Some cleanups to the callout lists recently added.

note that at_shutdown has a new parameter to indicate When
during a shutdown the callout should be made. also
add a RB_POWEROFF flag to reboot "howto" parameter..
tells the reboot code in our at_shutdown module to turn off the UPS
and kill the power. bound to be useful eventually on laptops

1 files changed, 37 insertions, 30 deletions

diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index f6bb2840748b..d037fbd8240f 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)kern_fork.c	8.6 (Berkeley) 4/8/94
- * $Id: kern_fork.c,v 1.23 1996/07/31 09:26:34 davidg Exp $
+ * $Id: kern_fork.c,v 1.24 1996/08/19 02:28:24 julian Exp $
  */
 
 #include "opt_ktrace.h"
@@ -65,18 +65,19 @@
 static int fork1 __P((struct proc *p, int flags, int *retval));
 
 /*
- * callout list for things to do at fork time
+ * These are the stuctures used to create a callout list for things to do
+ * when forking a process
  */
 typedef struct fork_list_element {
 	struct fork_list_element *next;
 	forklist_fn function;
 } *fle_p;
 
-static fle_p fork_list;
+static fle_p	fork_list;
 
 #ifndef _SYS_SYSPROTO_H_
 struct fork_args {
-        int     dummy;
+	int     dummy;
 };
 #endif
 
@@ -124,8 +125,9 @@ fork1(p1, flags, retval)
 	struct proc *newproc;
 	int count;
 	static int nextpid, pidchecked = 0;
-	fle_p ep = fork_list;
+	fle_p ep ;
 
+	ep = fork_list;
 	if ((flags & RFPROC) == 0)
 		return (EINVAL);
 	if ((flags & (RFFDG|RFCFDG)) == (RFFDG|RFCFDG))
@@ -346,14 +348,14 @@ again:
 	}
 
 	/*
-	 * Both processes are set up, 
-	 * check if any LKMs want to adjust anything
-	 * What if they have an error? XXX
+	 * Both processes are set up, now check if any LKMs want
+	 * to adjust anything.
+	 *   What if they have an error? XXX
 	 */
-        while(ep) {
-                (*ep->function)(p1,p2,flags);
-                ep = ep->next;
-        }
+	while (ep) {
+		(*ep->function)(p1, p2, flags);
+		ep = ep->next;
+	}
 
 	/*
 	 * Make child runnable and add to run queue.
@@ -385,52 +387,57 @@ again:
 	return (0);
 }
 
-
-/*********************************************************
- * general routines to handle adding/deleting items on the
- * fork callout list
- *****
- * Take the arguments given and put them onto the fork callout list.
+/*
+ * The next two functionms are general routines to handle adding/deleting
+ * items on the fork callout list.
+ *
+ * at_fork():
+ * Take the arguments given and put them onto the fork callout list,
  * However first make sure that it's not already there.
- * returns 0 on success.
+ * Returns 0 on success or a standard error number.
  */
 int
 at_fork(forklist_fn function)
 {
 	fle_p ep;
-	if(rm_at_fork(function)) {
+
+	/* let the programmer know if he's been stupid */
+	if (rm_at_fork(function)) 
 		printf("fork callout entry already present\n");
-	}
-	ep = malloc(sizeof(*ep),M_TEMP,M_NOWAIT);
-	if(!ep) return ENOMEM;
+	ep = malloc(sizeof(*ep), M_TEMP, M_NOWAIT);
+	if (ep == NULL)
+		return (ENOMEM);
 	ep->next = fork_list;
 	ep->function = function;
 	fork_list = ep;
-	return 0;
+	return (0);
 }
+
 /*
  * Scan the exit callout list for the given items and remove them.
  * Returns the number of items removed.
+ * Theoretically this value can only be 0 or 1.
  */
 int
 rm_at_fork(forklist_fn function)
 {
-	fle_p *epp,ep;
-	int count = 0;
+	fle_p *epp, ep;
+	int count;
 
+	count= 0;
 	epp = &fork_list;
 	ep = *epp;
-	while(ep) {
-		if(ep->function == function) {
+	while (ep) {
+		if (ep->function == function) {
 			*epp = ep->next;
-			free(ep,M_TEMP);
+			free(ep, M_TEMP);
 			count++;
 		} else {
 			epp = &ep->next;
 		}
 		ep = *epp;
 	}
-	return count;
+	return (count);
 }