Installation Instructions

*************************

Copyright (C) 1994, 1995, 1996, 1999, 2000, 2001, 2002, 2004, 2005,

   This file is free documentation; the Free Software Foundation gives

unlimited permission to copy, distribute and modify it.

Basic Installation

==================

   Briefly, the shell commands `./configure; make; make install' should

configure, build, and install this package.  The following

more-detailed instructions are generic; see the `README' file for

instructions specific to this package.

   The `configure' shell script attempts to guess correct values for

various system-dependent variables used during compilation.  It uses

those values to create a `Makefile' in each directory of the package.

It may also create one or more `.h' files containing system-dependent

definitions.  Finally, it creates a shell script `config.status' that

you can run in the future to recreate the current configuration, and a

file `config.log' containing compiler output (useful mainly for

debugging `configure').

   It can also use an optional file (typically called `config.cache'

and enabled with `--cache-file=config.cache' or simply `-C') that saves

the results of its tests to speed up reconfiguring.  Caching is

disabled by default to prevent problems with accidental use of stale

cache files.

   If you need to do unusual things to compile the package, please try

to figure out how `configure' could check whether to do them, and mail

diffs or instructions to the address given in the `README' so they can

be considered for the next release.  If you are using the cache, and at

some point `config.cache' contains results you don't want to keep, you

may remove or edit it.

   The file `configure.ac' (or `configure.in') is used to create

`configure' by a program called `autoconf'.  You need `configure.ac' if

you want to change it or regenerate `configure' using a newer version

of `autoconf'.

The simplest way to compile this package is:

  1. `cd' to the directory containing the package's source code and type

     `./configure' to configure the package for your system.

     Running `configure' might take a while.  While running, it prints

     some messages telling which features it is checking for.

  2. Type `make' to compile the package.

  3. Optionally, type `make check' to run any self-tests that come with

     the package.

  4. Type `make install' to install the programs and any data files and

     documentation.

  5. You can remove the program binaries and object files from the

     source code directory by typing `make clean'.  To also remove the

     files that `configure' created (so you can compile the package for

     a different kind of computer), type `make distclean'.  There is

     also a `make maintainer-clean' target, but that is intended mainly

     for the package's developers.  If you use it, you may have to get

     all sorts of other programs in order to regenerate files that came

     with the distribution.

  6. Often, you can also type `make uninstall' to remove the installed

     files again.

Compilers and Options

=====================

   Some systems require unusual options for compilation or linking that

the `configure' script does not know about.  Run `./configure --help'

for details on some of the pertinent environment variables.

   You can give `configure' initial values for configuration parameters

by setting variables in the command line or in the environment.  Here

is an example:

     ./configure CC=c99 CFLAGS=-g LIBS=-lposix

   *Note Defining Variables::, for more details.

Compiling For Multiple Architectures

====================================

   You can compile the package for more than one kind of computer at the

same time, by placing the object files for each architecture in their

own directory.  To do this, you can use GNU `make'.  `cd' to the

directory where you want the object files and executables to go and run

the `configure' script.  `configure' automatically checks for the

source code in the directory that `configure' is in and in `..'.

   With a non-GNU `make', it is safer to compile the package for one

architecture at a time in the source code directory.  After you have

installed the package for one architecture, use `make distclean' before

reconfiguring for another architecture.

   On MacOS X 10.5 and later systems, you can create libraries and

executables that work on multiple system types--known as "fat" or

"universal" binaries--by specifying multiple `-arch' options to the

compiler but only a single `-arch' option to the preprocessor.  Like

this:

     ./configure CC="gcc -arch i386 -arch x86_64 -arch ppc -arch ppc64" \

                 CXX="g++ -arch i386 -arch x86_64 -arch ppc -arch ppc64" \

                 CPP="gcc -E" CXXCPP="g++ -E"

   This is not guaranteed to produce working output in all cases, you

may have to build one architecture at a time and combine the results

using the `lipo' tool if you have problems.

