PS: Help pickling across sockets

[Jonathan Hayward]

Just after posting the previous request, 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 result

TIA,
++ Jonathan Hayward, jonathan.hayward at pobox.com
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