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Annotation of coherent/b/bin/ipcs/fifo.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * File:       fifo.c
        !             3:  *
        !             4:  * Purpose:    allow kernel to fetch data from real-mode bootstrap data area
        !             5:  *
        !             6:  * $Log:       fifo.c,v $
        !             7:  * Revision 1.2  93/04/12  13:54:26  bin
        !             8:  * vlad: mods supplied with 386 semaphores
        !             9:  * 
        !            10:  * Revision 1.1  92/10/05  13:10:43  bin
        !            11:  * Initial revision
        !            12:  * 
        !            13:  * Revision 1.5  92/09/18  09:42:03  bin
        !            14:  * version 210 fom piggy
        !            15:  * 
        !            16:  * Revision 1.2  92/01/06  11:59:11  hal
        !            17:  * Compile with cc.mwc.
        !            18:  * 
        !            19:  */
        !            20: 
        !            21: /*
        !            22:  * Includes.
        !            23:  */
        !            24: #define KERNEL
        !            25: #include <sys/typed.h>
        !            26: 
        !            27: #ifndef T_NULL
        !            28: #define T_NULL ((char *)0)
        !            29: #endif
        !            30: 
        !            31: /*
        !            32:  * Definitions.
        !            33:  *     Constants.
        !            34:  *     Macros with argument lists.
        !            35:  *     Typedefs.
        !            36:  *     Enums.
        !            37:  */
        !            38: 
        !            39: typedef unsigned char uchar;
        !            40: typedef unsigned int  uint;
        !            41: typedef unsigned long ulong;
        !            42: 
        !            43: /*
        !            44:  * Functions.
        !            45:  *     Import Functions.
        !            46:  *     Export Functions.
        !            47:  *     Local Functions.
        !            48:  */
        !            49: FIFO * fifo_open();
        !            50: int fifo_close();
        !            51: typed_space * fifo_read();
        !            52: 
        !            53: /*
        !            54:  * Global Data.
        !            55:  *     Import Variables.
        !            56:  *     Export Variables.
        !            57:  *     Local Variables.
        !            58:  *
        !            59:  * Arguments are passed into the kernel through boot_gift.
        !            60:  * If you start getting "Not enough room for all arguments." messages
        !            61:  * at boot time, just increase the BG_LEN  to whatever you need.
        !            62:  * This structure is EXACTLY BG_LEN bytes long.
        !            63:  */
        !            64: TYPED_SPACE(boot_gift, BG_LEN, T_FIFO_SIC);
        !            65: 
        !            66: /*
        !            67:  * fifo_open()
        !            68:  *
        !            69:  * Open a typed space as a fifo.
        !            70:  *
        !            71:  * Takes a typed_space that is already allocated, and a mode.    The type of
        !            72:  * the typed space must be a FIFO.  Only T_FIFO_SIC has been implimented
        !            73:  * (static, in-core fifo).
        !            74:  *
        !            75:  * The mode indicates whether to open for reading or writing.
        !            76:  *  mode == 0 means read only.
        !            77:  *  mode == 1 means write only.
        !            78:  *  Other values are illegal.
        !            79:  *
        !            80:  * Returns a pointer to an initialized FIFO structure.  FIFO structures are
        !            81:  * allocated from a pre-allocated array.  Returns F_NULL if it can't open
        !            82:  * the fifo.
        !            83:  */
        !            84: FIFO *
        !            85: fifo_open(fifo_space, mode)
        !            86:        typed_space *fifo_space;
        !            87:        int mode;
        !            88: {
        !            89:        /* ff_table is a table of FIFO structures which can be allocated on
        !            90:         * demand.  It is functionally similiar to the file descritor table
        !            91:         * in the kernel.
        !            92:         */
        !            93:        static FIFO ff_table[NFIFOS];
        !            94:        static int inited = (1==2);     /* Has ff_table been initialized?  */
        !            95: 
        !            96:        int i;          /* A handy counter.  */
        !            97:        FIFO *the_fifo; /* The fifo we are going to allocate.  */
        !            98: 
        !            99:        /* Initilize ff_table the first time we get called.  */
        !           100:        if (!inited) {
        !           101:                for (i = 0; i < NFIFOS; ++i) {
        !           102:                        ff_table[i].f_space = F_NULL;
        !           103:                        ff_table[i].f_flags = 0;
        !           104:                }
        !           105:                inited = 1;
        !           106:        }
        !           107: 
        !           108:        /* Check the type of the space we were passed.  */
        !           109:        switch (fifo_space->ts_type) {
        !           110:        case T_FIFO:    /* Overly general type, assuming SIC.  */
        !           111:                fifo_space->ts_type = T_FIFO_SIC;
        !           112:                break;
        !           113:        case T_FIFO_SIC:        /* Static In-core Fifo.  */
        !           114:                break;
        !           115:        case T_FIFO_DIC:        /* Dynamic In-core Fifo (can grow).  */
        !           116:                return(F_NULL); /* Unimplimented.  */
        !           117:        case T_FIFO_SP: /* Static Permanent Fifo (fixed size file). */
        !           118:                return(F_NULL); /* Unimplimented.  */
        !           119:        case T_FIFO_DP: /* Dynamic Permanent Fifo (ordinary file).  */
        !           120:                return(F_NULL); /* Unimplimented.  */
        !           121:        default:
        !           122:                return(F_NULL); /* Illegal type encountered.  */
        !           123:        }
        !           124: 
        !           125:        /* ASSERTION: fifo_space is a valid and implimented FIFO.  */
        !           126: 
        !           127:        /* Find the first free FIFO structure.  */
        !           128: 
        !           129:        /* This should be re-implimented using a malloc-based scheme.
        !           130:         * At the moment, the tertiary boot libraries do not include a
        !           131:         * malloc.
        !           132:         */
        !           133:        for (i = 0; (i < NFIFOS) && (0 != ff_table[i].f_flags); ++i) {
        !           134:                /* Do nothing else.  */
        !           135:        }
        !           136: 
        !           137:        if (NFIFOS == i) {
        !           138:                return(F_NULL); /* No more free fifo structs.  */
        !           139:        }
        !           140: 
        !           141:        the_fifo = &(ff_table[i]);
        !           142: 
        !           143:        /* ASSERTION: the_fifo points at a FIFO we can take.  */
        !           144: 
        !           145:        /* Initialize the FIFO struct.  */
        !           146:        the_fifo->f_space = fifo_space;
        !           147:        the_fifo->f_offset = fifo_space->ts_data;
        !           148: 
        !           149:        /* Initilize the flags.  */
        !           150:        switch(mode) {
        !           151:        case 0: /* read */
        !           152:                the_fifo->f_flags |= F_READ;
        !           153:                break;
        !           154:        case 1: /* write */
        !           155:                the_fifo->f_flags |= F_WRITE;
        !           156:                break;
        !           157:        default:
        !           158:                return(F_NULL); /* Illegal mode flag.  */
        !           159:        }
        !           160:                
        !           161:        return(the_fifo);
        !           162: } /* fifo_open() */
        !           163: 
        !           164: /*
        !           165:  * fifo_close()
        !           166:  *
        !           167:  * Finish with using a typed space as a fifo.
        !           168:  * Free up FIFO structure associated with a typed space.
        !           169:  * Returns 0 if ffp was not open, 1 otherwise.
        !           170:  */
        !           171: int
        !           172: fifo_close(ffp)
        !           173:        FIFO *ffp;
        !           174: {
        !           175:        if (0 == ffp->f_flags) {
        !           176:                return(0);      /* This ffp is not open.  */
        !           177:        }
        !           178:        ffp->f_space = F_NULL;
        !           179:        ffp->f_offset = T_NULL;
        !           180:        ffp->f_flags = 0;
        !           181: 
        !           182:        return(1);
        !           183: } /* fifo_close() */
        !           184: 
        !           185: /*
        !           186:  * fifo_read()
        !           187:  *
        !           188:  * Read a typed space from a fifo.
        !           189:  * Return a pointer to the next typed space in the fifo ffp.  Returns
        !           190:  * NULL on end of fifo.
        !           191:  *
        !           192:  * This read assumes that ffp->f_space has type T_FIFO_SIC.