Installation Names

==================

   By default, `make install' installs the package's commands under

`/usr/local/bin', include files under `/usr/local/include', etc.  You

can specify an installation prefix other than `/usr/local' by giving

`configure' the option `--prefix=PREFIX'.

   You can specify separate installation prefixes for

architecture-specific files and architecture-independent files.  If you

pass the option `--exec-prefix=PREFIX' to `configure', the package uses

PREFIX as the prefix for installing programs and libraries.

Documentation and other data files still use the regular prefix.

   In addition, if you use an unusual directory layout you can give

options like `--bindir=DIR' to specify different values for particular

kinds of files.  Run `configure --help' for a list of the directories

you can set and what kinds of files go in them.

   If the package supports it, you can cause programs to be installed

with an extra prefix or suffix on their names by giving `configure' the

option `--program-prefix=PREFIX' or `--program-suffix=SUFFIX'.

Optional Features

=================

   Some packages pay attention to `--enable-FEATURE' options to

`configure', where FEATURE indicates an optional part of the package.

They may also pay attention to `--with-PACKAGE' options, where PACKAGE

is something like `gnu-as' or `x' (for the X Window System).  The

`README' should mention any `--enable-' and `--with-' options that the

package recognizes.

   For packages that use the X Window System, `configure' can usually

find the X include and library files automatically, but if it doesn't,

you can use the `configure' options `--x-includes=DIR' and

`--x-libraries=DIR' to specify their locations.

Particular systems

==================

   On HP-UX, the default C compiler is not ANSI C compatible.  If GNU

CC is not installed, it is recommended to use the following options in

order to use an ANSI C compiler:

and if that doesn't work, install pre-built binaries of GCC for HP-UX.

   On OSF/1 a.k.a. Tru64, some versions of the default C compiler cannot

parse its `<wchar.h>' header file.  The option `-nodtk' can be used as

a workaround.  If GNU CC is not installed, it is therefore recommended

to try

     ./configure CC="cc"

and if that doesn't work, try

     ./configure CC="cc -nodtk"

Specifying the System Type

==========================

   There may be some features `configure' cannot figure out

automatically, but needs to determine by the type of machine the package

will run on.  Usually, assuming the package is built to be run on the

_same_ architectures, `configure' can figure that out, but if it prints

a message saying it cannot guess the machine type, give it the

`--build=TYPE' option.  TYPE can either be a short name for the system

type, such as `sun4', or a canonical name which has the form:

     CPU-COMPANY-SYSTEM

where SYSTEM can have one of these forms:

   See the file `config.sub' for the possible values of each field.  If

`config.sub' isn't included in this package, then this package doesn't

need to know the machine type.

   If you are _building_ compiler tools for cross-compiling, you should

use the option `--target=TYPE' to select the type of system they will

produce code for.

   If you want to _use_ a cross compiler, that generates code for a

platform different from the build platform, you should specify the

"host" platform (i.e., that on which the generated programs will

eventually be run) with `--host=TYPE'.

Sharing Defaults

================

   If you want to set default values for `configure' scripts to share,

you can create a site shell script called `config.site' that gives

default values for variables like `CC', `cache_file', and `prefix'.

`configure' looks for `PREFIX/share/config.site' if it exists, then

`PREFIX/etc/config.site' if it exists.  Or, you can set the

`CONFIG_SITE' environment variable to the location of the site script.

A warning: not all `configure' scripts look for a site script.

Defining Variables

==================

   Variables not defined in a site shell script can be set in the

environment passed to `configure'.  However, some packages may run

configure again during the build, and the customized values of these

variables may be lost.  In order to avoid this problem, you should set

them in the `configure' command line, using `VAR=value'.  For example:

     ./configure CC=/usr/local2/bin/gcc

causes the specified `gcc' to be used as the C compiler (unless it is

overridden in the site shell script).

Unfortunately, this technique does not work for `CONFIG_SHELL' due to

an Autoconf bug.  Until the bug is fixed you can use this workaround:

     CONFIG_SHELL=/bin/bash /bin/bash ./configure CONFIG_SHELL=/bin/bash

`configure' Invocation

======================

   `configure' recognizes the following options to control how it

operates.

