Timers

examples/timer_demo/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "examples_timer_demo"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+rclrs = "0.4"
+example_interfaces = "*"

examples/timer_demo/package.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0"?>
+<?xml-model
+   href="http://download.ros.org/schema/package_format3.xsd"
+   schematypens="http://www.w3.org/2001/XMLSchema"?>
+<package format="3">
+  <name>examples_timer_demo</name>
+  <maintainer email="[email protected]">Esteve Fernandez</maintainer>
+  <!-- This project is not military-sponsored, Jacob's employment contract just requires him to use this email address -->
+  <maintainer email="[email protected]">Jacob Hassold</maintainer>
+  <version>0.4.1</version>
+  <description>Package containing an example of how to use a worker in rclrs.</description>
+  <license>Apache License 2.0</license>
+
+  <depend>rclrs</depend>
+  <depend>rosidl_runtime_rs</depend>
+  <depend>example_interfaces</depend>
+
+  <export>
+    <build_type>ament_cargo</build_type>
+  </export>
+</package>

examples/timer_demo/src/main.rs

@@ -0,0 +1,22 @@
+/// Creates a SimpleTimerNode, initializes a node and the timer with a callback
+/// that prints the timer callback execution iteration. The callback is executed
+/// thanks to the spin, which is in charge of executing the timer's events among
+/// other entities' events.
+use rclrs::*;
+use std::time::Duration;
+
+fn main() -> Result<(), RclrsError> {
+    let mut executor = Context::default_from_env()?.create_basic_executor();
+    let node = executor.create_node("timer_demo")?;
+    let worker = node.create_worker::<usize>(0);
+    let timer_period = Duration::from_secs(1);
+    let _timer = worker.create_timer_repeating(timer_period, move |count: &mut usize| {
+        *count += 1;
+        println!(
+            "Drinking 🧉 for the {}th time every {:?}.",
+            *count, timer_period,
+        );
+    })?;
+
+    executor.spin(SpinOptions::default()).first_error()
+}

examples/worker_demo/src/main.rs

@@ -1,5 +1,5 @@
 use rclrs::*;
-use std::sync::Arc;
+use std::time::Duration;
 
 fn main() -> Result<(), RclrsError> {
     let mut executor = Context::default_from_env()?.create_basic_executor();
@@ -15,27 +15,12 @@ fn main() -> Result<(), RclrsError> {
         },
     )?;
 
-    // // Use this timer-based implementation when timers are available instead
-    // // of using std::thread::spawn.
-    // let _timer = worker.create_timer_repeating(
-    //     Duration::from_secs(1),
-    //     move |data: &mut String| {
-    //         let msg = example_interfaces::msg::String {
-    //             data: data.clone()
-    //         };
-
-    //         publisher.publish(msg).ok();
-    //     }
-    // )?;
-
-    std::thread::spawn(move || loop {
-        std::thread::sleep(std::time::Duration::from_secs(1));
-        let publisher = Arc::clone(&publisher);
-        let _ = worker.run(move |data: &mut String| {
+    let _timer =
+        worker.create_timer_repeating(Duration::from_secs(1), move |data: &mut String| {
             let msg = example_interfaces::msg::String { data: data.clone() };
-            publisher.publish(msg).unwrap();
-        });
-    });
+
+            publisher.publish(msg).ok();
+        })?;
 
     println!(
         "Beginning repeater... \n >> \