Abgabe

kawaii/kawaii-rs/dependencies/emergency-stop/src/lib.rs

@@ -0,0 +1,96 @@
+extern crate kawaii;
+
+use std::time::Duration;
+use std::thread;
+use std::thread::JoinHandle;
+use std::sync::Arc;
+use std::sync::atomic::{AtomicBool, Ordering};
+
+use self::kawaii::gpio::{AsyncPort, Edge, Value};
+
+#[cfg(feature = "measure")]
+use self::kawaii::Measure;
+
+#[derive(Debug)]
+pub struct EmergencyStop {
+    thread: Option<JoinHandle<()>>,
+    pub state: Arc<AtomicBool>,
+}
+
+impl EmergencyStop {
+    pub fn new(stop_port: u8) -> std::io::Result<Self> {
+        let name = format!("EmergencyStop(port = {})", stop_port);
+        let state = Arc::new(AtomicBool::new(false));
+        let mut port = AsyncPort::new(stop_port, Edge::Both)?;
+
+        let state_clone = state.clone();
+        let thread = thread::Builder::new()
+            .name(name)
+            .spawn(move || EmergencyStop::thread(&mut port, state_clone))?;
+
+        Ok(EmergencyStop {
+            thread: Some(thread),
+            state: state,
+        })
+    }
+
+    fn thread(port: &mut AsyncPort, state: Arc<AtomicBool>) {
+        #[cfg(feature = "measure")]
+        let mut measure = Measure::new(format!("EmergencyStop(port = {})", port.port.number));
+
+        // clear first value
+        port.poll(Some(Duration::new(0, 0))).is_ok();
+
+        while !state.load(Ordering::Relaxed) {
+            #[cfg(feature = "measure")]
+            measure.start();
+
+            let timeout = Some(Duration::new(1, 0));
+
+            #[cfg(not(feature = "measure"))]
+            let value = port.poll(timeout);
+
+            #[cfg(feature = "measure")]
+            let value = port.poll_measure(timeout, &mut measure);
+
+            // continue on timeout
+            match value {
+                Ok(value) => {
+                    if let Some(value) = value {
+                        match value {
+                            Value::High => {
+                                #[cfg(debug_assertions)]
+                                println!("EmergencyStop! ({:?})", value);
+
+                                state.store(true, Ordering::Relaxed);
+                            }
+                            _ => {
+                                #[cfg(debug_assertions)]
+                                println!("EmergencyStop ignored: ({:?})", value);
+                            }
+                        }
+                    }
+                }
+                Err(e) => {
+                    #[cfg(debug_assertions)]
+                    println!("EmergencyStop! ({:?})", e);
+
+                    state.store(true, Ordering::Relaxed);
+                }
+            }
+
+            #[cfg(feature = "measure")]
+            measure.stop();
+        }
+    }
+}
+
+impl Drop for EmergencyStop {
+    fn drop(&mut self) {
+        self.state.store(true, Ordering::Relaxed);
+
+        if let Some(thread) = self.thread.take() {
+            thread.join().is_ok();
+        }
+    }
+}