Re: [Zope] Asynchronous DTML

5 Oct 2001

      Thanks Chris,

Anybody else able to shed some light on my problem?

If the promises of .NET are realised we should be doing a lot more calling
out to external servers like this from Zope.
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W.Robert Kellock                                    Ph:
+64 3 326 6115
Sales Manager                                        Fax:
+64 3 326 6115
Credit Systems Control Ltd                      Web:
www.creditscore.co.nz
                                              "making decisions easy"
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----- Original Message -----
From: "Chris McDonough" <chrism@digicool.com>
To: "W. Robert Kellock" <sales@creditscore.co.nz>
Sent: Friday, 5 October 2001 14:32
Subject: Re: [Zope] Asynchronous DTML
...
Hmm... not exactly a socket programming guru here.. would you mind
sending this to the list?  I wonder if there's a system call somewhere
in here that locks a mutex.  I'm not sure but someone else might know.
Just for a sanity check, you might want to write an external method like:
import thread, time, zLOG
def test(self):
     ident = thread.get_ident()
     zLOG.LOG('test', 0, "starting in %s at %s" % (ident, time.time()))
     time.sleep(10)
     zLOG.LOG('test', 0, "  ending in %s at %s" % (ident, time.time()))
Then fire off a few requests to it to prove to yourself that it's not
serializing the calls (if no time periods in the log overlap, it's
serializing).  Youc an see the log by starting Zope up like this:
./start STUPID_LOG_FILE=debug.log
- C
W. Robert Kellock wrote:
...
The following external method definitely blocks on my RedHat 7.1 Linux
box.
Any ideas?
from socket import *
import time
import string
def GetBureau(self,host,port,request,terminator):
      s = socket(AF_INET,SOCK_STREAM)
      s.connect((host,port))
      s.setblocking(0) #non-blocking to allow us to time out
      s.send(request)
      start  = time.time()
      data   = ''
      buffer = ''
      cont = 1
      while cont:
       cont = 0
        try:
            buffer = s.recv(256)
       except:
           pass
       if len(buffer):
            cont = 1
            last = string.count(buffer,terminator)
            if (last > 0):
                cont = 0
                buffer = buffer[:string.find(buffer,terminator) +
len(terminator)]
            data = data + buffer
            buffer = ''
       else:
           if (start + 60 > time.time()):# time out if no response
               cont = 1
            else:
               if (len(data) > 0):
                   pass
               else:
                   data = ''
      s.close()
      return data
--------------------------------------------------------------------------
--
...
---------------------------------
W.Robert Kellock                                    Ph:
+64 3 326 6115
Sales Manager                                        Fax:
+64 3 326 6115
Credit Systems Control Ltd                      Web:
www.creditscore.co.nz
                                              "making decisions easy"
--------------------------------------------------------------------------
--
...
---------------------------------
----- Original Message -----
From: "Chris McDonough" <chrism@digicool.com>
To: "W. Robert Kellock" <sales@creditscore.co.nz>
Cc: <zope@zope.org>
Sent: Friday, 5 October 2001 13:56
Subject: Re: [Zope] Asynchronous DTML
...
Zope is multithreaded and there are typically no locks on any resources
that prevents one thread from operating independently of another, so
what you want is likely available out of the box.
W. Robert Kellock wrote:
...
Hello,
Does anyone know how to prevent an external method from blocking?
What I need is an external method that contacts an external server and
returns the result to be displayed in my dtml page.  It's quite alright
for the person requesting the page to wait for the response. What I
don't want is for other users to be blocked while the external server
formulates it's response to that user.
From the archives it seems I need to piggyback onto Zopes asyncore /
asynchat to achieve this, but I'm not sure how.
Thanks.
...
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-----------------------------------
...
...
W.Robert Kellock
Ph:                   +64 3 326 6115
Sales Manager
Fax:                  +64 3 326 6115
Credit Systems Control Ltd                      Web:
www.creditscore.co.nz <http://www.creditscore.co.nz>
                                             "making decisions easy"
...
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...
-----------------------------------
...
--
Chris McDonough                    Zope Corporation
http://www.zope.org             http://www.zope.com
"Killing hundreds of birds with thousands of stones"
--
Chris McDonough                    Zope Corporation
http://www.zope.org             http://www.zope.com
"Killing hundreds of birds with thousands of stones"