(shutdown_initiate): New.
(shut): Use it. Shutdown in zero minutes no longer cancels the
shutdown, it just works. Use negative argument to cancel. Logging is
less detailed.
(shutdown_sequence): Internal linkage.
(pr_wall): All callers prefix text it with the same header. Move it
into the function.
(update_trigger): New.
(force, zdon): Use it.
(update_sem, update_force): Internal linkage.
(update_trigger, update_force): Passing a pointer to static storage as
thread argument is racy. Use dynamic allocation.
(update_main): No longer a thread entry point. Remove the parameter.
Remove *player setup. Don't terminate the thread when done.
(update_pending): Move to src/server/update.c.
(update_wait): Call update_main() instead of running it in its own
thread. Set up *player for it.
(update_init): Create the fused update thread instead of the update
wait thread.
resolving #1458175 and #1504036):
(update_lock): New.
(update_shed): Initialize it.
(update_wait, dispatch): Take exclusive update_lock around the update,
shared update_lock around commands. This makes the update block until
all aborted commands terminated and gave up their lock. Remove the
cheesy and unsafe two second wait for commands to finish. It also
makes player threads block before executing commands while the update
is pending, removing the need to fail commands then. So don't.
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.
between headers. Code is now fully prototyped and compiles cleanly
with gcc -Wstrict-prototypes -Wmissing-prototypes -Wnested-externs
-Wredundant-decls. Closes#723788.
