[Tutor] Test case

[Jonathan Hayward http://JonathansCorner.com]

Just after posting the below, I realised that my test case worked after 
I added flushes. The next problem I have is that, in the real program, 
the server gets an EOFError when it first tries to read from the socket. 
Relevant portions follow the error message below:

Traceback (most recent call last):
  File "/var/www/cgi-bin/datamine", line 1633, in ?
    find_and_output_appropriate_page()
  File "/var/www/cgi-bin/datamine", line 1461, in 
find_and_output_appropriate_page
    sys.stdout.write(get_output())
  File "/var/www/cgi-bin/datamine", line 1497, in get_output
    return multitasking.get_page_from_oracle()
  File "/var/www/cgi-bin/datamine", line 976, in get_page_from_oracle
    self.check_and_start_oracle()
  File "/var/www/cgi-bin/datamine", line 972, in check_and_start_oracle
    self.start_oracle()
  File "/var/www/cgi-bin/datamine", line 1083, in start_oracle
    self.run_oracle()
  File "/var/www/cgi-bin/datamine", line 1056, in run_oracle
    self.handle_oracle_query(newsocket, address)
  File "/var/www/cgi-bin/datamine", line 1015, in handle_oracle_query
    self.get_thread_specific_storage()["environment_variables"] = \
EOFError
Traceback (most recent call last):
  File "/var/www/cgi-bin/datamine", line 1633, in ?
    find_and_output_appropriate_page()
  File "/var/www/cgi-bin/datamine", line 1461, in 
find_and_output_appropriate_page
    sys.stdout.write(get_output())
  File "/var/www/cgi-bin/datamine", line 1497, in get_output
    return multitasking.get_page_from_oracle()
  File "/var/www/cgi-bin/datamine", line 988, in get_page_from_oracle
    result = cPickle.load(sockIn)
IOError: [Errno 104] Connection reset by peer

 From the server side, here are run_oracle() and handle_oracle_query():

    def run_oracle(self):
        #thread.start_new_thread(\
          #self.initialize, ())
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        sock.bind(("", configuration.get_search_server_port()))
        sock.listen(5)
        while 1:
            try:
                newsocket, address = sock.accept()
                self.handle_oracle_query(newsocket, address)
                #thread.start_new_thread(self.handle_oracle_query, 
(newsocket, \                  #address))
            except socket.error:
                sock.close()
                sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
                sock.bind(("", configuration.get_search_server_port()))
                sock.listen(5)

    def handle_oracle_query(self, sock, address):
        sockIn = sock.makefile("rb")
        sockOut = sock.makefile("wb")
        sockIn.flush()
### Line 1015, immediately below, is where the EOF error is reported.
        self.get_thread_specific_storage()["environment_variables"] = \
          cPickle.load(sockIn)
        sockIn.flush()
        self.get_thread_specific_storage()["cgi"] = cPickle.load(sockIn)
        generate_output()
        print_output(sockOut)
        sockOut.flush()
        sock.close()
        sockIn.close()
        sockOut.close()

 From the client side, here is get_page_from_oracle():

    def get_page_from_oracle(self):
        self.check_and_start_oracle()
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        try:
            sock.connect((configuration.get_search_server_ip(), \
              configuration.get_search_server_port()))
            sockIn = sock.makefile("rb")
            sockOut = sock.makefile("wb")
            cPickle.dump(os.environ, sockOut)
            sockOut.flush()
            cPickle.dump(cgi.FieldStorage(), sockOut)
            sockOut.flush()
            sockIn.flush()
### Line 988, immediately below, also gets an error, but I believe this 
is secondary damage.
            result = cPickle.load(sockIn)
            sock.close()
            sockIn.close()
            sockOut.close()
            #return "Content-type: text/html\n\nget_page_from_oracle"
            return result



Jonathan Hayward http://JonathansCorner.com wrote:

> I'm trying to have a client open a socket, send two pickled hashes,
> and receive a pickled object (I'm also writing the server, to listen,
> read two pickled hashes, and send a pickled object). I've been able to
> boil down what doesn't work to a small demo case:
> ____________________________________________________________
>
> SERVER:
> #!/usr/bin/python
>
> import cPickle, socket
>
> sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
> sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
> sock.bind(("", 1234))
> sock.listen(5)
>
> try:
>    newsocket, address = sock.accept()
>    sockOut = newsocket.makefile("wb")
>    sockIn = newsocket.makefile("rb")
>    cPickle.load(sockIn)
>    cPickle.load(sockIn)
>    cPickle.dump("Hello, world!", sockOut)
>    newsocket.close()
>    sockOut.close()
>    sockIn.close()
> finally:
>    sock.close()
> ____________________________________________________________
>
> CLIENT:
> #!/usr/bin/python
>
> import cPickle, socket
>
> sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
> sock.connect(("127.0.0.1", 1234))
> sockOut = sock.makefile("wb")
> sockIn = sock.makefile("r")
> cPickle.dump({}, sockOut)
> cPickle.dump({}, sockOut)
> response_data = cPickle.load(sockIn)
> print response_data
> sockOut.close()
> sockIn.close()
> sock.close()
> ____________________________________________________________
>
> When I start the server and then start the client, they both hang, as
> has happened with the real script. Can you tell me what I am misusing
> and preferably how to correct it?
>
> TIA,
>


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