$ ./configure -$ make -$ sudo make install (or alternative install process, eg. checkinstall on debian-based distributions, such as Ubuntu) ----- - -With this, the Common API runtime library will be installed in /usr/local/lib. The package is accessible for your application -e.g. via pkgconfig. The pkgconfig data is located at /usr/local/lib/pkgconfig. - - -==== Setting up Common API D-Bus - -To build Common API D-Bus, the Common API runtime and libdbus version 1.4.16 patched with the marshaling patch must be available through PkgConfig. -The marshalling patch is provided within the Common API D-Bus package. - -Download the Common API D-Bus library via git from the download site of http://projects.genivi.org/commonapi/: ----- -$ git clone git://git.projects.genivi.org/ipc/common-api-dbus-runtime.git ----- - -Download, patch and install version 1.4.16 of libdbus (*WARNING*: _Not_ following these instructions may result in corruption of the preinstalled libdbus -library of your computer, thereby rendering your system unusable): ----- -$ wget http://dbus.freedesktop.org/releases/dbus/dbus-1.4.16.tar.gz -$ tar -xzf dbus-1.4.16.tar.gz -$ cd dbus-1.4.16 -$ patch -p1 < /common-api-dbus-runtime/dbus-DBusMessage-add-support-for-custom-marshaling.patch -$ ./configure --prefix=/usr/local -$ make -C dbus -$ sudo make -C dbus install -$ sudo make install-pkgconfigDATA ----- - -The path to CommonAPI and patched libdbus pkgconfig files must be added to the PKG_CONFIG_PATH for the rest of the entire build process. -If you followed the instructions above, both will be located in _/usr/local/lib/pkgconfig_, so you can just type: ----- -$ export PKG_CONFIG_PATH="/usr/local/lib/pkgconfig:$PKG_CONFIG_PATH" ----- - -Now, compile and install the Common API D-Bus library on your computer ----- -$ cd /common-api-dbus-runtime -$ autoreconf -i -$ ./configure -$ make -$ sudo make install (or alternative install process, eg. checkinstall on debian-based distributions, such as Ubuntu) ----- - -With this, the libraries for Common API and Common API D-Bus are installed and ready for use. The next steps will provide you with the means -to efficiently design and implement your Common API applications via Eclipse. - - -==== Setting up Eclipse - -In order to generate the Common API code that will be used by your client and your service, the Common API generator plugin is -required. This plugin is an Eclipse plugin, and is provided as an Eclipse update site. For convenience, the generator plugins -for Common API and Common API D-Bus are packed together. - -First, get an appropriate Eclipse up and running. The version of the Common API generator plugin contained in this package was tested -with the Eclipse Modeling Tools package of Eclipse Juno (4.1) and Eclipse Kepler (4.2). You can get one of them from www.eclipse.org: ----- -Eclipse Juno: http://www.eclipse.org/downloads/packages/eclipse-modeling-tools/junosr1 -Eclipse Kepler: http://www.eclipse.org/downloads/packages/eclipse-modeling-tools/keplerrc3 ----- - -Because the generator plugin generates code from Franca IDL files (https://code.google.com/a/eclipselabs.org/p/franca/), -you will need to have installed the Franca IDL feature in your Eclipse. The plugin was created for Franca IDL version 0.8.9. -Franca IDL is a language to efficiently design the RMI interface of your applications, independent from specific communication -mechanisms and also independent from specific programming languages. - -Get the appropriate zipped Franca IDL update site (named site_franca_0.8.9.xxx.zip) from ----- -https://code.google.com/a/eclipselabs.org/p/franca/downloads/list ----- -Also, download the Common API D-Bus Tooling via git from the download site of http://projects.genivi.org/commonapi/: ----- -$ git clone git://git.projects.genivi.org/ipc/common-api-dbus-tools.git ----- - -Install the Franca IDL plugin and the CommonAPI generator plugins in your Eclipse: ----- -Help->Install New Software...->Add...->Archive... ----- -From Franca IDL, you will only need to install the sub-category "Franca Feature" for the Common API and Common API D-Bus generators to work. -The update site of the Common API generator plugin is located at ----- -/common-api-dbus-tools/org.genivi.commonapi.dbus.feature/org.genivi.commonapi.dbus.updatesite.zip ----- -To develop your application, you will only need the _GENIVI Common API C++ Core Generator_. However, for this tutorial to work and/or if you -intend to enable your Common API application to communicate via D-Bus, you will also need the _GENIVI Common API C++ D-Bus Generator_. - -Restart Eclipse when you are prompted to do so. Now you should be able to use the CommonAPI generators in your Eclipse. - - -=== Creating the Example - -The example that will be created in this tutorial from now onwards is provided as ready-to-use source package in ----- -/common-api-dbus-tools/CommonAPI-Examples ----- -The example found here is more verbose than the one we will create, but functionally it will be the same. - -It is assumed that you have created a C++ project in your Eclipse in which all further development will happen. - - -==== Creating the RMI interface definition - -The first step in developing a Common API application likely will be the definition of the RMI interface the client will use to communicate with -the server. In the context of CommonAPI, the definition of this interface always happens via the Franca IDL, regardless of which communication -mechanism you intend to use in the