`--help'

`-h'

     Print a summary of all of the options to `configure', and exit.

`--help=short'

`--help=recursive'

     Print a summary of the options unique to this package's

     `configure', and exit.  The `short' variant lists options used

     only in the top level, while the `recursive' variant lists options

     also present in any nested packages.

`--version'

`-V'

     Print the version of Autoconf used to generate the `configure'

     script, and exit.

`--cache-file=FILE'

     Enable the cache: use and save the results of the tests in FILE,

     traditionally `config.cache'.  FILE defaults to `/dev/null' to

     disable caching.

`--config-cache'

`-C'

     Alias for `--cache-file=config.cache'.

`--quiet'

`--silent'

`-q'

     Do not print messages saying which checks are being made.  To

     suppress all normal output, redirect it to `/dev/null' (any error

     messages will still be shown).

`--srcdir=DIR'

     Look for the package's source code in directory DIR.  Usually

     `configure' can determine that directory automatically.

`--prefix=DIR'

     Use DIR as the installation prefix.  *Note Installation Names::

     for more details, including other options available for fine-tuning

     the installation locations.

`--no-create'

`-n'

     Run the configure checks, but stop before creating any output

     files.

`configure' also accepts some other, not widely useful, options.  Run

`configure --help' for more details.

/*

  Copyright 2009 Nathan Phillip Brink, Ethan Zonca, Matthew Orlando

  This file is a part of DistRen.

  DistRen is free software: you can redistribute it and/or modify

  it under the terms of the GNU Affero General Public License as published by

  the Free Software Foundation, either version 3 of the License, or

  (at your option) any later version.

  DistRen is distributed in the hope that it will be useful,

  but WITHOUT ANY WARRANTY; without even the implied warranty of

  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  GNU Affero General Public License for more details.

  You should have received a copy of the GNU Affero General Public License

  along with DistRen.  If not, see <http://www.gnu.org/licenses/>.

*/

/* This file contains the code which both processes (renders) jobs as a slave, and the code which distributes frames to slaves after receiving them from the client portion of the codebase. */

#include "execio.h"

#include "options.h"

#include "distrenjob.h"

#include "protocol.h"

#include "slavefuncs.h"

#include <confuse.h>

#include <stdio.h>

#include <stdlib.h>

#include <malloc.h>

#include <unistd.h> /* getopt */

#include <time.h>

#include <sys/stat.h>

/* ******************* Structs ************************ */

// Gets config info from confs

struct distrend_config

{

  cfg_t *mycfg;

  struct options_common *options;

  struct distrend_listen **listens; /*< Null terminated array of structs */

  char *datadir;

};

/*

 frame[frame] Status Assignments:

  "NULL" - don't render me

  "0" - canceled

  "1" - unassigned

  "2" - assigned to slave

  "3" - completed by slave and uploaded

*/

struct general_info {

  short int jobs_in_queue; //

  unsigned short int free_clients;

  unsigned short int rendering_clients;//

  unsigned short int total_finished_jobs; //

  unsigned int total_frames_rendered; //

  unsigned int highest_jobnum;

} general_info;

/*

  internally defined funcs's prototypes

*/

void status_report_generator(struct distrenjob **distrenjobs_head);

void distrenjob_remove(struct distrenjob **head, struct distrenjob *bj);

struct distrenjob *distrenjob_get(struct distrenjob *head, jobnum_t jobnum);

void distrenjob_enqueue(struct distrenjob *head, struct distrenjob *job);

/* Global Vars, try to cut down on these */

jobnum_t jobnum = 0; // The next job number to create in the queue

int hcfjob; // Highest consecutively finished job

int highest_jobnum; // The job number of the most recently created job, this is used when creating new jobs

/* ********************** Functions ************************* */

/** Dumps all data in RAM to an xml file (such as current jobs, etc) which is parsed by start_data. Remember to invoke this before shutting down! */

int xml_dump()

{

  return 0;

}

/**

   Performs command stored in a client's request.

