SocketException (code = 10055)

Question

Hi all,
Here i go again. We are doing some data sending from a java socket to a C socket. Now the java side is receiving data from a serial port. The data is in the order of 7920 bytes per min. Great everything works fine, till 139 thousand odd messages are send (each message i mean a byte array of 11 bytes). But after those number of messages the java side receives a socketexception and code was indicated 10055. I looked up for this code, and in MSDN could get this code to indicate a TCP buffer full
(WSAENOBUFS (10055)
No buffer space available.
An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full).
and the c side hangs. The best part is till we kill (ctrl-c) the C side i cannot even browse. I found out that if we increase the sendbuffer size on java side and c side increases the recv buffer size it would work just fine. I did that and the buffer size now is at 128K on both ends and decreased the number of bytes to 3300. But now the same error occurs after 170 thousand messages. Can anyone tell me
1. Is sending small chunks of data a problem.
2. What is the mbuff concept. I read someplace that the buff size is nothing but the number of mbuff the receiver tcp stack maintains.
To worsen my problems i am suppossed to do this whole thing on WINDOWS 2000 machine.
By the way the socket connection is to send data from a Java process to a C Process running in the same system. Does this complicate the problem??
Any help would be great. and all the ppl who reply will be given heartfelt good wishes:). HELPPPP MEEE B4 i go mad
arvind

Answer 1

Actually its 7920 bytes period in a minite. and i have
been able to find out that on the c side we have
threads that read data from sockets. each thread after
reading has to wait for few mutex and max time for
these is 200 millisecs. SO at max there can be only 5
messages(5*11 bytes = 55 bytes)that can be read every
second and i was sending 12 messages(12*11 = 132
bytes) per second before. So i did the flow control on
the jave side and i have been able to avoid the tcp
buffer full problem. But i still do not like this as
the messages will come slow and the data that has to
be received 10 secs earlier is received 10 secs
later..... is there any other method for this.
So each packet contains 11 bytes?
You can definitely read more than 5 per second. Even if all else fails one way is to buffer more than one message at a time. So instead of pushing every message to the queue. Push it every 5th packet.
Given that I have written socket handlers in java that pulled slightly more than 2000 TCP packets every second I am certain that you can increase the speed. Since java doesn't have 'mutexes' I am guessing that you are referring to synchronization and I would expect a faster time than that. How did you time the lock acquisition and release?