Oops when a stale copy is written back, i.e. the processor was yielded
since the copy was made. Such bugs are difficult to spot. Sequence
numbers catch them when they do actual harm (they also catch different
bugs). Generation numbers catch them even when they don't.
New ef_generation to count generations. Call new ef_make_stale() to
step it whenever the processor may be yielded.
New struct emptypedstr member generation. Make sure all members of
unit empobj_storage share it. It is only used in copies; its value on
disk and in the cache is meaningless. Set it to ef_generation by
calling new ef_mark_fresh() when making copies in ef_read() and
ef_blank(). Do the same in obj_changed() to make check_sect_ok() &
friends freshen their argument when it is unchanged. Copies with
generation other than ef_generation are stale.
Oops in ef_write() when a stale copy is written back.
This oopses on output dependency violations, e.g. two threads doing a
read-modify-write without synchronization, or the one thread nesting
several read-modify-writes. Such bugs are difficult to spot, and tend
to be abusable. I figure we have quite a few of them.
New struct emptypedstr member seqno. Make sure all members of unit
empobj_storage share it. Initialize it in files: main() and
file_sct_init(). Set it in ef_blank() and new ef_set_uid() by calling
new get_seqno(). Use ef_set_uid() when copying objects: swaps(),
doland(), doship(), doplane(), dounit(), delete_old_news(). Step it
in ef_write() by calling new new_seqno().
Factor do_read() out of fillcache() to make it available for
get_seqno().
Make sure all members of unit empobj_storage share it.
Add matching timestamp member to struct comstr, struct empobj, struct
gamestr, struct lonstr, struct natstr, struct nwsstr, struct trdstr,
struct trtstr. The timestamp isn't yet set for these. To be fixed.
Move the timestamp member to the right place in struct lndstr, struct
loststr, struct realmstr, struct nukstr, struct plnstr, struct sctstr,
struct shpstr.
Make sure all members of unit empobj_storage share uid in addition to
ef_type.
Add matching uid member to struct gamestr, struct natstr and struct
sctstr, and set them.
Swap struct empobj members uid and own to make that easier, and update
struct comstr, struct lndstr, struct lonstr, struct loststr, struct
nwsstr, struct nukstr, struct plnstr, struct realmstr, struct shpstr,
struct trdstr, struct trtstr accordingly.
Note that the uid isn't properly set for struct nwsstr, struct lonstr,
struct trdstr, struct comstr and struct loststr. To be fixed.
xdump:
(gamestr): New member game_upd_disable.
(game_ca): Update accordingly.
(game_ctrl_update): New.
(disa, enab): Use it.
(updates_disabled): Rewrite and move to game.c
(disablefil): Remove.
synchronized to updates (the one based on s_p_etu isn't synchronized):
(gamestr): New members game_turn, game_tick, game_rt.
(game_ca): New selectors for them. Restrict tick and rt to deity for
now. We'd need xdump update the Empire clock to make them safe for
players.
(game_record_update): New.
(update_main): Call it.
(game_tick_tick, game_tick_to_now, game_step_a_tick): New, not yet
used.
(gamestr, EF_GAME, game_ca): New.
(empfile): Declare the table.
(ef_open_srv, ef_close_srv): Open and close it.
(main): Create it.
(empobj_storage): New member game.
(EF_DYNMAX): New.
(EF_IS_GAME_STATE): Use it.