*/

int distrend_do()

{

  return 0;

}

/**

   Accepts a client's connection

 */

void distrend_accept()

{

}

/**

   Frees the action

*/

void distrend_action_free()

{

}

/**

   Start listening

*/

void distrend_listen()

{

}

/**

   Stop listening

*/

void distrend_unlisten()

{

}

/**

   This is probably just a placeholder for remotio

*/

void remotio_send_to_client()

{

	// I am futile!

}

/** Fill variables after crash / shutdown from XML dumps */

int start_data(){

  struct stat buffer;

  if(stat(SYSCONFDIR "/data.xml", &buffer) == 0){

    // @TODO: retrieve total_finished_jobs and total_finished_frames from xml file

    fprintf(stderr,"Parsing XML files and restoring previous state...\n");

    return 1;

  }

  else{

    general_info.total_finished_jobs = 0;

    general_info.total_frames_rendered = 0;

    fprintf(stderr,"Can't find XML dump, starting up fresh.\n");

    return 2;

  }

  free(&buffer); // @TODO: Is this pointless?

}

/** Finish-Setter: Sets a frame to the "completed" status.*/

void finish_frame(struct distrenjob *distrenjob, int frame){

  distrenjob->frameset[frame].status = 2;

  distrenjob->frameset[frame].time_to_render = (clock() - distrenjob[jobnum].frameset[frame].start_time); // Consider changing time-to-render to time-for-frame or something?

  general_info.total_frames_rendered++; // Increase total frames var for stats

}

/**

   creates a structure from starting data, then calls another function to actually add that struct to the queue

*/

void prepare_distrenjob(struct frameset *head, int type, char *name, char *submitter, char *email, int priority, int start_frame, int end_frame)

{

  int counter2;

  int counter;

  struct distrenjob *distrenjob;

  distrenjob->type = 1;

  distrenjob->name = name;

  distrenjob->submitter = submitter;

  distrenjob->email = email;

  distrenjob->priority = priority;

  distrenjob->frameset = malloc(end_frame - start_frame + 1);

  distrenjob->total_frames = (end_frame - start_frame + 1); // sets the total number of frames in animation for status purposes

  /* @TODO: what does this do? frameset array is declared above */

  /*

  distrenjob->frameset = malloc(sizeof(struct frameset) * numframes);

  if(!job->frameset)

    fprintf(stderr, "Error allocating memory\n");

  */

  /* prepares all the frames by setting that status to "unassigned" */

  counter2 = start_frame;

  for(counter = 0; counter <= (end_frame- start_frame + 1); counter++){

    distrenjob->frameset[counter].num = counter2;

    distrenjob->frameset[counter].status = 0;

    counter2++;

  }

  /* @TODO: change frame_num_struct_builder to add_blendjob_to_queue */

  distrenjob_enqueue(head, distrenjob);

  general_info.jobs_in_queue++;

}

/** -- OLD -- Queuer: Adds files to the queue

int queue(struct distrenjob *distrenjob, int type, char *name, char *submitter, char *email, int priority, int mode, int spp, struct frameset *frameset) {

  // Type: 1 = blender, add more types later

  // jobnum is the next available job number

  if(type == 1){

    distrenjob->name = name;

    distrenjob->submitter = submitter;

    distrenjob->email = email;

    distrenjob->priority = priority;

    distrenjob->frameset = frameset;

  }

  else{

    // Throw error.

    fprintf(stderr,"You tried to queue a job type that isn't supported by this version of DistRen.\nI have no idea how this would happen, but it just did.\n");

    return 0; // fail

  }

jobnum++; // Advance the jobnumber for the next queued job

return 0; // OK

}*/

/**

  Status Report Generator:

  -figures out how much of the job is done, where jobnum corresponds to the job number

  -removes finished jobs

  @param distrenjobs_head a pointer to a pointer because the head of the distrenjobs linked list may need to be changed by distrenjob_remove

