From 21f61c7d91985b71bf37eb64ab62d044265863df Mon Sep 17 00:00:00 2001
From: clowwindy <clowwindy42@gmail.com>
Date: Fri, 12 Sep 2014 23:56:37 +0800
Subject: [PATCH] avoid removing items of the handler list while iterating over
 it; #179

---
 shadowsocks/eventloop.py | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/shadowsocks/eventloop.py b/shadowsocks/eventloop.py
index a80a525..de0039e 100644
--- a/shadowsocks/eventloop.py
+++ b/shadowsocks/eventloop.py
@@ -154,6 +154,7 @@ class SelectLoop(object):
 
 class EventLoop(object):
     def __init__(self):
+        self._iterating = False
         if hasattr(select, 'epoll'):
             self._impl = EpollLoop()
             model = 'epoll'
@@ -169,6 +170,7 @@ class EventLoop(object):
         self._fd_to_f = {}
         self._handlers = []
         self._ref_handlers = []
+        self._handlers_to_remove = []
         logging.debug('using event model: %s', model)
 
     def poll(self, timeout=None):
@@ -196,11 +198,15 @@ class EventLoop(object):
             self._ref_handlers.append(handler)
 
     def remove_handler(self, handler):
-        self._handlers.remove(handler)
         if handler in self._ref_handlers:
             self._ref_handlers.remove(handler)
+        if self._iterating:
+            self._handlers_to_remove.append(handler)
+        else:
+            self._handlers.remove(handler)
 
     def run(self):
+        events = []
         while self._ref_handlers:
             try:
                 events = self.poll(1)
@@ -215,6 +221,7 @@ class EventLoop(object):
                     import traceback
                     traceback.print_exc()
                     continue
+            self._iterating = True
             for handler in self._handlers:
                 # TODO when there are a lot of handlers
                 try:
@@ -223,6 +230,10 @@ class EventLoop(object):
                     logging.error(e)
                     import traceback
                     traceback.print_exc()
+            for handler in self._handlers_to_remove:
+                self._handlers.remove(handler)
+                self._handlers_to_remove = []
+            self._iterating = False
 
 
 # from tornado