From dbb084da7ae091fff939cb8e724576642d775cef Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sun, 3 Jul 2022 21:42:34 +0530
Subject: [PATCH] Cleanup closing of socket child

---
 kitty/prewarm.py | 37 +++++++++++++++++++++++++++----------
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/kitty/prewarm.py b/kitty/prewarm.py
index bc1991c6f..36bd99bc6 100644
--- a/kitty/prewarm.py
+++ b/kitty/prewarm.py
@@ -362,8 +362,11 @@ class SocketClosed(Exception):
 
 class SocketChild:
 
-    def __init__(self, conn: socket.socket, addr: bytes):
+    def __init__(self, conn: socket.socket, addr: bytes, poll: select.poll):
         self.fd = conn.fileno()
+        poll.register(self.fd, select.POLLIN)
+        self.registered = True
+        self.poll = poll
         self.addr = addr
         self.conn = conn
         self.input_buf = self.output_buf = b''
@@ -375,6 +378,11 @@ class SocketChild:
         self.stdin = self.stdout = self.stderr = -1
         self.pid = -1
 
+    def unregister_from_poll(self) -> None:
+        if self.registered:
+            self.poll.unregister(self.fd)
+            self.registered = False
+
     def read(self) -> bool:
         import array
         fds = array.array("i")   # Array of ints
@@ -511,6 +519,12 @@ def main(stdin_fd: int, stdout_fd: int, notify_child_death_fd: int, unix_socket:
     warnings.filterwarnings('ignore', category=RuntimeWarning, module='runpy')
     prewarm()
 
+    def remove_socket_child(sc: SocketChild) -> None:
+        socket_children.pop(sc.fd, None)
+        sc.unregister_from_poll()
+        socket_pid_map.pop(sc.pid, None)
+        sc.conn.close()
+
     def get_all_non_child_fds() -> Iterator[int]:
         yield notify_child_death_fd
         yield stdin_fd
@@ -620,9 +634,12 @@ def main(stdin_fd: int, stdout_fd: int, notify_child_death_fd: int, unix_socket:
                     break
                 child_id = child_pid_map.pop(pid, None)
                 if child_id is None:
-                    sc = socket_pid_map.pop(pid, None)
+                    sc = socket_pid_map.get(pid)
                     if sc is not None:
-                        sc.handle_death(status)
+                        try:
+                            sc.handle_death(status)
+                        finally:
+                            remove_socket_child(sc)
                 else:
                     handle_child_death(child_id, pid)
 
@@ -631,9 +648,8 @@ def main(stdin_fd: int, stdout_fd: int, notify_child_death_fd: int, unix_socket:
     def handle_socket_client(event: int) -> None:
         check_event(event, 'UNIX socket fd listener failed')
         conn, addr = unix_socket.accept()
-        sc = SocketChild(conn, addr)
+        sc = SocketChild(conn, addr, poll)
         socket_children[sc.fd] = sc
-        poll.register(sc.fd, select.POLLIN)
 
     def handle_socket_launch(fd: int, event: int) -> None:
         scq = socket_children.get(q)
@@ -642,20 +658,21 @@ def main(stdin_fd: int, stdout_fd: int, notify_child_death_fd: int, unix_socket:
         if event & select.POLLIN:
             try:
                 if scq.read():
-                    poll.unregister(scq.fd)
+                    scq.unregister_from_poll()
                     scq.fork(get_all_non_child_fds())
                     socket_pid_map[scq.pid] = scq
                     scq.child_id = next(child_id_counter)
             except SocketClosed:
-                socket_children.pop(q, None)
+                if is_zygote:
+                    remove_socket_child(scq)
             except OSError as e:
                 if is_zygote:
-                    socket_children.pop(q, None)
+                    remove_socket_child(scq)
                     print_error(f'Failed to fork socket child with error: {e}')
                 else:
                     raise
-        if event & error_events:
-            socket_children.pop(q, None)
+        if is_zygote and (event & error_events):
+            remove_socket_child(scq)
 
     keep_type_checker_happy = True
     try: