Handle OSes that have no native pipe2()

OS X, sigh.

kitty/boss.py

@@ -32,7 +32,7 @@ from .session import create_session
 from .shaders import Sprites, ShaderProgram
 from .tabs import TabManager, SpecialWindow
 from .timers import Timers
-from .utils import handle_unix_signals, safe_print
+from .utils import handle_unix_signals, safe_print, pipe2
 
 
 def conditional_run(w, i):
@@ -77,7 +77,7 @@ class Boss(Thread):
         self.shutting_down = False
         self.screen_update_delay = opts.repaint_delay / 1000.0
         self.signal_fd = handle_unix_signals()
-        self.read_wakeup_fd, self.write_wakeup_fd = os.pipe2(os.O_NONBLOCK | os.O_CLOEXEC)
+        self.read_wakeup_fd, self.write_wakeup_fd = pipe2()
         self.read_dispatch_map = {self.signal_fd: self.signal_received, self.read_wakeup_fd: self.on_wakeup}
         self.all_writers = []
         self.timers = Timers()

kitty/utils.py

@@ -271,8 +271,22 @@ def parse_color_set(raw):
             continue
 
 
+def pipe2():
+    try:
+        read_fd, write_fd = os.pipe2(os.O_NONBLOCK | os.O_CLOEXEC)
+    except AttributeError:
+        import fcntl
+        read_fd, write_fd = os.pipe()
+        for fd in (read_fd, write_fd):
+            flag = fcntl.fcntl(fd, fcntl.F_GETFD)
+            fcntl.fcntl(fd, fcntl.F_SETFD, flag | fcntl.FD_CLOEXEC)
+            flag = fcntl.fcntl(fd, fcntl.F_GETFL)
+            fcntl.fcntl(fd, fcntl.F_SETFL, flag | os.O_NONBLOCK)
+    return read_fd, write_fd
+
+
 def handle_unix_signals():
-    read_fd, write_fd = os.pipe2(os.O_NONBLOCK | os.O_CLOEXEC)
+    read_fd, write_fd = pipe2()
     for sig in (signal.SIGINT, signal.SIGTERM):
         signal.signal(sig, lambda x, y: None)
         signal.siginterrupt(sig, False)