patch by braph: use decorator for config lock, drop IPC lock

common.py

@@ -7,6 +7,7 @@ import time
 import requests
 from collections import namedtuple
 from urllib.error import URLError
+import threading
 
 RATE_NO_LIMIT = 0x00
 RATE_GLOBAL = 0x01
@@ -43,6 +44,8 @@ buckets = {
 
 rate_limit_classes = buckets.keys()
 
+plugin_lock = threading.Lock()
+
 
 def rate_limit(rate_class=RATE_GLOBAL):
     """
@@ -182,6 +185,23 @@ def giphy(subject, api_key):
     return giphy_url
 
 
+def config_locked(f):
+    """A decorator that makes access to the config thread-safe"""
+
+    def decorate(*args, **kwargs):
+
+        plugin_lock.acquire()
+
+        try:
+            return f(*args, **kwargs)
+        except:
+            raise
+        finally:
+            plugin_lock.release()
+
+    return decorate
+
+
 def pluginfunction(name, desc, plugin_type, ratelimit_class=RATE_GLOBAL, enabled=True):
     """A decorator to make a plugin out of a function
     :param enabled: