#! /usr/bin/env isis-script
% -*- mode: SLang; mode: fold -*-

%  cl_slave:	Slave program for parallel computation of single-parameter
%		confidence limits in ISIS, using PVM, as described in
%		"Using the Parallel Virtual Machine for Everyday Analysis,"
%		by Noble et al 2006 (http://arxiv.org/abs/astro-ph/0510688)
%
%  Authors: John C. Houck <houck@space.mit.edu>
%	    Michael S. Noble <mnoble@space.mit.edu>
%
%  Version: 0.3.0  (Fri Oct  3 11:53:50 EDT 2008)

require ("pvm_ms");
require ("pvm_msgid");

pvm_sigterm_enable (1);

variable Sub_Dir;
variable Level = 1;
variable Tolerance = 10^-3;

define exit_slave (status) %{{{
{
   pvm_ms_slave_exit (status);
   exit (status);
}

%}}}

define initialize (argc, argv) %{{{
{
   if (argc < 3)
     {
	usage ("cl_slave param_name subdir [conf_level] [tolerance]");
	exit_slave (1);
     }

   variable conf_info = struct
     {
	name, value, lo, hi, hostname, params, statistic
     };
   conf_info.name = argv[1];
   conf_info.hostname = uname().nodename;

   Sub_Dir = argv[2];

   if (argc > 3)
	Level = integer(argv[3]);

   if (argc > 4)
	Tolerance = eval(argv[4]);	% eval(10^-3) better than atof(10^-3)

   return conf_info;
}

%}}}

variable Conf_Info = initialize (__argc, __argv);

define load_file (file) %{{{
{
   ERROR_BLOCK { exit_slave (1); }
   () = evalfile (file);
}

%}}}

if (-1 == chdir (Sub_Dir))
{
   vmessage ("couldnt chdir to %s", Sub_Dir);
   exit_slave (1);
}

% Look for code first in the target directory,
% then in the parent directory.
prepend_to_isis_load_path (path_dirname(Sub_Dir));
prepend_to_isis_load_path (Sub_Dir);

% load all data files
load_file ("init.sl");

variable Have_New_Params = 0;

define doit (info, level, tolerance) %{{{
{
   (info.lo, info.hi) = conf (info.name, level, tolerance);
   info.value = get_par (info.name);

   if (Have_New_Params)
     return;

   variable parent_tid = pvm_parent ();

   if (info.lo == info.hi)			% Found better fit
     {
	variable x;
	() = fit_counts(&x);
	info.statistic = x.statistic;
	info.params = get_params();
        pvm_send_obj (parent_tid, USER_SLAVE_NEWTASK, info);
        return;
     }

   info.params = NULL;
   info.statistic = NULL;
   pvm_send_obj (parent_tid, USER_SLAVE_RESULT, info);
}

%}}}

public define isis_fit_improved_hook () %{{{
{
   % Non-blocking receive
   variable bufid = pvm_nrecv(pvm_parent(), USER_SLAVE_NEWTASK);

   if (bufid > 0)
     {
        Have_New_Params = 1;
        return 1;
     }

   return 0;
}

%}}}

define slave_next_task ();
define slave_next_task () %{{{
{
   variable parent_tid, bufid, msgid;
   parent_tid = pvm_parent ();
   % Blocking receive
   bufid = pvm_recv (parent_tid, -1);
   (,msgid,) = pvm_bufinfo (bufid);

   switch (msgid)
     {
      case USER_SLAVE_RESULT:
        variable params = pvm_recv_obj ();
        set_params (params);
        return 1;
     }
     {
      case USER_SLAVE_NEWTASK:
        return slave_next_task ();
     }

   return 0;
}

%}}}

define isis_main ()  % {{{
{
   variable status = 1;

   ERROR_BLOCK
     {
	exit_slave (status);
     }

   forever
     {
        Have_New_Params = 0;
        doit (Conf_Info, Level, Tolerance);
        if (0 == slave_next_task ())
          break;
     }

   status = 0;
   EXECUTE_ERROR_BLOCK;
}  % }}}