SeamlessReboot - to reboot your talker w/o losing connections. (v.5b)
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Simply that.   Seems sorta questionable as to why you'd go to the trouble
of putting in code just for it, but when you think about being able to
add any new code, or just a maintance reboot, without having to shutdown,
without the players even noticing they are running on a new process,
it's quiet a nice bit.

The entrance points in the talker are easy enough... adding a member
to the player struct, putting a lil bit at boot to check for a pending
reboot, and changing the player socket shutdowns to be clean.
The biggest trick for me was getting the angel to do right.  As it's
written, it's made to watch a single process which it spawns.  But
with this code, the talker itself spawns a child... needless to say
there's quiet a bit of creativity in the new angel-talker relationship.
Those installations will be the easiest, as everything there is to do
is shown step by step in INSTALLTING and ANGEL_INSTALL.  The biggest
installing procs for you will be configing the reboot.c code itself
to just how you talker needs.   I've tried to include #define's and
make each point where you may possibly need to modify as clear as can be.


--- notes ---
this version has an entry to add to handle_error and a few file mods
  to allow you to have it automatically reboot instead of shutdown
  on wibble.

this was coded on linux....with a proc system...
  if you dont have a proc system, youll have to play with the
  way the angel checks for the talker being alive or not.
  it doesnt depend on it, so there arent any major rewrites...
  just will have to hack on it.

the fd handling (mainly close_fds()) is to cover any left over fds
  that arent closed in the code.  basicallly it runs up to
  (1<<12), trying to close everything in its path except for
  the fds that are needed for the reboot (stdout, stdin, main_descriptor,
  alive_descriptor, and the players' fds).  initally, i thought
  the code for it would take an overly long time to execute,
  but after putting it under a timer, i got from 10000 ms -
  20000 ms... 1 or 2 hundreths of a second, nothing at all
  to cause any slowdowns.   without this... after many reboots..
  the talker will have all kinda open dangling fd's which will
  eventually grind it to a abrupt halt.

to do the actual reboot, the talker saves system information,
  runs through the players, saves them all into a seperate file
  exactly as they are in the program, then forks itself, and
  reloads all the info that was saved, rebuilding as it goes along.

for about 5 - 10 seconds there will be an increase in disk usage.
  each player is stored in its entirity (via fsave) so the amount
  of space needed will be
       online_players * sizeof (player struct)
  for example, if you have 30 players logged in, and your player
  struct is 20k in size, youll use ~600k of disk space.
  if you have a really tight quota you could run out of room.
  note however, these files only live a short period, as they are
  removed as soon as the restoration is complete

the flatlist order, current locations, etc are maintained,
  however the order that players are within a room isnt.
  its doubtful that this will ever be noticed.

its beta, as of this release, ive only written it in the past few days
  so if there are any bugs (its doubtful there are any major ones)
  please let me know of them so the final release will be stronger.


--- license ---
If you chose to use this code, you may do so without restriction,
as long as due credit be given in your talker's help credits
or equvelant file, "SeamlessReboot package written by phypor" is sufficent.
If you wish to put an entry in your version output,
that's good as well, tho its not required.

If you chose to redistribute this code, you may do so as long as
all the files that are in the offical distribution are included.
Exceptions, the INSTALLING and ANGEL_INSTALL files, need not be included
if you redistribute the code preinstalled in a talker.   Any modifications
must be plainly documented.  Credit must be given as stated above.


--- author ---
phypor is the author of this code and release package.


--- maintainer ---
Any bug reports should be mailed to phypor@benland.muc.edu


--- disclaimer ---
There is no warrenty nor statement of fitness or usablity made
about this code...  If you chose to install it you are responsible
fully for its implementation, and effects, be they good or ill.


--- history ---
v.5b      - added wibble entry points so that it will
            reboot instead of shutdown in handle_error

v.4b      - fixed cleaning up of fds with close_fds()

v.3b      - first offical release