Liren Large Software Subsidy 7/07.iso/c/c004/2.ddi/UNIX/CTSMSG.C

C/C++ Source or Header | 1989-04-18 | 4.9 KB | 221 lines

/*
 *    System Dependent Server Message Handler
 *    Two Queue Approach
 *    Unix/Xenix V Queue Implementation
 *
 *    This program is the CONFIDENTIAL and PROPRIETARY property
 *    of FairCom(R) Corporation. Any unauthorized use, reproduction or
 *    transfer of this program is strictly prohibited.
 *
 *      Copyright (c) 1987, 1988, 1989 FairCom Corporation
 *    (Subject to limited distribution and
 *     restricted disclosure only.)
 *    *** ALL RIGHTS RESERVED ***
 *
 *    4006 West Broadway
 *    Columbia, MO 65203
 *
 *
 *    c-tree(R)    Version 4.3
 *            Release C
 *            February 7, 1989 17:30
 *
 */

#include "ctstdr.h"
#include "ctoptn.h"
#include "ctstrc.h"
#include "cterrc.h"
#include "ctcomm.h"
#include "ctmssg.h"
#include <errno.h>
#include <signal.h>

LOCAL UCOUNT msgsiz;
LOCAL LONG  *ausrmid;

extern COUNT uerr_cod;
extern COUNT cts_mxusr;
extern int   errno;

/* elapsed time before unread user queue declared inactive */
#define INDEFINITE 5    /* seconds */

/* LTYPE is defined in ctmsgg.h */

TEXT *getmid(sizmsg,maxusr)
UCOUNT         sizmsg;
COUNT            maxusr;
{
    TEXT *retval;
    int   chfd;

    key_t ftok();
    TEXT *mballc();

    /* server ignores hangup */
    signal(SIGHUP,SIG_IGN);

    /* create SERVER3 to prove no other server is running */
    if ((chfd = open(SERVER3,O_RDWR | O_EXCL | O_CREAT,BCREATE)) < 0) {
        fprintf(stderr,"\nIs a c-tree Server already running?\n");
        fprintf(stderr,"\nIf a c-tree Server has terminated abnormally,");
        fprintf(stderr,"\nremove the file %s before starting the server.\n\n",
            SERVER3);
        exit(2);
    } else
        close(chfd);

    /* allocate an array for message ids: assumes long is OK */
    if ((ausrmid = (LONG *) mballc(maxusr + 1,sizeof(LONG))) == NULL) {
        uerr_cod = SSCB_ERR;
        return(NULL);
    }

    /* get message id for server */
    uerr_cod = 0;

    if ((srvkey = ftok(SERVER,'q')) == NOKEY) /* get "key" for input Q */
        uerr_cod = SSKY_ERR;
    else if ((srvid = msgget(srvkey,IPC_CREAT | 0666)) < 0) /* get msg id */
        uerr_cod = SSID_ERR;
    else if (msgctl(srvid,IPC_STAT,&qidbuf) < 0) /* get msg specs */
        uerr_cod = SMST_ERR;
    else {
        /* set message size specifications */
        msgsiz          = sizmsg;
        qidbuf.msg_qbytes = sizmsg + LTYPE;
        if (msgctl(srvid,IPC_SET,&qidbuf) < 0)
            uerr_cod = SMQZ_ERR;
    }
    if (uerr_cod)
        return(NULL);


    /* get space for server message */
    if ((retval = mballc(1,sizmsg + LTYPE)) == NULL) {
        uerr_cod = SSPC_ERR;
        return(NULL);
    }

    if ((appkey = ftok(SERVER2,'q')) == NOKEY) /* get "key" for output Q */
        uerr_cod = ASKY_ERR;
    else if ((apxid = msgget(appkey,IPC_CREAT | 0666)) < 0) /* get msg id */
        uerr_cod = ASID_ERR;
    else if (msgctl(apxid,IPC_STAT,&qidbuf) < 0) /* get msg specs */
        uerr_cod = AMST_ERR;
    else {
        /* set message size specifications */
        qidbuf.msg_qbytes = cts_mxusr * (sizmsg + LTYPE); /* ???? */
        if (msgctl(apxid,IPC_SET,&qidbuf) < 0)
            uerr_cod = AMQZ_ERR;
    }

    return(retval + LTYPE);
}

LONG getumsg(pmsg,usrn,msgptr) /* assumes that mpntr member contains msg id */
MESSAGE        *pmsg;
COUNT          usrn;
TEXT              *msgptr;
{
    /* save message id of application: assumes that a long is sufficient */
    if (usrn >= 0)
        ausrmid[usrn] = pmsg->mpntr;

    return(pmsg->mpntr);
}

COUNT dedusr(msgid)
LONG         msgid;
{
    COUNT usrn;

    for (usrn = 0; usrn < cts_mxusr; usrn++)
        if (msgid == ausrmid[usrn]) {
            ausrmid[usrn] = 0;
            return(usrn);
        }
    return(-1);
}

COUNT ridmid()
{
    /* remove check file */
    unlink(SERVER3);

    /* remove application message handling */
    if (msgctl(srvid,IPC_RMID,NULL) < 0)
        return(uerr_cod = SMRD_ERR);
    sleep(5);
    if (msgctl(apxid,IPC_RMID,NULL) < 0)
        return(uerr_cod = SMRD_ERR);
    return(NO_ERROR);
}

COUNT ctrqst(msgadr,pmsg)
PFAST TEXT **msgadr;
MESSAGE           *pmsg;
{
    /* read input message */
    if (msgrcv(srvid,*msgadr - LTYPE,msgsiz,0L,0) < 0)
        return(uerr_cod = SRQS_ERR);

    /* copy message header */
    cpybuf(pmsg,*msgadr,sizeof(MESSAGE));

    return(NO_ERROR);
}

COUNT ctrspn(msgadr,pmsg,sizmsg,usrn)
PFAST TEXT  *msgadr;
MESSAGE           *pmsg;
UCOUNT             sizmsg;
COUNT                usrn;
{
    /* local copy of message id with correct type */
    long int locmid;

    if (usrn < 0) {
        usrn = - (usrn + 1);
        locmid = ausrmid[usrn];
        ausrmid[usrn] = 0;
    } else
        locmid = ausrmid[usrn];

    /* copy message header */
    cpybuf(msgadr,pmsg,sizeof(MESSAGE));

    /* send response */
    msgadr -= LTYPE;
    *((LONG *) msgadr) = locmid;

    if (msgsnd(apxid,msgadr,sizmsg,IPC_NOWAIT) < 0)
        if (errno != EAGAIN || msgsnd(apxid,msgadr,sizmsg,0) < 0)
        return(uerr_cod = SRSP_ERR);

    return(NO_ERROR);

}

COUNT norspn(usrn)
COUNT         usrn;
{
    return(NO);
}

chkusrtim(usrtim,usrmap,usrtrn)
LONG     *usrtim;
COUNT        *usrmap;
LONG               *usrtrn;
{
    /*
     * This function can interrogate the usrtim[] array to
     * determine if any active user slot is in fact dead.
     */
    return(NO_ERROR);
}

/* end of ctsmsg.c */