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Annotation of prex-old/usr/server/proc/hash.c, Revision 1.1.1.1.2.1

1.1       nbrk        1: /*
                      2:  * Copyright (c) 2005-2006, Kohsuke Ohtani
                      3:  * All rights reserved.
                      4:  *
                      5:  * Redistribution and use in source and binary forms, with or without
                      6:  * modification, are permitted provided that the following conditions
                      7:  * are met:
                      8:  * 1. Redistributions of source code must retain the above copyright
                      9:  *    notice, this list of conditions and the following disclaimer.
                     10:  * 2. Redistributions in binary form must reproduce the above copyright
                     11:  *    notice, this list of conditions and the following disclaimer in the
                     12:  *    documentation and/or other materials provided with the distribution.
                     13:  * 3. Neither the name of the author nor the names of any co-contributors
                     14:  *    may be used to endorse or promote products derived from this software
                     15:  *    without specific prior written permission.
                     16:  *
                     17:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
                     18:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     19:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     20:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
                     21:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     22:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     23:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     24:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     25:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     26:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     27:  * SUCH DAMAGE.
                     28:  */
                     29:
                     30: /*
                     31:  * hash.c - pid/pgid mapping tables.
                     32:  */
                     33:
                     34: #include <server/stdmsg.h>
                     35: #include <sys/list.h>
                     36: #include <unistd.h>
                     37:
                     38: #include "proc.h"
                     39:
                     40: /*
                     41:  * Hash tables for ID mapping
                     42:  */
                     43: static struct list pid_hash[ID_MAXBUCKETS];    /* mapping: pid  -> proc */
                     44: static struct list task_hash[ID_MAXBUCKETS];   /* mapping: task -> proc */
                     45: static struct list pgid_hash[ID_MAXBUCKETS];   /* mapping: pgid -> pgrp */
                     46:
                     47: /*
                     48:  * Find process by pid.
                     49:  */
                     50: struct proc *
                     51: proc_find(pid_t pid)
                     52: {
                     53:        list_t head, n;
                     54:        struct proc *p = NULL;
                     55:
                     56:        head = &pid_hash[IDHASH(pid)];
                     57:        n = list_first(head);
                     58:        while (n != head) {
1.1.1.1.2.1! nbrk       59:                p = list_entry(n, struct proc, p_pid_link);
        !            60:                if (p->p_pid == pid)
1.1       nbrk       61:                        return p;
                     62:                n = list_next(n);
                     63:        }
                     64:        return NULL;
                     65: }
                     66:
                     67: /*
                     68:  * Find process group by pgid.
                     69:  */
                     70: struct pgrp *
                     71: pgrp_find(pid_t pgid)
                     72: {
                     73:        list_t head, n;
                     74:        struct pgrp *g = NULL;
                     75:
                     76:        head = &pgid_hash[IDHASH(pgid)];
                     77:        n = list_first(head);
                     78:        while (n != head) {
1.1.1.1.2.1! nbrk       79:                g = list_entry(n, struct pgrp, pg_link);
        !            80:                if (g->pg_pgid == pgid)
1.1       nbrk       81:                        return g;
                     82:                n = list_next(n);
                     83:        }
                     84:        return NULL;
                     85: }
                     86:
                     87: /*
                     88:  * Find process by task ID.
                     89:  */
                     90: struct proc *
                     91: task_to_proc(task_t task)
                     92: {
                     93:        list_t head, n;
                     94:        struct proc *p = NULL;
                     95:
                     96:        head = &task_hash[IDHASH(task)];
                     97:        n = list_first(head);
                     98:        while (n != head) {
1.1.1.1.2.1! nbrk       99:                p = list_entry(n, struct proc, p_task_link);
        !           100:                if (p->p_task == task)
1.1       nbrk      101:                        return p;
                    102:                n = list_next(n);
                    103:        }
                    104:        return NULL;
                    105: }
                    106:
                    107: /*
                    108:  * Add process to the pid table and the task table.
                    109:  * This routine assumes pid and task data has been already initialized.
                    110:  */
                    111: void
1.1.1.1.2.1! nbrk      112: proc_add(struct proc *p)
1.1       nbrk      113: {
                    114:
1.1.1.1.2.1! nbrk      115:        list_insert(&pid_hash[IDHASH(p->p_pid)], &p->p_pid_link);
        !           116:        list_insert(&task_hash[IDHASH(p->p_task)], &p->p_task_link);
1.1       nbrk      117: }
                    118:
                    119: /*
                    120:  * Remove process from both of pid table and task table.
                    121:  */
                    122: void
1.1.1.1.2.1! nbrk      123: proc_remove(struct proc *p)
1.1       nbrk      124: {
                    125:
1.1.1.1.2.1! nbrk      126:        list_remove(&p->p_pid_link);
        !           127:        list_remove(&p->p_task_link);
1.1       nbrk      128: }
                    129:
                    130: /*
                    131:  * Add process group to table.
                    132:  * This routine assumes pgid has been already initialized.
                    133:  */
                    134: void
                    135: pgrp_add(struct pgrp *pgrp)
                    136: {
                    137:
1.1.1.1.2.1! nbrk      138:        list_insert(&pgid_hash[IDHASH(pgrp->pg_pgid)], &pgrp->pg_link);
1.1       nbrk      139: }
                    140:
                    141: /*
                    142:  * Remove process from pgid table.
                    143:  */
                    144: void
                    145: pgrp_remove(struct pgrp *pgrp)
                    146: {
                    147:
1.1.1.1.2.1! nbrk      148:        list_remove(&pgrp->pg_link);
1.1       nbrk      149: }
                    150:
                    151: /*
                    152:  * Initialize tables.
                    153:  */
                    154: void
                    155: table_init(void)
                    156: {
                    157:        int i;
                    158:
                    159:        for (i = 0; i < ID_MAXBUCKETS; i++) {
                    160:                list_init(&pid_hash[i]);
                    161:                list_init(&task_hash[i]);
                    162:                list_init(&pgid_hash[i]);
                    163:        }
                    164: }