[Zodb-checkins] CVS: ZEO/ZEO/zrpc - client.py:1.1.2.8

[Tim Peters]

Update of /cvs-repository/ZEO/ZEO/zrpc
In directory cvs.zope.org:/tmp/cvs-serv3077/zrpc

Modified Files:
      Tag: Standby-branch
	client.py 
Log Message:
XXX comments for Jeremy.
Minor docstring repair and code cleanup.


=== ZEO/ZEO/zrpc/client.py 1.1.2.7 => 1.1.2.8 ===
 
     def attempt_connects(self):
-        "Return true if any connect attempt succeeds."
-        self.sockets = {}
+        """Try connecting to all self.addrs addresses.
+
+        If at least one succeeds, pick a success arbitrarily, close all other
+        successes (if any), and return true.  If none succeed, return false.
+        """
+
+        self.sockets = {}  # {open socket:  connection address}
 
         log("attempting connection on %d sockets" % len(self.addrs))
         try:
@@ -224,8 +229,9 @@
                 s = socket.socket(domain, socket.SOCK_STREAM)
                 s.setblocking(0)
                 self.sockets[s] = addr
+                # connect() raises Connected iff it succeeds
                 # XXX can still block for a while if addr requires DNS
-                e = self.connect(s)
+                self.connect(s)
 
             # next wait until they actually connect
             while self.sockets:
@@ -237,8 +243,8 @@
                 except select.error:
                     continue
                 for s in w:
-                    # connect() will raise Connected if it succeeds
-                    e = self.connect(s)
+                    # connect() raises Connected iff it succeeds
+                    self.connect(s)
         except Connected, container:
             s = container.sock
             del self.sockets[s] # don't close the newly connected socket
@@ -247,7 +253,7 @@
         return 0
 
     def connect(self, s):
-        """Call s.connect_ex(addr) and return true if loop should continue.
+        """Call s.connect_ex(addr); raise Connected iff connection succeeds.
 
         We have to handle several possible return values from
         connect_ex().  If the socket is connected and the initial ZEO
@@ -258,6 +264,9 @@
 
         If the socket sonnects and the initial ZEO setup fails or the
         connect_ex() returns an error, we close the socket and ignore it.
+        XXX If test_connection() fails (I assume that's what's meant by
+        XXX "the initial ZEO setup fails", the code below doesn't do anything
+        XXX with the socket.  So the comment or the code is wrong.
         When the socket is closed, it is removed from self.sockets.
 
         If connect_ex() returns EINPROGRESS, we need to try again later.
@@ -265,7 +274,7 @@
         addr = self.sockets[s]
         e = s.connect_ex(addr)
         if e in _CONNECT_IN_PROGRESS:
-            return 1
+            pass
         elif e in _CONNECT_OK:
             c = self.test_connection(s, addr)
             log("connected to %s" % repr(addr), level=zLOG.DEBUG)
@@ -286,6 +295,9 @@
             log("error connecting to server: %s" % str(addr),
                 level=zLOG.ERROR, error=sys.exc_info())
             c.close()
+            # XXX what's the state of s at this point?  If s got closed,
+            # XXX self.sockets contains a closed socket, and the
+            # XXX next attempt_connects() select() will blow up.
             return 0
         self.mgr.connect_done(c)
         return 1