        !           193:  */
        !           194: typed_space *
        !           195: fifo_read(ffp)
        !           196:        register FIFO *ffp;
        !           197: {
        !           198:        typed_space *retval;
        !           199: 
        !           200:        /* Read MUST be set.  */
        !           201:        if (F_READ != F_READ & ffp->f_flags ) {
        !           202:                return(T_NULL);  /* This ffp is not open for reading.  */
        !           203:        }
        !           204: 
        !           205:        /* From here to the end of fifo_read is really fifo_read_sic().  */
        !           206: 
        !           207: 
        !           208:        /* Space of size 0 marks EOFIFO.  */
        !           209:        if ((long)0 == ffp->f_offset->ts_size) {
        !           210:                retval = T_NULL;
        !           211:        } else {
        !           212:                /* Return the next space.  */
        !           213:                retval = ffp->f_offset;
        !           214:                /* Advance to the next space.  */
        !           215:                (char *) ffp->f_offset += ffp->f_offset->ts_size;
        !           216:        }
        !           217: 
        !           218:        return(retval);
        !           219: } /* fifo_read() */
        !           220: 
        !           221: #ifdef TEST
        !           222: #include <stdio.h>
        !           223: 
        !           224: /* This is the typed space we will use for our FIFO operations.  */
        !           225: TYPED_SPACE(global_space, 128, T_FIFO_SIC);    /* Static In-Core Fifo.  */
        !           226: 
        !           227: int
        !           228: main()
        !           229: {
        !           230:        FIFO *ffp;              /* Fifo pointer for a handle.  */
        !           231:        char line[1024];        /* Place to put input lines.  */
        !           232:        long size;              /* Length for line.  (Sizes are all long.)  */
        !           233:        int i;
        !           234: 
        !           235:        typed_space *local_space;
        !           236: 
        !           237:        /* Open the fifo for writing.  */
        !           238:        if (F_NULL == (ffp = fifo_open(&global_space, 1))) {
        !           239:                fprintf(stderr, "Can't open global_space for writing.\n");
        !           240:                exit(1);
        !           241:        }
        !           242: 
        !           243:        do {
        !           244:                printf("Feed me: ");
        !           245:                gets(line);
        !           246:                size = (long) (strlen(line) + 1);
        !           247:        } while (T_NULL != fifo_write_untyped(ffp, line, size, T_STR_STR));
        !           248: 
        !           249:        if (0 == fifo_close(ffp)) {
        !           250:                fprintf(stderr, "Failed to close global_space.\n");
        !           251:                exit(1);
        !           252:        }
        !           253: 
        !           254:        printf("OK, global_space is now full.\n");
        !           255:        /* ASSERTION: We've filled global_space with strings.  */
        !           256: 
        !           257:        /* Open the fifo for reading.  */
        !           258:        if (F_NULL == (ffp = fifo_open(&global_space, 0))) {
        !           259:                fprintf(stderr, "Can't open global_space for reading.\n");
        !           260:                exit(1);
        !           261:        }
        !           262: 
        !           263:        /* Dump the contents of this FIFO.  */
        !           264:        for (i = 1; T_NULL != (local_space = fifo_read(ffp)); ++i) {
        !           265:                printf("%d: size: %ld: type: 0x%x\n", i,
        !           266:                        local_space->ts_size,
        !           267:                        local_space->ts_type);
        !           268: 
        !           269:                /* Assume everything is a NUL terminated string.  */
        !           270:                printf("datum: %s\n\n", local_space->ts_data);
        !           271:                printf("Hit <RETURN>");
        !           272:                gets(line);
        !           273:        }
        !           274: 
        !           275: 
        !           276:        /* Rewind the file, and dump it out again.  */
        !           277:        printf("Rewinding.\n");
        !           278:        if (0 == fifo_rewind(ffp)) {
        !           279:                fprintf("Can't rewind global_space.\n");
        !           280:                exit(1);
        !           281:        }
        !           282: 
        !           283:        for (i = 1; T_NULL != (local_space = fifo_read(ffp)); ++i) {
        !           284:                printf("%d: size: %ld: type: 0x%x\n", i,
        !           285:                        local_space->ts_size,
        !           286:                        local_space->ts_type);
        !           287: 
        !           288:                /* Assume everything is a NUL terminated string.  */
        !           289:                printf("datum: %s\n\n", local_space->ts_data);
        !           290:        }
        !           291: 
        !           292:        if (0 == fifo_close(ffp)) {
        !           293:                fprintf(stderr, "Failed to close global_space.\n");
        !           294:                exit(1);
        !           295:        }
        !           296: 
        !           297:        exit(0);
        !           298: } /* main() */
        !           299: 
        !           300: #endif /* TEST */

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