*/

void status_report_generator(struct distrenjob **distrenjobs_head)

{

  struct distrenjob *distrenjob_ptr;

  unsigned short workers_working; /*< used to count the total number of workers working */

  unsigned int numjobs; /*< used to track number of jobs */

  workers_working = 0; /*@TODO is there another way to trade how many workers are working, this is equal to assigned frames*/

  numjobs = 0;

  for(distrenjob_ptr = *distrenjobs_head; distrenjob_ptr; distrenjob_ptr = distrenjob_ptr->next)

    {

      if(distrenjob_ptr->frameset[0].status == 0 && distrenjob_ptr->frameset[1].status == 0)

	/* If the job has been started, scan it */

	{

	  unsigned int framecounter;  /*< to scan through frames */

	  unsigned long finished_frames; /*< variable that counts the completed frames */

	  unsigned int pending_frames; /*< variable that counts the assigned frames */

	  float percent_frames_finished;  /*< variable that stores the percent done of the distrenjob */

	  unsigned int total_time;  /*< total time taken to render all the completed frames for a job */

	  framecounter = 0;

	  finished_frames = 0;

	  pending_frames = 0;

	  percent_frames_finished = 0;

	  total_time = 0;

	  while(framecounter < distrenjob_ptr->total_frames)

	    /* scans through frames, based on their status it runs a statement(s) */

	    {

	      if(distrenjob_ptr->frameset[framecounter].status == 2)

		/* If the frame is done */

		{

		  finished_frames ++;

		}

	      if(distrenjob_ptr->frameset[framecounter].status == 1)

		/* If the frame is assigned */

		{

		  pending_frames ++;

		  workers_working ++;

		}

	      framecounter ++;

	    } /* while(framecounter < distrenjob_ptr->total_frames) */

	  // find the percent of completed frames

	  percent_frames_finished = (finished_frames / distrenjob_ptr->total_frames) * 100; /*< @LordofWar: extraneous parentheses! */

	  /* updates values in the distrenjob struct */

	  distrenjob_ptr->completed_frames = finished_frames;

	  distrenjob_ptr->assigned_frames = pending_frames;

	  distrenjob_ptr->percent_done = percent_frames_finished;

	  distrenjob_ptr->time_remaining = (distrenjob_ptr->avg_render_time * (distrenjob_ptr->total_frames - finished_frames)); /*< extraneous parentheses! */

	  if(finished_frames == distrenjob_ptr->total_frames)

	    /* If all frames are complete */

	    {

	      distrenjob_remove(distrenjobs_head, distrenjob_ptr); /*< remove this job from the linkedlist */

	      distrenjob_free(distrenjob_ptr);

	      general_info.total_finished_jobs++; /*< add one to the total finished jobs */

	    }

	  else if (finished_frames > distrenjob_ptr->total_frames)

	    /* just in case ;-) */

	    {

	      fprintf(stderr, "%s:%d: finished_frames (%lu) > distrenjob_ptr->total_frames (%d)",

		      __FILE__, __LINE__,

		      finished_frames,

		      distrenjob_ptr->total_frames);

	      abort();

	    }

	}

      general_info.rendering_clients = workers_working; /*< should this be a +=? */

      numjobs ++;

    } /* while(distrenjob_ptr) */

  general_info.jobs_in_queue = numjobs;

}

/**

   Structure Builder: This function creates frame array based on the total number of frames to be rendered, which will then be parsed by function frame_farmer.

