change loop exception handler

Author: swordfeng

par.py

@@ -1,8 +1,17 @@
 import asyncio
 import concurrent
+import logging
+
+logger = logging.getLogger('par')
 
 thread_pool = concurrent.futures.ThreadPoolExecutor()
 event_loop = asyncio.get_event_loop()
+event_loop.set_default_executor(thread_pool)
+
+def event_loop_exeception_handler(loop, context):
+    if 'exception' in context:
+        logger.info(context['exception'])
+event_loop.set_exception_handler(event_loop_exeception_handler)
 
 def async_execute(func, *args, **kw):
     return asyncio.wrap_future(thread_pool.submit(func, *args, **kw), loop=event_loop)