From 70a1361200d3b32539bc93058813a57b8a7aa73a Mon Sep 17 00:00:00 2001
From: Frank Dai <fydai@ocf.berkeley.edu>
Date: Mon, 4 Nov 2019 21:07:39 -0800
Subject: [PATCH] Add overly-safe synchronization

---
 ircbot/ircbot.py | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/ircbot/ircbot.py b/ircbot/ircbot.py
index 16da42c..9b21e2d 100644
--- a/ircbot/ircbot.py
+++ b/ircbot/ircbot.py
@@ -54,6 +54,15 @@
 MAX_CLIENT_MSG = 435
 
 
+def synchronize(method):
+    """Decorator to wrap a method in a lock-acquiring context manager"""
+    @functools.wraps(method)
+    def new_method(self, *args, **kwargs):
+        with self.lock:
+            return method(self, *args, **kwargs)
+    return new_method
+
+
 class Listener(NamedTuple):
     pattern: Pattern
     fn: FunctionType
@@ -135,6 +144,9 @@ def __init__(
         self.plugins: Dict[str, ModuleType] = {}
         self.extra_channels: Set[str] = set()  # plugins can add stuff here
 
+        # As we use threads, we should ensure that we use them safely
+        self.lock = threading.RLock()
+
         # Register plugins before joining the server.
         self.register_plugins()
 
@@ -146,6 +158,7 @@ def __init__(
             connect_factory=factory,
         )
 
+    @synchronize
     def register_plugins(self):
         for importer, mod_name, _ in pkgutil.iter_modules(['ircbot/plugin']):
             mod = importer.find_module(mod_name).load_module(mod_name)
@@ -154,6 +167,7 @@ def register_plugins(self):
             if register is not None:
                 register(self)
 
+    @synchronize
     def handle_error(self, error_message):
         # for debugging purposes
         print(error_message)
@@ -162,6 +176,7 @@ def handle_error(self, error_message):
         if not TESTING:
             send_problem_report(error_message)
 
+    @synchronize
     def listen(
             self,
             pattern,
@@ -183,6 +198,7 @@ def listen(
             ),
         )
 
+    @synchronize
     def on_welcome(self, conn, _):
         conn.privmsg('NickServ', f'identify {self.nickserv_password}')
 
@@ -190,6 +206,7 @@ def on_welcome(self, conn, _):
         for channel in IRC_CHANNELS_OPER | IRC_CHANNELS_ANNOUNCE | self.extra_channels:
             conn.join(channel)
 
+    @synchronize
     def on_pubmsg(self, conn, event):
         if event.target in self.channels:
             is_oper = False
@@ -286,10 +303,12 @@ def respond(raw_text, ping=True):
             if raw_text[0] != '!':
                 self.recent_messages[event.target].appendleft((user, raw_text))
 
+    @synchronize
     def on_currenttopic(self, connection, event):
         channel, topic = event.arguments
         self.topics[channel] = topic
 
+    @synchronize
     def on_topic(self, connection, event):
         topic, = event.arguments
         self.topics[event.target] = topic
@@ -299,6 +318,7 @@ def on_invite(self, connection, event):
         import ircbot.plugin.channels
         return ircbot.plugin.channels.on_invite(self, connection, event)
 
+    @synchronize
     def add_thread(self, func):
         def thread_func():
             try:
@@ -330,6 +350,7 @@ def thread_func():
         thread = threading.Thread(target=thread_func, daemon=True)
         thread.start()
 
+    @synchronize
     def bump_topic(self):
         for channel, topic in self.topics.items():
             def plusone(m):
@@ -339,6 +360,7 @@ def plusone(m):
             if topic != new_topic:
                 self.connection.topic(channel, new_topic=new_topic)
 
+    @synchronize
     def say(self, channel, message):
         # Find the length of the full message
         msg_len = len(f'PRIVMSG {channel} :{message}\r\n'.encode('utf-8'))