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Full Discussion: Daemon...Zombie?? Please help me
Top Forums Programming Daemon...Zombie?? Please help me Post 71294 by Perderabo on Monday 9th of May 2005 09:18:53 PM
Old 05-09-2005
Please make sure that you have read our rules. And note:
(6) Do not post classroom or homework problems.

But we sometimes bend this rule when a student has done a lot of work. So I'll make a few comments based on a quick scan of your code. This line of code:
while(1) sleep(1);//run
is dangerous. Why do you have it? I would delete it. If you meant to do something like:
while (1) { List() ; sleep(1) ; }
then you have the fork() in the wrong place. You need to fork() once at the beginning of the program. At present, your program is running List() once and then falling into your infinite sleep loop. You have some re-writing to do.

wait(30);
is illegal and also dangerous. I don't even know what you want to happen there. The last thing you do in List is to ignore some signals. You should ignore signals earlier. If you put List() in a loop, you need to move the signal calls to near the beginning somewhere.

Your instructor probably told you to check if the parent pid is 1, but your instructor is wrong. That is not the definition of a daemon. As it happens, you can probably get away with test you have. But the definition of a daemon is a program with no controlling terminal. You could check that by attempting to open /dev/tty. A daemon must fail but a non-damon must succeed.
 

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LEARN ABOUT SUNOS

kcfd

kcfd(1M)						  System Administration Commands						  kcfd(1M)

NAME

       kcfd - kernel-level cryptographic framework daemon

SYNOPSIS

       kcfd

DESCRIPTION

       The  kcfd  daemon  helps  in managing CPU usage by cryptographic operations performed in software by kernel threads. The system utilization
       associated with these threads is charged to the kcfd process. It also does module verification for kernel cryptographic modules.

       Only a privileged user can run this daemon.

       The kcfd daemon is automatically invoked in run level 1, after /usr is mounted. A previously invoked kcfd daemon that is still running must
       be stopped before invoking another kcfd command.

       Manually starting and restarting kcfd is not recommended. If it is necessary to do so, use the cryptoadm(1M) start and stop subcommands.

EXIT STATUS

       The following exit values are returned:

       0

	   Daemon started successfully.

       > 1

	   Daemon failed to start.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsl/SUNWcslx		   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Evolving			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       cryptoadm(1M), attributes(5)

SunOS 5.10							    30 Sep 2003 							  kcfd(1M)
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