From afc2068a98b5fe6eb367822d264b9e69b4dc37e0 Mon Sep 17 00:00:00 2001
From: rdw <rdw@reimplemented.local>
Date: Tue, 18 Mar 2008 17:32:07 -0500
Subject: [PATCH] Some Hub documentation, made
 wrap_socket_with_coroutine_socket happen only once.

---
 eventlet/hubs/hub.py | 17 +++++++++++++++++
 eventlet/util.py     |  8 +++++++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/eventlet/hubs/hub.py b/eventlet/hubs/hub.py
index ada6af7..a02104f 100644
--- a/eventlet/hubs/hub.py
+++ b/eventlet/hubs/hub.py
@@ -34,6 +34,9 @@ from eventlet import greenlib
 from eventlet.timer import Timer
 
 class BaseHub(object):
+    """ Base hub class for easing the implementation of subclasses that are 
+    specific to a particular underlying event architecture. """
+
     SYSTEM_EXCEPTIONS = (KeyboardInterrupt, SystemExit)
     
     def __init__(self, clock=time.time):
@@ -58,6 +61,20 @@ class BaseHub(object):
         }
 
     def add_descriptor(self, fileno, read=None, write=None, exc=None):
+        """ Signals an intent to read/write from a particular file descriptor.
+        
+        The fileno argument is the file number of the file of interest.  The other
+        arguments are either callbacks or None.  If there is a callback for read
+        or write, the hub sets things up so that when the file descriptor is
+        ready to be read or written, the callback is called.
+        
+        The exc callback is called when the socket represented by the file
+        descriptor is closed.  The intent is that the the exc callbacks should
+        only be present when either a read or write callback is also present,
+        so the exc callback happens instead of the respective read or write
+        callback.
+        """
+        
         self.readers[fileno] = read or self.readers.get(fileno)
         self.writers[fileno] = write or self.writers.get(fileno)
         self.excs[fileno] = exc or self.excs.get(fileno)
diff --git a/eventlet/util.py b/eventlet/util.py
index 994ff4c..237aa95 100644
--- a/eventlet/util.py
+++ b/eventlet/util.py
@@ -90,8 +90,12 @@ def wrap_ssl(sock, certificate=None, private_key=None):
     connection.set_connect_state()
     return greenio.GreenSocket(connection)
 
-
+socket_already_wrapped = False
 def wrap_socket_with_coroutine_socket():
+    global socket_already_wrapped
+    if socket_already_wrapped:
+        return
+
     def new_socket(*args, **kw):
         from eventlet import greenio
         s = __original_socket__(*args, **kw)
@@ -100,6 +104,8 @@ def wrap_socket_with_coroutine_socket():
     socket.socket = new_socket
 
     socket.ssl = wrap_ssl
+    
+    socket_already_wrapped = True
 
 
 def socket_bind_and_listen(descriptor, addr=('', 0), backlog=50):