enh: no memory leaks for blacs_exit and allow re-call

This should enable ScaLAPACK/BLACS to be exited and restarted
at will without memory leaks or problems.

When called with blacs_exit(true), the comm_world will be
retained and MPI_Finalized won't be called.
Only when blacs_exit(false) is called will the BI_COMM_WORLD
be de-allocated. So one should expect a memory leak of
an integer if the hosting application calls MPI_Finalize.

Author: zerothi

BLACS/SRC/blacs_exit_.c

@@ -12,6 +12,7 @@ F_VOID_FUNC blacs_exit_(Int *NotDone)
    Int BI_BuffIsFree(BLACBUFF *, Int);
    BLACBUFF *bp;
    extern BLACBUFF *BI_ReadyB, *BI_ActiveQ, BI_AuxBuff;
+   extern MPI_Status *BI_Stats;
    Int i;
    extern Int BI_MaxNCtxt, BI_Np;
    extern BLACSCONTEXT **BI_MyContxts;
@@ -30,6 +31,7 @@ F_VOID_FUNC blacs_exit_(Int *NotDone)
       free(bp);
    }
    free (BI_AuxBuff.Aops);
+   free (BI_Stats);
 
 /*
  * Reset parameters to initial values
@@ -39,7 +41,12 @@ F_VOID_FUNC blacs_exit_(Int *NotDone)
    BI_Np = -1;
    if (!Mpval(NotDone))
    {
-      MPI_Finalize();
+     free(BI_COMM_WORLD);
+     BI_COMM_WORLD = NULL;
+     MPI_Finalize();
    }
    BI_ReadyB = NULL;
+   BI_ActiveQ = NULL;
+   BI_AuxBuff.Aops = NULL;
+   BI_Stats = NULL;
 }

BLACS/SRC/blacs_pinfo_.c

@@ -20,9 +20,9 @@ F_VOID_FUNC blacs_pinfo_(Int *mypnum, Int *nprocs)
 
       BI_COMM_WORLD = (Int *) malloc(sizeof(Int));
       *BI_COMM_WORLD = MPI_Comm_c2f(MPI_COMM_WORLD);
-      MPI_Comm_size(MPI_COMM_WORLD, &Np);
-      MPI_Comm_rank(MPI_COMM_WORLD, &Iam);
    }
+   MPI_Comm_size(MPI_COMM_WORLD, &Np);
+   MPI_Comm_rank(MPI_COMM_WORLD, &Iam);
    *mypnum = BI_Iam = Iam;
    *nprocs = BI_Np  = Np;
 }