*/

/** Structure Builder: This function creates frame array based on the total number of frames to be rendered, which will then be parsed by function frame_farmer. */

void distrenjob_enqueue(struct distrenjob *head, struct distrenjob *job) {

  struct distrenjob *prev_job = head; // create pointer to previous job

  struct distrenjob *current_job;     // create pointer to current_job (which job is being compared to)

  // iterate through linked list of jobs

  for(current_job = head; current_job != NULL; current_job = current_job->next){

    if(current_job == NULL){ // if it has reached the end of the list, add job there

      current_job = job;

      break;

    }

    else if(job->priority < current_job->priority){ // if job's priority is less than current_job's priority, insert job

      prev_job->next = job;                        // keep in mind 1 is the highest priority given to jobs, head has a

      job->next = current_job;                     // priority of zero so it will always be before other jobs

      break;

    }

    prev_job = current_job;

  } /* for(current_job) */

}

/**

   @arg head I may end up changing the head if job == head

 */

void change_job_priority(struct distrenjob *head, struct distrenjob *job, int new_priority){

  distrenjob_remove(head, job);

  job->priority = new_priority;

  struct distrenjob *current_job;

  struct distrenjob *prev_job = head;

  if(job->frameset[0].status == 0){ // if job was not yet started

    distrenjob_enqueue(head, job);

  }

  else{ // if job has already been started then place it before the jobs with the same priority

    // iterate through linked list of jobs

    for(current_job = head; current_job != NULL; current_job = current_job->next){

      if(current_job == NULL){ // if it has reached the end of the list, add job there

        current_job = job;

        break;

      }

      else if(job->priority <= current_job->priority){ // if job's priority is less than or equal to current_job's priority, insert job

        prev_job->next = job;                        // keep in mind 1 is the highest priority given to jobs, head has a

        job->next = current_job;                     // priority of zero so it will always be before other jobs

        break;

      }

      prev_job = current_job;

    }

  }

}

/**

  Frame Finder: matches your computer up with a lovely frame to render

  TODO: Major issue here, the client needs to know the frame number, AND the job number!

  Notice that this function starts by looking at the oldest job first

	TODO: Link this up with the main() function to check if there are frames available or not and provide jobnum/framenum to the client

  @return 0 success, other: error

*/

int frame_finder(struct distrenjob *head, struct distrenjob **job, struct frameset **frame)

{

  int your_frame;  // your_frame is an integer value that will be given to the client as the frame number to render

  unsigned short int found;

  unsigned short int priority;

  struct distrenjob *distrenjob_ptr;

  found = 0;

  while(!found)

    {

      /* enumerate through priority levels */

      for(priority = 10;

        priority > 0

            && !found;

           priority --)

	/* Find the job with the highest priority */

        for(distrenjob_ptr = head;

            distrenjob_ptr != NULL

            && !found;

            distrenjob_ptr = distrenjob_ptr->next)

          if(distrenjob_ptr->priority == priority)

	    found = 1;

      if(!found)

        {

          fprintf(stderr, "No more jobs to render\n");

          return 1;

        }

      found = 0;

      for(your_frame = 0;

        your_frame < distrenjob_ptr->total_frames;

        your_frame ++)

        if(distrenjob_ptr->frameset[your_frame].status == 0)

          found = 1;

      if(!found)

        {

          /* there are no frames left in this job */

          distrenjob_ptr->priority --;

	  /* If that job had no open frames for some reason, run the status report generator so that */

          status_report_generator(&head);

          /* should the job be removed now? */

          fprintf(stderr, "Job %d is finished, this is probably the place to call the job-removal function\n", distrenjob_ptr->jobnum);

          /* @TODO: At this point, all slaves should be instructed to delete the source data for this job. */

        }

    }

  /* Sets the value of the frame to 1, which means it is taken */

  distrenjob_ptr->frameset[your_frame].status++;

  distrenjob_ptr->frameset[your_frame].start_time = clock();

  *job = distrenjob_ptr;

  *frame =  &distrenjob_ptr->frameset[your_frame];

  return 0;

}

/** Checks for dead, laggy, or stale slaves */

void blend_frame_watchdog(struct distrenjob *distrenjob_head)

{

  unsigned short int watchdog_forgiveness; /*< seconds to wait on a frame before re-assigning it */

  struct distrenjob *distrenjob_ptr;

  unsigned int counter;

  watchdog_forgiveness = 1; /*< hours of forgiveness before frame is re-assigned @TODO: Make this more user-configurable (maybe per-job), 3 hours is a LONG time */

  distrenjob_ptr = distrenjob_head;

  for(distrenjob_ptr = distrenjob_head; distrenjob_ptr; distrenjob_ptr = distrenjob_ptr->next)

