Return to candidate.c CVS log

Up to [CSRG BSD Unix] / 43BSDTahoe / etc / timed

Annotation of 43BSDTahoe/etc/timed/candidate.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 1983 Regents of the University of California.
        !             3:  * All rights reserved.
        !             4:  *
        !             5:  * Redistribution and use in source and binary forms are permitted
        !             6:  * provided that the above copyright notice and this paragraph are
        !             7:  * duplicated in all such forms and that any documentation,
        !             8:  * advertising materials, and other materials related to such
        !             9:  * distribution and use acknowledge that the software was developed
        !            10:  * by the University of California, Berkeley.  The name of the
        !            11:  * University may not be used to endorse or promote products derived
        !            12:  * from this software without specific prior written permission.
        !            13:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
        !            14:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
        !            15:  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
        !            16:  */
        !            17: 
        !            18: #ifndef lint
        !            19: static char sccsid[] = "@(#)candidate.c        2.5 (Berkeley) 6/18/88";
        !            20: #endif /* not lint */
        !            21: 
        !            22: #include "globals.h"
        !            23: #include <protocols/timed.h>
        !            24: 
        !            25: #define ELECTIONWAIT   3       /* seconds */
        !            26: 
        !            27: /*
        !            28:  * `election' candidates a host as master: it is called by a slave 
        !            29:  * which runs with the -M option set when its election timeout expires. 
        !            30:  * Note the conservative approach: if a new timed comes up, or another
        !            31:  * candidate sends an election request, the candidature is withdrawn.
        !            32:  */
        !            33: 
        !            34: election(net)
        !            35: struct netinfo *net;
        !            36: {
        !            37:        int ret;
        !            38:        struct tsp *resp, msg, *readmsg();
        !            39:        struct timeval wait;
        !            40:        struct tsp *answer, *acksend();
        !            41:        long casual();
        !            42:        struct sockaddr_in server;
        !            43: 
        !            44:        syslog(LOG_INFO, "THIS MACHINE IS A CANDIDATE");
        !            45:        if (trace) {
        !            46:                fprintf(fd, "THIS MACHINE IS A CANDIDATE\n");
        !            47:        }
        !            48: 
        !            49:        ret = MASTER;
        !            50:        slvcount = 1;
        !            51: 
        !            52:        msg.tsp_type = TSP_ELECTION;
        !            53:        msg.tsp_vers = TSPVERSION;
        !            54:        (void)strcpy(msg.tsp_name, hostname);
        !            55:        bytenetorder(&msg);
        !            56:        if (sendto(sock, (char *)&msg, sizeof(struct tsp), 0, &net->dest_addr,
        !            57:            sizeof(struct sockaddr_in)) < 0) {
        !            58:                syslog(LOG_ERR, "sendto: %m");
        !            59:                exit(1);
        !            60:        }
        !            61: 
        !            62:        do {
        !            63:                wait.tv_sec = ELECTIONWAIT;
        !            64:                wait.tv_usec = 0;
        !            65:                resp = readmsg(TSP_ANY, (char *)ANYADDR, &wait, net);
        !            66:                if (resp != NULL) {
        !            67:                        switch (resp->tsp_type) {
        !            68: 
        !            69:                        case TSP_ACCEPT:
        !            70:                                (void) addmach(resp->tsp_name, &from);
        !            71:                                break;
        !            72: 
        !            73:                        case TSP_MASTERUP:
        !            74:                        case TSP_MASTERREQ:
        !            75:                                /*
        !            76:                                 * If a timedaemon is coming up at the same time,
        !            77:                                 * give up the candidature: it will be the master.
        !            78:                                 */
        !            79:                                ret = SLAVE;
        !            80:                                break;
        !            81: 
        !            82:                        case TSP_QUIT:
        !            83:                        case TSP_REFUSE:
        !            84:                                /*
        !            85:                                 * Collision: change value of election timer 
        !            86:                                 * using exponential backoff.
        !            87:                                 * The value of timer will be recomputed (in slave.c)
        !            88:                                 * using the original interval when election will 
        !            89:                                 * be successfully completed.
        !            90:                                 */
        !            91:                                backoff *= 2;
        !            92:                                delay2 = casual((long)MINTOUT, 
        !            93:                                                        (long)(MAXTOUT * backoff));
        !            94:                                ret = SLAVE;
        !            95:                                break;
        !            96: 
        !            97:                        case TSP_ELECTION:
        !            98:                                /* no master for another round */
        !            99:                                msg.tsp_type = TSP_REFUSE;
        !           100:                                (void)strcpy(msg.tsp_name, hostname);
        !           101:                                server = from;
        !           102:                                answer = acksend(&msg, &server, resp->tsp_name,
        !           103:                                    TSP_ACK, (struct netinfo *)NULL);
        !           104:                                if (answer == NULL) {
        !           105:                                        syslog(LOG_ERR, "error in election");
        !           106:                                } else {
        !           107:                                        (void) addmach(resp->tsp_name, &from);
        !           108:                                }
        !           109:                                break;
        !           110: 
        !           111:                        case TSP_SLAVEUP:
        !           112:                                (void) addmach(resp->tsp_name, &from);
        !           113:                                break;
        !           114: 
        !           115:                        case TSP_SETDATE:
        !           116:                        case TSP_SETDATEREQ:
        !           117:                                break;
        !           118: 
        !           119:                        default:
        !           120:                                if (trace) {
        !           121:                                        fprintf(fd, "candidate: ");
        !           122:                                        print(resp, &from);
        !           123:                                }
        !           124:                                break;
        !           125:                        }
        !           126:                } else {
        !           127:                        break;
        !           128:                }
        !           129:        } while (ret == MASTER);
        !           130:        return(ret);
        !           131: }

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.