domains

Domains

Before proceeding, all dependencies need to be installed. You can find instructions in the C Examples Readme.

Let's assume you want to create multiple iceoryx2 groups of processes where the processes inside a group can communicate and interact with each other. However, the groups themselves should remain isolated, meaning a process from one group cannot interact with a process from another group.

In other words, we aim to create different iceoryx2 domains on a local machine that are strictly separated.

This strict separation can be achieved by using the iceoryx2 configuration. Within the configuration, a wide range of parameters can be adjusted, such as the directory used for files containing static service information (a detailed description of the service) or static node information (a detailed description of a node). Additionally, the prefix of all files, which is by default iox2_, can be modified.

In this example, we use the prefix to separate the iceoryx2 groups. For all examples, the user can set the iceoryx2 domain using -d $DOMAIN_NAME$. The domain name must be a valid file name. The example will only operate within this domain and cannot interact with any services in other domains with different names.

The domains_discovery binary illustrates this by listing all services available in a given domain. Similarly, the domains_publisher will send data only to subscribers within the same domain. Subscribers in other domains will not receive any data.

Implementation

To achieve this, we create a copy of the global configuration, modify the setting config.global.prefix using the user-provided CLI argument, and then set up the example accordingly.

Running The Example

You can experiment with this setup by creating multiple publishers and subscribers with different service names using -s $SERVICE_NAME. Only publisher-subscriber pairs within the same domain will be able to communicate, and the discovery tool will only detect services from within the same domain.

First you have to build the C++ examples:

cmake -S . -B target/ffi/build -DBUILD_EXAMPLES=ON
cmake --build target/ffi/build

Terminal 1: Subscriber in domain "fuu" subscribing to service "bar"

./target/ffi/build/examples/c/domains/example_c_domains_subscriber "fuu" "bar"

Terminal 2 Publisher in domain "fuu" publishing on service "bar"

./target/ffi/build/examples/c/domains/example_c_domains_publisher "fuu" "bar"

Terminal 3 List all services of domain "fuu"

./target/ffi/build/examples/c/domains/example_c_domains_discovery "fuu"