Fix pty read sometimes not triggering draw

There was a lot of complexity around the threadsafe `Flag` type and
waking up the event loop. The idea was to prevent unnecessary calls to
the glutin window's wakeup_event_loop() method which can be expensive.
This complexity made it difficult to get synchronization between the pty
reader and the render thread correct. Now, the `dirty` flag on the
terminal is also used to prevent spurious wakeups. It is only changed
when the mutex is held, so race conditions associated with that flag
shouldn't happen.

1 files changed, 6 insertions, 1 deletions

diff --git a/src/term/mod.rs b/src/term/mod.rs
index 29bf6b83..4e4a022c 100644
--- a/src/term/mod.rs
+++ b/src/term/mod.rs
@@ -298,7 +298,7 @@ impl Term {
         let scroll_region = Line(0)..grid.num_lines();
 
         Term {
-            dirty: true,
+            dirty: false,
             grid: grid,
             alt_grid: alt,
             alt: false,
@@ -313,6 +313,11 @@ impl Term {
         }
     }
 
+    #[inline]
+    pub fn needs_draw(&self) -> bool {
+        self.dirty
+    }
+
     pub fn string_from_selection(&self, span: &Span) -> String {
         /// Need a generic push() for the Append trait
         trait PushChar {