Id Counter Server

id_counter_server.py

Unique ID Generation Service – thread-safe counter persisted via ROS Parameter Server

This node provides a simple ROS service that hands out globally unique integer IDs to clients on demand. It stores the current counter in the ROS Parameter Server under id_client_counter, so the count survives node restarts, and uses a threading lock to serialize concurrent requests safely.

Interfaces (strongly-typed, stateful)

Interface	Type	Semantics
Service: /get_next_id	tiago1/GetNextId	Stateful RPC – returns the next integer in a persisted counter; the service maintains and updates its internal state (the counter) on each call.

ROS Service

Service Name	Type	Description
/get_next_id	tiago1/GetNextId	Returns the next unique integer ID in the sequence.

class id_counter_server.IdCounterServer

Bases: object

Provides the /get_next_id service and manages the counter state.

Variables

id_counterint

Current value of the ID counter (loaded from Parameter Server).

_id_lockthreading.Lock

Ensures only one thread can increment id_counter at a time.

id_servicerospy.Service

Service handle for /get_next_id.

handle_get_next_id(req)

Service callback: safely return the next ID and update the counter.

Parameters:

req (GetNextIdRequest) – Empty request (no fields).

Returns:

Contains the allocated ID.

Return type:

GetNextIdResponse