deliberate versus os socket timeout

Robin Becker robin at reportlab.com
Thu Jul 5 19:28:45 CEST 2007


While messing about with some deliberate socket timeout code I got an unexpected 
timeout after 20 seconds when my code was doing socket.setdefaulttimeout(120).

Closer inspection revealed that this error in fact seemed to come from the os 
(in this case windows xp).

By inspection of test cases the error.reason from the deliberate socket timeout 
looks like
     'timed out'
whereas the windows caused timeout error.reason looks like
     '(10060 operation timed out)'

it would be nice to know if that is in fact true and whether there is any way to 
do the attribution of errors more sensibly.

Both of these seem to cause urllib2.URLError and presumably appear somewhere in 
the socket code.

It might be nice if the deliberate timeout could be something like 'timed out 
deliberately after xxx seconds'.

More importantly is there anything I can do to avoid these wrong os inspired 
timeouts? I'm just using urllib2 to read from a remote site inside of a cgi 
script. I'm not sure it's a big problem, but I have no idea what could cause it.

The code I'm using is based on one of jjlee's recipes

def httpGet(self):
     import urllib2, socket
     from xml.sax.saxutils import escape
     oto = socket.getdefaulttimeout()
     try:
         socket.setdefaulttimeout(self.timeout)
         self.url = url = self.makeUrl(self.params)
         try:
             self.response = r = urllib2.urlopen(url)
         except urllib2.URLError, e:
             if hasattr(e, 'reason'):
                 msg = 'HTTP error '+str(e.reason)
                 if 'time' in msg:
                     msg += '(our timeout=%s)' % socket.getdefaulttimeout()
                 return 1,escape(msg)
             elif hasattr(e, 'code'):
                 return 1, escape('The server couldn\'t fulfill the 
request.\nError code: '+str(e.code))
         else:
             # everything is fine
             h = self.headers = {}
             ........
             return 0,......
     finally:
         socket.setdefaulttimeout(oto)

-- 
Robin Becker




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