Consolidate redraws if unable to draw for a while

When the menu's open for a while we block the graph panel from redrawing itself, causing events to accumilate. Then when the menu's closed we perform a flurry of updates which makes the graph appear to catch up in fast forward. Instead, if a panel is unable to draw itself after a second it gives up the redraw attempt. This way when the menu's closed we perform just a single redraw that catches us up. Caught thanks to Guinness on tor-relays@.

Consolidate redraws if unable to draw for a while
2c8c116d · Damian Johnson · b29878e7 · 2c8c116d
Commit 2c8c116d authored 7 years ago by Damian Johnson
--- a/nyx/curses.py
+++ b/nyx/curses.py
@@ -92,6 +92,7 @@ import functools
 import os
 import re
 import threading
+import time

 import stem.util.conf
 import stem.util.enum
@@ -709,7 +710,15 @@ def draw(func, left = 0, top = 0, width = None, height = None, background = None
  :returns: :class:`~nyx.curses.Dimension` for the space we drew within
  """

-  with CURSES_LOCK:
+  start = time.time()
+
+  while not CURSES_LOCK.acquire(False):
+    if (time.time() - start) > 1:
+      return  # if we've been blocked from drawing for a full second then abort
+
+    time.sleep(0.05)
+
+  try:
    if HALT_ACTIVITY:
      return

@@ -738,6 +747,8 @@ def draw(func, left = 0, top = 0, width = None, height = None, background = None
    curses_subwindow.refresh()

    return subwindow_dimensions
+  finally:
+    CURSES_LOCK.release()


 class _Subwindow(object):