Second attempt to add @every_second keyword support. Due to multiple

requests, default to the previous 60-seconds scheduling method
unless there is any @every_second entries to conserve CPU cycles and
power.

This change also improves scheduling in the default mode by running
as close to the beginning of the minnute as possible by replacing
sleep(3) with nanosleep(2). Previously, the tasks would run anywhere
within the first second of the minute and that offset drifted back
and forth each time cron(8) was engaged.

MFC after:	1 month

1 files changed, 23 insertions, 0 deletions

diff --git a/usr.sbin/cron/lib/entry.c b/usr.sbin/cron/lib/entry.c
index ea015da62704..57f72554d344 100644
--- a/usr.sbin/cron/lib/entry.c
+++ b/usr.sbin/cron/lib/entry.c
@@ -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 +186,29 @@ 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"))
+			e->flags |= SEC_RES;
+			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;
@@ -201,6 +223,7 @@ load_entry(file, error_func, pw, envp)
 		}
 	} else {
 		Debug(DPARS, ("load_entry()...about to parse numerics\n"))
+		bit_set(e->second, 0);
 
 		ch = get_list(e->minute, FIRST_MINUTE, LAST_MINUTE,
 			      PPC_NULL, ch, file);