Description
Enhance p1 by supplying a port number to each of the ranks so they
can use it in MPI_Init etc. It can be used to connect back to the
process running mpiexec and retrieve information such as how to
contact other ranks.
Then, implement your own MPI that supports the following functions:
MPI_Comm_rank from env
MPI_Comm_size from env
MPI_Finalize fork parent handles this
MPI_Init start here, with calling socket.
send rank sockets back to calling machine
sin.sin_port = htons(port); –> htons(0);
set port to 0, and OS will choose one, then use getsockname() to find port
i am assigned 4401-4499. or can use any ports from 0-3999,6001-65000
rank, size, host from env
get accept(listen) socket – set port — connect to host
return MPI_SUCCESS
ppexec accepts connections in a loop — save host and port info from sender
send info about all ranks to all ranks?
hosts have to know the cwd – in mpiexec:
getcwd() -> into env var -> send to host –> cd \$PWD
fix ppexec for looking for child process end
MPI_Send (just wrapper for Ssend)
validate args (including comm)
get connection to dest (if don’t have)
connect to dest
send msg (char or int)
progress engine!! – could handle multiple things at once (ie receives)
send is done when buffer is reusable by the user
read MPI standards: advice to users/implementors
… could send header first, and then send buffer in PE()
MPI_Ssend
MPI_Recv
MPI_Barrier no one leaves until we’re all here
progress engine:
is there something to do? // in separate thread? whatever, whenever
// as uni-process after every MPI call
select system call
nfds – FD_SETSIZE
timeout – NULL: indef, 0: poll, !=0: =hang time
EOF shows something there
remind dr butler about test files
library blahblah in 6430rmb/DEMOS/LIB
https://www.cs.mtsu.edu/~rbutler/courses/pp6330/pp.html
You only need to support MPI_COMM_WORLD for this project.
Place your object code into a library named libpp.a which
test files can link against.
Compile and link the program previously named p1 as ppexec.
Have a makefile that will build libpp.a and compile and link
ppexec as well as any test programs that we develop.
I will cd to my dir containing your project files and type:
rm -f libpp.a
rm -f *.o
make
Use turnin as in p1.
