made connections thread safe

db.py

@@ -4,6 +4,7 @@ The bot's database connection class.
 """
 import os
 import sqlite3
+import threading
 
 class FulviaDB(object):
 	"""
@@ -13,6 +14,7 @@ class FulviaDB(object):
 	def __init__(self, config):
 		path = config.core.db_filename
 		self.filename = path
+		self.db_lock = threading.Lock()
 
 	def connect(self):
 		"""Return a raw database connection object."""
@@ -26,5 +28,8 @@ class FulviaDB(object):
 		called per PEP 249.
 		"""
 		with self.connect() as conn:
+			self.db_lock.acquire()
 			cur = conn.cursor()
-			return cur.execute(*args, **kwargs)
+			res = cur.execute(*args, **kwargs)
+			self.db_lock.release()
+			return res