DPLACE(3)                                                            DPLACE(3)


NAME
     dplace_file, dplace_line, libdplace - a library interface to dplace

C SYNOPSIS
         void dplace_file( char *filename);
         void dplace_line( char *line);


FORTRAN SYNOPSIS
          CHARACTER*n string
          CALL dplace_file( string)
          CALL dplace_line( string)


DESCRIPTION
     These library routines provide high level access to a subset of the
     memory management and control mechanisms of IRIX. Dynamic dplace(1)
     functionality is provided from within a user's program.  The first form
     takes a filename as an argument and all commands within the file are
     processed. The second form operates on a single command.  Errors are
     handled in the same way as dplace(1); the program exits and a diagnostic
     message is printed to standard error.  The library can be used with or
     without using dplace(1).


EXAMPLE CODE
     Here is a fragment of FORTRAN code

             CHARACTER*128 s
             np = mp_numthreads()
             WRITE(s,*) 'memories ',np,' in cube'
             CALL dplace_line(s)

             WRITE(s,*) 'threads ',np
             CALL dplace_line(s)

             DO i=0, np-1
                 WRITE(s,*) 'run thread',i,' on memory',i
                 CALL dplace_line(s)
                 head = %loc( a( 1+i*(n/np) ) )
                 tail = %loc( a( (i+1)*(n/np) ) )
                 WRITE(s,*) 'place range',head,' to',tail,' on memory',i
                 CALL dplace_line(s)
             END DO

             DO i=0, np-1
                 WRITE(s,*) 'move thread',i,' to memory',np-1-i
                 CALL dplace_line(s)
             END DO


             DO i=0, np-1
                 head = %loc( a( 1+i*(n/np) ) )
                 tail = %loc( a( (i+1)*(n/np) ) )
                 WRITE(s,*) 'migrate range',head,' to',tail,' to memory',np-1-i
                 CALL dplace_line(s)
             END DO


     and here is a C language code fragment:

          main(){ /* C  example code */
          ...
              dplace_file("initial_placement_file");
          ...
          ... data initialization,sprocs etc.
          ...
              for(i=0;i<nthreads;i++){
               sprintf(cmd,"run thread %d on memory %d\n",i,i/2);
              dplace_line(cmd);
          ...
              sprintf(cmd,"migrate range %d to %d to memory %d\n"
               ,&a[i*size],&a[(i+1)size-1],i/2);
              dplace_line(cmd);
          ...
              }
          }

     When linking C or FORTRAN programs, the flag -ldplace will automatically
     invokes the correct libdplace library.

FILES
     /usr/lib/libdplace.so

     /usr/lib64/libdplace.so

     /usr/lib32/libdplace.so


DEPENDENCIES
     These procedures are only available on NUMA systems. In order to avoid
     conflicts with Fortran's libmp, it is advisable to set the environment
     variable _DSM_OFF to disable libmp's NUMA functionality before running
     programs that are linked with libdplace.


BUGS
     Operations on the default policy module, such as the setting of default
     page sizes, should be done prior to an exec call to take effect. For
     example, setting the data page size with dplace_line or dplace_file from
     the program in question will not have the desired effect.


SEE ALSO


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