On Mon, Oct 15, 2012 at 08:21:50AM +0000, Maxim Sobolev wrote: > Author: sobomax > Date: Mon Oct 15 08:21:49 2012 > New Revision: 241576 > URL: http://svn.freebsd.org/changeset/base/241576 > > Log: > Add per-second scheduling into the cron(8). Right now it's > only available via the new @every_second shortcut. ENOTIME to > implement crontab(5) format extensions to allow more flexible > scheduling. > > In order to address some concerns expressed by Terry Lambert > while discussing the topic few years ago, about per-second cron > possibly causing some bad effects on /etc/crontab by stat()ing > it every second instead of every minute now (i.e. atime update), > only check that database needs to be reloaded on every 60-th > loop run. This should be close enough to the current behaviour. > > Add "@every_minute" shortcut while I am here.
Do I read the code correctly and the cron deamon will wake up every
second now even if @every_second is not used at all?
>
> MFC after: 1 month
>
> Modified:
> head/usr.sbin/cron/cron/cron.c
> head/usr.sbin/cron/cron/cron.h
> head/usr.sbin/cron/crontab/crontab.5
> head/usr.sbin/cron/lib/entry.c
>
> Modified: head/usr.sbin/cron/cron/cron.c
> ==============================================================================
> --- head/usr.sbin/cron/cron/cron.c Mon Oct 15 07:57:55 2012
> (r241575)
> +++ head/usr.sbin/cron/cron/cron.c Mon Oct 15 08:21:49 2012
> (r241576)
> @@ -98,6 +98,7 @@ main(argc, argv)
> char *argv[];
> {
> cron_db database;
> + int runnum;
>
> ProgramName = argv[0];
>
> @@ -149,21 +150,24 @@ main(argc, argv)
> load_database(&database);
> run_reboot_jobs(&database);
> cron_sync();
> + runnum = 0;
> while (TRUE) {
> # if DEBUGGING
> /* if (!(DebugFlags & DTEST)) */
> # endif /*DEBUGGING*/
> cron_sleep(&database);
>
> - load_database(&database);
> + if (runnum % 60 == 0)
> + load_database(&database);
>
> /* do this iteration
> */
> cron_tick(&database);
>
> - /* sleep 1 minute
> + /* sleep 1 second
> */
> - TargetTime += 60;
> + TargetTime += 1;
> + runnum += 1;
> }
> }
>
> @@ -194,22 +198,23 @@ cron_tick(db)
> static time_t diff = 0, /* time difference in seconds from the last
> offset change */
> difflimit = 0; /* end point for the time zone correction */
> struct tm otztm; /* time in the old time zone */
> - int otzminute, otzhour, otzdom, otzmonth, otzdow;
> + int otzsecond, otzminute, otzhour, otzdom, otzmonth, otzdow;
> register struct tm *tm = localtime(&TargetTime);
> - register int minute, hour, dom, month, dow;
> + register int second, minute, hour, dom, month, dow;
> register user *u;
> register entry *e;
>
> /* make 0-based values out of these so we can use them as indicies
> */
> + second = tm->tm_sec -FIRST_SECOND;
> minute = tm->tm_min -FIRST_MINUTE;
> hour = tm->tm_hour -FIRST_HOUR;
> dom = tm->tm_mday -FIRST_DOM;
> month = tm->tm_mon +1 /* 0..11 -> 1..12 */ -FIRST_MONTH;
> dow = tm->tm_wday -FIRST_DOW;
>
> - Debug(DSCH, ("[%d] tick(%d,%d,%d,%d,%d)\n",
> - getpid(), minute, hour, dom, month, dow))
> + Debug(DSCH, ("[%d] tick(%d,%d,%d,%d,%d,%d)\n",
> + getpid(), second, minute, hour, dom, month, dow))
>
> if (dst_enabled && last_time != 0
> && TargetTime > last_time /* exclude stepping back */
> @@ -262,6 +267,7 @@ cron_tick(db)
>
> /* make 0-based values out of these so we can use them
> as indicies
> */
> + otzsecond = otztm.tm_sec -FIRST_SECOND;
> otzminute = otztm.tm_min -FIRST_MINUTE;
> otzhour = otztm.tm_hour -FIRST_HOUR;
> otzdom = otztm.tm_mday -FIRST_DOM;
> @@ -283,7 +289,8 @@ cron_tick(db)
> e->uid, e->gid, e->cmd))
>
> if ( diff != 0 && (e->flags & (RUN_AT|NOT_UNTIL)) ) {
> - if (bit_test(e->minute, otzminute)
> + if (bit_test(e->second, otzsecond)
> + && bit_test(e->minute, otzminute)
> && bit_test(e->hour, otzhour)
> && bit_test(e->month, otzmonth)
> && ( ((e->flags & DOM_STAR) || (e->flags &
> DOW_STAR))
> @@ -302,7 +309,8 @@ cron_tick(db)
> continue;
> }
>
> - if (bit_test(e->minute, minute)
> + if (bit_test(e->second, second)
> + && bit_test(e->minute, minute)
> && bit_test(e->hour, hour)
> && bit_test(e->month, month)
> && ( ((e->flags & DOM_STAR) || (e->flags & DOW_STAR))
>
> Modified: head/usr.sbin/cron/cron/cron.h
> ==============================================================================
> --- head/usr.sbin/cron/cron/cron.h Mon Oct 15 07:57:55 2012
> (r241575)
> +++ head/usr.sbin/cron/cron/cron.h Mon Oct 15 08:21:49 2012
> (r241576)
> @@ -124,6 +124,10 @@
> LineNumber = ln; \
> }
>
> +#define FIRST_SECOND 0
> +#define LAST_SECOND 59
> +#define SECOND_COUNT (LAST_SECOND - FIRST_SECOND + 1)
> +
> #define FIRST_MINUTE 0
> #define LAST_MINUTE 59
> #define MINUTE_COUNT (LAST_MINUTE - FIRST_MINUTE + 1)
> @@ -165,6 +169,7 @@ typedef struct _entry {
> #endif
> char **envp;
> char *cmd;
> + bitstr_t bit_decl(second, SECOND_COUNT);
> bitstr_t bit_decl(minute, MINUTE_COUNT);
> bitstr_t bit_decl(hour, HOUR_COUNT);
> bitstr_t bit_decl(dom, DOM_COUNT);
>
> Modified: head/usr.sbin/cron/crontab/crontab.5
> ==============================================================================
> --- head/usr.sbin/cron/crontab/crontab.5 Mon Oct 15 07:57:55 2012
> (r241575)
> +++ head/usr.sbin/cron/crontab/crontab.5 Mon Oct 15 08:21:49 2012
> (r241576)
> @@ -232,6 +232,8 @@ string meaning
> @daily Run once a day, "0 0 * * *".
