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- Improve the wait4data() routine so it behaves better when checking

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print-jobs which have last-modification times that are in the future.
  This shouldn't happen, of course, but it can.  And when it did happen,
  the previous check could cause completely-spooled jobs to sit in the
  queue for 20 minutes per job.  The new code waits until the last-modify
  time is not changing, instead of making decisions based on the specific
  value of last-modify.

MFC after:	2 weeks
This commit is contained in:
Garance A Drosehn 2010-08-11 19:32:49 +00:00
parent 65a13e8549
commit 422605a3b9
1 changed files with 23 additions and 7 deletions
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30
usr.sbin/lpr/lpd/printjob.c
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@ -1263,8 +1263,9 @@ wait4data(struct printer *pp, const char *dfile)
{
const char *cp;
int statres;
u_int sleepreq;
size_t dlen, hlen;
time_t amtslept, checktime;
time_t amtslept, cur_time, prev_mtime;
struct stat statdf;
/* Skip these checks if the print job is from the local host. */
@ -1297,15 +1298,30 @@ wait4data(struct printer *pp, const char *dfile)
/*
* The file exists, so keep waiting until the data file has not
* changed for some reasonable amount of time.
* changed for some reasonable amount of time. Extra care is
* taken when computing wait-times, just in case there are data
* files with a last-modify time in the future. While that is
* very unlikely to happen, it can happen when the system has
* a flakey time-of-day clock.
*/
while (statres == 0 && amtslept < MAXWAIT_4DATA) {
checktime = time(NULL) - MINWAIT_4DATA;
if (statdf.st_mtime <= checktime)
break;
prev_mtime = statdf.st_mtime;
cur_time = time(NULL);
if (statdf.st_mtime >= cur_time - MINWAIT_4DATA) {
if (statdf.st_mtime >= cur_time) /* some TOD oddity */
sleepreq = MINWAIT_4DATA;
else
sleepreq = cur_time - statdf.st_mtime;
if (amtslept == 0)
pstatus(pp, "Waiting for data file from remote host");
amtslept += MINWAIT_4DATA - sleep(MINWAIT_4DATA);
amtslept += sleepreq - sleep(sleepreq);
statres = stat(dfile, &statdf);
}
sleepreq = MINWAIT_4DATA;
while (statres == 0 && amtslept < MAXWAIT_4DATA) {
if (statdf.st_mtime == prev_mtime)
break;
prev_mtime = statdf.st_mtime;
amtslept += sleepreq - sleep(sleepreq);
statres = stat(dfile, &statdf);
}