utils: by default use OS implemented pick port which is WAAAY faster, leave fallback if we need specific range.

rhodecode/lib/utils2.py

@@ -39,6 +39,7 b' import socket'
 import errno
 import random
 from functools import update_wrapper, partial, wraps
+from contextlib import closing
 
 import pygments.lexers
 import sqlalchemy
@@ -1190,23 +1191,21 b' def user_agent_normalizer(user_agent_raw'
     return ua
 
 
-def get_available_port(min_port=40000, max_port=55555):
-    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-    hostname = '127.0.0.1'
-    pick_port = min_port
-
+def get_available_port(min_port=40000, max_port=55555, use_range=False):
+    hostname = ''
     for _ in range(min_port, max_port):
+        pick_port = 0
+        if use_range:
         pick_port = random.randint(min_port, max_port)
+
+        with closing(socket.socket(socket.AF_INET, socket.SOCK_STREAM)) as s:
         try:
-            sock.bind((hostname, pick_port))
-            sock.close()
-            break
+                s.bind((hostname, pick_port))
+                s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+                return s.getsockname()[1]
         except OSError:
             continue
         except socket.error as e:
             if e.args[0] in [errno.EADDRINUSE, errno.ECONNREFUSED]:
                 continue
             raise
-
-    del sock
-    return pick_port