From c75d7f60cb3334817ae5017d4ee4064319e132f3 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 2 Dec 2016 16:56:26 +0530
Subject: [PATCH] Speed up draining of the wakeup_fd buffer

---
 kitty/data-types.c | 9 +++++++++
 kitty/tabs.py      | 7 ++-----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/kitty/data-types.c b/kitty/data-types.c
index 872683226..fe8977e15 100644
--- a/kitty/data-types.c
+++ b/kitty/data-types.c
@@ -10,8 +10,17 @@
 #include "gl.h"
 #include "modes.h"
 
+static char drain_buf[1024] = {0};
+
+static PyObject*
+drain_read(PyObject UNUSED *self, PyObject *fd) {
+    read(PyLong_AsLong(fd), drain_buf, sizeof(drain_buf));
+    Py_RETURN_NONE;
+}
+
 static PyMethodDef module_methods[] = {
     GL_METHODS
+    {"drain_read", (PyCFunction)drain_read, METH_O, ""},
     {"parse_bytes", (PyCFunction)parse_bytes, METH_VARARGS, ""},
     {"parse_bytes_dump", (PyCFunction)parse_bytes_dump, METH_VARARGS, ""},
     {"read_bytes", (PyCFunction)read_bytes, METH_VARARGS, ""},
diff --git a/kitty/tabs.py b/kitty/tabs.py
index 6fec2f69f..283f8c429 100644
--- a/kitty/tabs.py
+++ b/kitty/tabs.py
@@ -22,7 +22,7 @@ from .constants import (
 from .fast_data_types import (
     glViewport, glBlendFunc, GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GLFW_PRESS,
     GLFW_REPEAT, GLFW_MOUSE_BUTTON_1, glfw_post_empty_event,
-    GLFW_CURSOR_NORMAL, GLFW_CURSOR, GLFW_CURSOR_HIDDEN,
+    GLFW_CURSOR_NORMAL, GLFW_CURSOR, GLFW_CURSOR_HIDDEN, drain_read
 )
 from .fonts import set_font_family
 from .borders import Borders, BordersProgram
@@ -199,10 +199,7 @@ class TabManager(Thread):
 
     def on_wakeup(self):
         if not self.shutting_down:
-            try:
-                os.read(self.read_wakeup_fd, io.DEFAULT_BUFFER_SIZE)
-            except (EnvironmentError, BlockingIOError):
-                pass
+            drain_read(self.read_wakeup_fd)
             while True:
                 try:
                     func, args = self.action_queue.get_nowait()