MPI fixes

library/lammpi/examples/gowait

@@ -0,0 +1,47 @@
+#!/usr/local/bin/yap -L --
+
+% called with
+% mpirun -np 2 gowait.
+% prints
+% ------
+% main
+% main
+% after_init
+% after_init
+% [0,2]
+% [1,2]
+% irecv
+% wait_end
+% after_send
+% c(535755152,)
+
+:- use_module(library(lam_mpi)).
+:- use_module(library(system)).
+main:-
+	write(main),nl,
+	mpi_init,
+	write(after_init),nl,
+	mpi_comm_size(S),
+	mpi_comm_rank(R),
+	write([R,S]),nl,
+	(R == 0->
+	 sleep(2),
+	 write(wait_end),nl,
+	 mpi_send(ciao,1,201),
+	 write(after_send),nl
+	;
+	 mpi_irecv(0,_201,H),
+	 write(irecv),nl,
+	 test(H)
+	),
+	mpi_finalize.
+
+test(H):-
+	(mpi_wait_recv(H,S,Data)->
+	 write(c(S,Data)),nl
+	;
+	 write(no),nl,
+	 test(H)
+	).
+
+:-main.