From 19e59d9575d587b53bedf551a232781290f43b75 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 1 Mar 2018 15:31:13 +0530
Subject: [PATCH] Start refactoring peer message handling to allow multiple
 listening sockets and responses

---
 kitty/boss.py         | 23 +++++++++++------------
 kitty/child-monitor.c | 37 +++++++++++++++++++++++++++----------
 2 files changed, 38 insertions(+), 22 deletions(-)

diff --git a/kitty/boss.py b/kitty/boss.py
index 47cc3a689..bba6ad079 100644
--- a/kitty/boss.py
+++ b/kitty/boss.py
@@ -166,19 +166,18 @@ class Boss:
         self.child_monitor.add_child(window.id, window.child.pid, window.child.child_fd, window.screen)
         self.window_id_map[window.id] = window
 
-    def peer_messages_received(self, messages):
+    def peer_message_received(self, msg):
         import json
-        for msg in messages:
-            msg = json.loads(msg.decode('utf-8'))
-            if isinstance(msg, dict) and msg.get('cmd') == 'new_instance':
-                startup_id = msg.get('startup_id')
-                args, rest = parse_args(msg['args'][1:])
-                args.args = rest
-                opts = create_opts(args)
-                session = create_session(opts, args)
-                self.add_os_window(session, wclass=args.cls, wname=args.name, size=initial_window_size(opts, self.cached_values), startup_id=startup_id)
-            else:
-                safe_print('Unknown message received from peer, ignoring')
+        msg = json.loads(msg.decode('utf-8'))
+        if isinstance(msg, dict) and msg.get('cmd') == 'new_instance':
+            startup_id = msg.get('startup_id')
+            args, rest = parse_args(msg['args'][1:])
+            args.args = rest
+            opts = create_opts(args)
+            session = create_session(opts, args)
+            self.add_os_window(session, wclass=args.cls, wname=args.name, size=initial_window_size(opts, self.cached_values), startup_id=startup_id)
+        else:
+            safe_print('Unknown message received from peer, ignoring')
 
     def handle_remote_cmd(self, cmd, window=None):
         response = None
diff --git a/kitty/child-monitor.c b/kitty/child-monitor.c
index 8df832f78..56d06a767 100644
--- a/kitty/child-monitor.c
+++ b/kitty/child-monitor.c
@@ -25,6 +25,7 @@ static void (*parse_func)(Screen*, PyObject*);
 typedef struct {
     char *data;
     size_t sz;
+    int fd;
 } Message;
 
 typedef struct {
@@ -185,6 +186,7 @@ wakeup_io_loop(bool in_signal_handler) {
 
 static void* io_loop(void *data);
 static void* talk_loop(void *data);
+static void send_response(int fd, const char *msg, size_t msg_sz);
 
 static PyObject *
 start(ChildMonitor *self) {
@@ -323,7 +325,7 @@ parse_input(ChildMonitor *self) {
         if (msg) {
             for (size_t i = 0; i < self->messages_count; i++) {
                 Message *m = self->messages + i;
-                PyTuple_SET_ITEM(msg, i, PyBytes_FromStringAndSize(m->data, m->sz));
+                PyTuple_SET_ITEM(msg, i, Py_BuildValue("y#i", m->data, (int)m->sz, m->fd));
                 free(m->data); m->data = NULL; m->sz = 0;
             }
             self->messages_count = 0;
@@ -341,7 +343,13 @@ parse_input(ChildMonitor *self) {
     }
     children_mutex(unlock);
     if (msg) {
-        call_boss(peer_messages_received, "(O)", msg);
+        for (Py_ssize_t i = 0; i < PyTuple_GET_SIZE(msg); i++) {
+            PyObject *resp = PyObject_CallMethod(global_state.boss, "peer_message_received", "O", PyTuple_GET_ITEM(PyTuple_GET_ITEM(msg, i), 0));
+            int peer_fd = (int)PyLong_AsLong(PyTuple_GET_ITEM(PyTuple_GET_ITEM(msg, i), 1));
+            if (resp && PyBytes_Check(resp)) send_response(peer_fd, PyBytes_AS_STRING(PyTuple_GET_ITEM(PyTuple_GET_ITEM(msg, i), 0)), PyBytes_GET_SIZE(PyTuple_GET_ITEM(PyTuple_GET_ITEM(msg, i), 0)));
+            else { send_response(peer_fd, NULL, 0); if (!resp) PyErr_Print(); }
+            Py_CLEAR(resp);
+        }
         Py_CLEAR(msg);
     }
 
@@ -955,7 +963,7 @@ io_loop(void *data) {
 
 // {{{ Talk thread functions
 
-static inline void
+static inline bool
 handle_peer(ChildMonitor *self, int s) {
     size_t bufsz = 0;
     char *buf = NULL;
@@ -964,9 +972,9 @@ handle_peer(ChildMonitor *self, int s) {
     while(true) {
         if (buf_used >= bufsz) {
             bufsz = MAX(1024, bufsz) * 2;
-            if (bufsz > 1024 * 1024) return;
+            if (bufsz > 16 * 1024 * 1024) return false;
             buf = realloc(buf, bufsz);
-            if (buf == NULL) return;
+            if (buf == NULL) return false;
         }
         ssize_t n = recv(s, buf + buf_used, bufsz - buf_used, 0);
         if (n == 0) break;
@@ -981,15 +989,17 @@ handle_peer(ChildMonitor *self, int s) {
         children_mutex(lock);
         ensure_space_for(self, messages, Message, self->messages_count + 1, messages_capacity, 16, true);
         Message *m = self->messages + self->messages_count++;
-        m->data = buf; m->sz = buf_used;
+        m->data = buf; m->sz = buf_used; m->fd = s;
         children_mutex(unlock);
         wakeup_main_loop();
+        return true;
     } else free(buf);
+    return false;
 }
 
 static void*
 talk_loop(void *data) {
-    // The I/O thread loop
+    // The talk thread loop
 
     ChildMonitor *self = (ChildMonitor*)data;
     set_thread_name("KittyTalkMon");
@@ -1001,12 +1011,19 @@ talk_loop(void *data) {
             if (!self->shutting_down) perror("accept() on talk socket failed!");
             break;
         }
-        handle_peer(self, peer);
-        shutdown(peer, SHUT_RDWR);
-        close(peer);
+        if (handle_peer(self, peer)) shutdown(peer, SHUT_RD);
+        else { shutdown(peer, SHUT_RDWR); close(peer); }
     }
     return 0;
 }
+
+static void
+send_response(int fd, const char *msg, size_t msg_sz) {
+    if (msg == NULL) { shutdown(fd, SHUT_WR); close(fd); return; }
+    (void)msg_sz; // TODO: Implement this
+    shutdown(fd, SHUT_WR); close(fd);
+}
+
 // }}}
 
 // Boilerplate {{{