end. For this tutorial, create an arbitrarily namend file ending in _.fidl_ in your Eclipse project. It is -not relevant where in your project you have placed this file, as the the code generated from this file will always be put in the automatically -created src-gen folder at the top level of the project hierarchy. - -Open your newly created _.fidl_-file, and type the following lines: ----- -package commonapi.examples - -interface HelloWorldInterface { - version { major 1 minor 0 } - - method sayHello { - in { - String name - } - out { - String message - } - } -} ----- -Note that the _version_ parameter in every interface is mandatory! No code will be generated if it is malformed or not present! - -Now, save the _.fidl_ file and right click it. As you have installed the Common API and Common API D-Bus generators, you will see -a menu item saying _"Common API"_, with sub menu items for generating either the Common API level code only ("_Generate C++ Code_") -or for generating both the Common API level code and the glue code required to run applications with using Common API D-Bus -("_Generate D-Bus C++ Code_"). - - -==== Generating code - -We do want to use D-Bus as middleware, so we will need the D-Bus specific glue code as well as the Common API level code which we will -program agains. Therefore, you might want to chose the latter of the two options provided by the generator plugin ("_Generate D-Bus C++ Code_"). -After having done so, you will see the newly created src-gen folder and it's contents. The files will be created according to their -fully qualified names relative to src-gen as the top level folder, as defined in the _.fidl_-file: ----- -HelloWorldInterface.h -HelloWorldInterfaceProxy.h -HelloWorldInterfaceProxyBase.h -HelloWorldInterfaceStub.h -HelloWorldInterfaceStubDefault.cpp -HelloWorldInterfaceStubDefault.h - -HelloWorldInterfaceDBusProxy.cpp -HelloWorldInterfaceDBusProxy.h -HelloWorldInterfaceDBusStubAdapter.cpp -HelloWorldInterfaceDBusStubAdapter.h ----- - -All files that have a "DBus" in their name are glue code required by the D-Bus binding and are not relevant while developing your application, -they only need to be compiled with your application (there are ways to NOT compile these sources with your applications and include them at -runtime instead; see the README of Common API D-Bus for details). - -All other files that have a _Proxy_ in their name are relevant for you if you develop a client, all other files that have a _Stub_ in their name -are relevant for you if you develop a service. - -A proxy is a class that provides method calls that will result in remote method invocations on the service, plus registration methods for events -that can be broadcasted by the service. - -A stub is the part of the service that will be called when a remote method invocation from a client arrives. It also contains methods to fire -events (broadcasts) to several or all clients. The Stub comes in two flavors: One default stub that contains empty implementations of all methods, -thereby allowing you to implement only the ones you are interested in, and a Stub skeleton where you have to implement everything yourself before -you can use it. A service will have to implement a subclass of either of the two in order to make itself available to the outside world -(or just use the default stub if your service should not be able to do anything except firing events). - -In this tutorial, we will create both a client and a service in order to be able to see some communication going on. - - -==== Implement the Client - -Start by creating a new .cpp source file in your project (e.g. helloworld-proxy.cpp). Make sure you have a main method in order to start the client application. - -Here, you will need two includes in order to access the Common API client functionality: ----- -#include //Defined in the Common API Runtime library -#include //Part of the code we just generated - -#include -#include ----- - -The first thing each and every Common API application will do is to load a runtime: ----- -std::shared_ptr runtime = CommonAPI::Runtime::load(); ----- -If you link the Common API DBus library to and compile the generated DBus specific code with your executable, this runtime "magically" will be a -runtime that provides access to the DBus communication infrastructure via a strictly CommonAPI level interface. If you link the library and add -the generated code of another Common API middleware binding instead, this runtime will provide access to this other communication infrastructure. -To not interrupt this tutorial, further explanation on this mechanism is done below in a separate chapter in "Further Reading". - -In order to be able to communicate with a specific service, we need a proxy. We can create a proxy by using a factory, which in turn we can get from -the runtime we just created: ----- -std::shared_ptr factory = runtime->createFactory(); -const std::string& commonApiAddress = "local:commonapi.examples.HelloWorld:commonapi.examples.HelloWorld"; -std::shared_ptr> helloWorldProxy = factory->buildProxy(commonApiAddress); ----- -The parameter _commonApiAddress_ is the address at which the service that shall be accessed will be available. This address will be translated -internally to an actual DBus-Address - or whatever format fits the communication infrastructure you use. Semantically, this address consists of three parts, -separated by colons: -* Domain: The first part, defines in which domain the service is