/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include "rcapd.h"
#include "utils.h"

/*
 * An abstract "collection" of processes.  Multiple types of collections can
 * exist, one of which is selected at run-time.  Currently, the only one
 * defined corresponds to project(5)s.
 */

#define MAX(x, y) (((x) > (y)) ? (x) : (y))

typedef struct {
        rcid_t          *lfa_colidp;
        lcollection_t   *lfa_found;
} lcollection_find_arg_t;

extern void lcollection_update_project(lcollection_update_type_t,
    void(*)(char *, char *, int, uint64_t, int));
extern void lcollection_update_zone(lcollection_update_type_t,
    void(*)(char *, char *, int, uint64_t, int));
static void lcollection_update_notification_cb(char *, char *, int, uint64_t,
    int);

rcid_t(*rc_getidbypsinfo)(psinfo_t *);
uint64_t phys_total = 0;
static lcollection_t *lcollection_head = NULL;

void
lcollection_update(lcollection_update_type_t ut)
{
        lcollection_update_zone(ut, lcollection_update_notification_cb);
        lcollection_update_project(ut, lcollection_update_notification_cb);
}

/*
 * Inserts a collection with the supplied identity, or updates the caps of an
 * existing one.  The return value will have these bits set, depending on the
 * previous and new cap values.  If no cap was displaced, and the requested cap
 * is 0, no collection will be added, and the applicable *ZERO flags will be
 * set.
 *
 *      LCST_CAP_CHANGED
 *      LCST_CAP_REMOVED
 *      LCSS_CAP_ZERO
 */
lcollection_t *
lcollection_insert_update(rcid_t *colidp, uint64_t rss_cap, char *name,
    int *changes)
{
        lcollection_t *lcol;

        *changes = 0;

        if (rss_cap == 0)
                *changes |= LCST_CAP_ZERO;

        lcol = lcollection_find(colidp);

        /*
         * If the specified collection is capped, add it to lcollection.
         */
        if (lcol == NULL) {
                /*
                 * If the cap has been zeroed and the collection doesn't exist,
                 * don't create the collection just to remvoe the cap later.
                 */
                if (rss_cap == 0)
                        return (NULL);

                *changes |= LCST_CAP_CHANGED;
                lcol = malloc(sizeof (*lcol));
                if (lcol == NULL) {
                        debug("not enough memory to monitor %s %s",
                            (colidp->rcid_type == RCIDT_PROJECT ?
                            "project" : "zone"), name);
                        return (NULL);
                }
                (void) bzero(lcol, sizeof (*lcol));

                lcol->lcol_id = *colidp;
                debug("added collection %s\n", name);
                lcol->lcol_prev = NULL;
                lcol->lcol_next = lcollection_head;
                lcol->lcol_stat.lcols_min_rss = (uint64_t)-1;
                if (lcollection_head != NULL)
                        lcollection_head->lcol_prev = lcol;
                lcollection_head = lcol;
        }

        /*
         * Set/update the collection's name.
         */
        (void) strlcpy(lcol->lcol_name, name, sizeof (lcol->lcol_name));

        /*
         * Set cap flags.
         */
        if (rss_cap != lcol->lcol_rss_cap) {
                *changes |= LCST_CAP_CHANGED;
                lcol->lcol_rss_cap = rss_cap;
                if (lcol->lcol_rss_cap == 0)
                        *changes |= LCST_CAP_REMOVED;
        }

        if (rss_cap > 0)
                lcol->lcol_mark++;

        return (lcol);
}

static void
lcollection_update_notification_cb(char *col_type, char *name, int changes,
    uint64_t rss_cap, int mark)
{
        /*
         * Assume the collection has been updated redundantly if its mark count
         * exceeds 1, and that another notification is unnecessary.
         */
        if (mark > 1)
                return;

        if (changes & LCST_CAP_ZERO)
                debug("%s %s: %s\n", col_type, name,
                    (changes & LCST_CAP_REMOVED) ? "cap removed" : "uncapped");
        else
                debug("%s %s: cap: %llukB\n", col_type, name,
                    (unsigned long long)rss_cap);
}

/*
 * Function to walk list of collections and invoke the specified callback with
 * the specified argument.  Callbacks are allowed to change the linkage of the
 * collection on which they act.
 */
void
list_walk_collection(int (*cb)(lcollection_t *, void *), void *arg)
{
        lcollection_t *lcol;
        lcollection_t *next;

        lcol = lcollection_head;
        while (lcol != NULL) {
                next = lcol->lcol_next;
                if (cb(lcol, arg) != 0)
                        return;
                lcol = next;
        }
}

/*
 * Returns a nonzero value if an lprocess_t is still a valid member of a given
 * collection.
 */
int
lcollection_member(lcollection_t *lcol, lprocess_t *lpc)
{
        lprocess_t *cur = lcol->lcol_lprocess;

        while (cur != NULL)
                if (cur == lpc)
                        return (1);
                else
                        cur = cur->lpc_next;
        return (0);
}

static int
lcollection_find_cb(lcollection_t *lcol, void *arg)
{
        rcid_t *colidp = ((lcollection_find_arg_t *)arg)->lfa_colidp;

        if (lcol->lcol_id.rcid_type == colidp->rcid_type &&
            lcol->lcol_id.rcid_val == colidp->rcid_val) {
                ((lcollection_find_arg_t *)arg)->lfa_found = lcol;
                return (1);
        }

        return (0);
}

lcollection_t *
lcollection_find(rcid_t *colidp)
{
        lcollection_find_arg_t lfa;

        lfa.lfa_colidp = colidp;
        lfa.lfa_found = NULL;
        list_walk_collection(lcollection_find_cb, &lfa);

        return (lfa.lfa_found);
}

/*
 * Unlinks a collection from lcollection.
 */
void
lcollection_free(lcollection_t *lcol)
{
        lprocess_t *lpc;
        lprocess_t *next;

        lpc = lcol->lcol_lprocess;
        while (lpc != NULL) {
                next = lpc->lpc_next;
                if (lpc->lpc_collection == lcol)
                        lprocess_free(lpc);
                lpc = next;
        }

        /*
         * Unlink the collection.
         */
        if (lcol->lcol_prev != NULL)
                lcol->lcol_prev->lcol_next = lcol->lcol_next;
        if (lcol->lcol_next != NULL)
                lcol->lcol_next->lcol_prev = lcol->lcol_prev;
        if (lcollection_head == lcol)
                lcollection_head = lcol->lcol_next;
        lcol->lcol_next = lcol->lcol_prev = NULL;

        free(lcol);
}