Remote socket close doesn't raise error right away in Repy V2. about repy_v2

[choksi81]

Author: alexjh
Checking out the latest repy_v2 branch from SVN, I am unable to reproduce this problem on either Mac OS X (my laptop) or on Linux (through blackbox). Is there a chance this has been fixed already, or is anybody able to reproduce the problem?

[choksi81]

Author: mkaplan
I was able to reproduce this issue on my Linux machine:
Repy V2 revision 4872.
Linux version 2.6.38-11-generic (buildd@allspice) (gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-8ubuntu4) ) #50-Ubuntu SMP Mon Sep 12 21:17:25 UTC 2011
Python 2.6.6

On my Windows machine, the issue appears to be slightly different. The unit test fails in the normal case, when only one message is sent. However, if a second message is sent, it throws a exception_hierarchy.SocketClosedLocal exception. The log is attached below.
Repy V2 revision 4872.
Windows 7 (x86)
Python 2.5

[choksi81]

Author: vijay
By TCP rules, the only way for a server/client program to know if a server/client has disconnected,is to try to read from the socket. Specifically, if select() says there is data, but recv() returns 0 bytes of data, then this implies the client has disconnected.

A program might want to confirm that a tcp client is still connected without reading data. For example, before it performs some task or sends data to the client.

In our case as send() part is the problem focus,we will try to detect closed remote socket before sending data.

The method to do this:
select on socket (whose corresponding remote socket close we need to detect) as poll (no wait):Using select.select() especially on receiving function of the socket.
if no recv() data waiting, then remote side is still connected.
if recv() data waiting, the read one char using PEEK flag
if PEEK data len=0, then the remote side has disconnected, otherwise its connected.
In the following program sock is our socket whose corresponding remote socket close we need to detect.

[choksi81]

Author: vijay
Committed r4929.Fixed this problem