Share resize thread logic between all unix backends

src/backend/curses/mod.rs

@@ -6,14 +6,7 @@
 extern crate term_size;
 
 use std::collections::HashMap;
-use std::sync::atomic::{AtomicBool, Ordering};
-use std::sync::Arc;
-use std::thread;
 
-use crossbeam_channel::{Receiver, Sender};
-use signal_hook::iterator::Signals;
-
-use backend;
 use event::{Event, Key};
 use theme::{BaseColor, Color, ColorPair};
 use vec::Vec2;
@@ -141,43 +134,3 @@ fn find_closest(color: Color, max_colors: i16) -> i16 {
         }
     }
 }
-
-#[cfg(unix)]
-fn start_resize_thread(
-    signals: Signals, resize_sender: Sender<Option<Event>>,
-    resize_requests: Receiver<backend::InputRequest>,
-    resize_running: Arc<AtomicBool>, needs_resize: Arc<AtomicBool>,
-) {
-    thread::spawn(move || {
-        // This thread will listen to SIGWINCH events and report them.
-        while resize_running.load(Ordering::Relaxed) {
-            // We know it will only contain SIGWINCH signals, so no need to check.
-            if signals.wait().count() > 0 {
-                // Tell ncurses about the new terminal size.
-                // Well, do the actual resizing later on, in the main thread.
-                // Ncurses isn't really thread-safe so calling resize_term() can crash
-                // other calls like clear() or refresh().
-                needs_resize.store(true, Ordering::Relaxed);
-
-                resize_sender.send(Some(Event::WindowResize));
-                // We've sent the message.
-                // This means Cursive was listening, and will now soon be sending a new request.
-                // This means the input thread accepted a request, but hasn't sent a message yet.
-                // So we KNOW the input thread is not waiting for a new request.
-
-                // We sent an event for free, so pay for it now by consuming a request
-                while let Some(backend::InputRequest::Peek) =
-                    resize_requests.recv()
-                {
-                    // At this point Cursive will now listen for input.
-                    // There is a chance the input thread will send his event before us.
-                    // But without some extra atomic flag, it'd be hard to know.
-                    // So instead, keep sending `None`
-
-                    // Repeat until we receive a blocking call
-                    resize_sender.send(None);
-                }
-            }
-        }
-    });
-}

src/backend/curses/n.rs

@@ -305,12 +305,12 @@ impl backend::Backend for Backend {
     ) {
         let running = Arc::new(AtomicBool::new(true));
 
-        super::start_resize_thread(
+        backend::start_resize_thread(
             self.signals.take().unwrap(),
             event_sink.clone(),
             input_request.clone(),
             Arc::clone(&running),
-            Arc::clone(&self.needs_resize),
+            Some(Arc::clone(&self.needs_resize)),
         );
 
         let mut parser = InputParser::new();

src/backend/curses/pan.rs

@@ -285,6 +285,8 @@ fn find_closest_pair(pair: ColorPair) -> (i16, i16) {
 
 impl Backend {
     pub fn init() -> Box<backend::Backend> {
+        // We need to create this now, before ncurses initialization
+        // Otherwise ncurses starts its own signal handling and it's a mess.
         #[cfg(unix)]
         let signals = Some(Signals::new(&[libc::SIGWINCH]).unwrap());
 
@@ -455,12 +457,12 @@ impl backend::Backend for Backend {
 
         #[cfg(unix)]
         {
-            super::start_resize_thread(
+            backend::start_resize_thread(
                 self.signals.take().unwrap(),
                 event_sink.clone(),
                 input_request.clone(),
                 Arc::clone(&running),
-                Arc::clone(&self.needs_resize),
+                Some(Arc::clone(&self.needs_resize)),
             );
         }
 

src/backend/mod.rs

@@ -7,11 +7,15 @@
 //! using some common libraries. Each of those included backends needs a
 //! corresonding feature to be enabled.
 
-use event;
+use std::sync::atomic::{AtomicBool, Ordering};
-use theme;
+use std::sync::Arc;
+use std::thread;
 
 use crossbeam_channel::{Receiver, Sender};
+use signal_hook::iterator::Signals;
 
+use event::Event;
+use theme;
 use vec::Vec2;
 
