From ed8e068bf76574e20f49109bc378f2cb891d71bc Mon Sep 17 00:00:00 2001
From: Vladimir Didenko <cow@altlinux.org>
Date: Wed, 29 Apr 2015 11:08:29 +0300
Subject: [PATCH] Switch resolver to threaded variant since ExecutorResolver by
 default uses blocking implementation

---
 requirements/base.txt    |  2 ++
 salt/transport/client.py | 36 +++++++++++++++++++++++++++++-------
 salt/transport/tcp.py    | 12 +++++-------
 3 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/requirements/base.txt b/requirements/base.txt
index 44f8581db47..b142c05069f 100644
--- a/requirements/base.txt
+++ b/requirements/base.txt
@@ -4,3 +4,5 @@ PyYAML
 MarkupSafe
 requests >= 1.0.0
 tornado >= 4.0
+# Required by Tornado to handle threads stuff.
+futures >= 2.0
diff --git a/salt/transport/client.py b/salt/transport/client.py
index ef99bbbbc6c..9e64ace6e8d 100644
--- a/salt/transport/client.py
+++ b/salt/transport/client.py
@@ -37,12 +37,28 @@ def crypted_transfer_decode_dictentry(self, load, dictkey=None, tries=3, timeout
 
 
 # TODO: better doc strings
-class AsyncReqChannel(object):
+class AsyncChannel(object):
+    '''
+    Parent class for Async communication channels
+    '''
+    # Resolver used by Tornado TCPClient
+    # This static field is shared between
+    # AsyncReqChannel and AsyncPubChannel
+    _resolver = None
+
+    @classmethod
+    def _init_resolver(cls, num_threads=10):
+        from tornado.netutil import ThreadedResolver
+        cls._resolver = ThreadedResolver()
+        cls._resolver.initialize(num_threads=num_threads)
+
+# TODO: better doc strings
+class AsyncReqChannel(AsyncChannel):
     '''
     Factory class to create a Async communication channels to the ReqServer
     '''
-    @staticmethod
-    def factory(opts, **kwargs):
+    @classmethod
+    def factory(cls, opts, **kwargs):
         # Default to ZeroMQ for now
         ttype = 'zeromq'
 
@@ -60,8 +76,11 @@ def factory(opts, **kwargs):
             import salt.transport.raet
             return salt.transport.raet.AsyncRAETReqChannel(opts, **kwargs)
         elif ttype == 'tcp':
+            if not cls._resolver:
+                # TODO: add opt to specify number of resolver threads
+                AsyncChannel._init_resolver()
             import salt.transport.tcp
-            return salt.transport.tcp.AsyncTCPReqChannel(opts, **kwargs)
+            return salt.transport.tcp.AsyncTCPReqChannel(opts, resolver=cls._resolver, **kwargs)
         elif ttype == 'local':
             import salt.transport.local
             return salt.transport.local.AsyncLocalChannel(opts, **kwargs)
@@ -83,12 +102,12 @@ def crypted_transfer_decode_dictentry(self, load, dictkey=None, tries=3, timeout
         raise NotImplementedError()
 
 
-class AsyncPubChannel(object):
+class AsyncPubChannel(AsyncChannel):
     '''
     Factory class to create subscription channels to the master's Publisher
     '''
-    @staticmethod
-    def factory(opts, **kwargs):
+    @classmethod
+    def factory(cls, opts, **kwargs):
         # Default to ZeroMQ for now
         ttype = 'zeromq'
 
@@ -106,6 +125,9 @@ def factory(opts, **kwargs):
             import salt.transport.raet
             return salt.transport.raet.AsyncRAETPubChannel(opts, **kwargs)
         elif ttype == 'tcp':
+            if not cls._resolver:
+                # TODO: add opt to specify number of resolver threads
+                AsyncChannel._init_resolver()
             import salt.transport.tcp
             return salt.transport.tcp.AsyncTCPPubChannel(opts, **kwargs)
         elif ttype == 'local':  # TODO:
diff --git a/salt/transport/tcp.py b/salt/transport/tcp.py
index 14221ea5c53..e79eff8cf3b 100644
--- a/salt/transport/tcp.py
+++ b/salt/transport/tcp.py
@@ -119,11 +119,13 @@ def __init__(self, opts, **kwargs):
         if self.crypt != 'clear':
             self.auth = salt.crypt.AsyncAuth(self.opts, io_loop=self.io_loop)
 
+        resolver = kwargs.get('resolver')
+
         parse = urlparse.urlparse(self.opts['master_uri'])
         host, port = parse.netloc.rsplit(':', 1)
         self.master_addr = (host, int(port))
 
-        self.message_client = SaltMessageClient(host, int(port), io_loop=self.io_loop)
+        self.message_client = SaltMessageClient(host, int(port), io_loop=self.io_loop, resolver=resolver)
 
     def __del__(self):
         self.message_client.destroy()
@@ -379,17 +381,13 @@ class SaltMessageClient(object):
     '''
     Low-level message sending client
     '''
-    def __init__(self, host, port, io_loop=None):
+    def __init__(self, host, port, io_loop=None, resolver=None):
         self.host = host
         self.port = port
 
         self.io_loop = io_loop or tornado.ioloop.IOLoop.current()
 
-        # Configure the resolver to use a non-blocking one
-        # Not Threaded since we need to work on python2
-        tornado.netutil.Resolver.configure('tornado.netutil.ExecutorResolver')
-
-        self._tcp_client = tornado.tcpclient.TCPClient(io_loop=self.io_loop)
+        self._tcp_client = tornado.tcpclient.TCPClient(io_loop=self.io_loop, resolver=resolver)
 
         self._mid = 1
         self._max_messages = sys.maxint - 1  # number of IDs before we wrap