niklas/ros2_tracing
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Add client creation flow description

Browse source
This commit is contained in:
Christophe Bedard 2019-05-28 15:00:51 +02:00
parent 6e5f24f7d2
commit d7a4c7b386
1 changed files with 23 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

23
doc/design_ros_2.md
View file

@ -298,6 +298,29 @@ sequenceDiagram
### Client creation
Client creation is similar to publisher creation. The `Component` calls `create_client()` which ends up creating a `rclcpp::Client`. In its constructor, it allocates a `rcl_client_t` handle, then calls `rcl_client_init()`. This validates and processes the handle. It also calls `rmw_create_client()` which creates the `rmw_client_t` handle.
```mermaid
sequenceDiagram
participant Component
participant Node
participant Client
participant rcl
participant rmw
participant tracetools
Component->>Node: create_client(service_name, options)
Node->>Client: Client(service_name, options)
Note over Client: allocates a rcl_client_t handle
Client->>rcl: rcl_client_init(out rcl_client_t, rcl_node_t, service_name, options)
Note over rcl: validates and processes rcl_client_t handle
rcl->>rmw: rmw_create_client(rmw_node_t, service_name, qos_options) : rmw_client_t
Note over rmw: creates rmw_client_t handle
rcl-->>tracetools: TP(rcl_client_init, rcl_node_t *, rcl_client_t *, rmw_client_t *, service_name)
```
### Client request
### Timer creation
Timer creation is similar to subscription creation. The `Component` calls `create_service()` which ends up creating a `rclcpp::WallTimer`. In its constructor, it creates a `rclcpp::Clock` object, which (for a `WallTimer`) is simply a nanosecond clock. It then allocates a `rcl_timer_t` handle, then calls `rcl_timer_init()`. This processes the handle and validates the period.