schro@nixpbe (02/23/88)
Subject: problems with cron Hi there! Awhile ago i posted a version of cron by Mr. S. R. Sampson modified for minix. Mr. Bing H. Bang reported a problem: > i just noticed somebody posted a cron clone and just wanted to warn people > that if you put this cron in your /etc/rc, this may screw up the tty signal > handling for those of you who are using multiple screen tty drivers. There have been several posting in the past about signal handling so the problem may be with the kernel. I only have minix 1.1 with the original tty driver and don't have any problems with cron (otherwise i wouldn't have posted it :-)) except for running out of memory. In the meantime Mr. Sampson posted his own version for minix and i would like to hear if it has the same problem. I'd like to comment on the problems of the original version posted to comp.sources.wanted: The easy ones: 1. "#include <string.h>" is not needed. 2. fopen() doesn't automatically creat the file in append mode. 3. ctime() and localtime() are not in the library. and.. 4. When you fire it up it starts processing crontab immediately and then every minute, but its not synchronized with the clock. So every minute a second or more is lost especially when there are several entries in crontab. After a while it will skip the next minute and crontab is executed less than 60 times per hour. 5. Cron can't wait for termination of its child processes and therefore has to remove the zombies later +but+ the main loop was executed only once per minute and killed only one of them. If you started more than one process per minute the zombies piled up using all available memory so you couldn't even login. and in addition.. There is always not enough memory on my system and the situation became worse by running cron. So i tried to get rid of the zombies as soon as possible by executing the main loop more than once a minute. I hope this is will bring us one step further to the ultimate version. BTW: I'm running minix 1.1 on a 12.5MHz AT-clown with +only+ 512k base and 3MB extended memory. Although OS/2 runs without (additional :-)) problems, i'd rather have a protected mode minix! When i tried minix the first time the biggest thing i could run was mined and no way to compile. After moving everything possible to the harddisk and building a minimum root system (100K total, 50k ramdisk) i can run the compiler using option -F but i still can't use make. Is this normal??? Sometimes i go bananas getting messages like "can't..., out of memory" while having 3meg doing nothing but wasting power! Well, maybe this should be in another note... Best regards W.F.Schroeder As always: "The opinions of my employer are not ... " +---------------+------------------------+-----------------------------+ | W.F.Schroeder | Workstation Software | Paper-: Nixdorf Computer AG | +---------------+------------------------+ mail : Pontanusstr. 55 | | UUCP: {uunet,mcvax}!unido!nixpbe!schro | D-4790 Paderborn | | Phone: nat-5251-14-6694 | Fed. Rep of Germany | +----------------------------------------+-----------------------------+