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
increment it whenever the processor may be yielded.
New struct emptypedstr member generation. To conserve space, make it
a bit-field of twelve bits, i.e. generations are only recorded modulo
2^12. 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. Copies with generation other than ef_generation are
stale. Stale copies that are a multiple of 2^12 generations old can't
be detected, but that is sufficiently improbable.
Set generation to ef_generation by calling new ef_mark_fresh() when
making copies in ef_read() and ef_blank(). nav_ship() and
fltp_to_list() make copies without going through ef_read(), and
therefore need to call ef_mark_fresh() as well. Also call it in
obj_changed() to make check_sect_ok() & friends freshen their argument
when it is unchanged.
New must_be_fresh() oopses when its argument is stale. Call it in
ef_write() to catch write back of stale copies.
Store them and ef_type in bit-fields.
Allocate eight bits for ef_type. Values range from 0 to EF_GAME
(currently 16), so this is plenty.
Allocate twelve bits for sequence numbers. Sequence number mismatches
are now missed when the numbers are equal modulo 2^12. Still
sufficiently improbable.
Common machines store the bit-fields in a 32 bit word. There are
twelve bits left in that word for future use. Total savings 16 bits,
which is exactly what the previous commit spent on wider uids on
common machines.
Before, they were stored as short. Wider uids use more space, but the
next commit will recover it by narrowing other members.
The use of short has always limited the number of ships, planes, land
units and nukes to SHRT_MAX (commonly 32768). Only the most extreme
games ever came close.
Commit 49780e2c (v4.3.12) added struct sctstr member sct_uid to make
struct empobj member uid work for sectors. This made the limit apply
to sectors as well. We've had games with more than 32768 sectors.
Add check to ensure a country by that name does not exist.
Ensure the length is not too long. Note this is a change
behaviour for edit and change commands which used to silently
truncate long names. Enforce that a country name can not have
control characters in it. Ensure that a country name is not
blank or just spaces.
Replace daychange() and gettimeleft() by update_timeused_login(),
update_timeused() and enforce_minimum_session_time(). The new
code doesn't assume the day is always 24 hours long which can
occur when transitioning into or out of DST and such. Logging
in after more a multiple of 128 days now resets nat_timeused
properly.
Fix nat_timeused calculation on midnight rollover to include
the time since midnight.
struct natstr member nat_dayno and struct player member timeleft
are now unused, remove them.
This simplifies things. In particular, it gets rid of random rounding
in getcommand(), which created a variation in the nightly build
depending on whether the update starts before or after the deity logs
out.
Replace struct natstr member nat_minused by nat_timeused, and update
cou_ca[] accordingly (this affects xdump nat). Replace player member
minleft by timeleft, and getminleft() by gettimeleft(). Update
getcommand(), daychange(), player_main(), status() accordingly, taking
care not to change player output. Change edit country key 'u' to work
in seconds.
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.
The common nation wipe code is not quite identical, and it doesn't
wipe the nation thoroughly enough. The new code does.
Changes to both commands:
* Wipe nat_update, nat_ann, nat_access, and nat_contact. Bug: should
set nat_ann to the number of announcements.
Changes to add command:
* Don't wipe for status active and god. Before, nat_relate and
nat_flags where wiped then.
Changes to newcap command:
* Wipe nat_hostaddr, nat_hostname, nat_userid, nat_dayno, nat_minused,
nat_reserve, nat_last_login, nat_last_logout, nat_newstim,
nat_annotim, nat_relate, nat_rejects, nat_flags.
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.
(natstr): New member nat_access.
(cou_ca): New selector access.
(grant_btus, accrued_btus): New.
(prod_nat, init_nat): Use grant_btus(). BTUs are now made at the
update in addition to login, because that lets us get away with a
simple ETU stamp (nat_access).
(nat_cap): Replaced by grant_btus(), remove.
by design (by voting last players can tactically vote no and thus
build up veto rights), and its implementation is buggy:
(update_missed): Remove.
(zdone): Don't show it.
(demand_check): Remove veto check.
(natstr, cou_ca): Remove member nat_missed and its selector.
(zdone): Don't clear and don't show it.
(update_removewants): Don't increment it. This was buggy anyway; it
incremented even on non-demand updates.
(prnat): Don't show it, remove key 'U'.
(docountry): Don't change it, deprecate the now useless key 'U'.
other. Ensure headers in include/ can be included in any order
(except for econfig-spec.h, which is special). New header types.h to
help avoid inclusion cycles. Sort include directives. Remove some
superflous includes.
oprange, show_mission, nameofitem, build_mission_list_type,
unit_map, xdvisible, trdswitchown, ontradingblock, trad, check_trade,
unit_type_name, start_stop_unit, scut, scra, mission, multifire,
perform_mission, fuel, NSC_GENITEM): Replace struct genitem with
struct empobj. Remove genitem.h and create a new file empobj.h.
Replace multiple instances of unions of ef_type structures with
one standard union empobj_storage which is a superset of the individual
instances.
(meta_type): Add its entry.
(setnum, nstr_promote, nstr_exec_val): Deal with it. nstr_exec_val()
implements opt_HIDDEN by mapping unknown values to -1.
(natstr, nat_ca): Use it for member nat_relate. This also halves its
size. Fixes very minor leak: before, player could see relations to
all countries, regardless of contact.
(nation_relations): Add entry for -1.