located. For DBus use cases, only "local" makes any sense, as no services that are more remote than - "on the same operating system" are accessible. -* ServiceID: The second part. This defines the name or type of the service that shall be accessed. -* InstanceID: The third part. This defines the specific instance of this service that shall be accessed. - -There are ways to influence the translation of the Common API address to the specific address (of course once again without the need to change your code). -Please have a look at the README of Common API DBus if you want to know more about this possibility in the context of DBus, or the corresponding documentation -of the other middleware binding you are using. - -With this, the client is set up and ready to use. We should wait for the service to be available, then we can start issuing calls: ----- -while (!helloWorldProxy->isAvailable()) { - usleep(10); -} - -const std::string name = "World"; -CommonAPI::CallStatus callStatus; -std::string helloWorldReturnMessage; - -helloWorldProxy->sayHello(name, callStatus, helloWorldReturnMessage); -if (callStatus != CommonAPI::CallStatus::SUCCESS) { - std::cerr << "Remote call failed!\n"; - return -1; -} - -std::cout << "Got message: '" << helloWorldReturnMessage << "'\n"; ----- - - -==== Implement the Service - -Works about the same way as implementing the client. The includes that are required are the following: ----- -#include -#include - -#include -#include -#include ----- - -And we also need a stub that actually does something when the method we call in the client gets called: ----- -class MyHelloWorldStub: public commonapi::examples::HelloWorldInterfaceStubDefault { - public: - virtual void sayHello(std::string name, std::string& message) { - std::stringstream messageStream; - - messageStream << "Hello " << name << "!"; - message = messageStream.str(); - - std::cout << "sayHello('" << name << "'): '" << message << "'\n"; - } -}; ----- - -The rest looks quite similar to the client side, with the difference that we do not issue calls via a proxy, but instead register a service that then -will be provided to the outside world. The service is registered using the same Common API address, which allows the proxy to actually find the service. -Afterwards, we just wait for calls: ----- -std::shared_ptr runtime = CommonAPI::Runtime::load(); -std::shared_ptr factory = runtime->createFactory(); -std::shared_ptr servicePublisher = runtime->getServicePublisher(); - -const std::string& commonApiAddress = "local:commonapi.examples.HelloWorld:commonapi.examples.HelloWorld"; -std::shared_ptr helloWorldStub = std::make_shared(); -servicePublisher->registerService(helloWorldStub, commonApiAddress, factory); - -while(true) { - std::cout << "Waiting for calls... (Abort with CTRL+C)\n"; - std::this_thread::sleep_for(std::chrono::seconds(60)); -} ----- - - -=== Running the Demo - -Build the two applications using your favourite build system. If all worked well, you should see communication ongoing via DBus (e.g. via dbus-monitor), -and you should get output from your client once, saying ----- -"Got Message: 'Hello World'". ----- - - -== Further reading - -Aside from the README files of Common API and the specific bindings. - - -=== The middleware loading mechanism of Common API - - -==== CommonAPI::Runtime::load() returns no runtime object, why? - -As it was mentioned before, when you call _CommonAPI::Runtime::load()_. -you "magically" will have access to a specific middleware library. In a very basic case, the library and thereby communication mechanism you will have access to -will be the only Common API middleware library you linked to your executable during compilation. - -However, this call to _load()_ most likely will *FAIL* if you have no generated middleware specific code that is compiled with your application. Why that? -The reason is simple, once understood: Most linkers are lazy. They do not link libraries that seem to be unused. Due to the fact that there is no reference -whatsoever from Common API (and therefore your application) to any of the middleware libraries, the linker considers any and all middleware libraries -as unused if not referenced by middleware specific generated code, and therefore will not add them to the executable. - -You can disable this behavior by passing the linker flag _whole-archive_ during the build process. Note however that this behavior _normally_ is a good optimization -without repercussions - except probably in the context of CommonAPI. - - -==== Using more than one middleware binding - -CommonAPI provides the possibility to use more than one middleware binding at once. In this case, you should no longer use _CommonAPI::Runtime::load()_, -but instead _CommonAPI::Runtime::load("NameOfSomeMiddleware")_. - -The "NameOfSomeMiddleware" is the well known name of the middleware you want to load. It is defined and made public by each of the middlewares that support -Common API. For DBus, this name is simply "DBus". - - -==== Fully dynamic loading and additional information - -This topic is handled in-depth in the README of Common API. Please refer to this file for any further information. - - -=== Online Documentation and Guides - -For an in-depth introduction to Franca IDL, please refer to the current user manual found on ----- -https://code.google.com/a/eclipselabs.org/p/franca/downloads/list ----- -At the time of writing of this tutorial, _FrancaUserGuide-0.3.0.pdf_ is the most recent version. -- cgit v1.2.1