 pub mod dummy;
@@ -41,7 +45,7 @@ pub trait Backend {
     ///
     /// `event_trigger` will receive a value before any event is needed.
     fn start_input_thread(
-        &mut self, event_sink: Sender<Option<event::Event>>,
+        &mut self, event_sink: Sender<Option<Event>>,
         input_request: Receiver<InputRequest>,
     ) {
         // Dummy implementation for some backends.
@@ -54,7 +58,7 @@ pub trait Backend {
     /// This is only required for non-thread-safe backends like BearLibTerminal
     /// where we cannot collect input in a separate thread.
     fn prepare_input(
-        &mut self, event_sink: &Sender<Option<event::Event>>,
+        &mut self, event_sink: &Sender<Option<Event>>,
         input_request: InputRequest,
     ) {
         // Dummy implementation for most backends.
@@ -89,3 +93,49 @@ pub trait Backend {
     /// Disables the given effect.
     fn unset_effect(&self, effect: theme::Effect);
 }
+
+/// This starts a new thread to listen for SIGWINCH signals
+///
+/// As long as `resize_running` is true, it will listen for SIGWINCH, and,
+/// when detected, it wil set `needs_resize` to true and send an event to
+/// `resize_sender`. It will also consume an event from `resize_requests`
+/// afterward, to keep the balance in the force.
+#[cfg(unix)]
+fn start_resize_thread(
+    signals: Signals, resize_sender: Sender<Option<Event>>,
+    resize_requests: Receiver<InputRequest>, resize_running: Arc<AtomicBool>,
+    needs_resize: Option<Arc<AtomicBool>>,
+) {
+    thread::spawn(move || {
+        // This thread will listen to SIGWINCH events and report them.
+        while resize_running.load(Ordering::Relaxed) {
+            // We know it will only contain SIGWINCH signals, so no need to check.
+            if signals.wait().count() > 0 {
+                // Tell ncurses about the new terminal size.
+                // Well, do the actual resizing later on, in the main thread.
+                // Ncurses isn't really thread-safe so calling resize_term() can crash
+                // other calls like clear() or refresh().
+                if let Some(ref needs_resize) = needs_resize {
+                    needs_resize.store(true, Ordering::Relaxed);
+                }
+
+                resize_sender.send(Some(Event::WindowResize));
+                // We've sent the message.
+                // This means Cursive was listening, and will now soon be sending a new request.
+                // This means the input thread accepted a request, but hasn't sent a message yet.
+                // So we KNOW the input thread is not waiting for a new request.
+
+                // We sent an event for free, so pay for it now by consuming a request
+                while let Some(InputRequest::Peek) = resize_requests.recv() {
+                    // At this point Cursive will now listen for input.
+                    // There is a chance the input thread will send his event before us.
+                    // But without some extra atomic flag, it'd be hard to know.
+                    // So instead, keep sending `None`
+
+                    // Repeat until we receive a blocking call
+                    resize_sender.send(None);
+                }
+            }
+        }
+    });
+}

src/backend/termion.rs

@@ -5,7 +5,6 @@
 
 extern crate termion;
 
-use crossbeam_channel::{self, Sender, Receiver};
 use self::termion::color as tcolor;
 use self::termion::event::Event as TEvent;
 use self::termion::event::Key as TKey;
@@ -15,8 +14,9 @@ use self::termion::input::{MouseTerminal, TermRead};
 use self::termion::raw::{IntoRawMode, RawTerminal};
 use self::termion::screen::AlternateScreen;
 use self::termion::style as tstyle;
-use signal_hook::iterator::Signals;
+use crossbeam_channel::{self, Receiver, Sender};
 use libc;
+use signal_hook::iterator::Signals;
 
 use backend;
 use event::{Event, Key, MouseButton, MouseEvent};
@@ -25,9 +25,9 @@ use vec::Vec2;
 
 use std::cell::Cell;
 use std::io::{Stdout, Write};
-use std::thread;
-use std::sync::Arc;
 use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::Arc;
+use std::thread;
 
 pub struct Backend {
     terminal: AlternateScreen<MouseTerminal<RawTerminal<Stdout>>>,
@@ -56,7 +56,8 @@ impl InputParser {
             let mut events = stdin.events();
 
             for _ in request_receiver {
-                let event: Result<TEvent, ::std::io::Error> = events.next().unwrap();
+                let event: Result<TEvent, ::std::io::Error> =
+                    events.next().unwrap();
                 input_sender.send(event.unwrap());
             }
         });
@@ -294,22 +295,17 @@ impl backend::Backend for Backend {
         input_request: Receiver<backend::InputRequest>,
     ) {
         let running = Arc::new(AtomicBool::new(true));
-        let resize_sender = event_sink.clone();
-        let signals = Signals::new(&[libc::SIGWINCH]).unwrap();
 
-        let resize_running = Arc::clone(&running);
+        #[cfg(unix)]
-        thread::spawn(move || {
+        {
-            while resize_running.load(Ordering::Relaxed) {
+            backend::start_resize_thread(
-                // We know it will only contain SIGWINCH signals, so no need to check.
+                Signals::new(&[libc::SIGWINCH]).unwrap(),
-                for _ in signals.pending() {
+                event_sink.clone(),
-                    // Tell ncurses about the new terminal size.
+                input_request.clone(),
-                    // Well, do the actual resizing later on, in the main thread.
+                Arc::clone(&running),
-                    // Ncurses isn't really thread-safe so calling resize_term() can crash
+                None,
-                    // other calls like clear() or refresh().
+            );
-                    resize_sender.send(Some(Event::WindowResize));
         }
-            }
-        });
 
         let mut parser = InputParser::new();
         thread::spawn(move || {