ramkumar@m.cs.uiuc.edu (02/13/90)
I am trying to port a program from the Suns to one of the Encores running at Univ. of Illinois (one runs unix 4.2 and the other 4.3 Beta version) and am having some problems. The program is supposed to simulate parallel processing on distributed machines I need to fork unix processes, however it is NOT important for me to have parallel processors. The program has been written to set up the parallel processing environment as follows: host process /..... | ......\ several node processes the processes are organized in a star configuration with the host in the centre. The processes communicate with each other using pipes (two nodes communicate via the host process). Now my problem: I use "fstat()" to find out whether there is some unread data on a pipe. One of the fields (st_size) in the structure (stat) filled in by fstat() returns this value correctly on the suns. This values is always 0 on both 4.2 and 4.3 on the Multimaxen. I modified that to use "fcntl" to set the FNDELAY flag to make possible a nonblocking read from the pipe - again this works on the suns but will not on the maxen. Any hints and/or suggestions will be welcome. ram