> @midnight (same as @daily)
> @hourly Run once an hour, "0 * * * *".
> +@every_minute Run once a minute, "*/1 * * * *".
> +@every_second Run once a second.
> .Ed
> .Sh EXAMPLE CRON FILE
> .Bd -literal
>
> Modified: head/usr.sbin/cron/lib/entry.c
> ==============================================================================
> --- head/usr.sbin/cron/lib/entry.c Mon Oct 15 07:57:55 2012
> (r241575)
> +++ head/usr.sbin/cron/lib/entry.c Mon Oct 15 08:21:49 2012
> (r241576)
> @@ -151,6 +151,7 @@ load_entry(file, error_func, pw, envp)
> e->flags |= WHEN_REBOOT;
> } else if (!strcmp("yearly", cmd) || !strcmp("annually", cmd)){
> Debug(DPARS, ("load_entry()...yearly shortcut\n"))
> + bit_set(e->second, 0);
> bit_set(e->minute, 0);
> bit_set(e->hour, 0);
> bit_set(e->dom, 0);
> @@ -159,6 +160,7 @@ load_entry(file, error_func, pw, envp)
> e->flags |= DOW_STAR;
> } else if (!strcmp("monthly", cmd)) {
> Debug(DPARS, ("load_entry()...monthly shortcut\n"))
> + bit_set(e->second, 0);
> bit_set(e->minute, 0);
> bit_set(e->hour, 0);
> bit_set(e->dom, 0);
> @@ -167,6 +169,7 @@ load_entry(file, error_func, pw, envp)
> e->flags |= DOW_STAR;
> } else if (!strcmp("weekly", cmd)) {
> Debug(DPARS, ("load_entry()...weekly shortcut\n"))
> + bit_set(e->second, 0);
> bit_set(e->minute, 0);
> bit_set(e->hour, 0);
> bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
> @@ -175,6 +178,7 @@ load_entry(file, error_func, pw, envp)
> bit_set(e->dow, 0);
> } else if (!strcmp("daily", cmd) || !strcmp("midnight", cmd)) {
> Debug(DPARS, ("load_entry()...daily shortcut\n"))
> + bit_set(e->second, 0);
> bit_set(e->minute, 0);
> bit_set(e->hour, 0);
> bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
> @@ -182,11 +186,28 @@ load_entry(file, error_func, pw, envp)
> bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
> } else if (!strcmp("hourly", cmd)) {
> Debug(DPARS, ("load_entry()...hourly shortcut\n"))
> + bit_set(e->second, 0);
> bit_set(e->minute, 0);
> bit_nset(e->hour, 0, (LAST_HOUR-FIRST_HOUR+1));
> bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
> bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
> bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
> + } else if (!strcmp("every_minute", cmd)) {
> + Debug(DPARS, ("load_entry()...every_minute shortcut\n"))
> + bit_set(e->second, 0);
> + bit_nset(e->minute, 0, (LAST_MINUTE-FIRST_MINUTE+1));
> + bit_nset(e->hour, 0, (LAST_HOUR-FIRST_HOUR+1));
> + bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
> + bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
> + bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
> + } else if (!strcmp("every_second", cmd)) {
> + Debug(DPARS, ("load_entry()...every_second shortcut\n"))
> + bit_nset(e->second, 0, (LAST_SECOND-FIRST_SECOND+1));
> + bit_nset(e->minute, 0, (LAST_MINUTE-FIRST_MINUTE+1));
> + bit_nset(e->hour, 0, (LAST_HOUR-FIRST_HOUR+1));
> + bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
> + bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
> + bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
> } else {
> ecode = e_timespec;
> goto eof;
--
Pawel Jakub Dawidek http://www.wheelsystems.com
FreeBSD committer http://www.FreeBSD.org
Am I Evil? Yes, I Am! http://tupytaj.pl
pgpKrkTH835bv.pgp
Description: PGP signature