    /* iterate through jobs */

    for(counter = 0; counter < distrenjob_ptr->total_frames; counter ++)

      /* iterate through all frames for this job*/

      {

        if((distrenjob_ptr->frameset[counter].start_time + (watchdog_forgiveness * 3600)) < clock())

          /*

            If frame is not completed within the number of hours specified by watchdog_forgiveness

            Then change the frame status to unassigned

           */

          distrenjob_ptr->frameset[counter].status = 0;

      }

}

/**

   Finds a distrenjob struct based on the jobnum

   @arg jobnum job number to search for

   @return NULL on job doesn't exist

 */

struct distrenjob *distrenjob_get(struct distrenjob *head, jobnum_t jobnum)

{

  struct distrenjob *distrenjob_ptr;

  /*

    The conditions of the for loop will leave distrenjob_ptr at NULL if the end of the list is reached. It will leave it pointing to the correct job if it is found.

   */

  for(distrenjob_ptr = head;

      distrenjob_ptr

        && distrenjob_ptr->jobnum != jobnum;

      distrenjob_ptr = distrenjob_ptr->next);

  return distrenjob_ptr;

}

/**

   Removes a distrenjob from the distrenjob linked list.

   @arg head a double pointer. the head pointer will have to be changed if distrenjob == *head. Thus, make sure that the pointer points to the pointer to the head that all functions use. (I'm going to come back to this and misunderstand myself ;-))

 */

void distrenjob_remove(struct distrenjob **head, struct distrenjob *bj)

{

  struct distrenjob *previous_distrenjob;

  if(bj == *head)

    *head = bj->next;

  else

    {

      for(previous_distrenjob = *head;

        previous_distrenjob

          && previous_distrenjob->next != bj; /*< stop on the distrenjob that comes before bj */

          previous_distrenjob = previous_distrenjob->next)

	/* all of the action is in the definition of the for loop itself */;

      /*

	This removes references to bj from the linked list. I.E., we now skip bj when iterating through the list

       */

      previous_distrenjob->next = bj->next;

    }

}

/* Grabs config info from confs */

int distrend_do_config(int argc, char *argv[], struct distrend_config **config)

{

  cfg_opt_t myopts_listen[] =

    {

      CFG_SIMPLE_STR("type", NULL),

      CFG_SIMPLE_STR("path", NULL),

      CFG_SIMPLE_INT("port", NULL),

      CFG_END()

    };

  cfg_opt_t myopts[] =

    {

      CFG_SEC("listen",  /* this must be imported into struct listens (which must still be declared) */

          myopts_listen,

          CFGF_MULTI),

      CFG_SIMPLE_STR("datadir", NULL),

      CFG_END()

    };

  struct distrenjob *distrenjob;

  int tmp;

  xmlinit();

  /*

   * test xml2distrenjob()

   */

  tmp = xml2distrenjob(&distrenjob, "distrenjob.xml.example");

  if(tmp)

    fprintf(stderr, "xml2distrenjob() returned %d. Try to cd to distren/doc if you want to test out the xml2distrenjob() function. (This will only fix this error if the error is due to an inability of the xml library to access distrenjob.xml.example)\n", tmp);

  else

    fprintf(stderr, "using email ``%s'' for user ``%s'' -- reading in XML files and pulling data from them using libxml2+XPath works!!!\n", distrenjob->email, distrenjob->submitter);

  fprintf(stderr, "%s:%d running config\n", __FILE__, __LINE__);

  *config = malloc(sizeof(struct distrend_config));

  myopts[1].simple_value = &(*config)->datadir;

  options_init(argc, argv, &(*config)->mycfg, myopts, "server", &(*config)->options);

  fprintf(stderr, "using %s as datadir\n", (*config)->datadir);

  xmlcleanup();

  return 0;

}