[f40a309] | 1 | /*
|
---|
| 2 | ============================================================================
|
---|
| 3 | setwq.c -- word queue functions
|
---|
| 4 | Version 1 -- 1988-11-02 -- D.N. Lynx Crowe
|
---|
| 5 | ============================================================================
|
---|
| 6 | */
|
---|
| 7 |
|
---|
| 8 | #define WORDQHDR /* so wordq.h gets it right */
|
---|
| 9 |
|
---|
| 10 | #include "stddefs.h"
|
---|
| 11 | #include "wordq.h"
|
---|
| 12 |
|
---|
| 13 | /*
|
---|
| 14 | ============================================================================
|
---|
| 15 | setwq(qp, qadr, qsiz, hi, lo) -- setup a word queue
|
---|
| 16 |
|
---|
| 17 | Where:
|
---|
| 18 |
|
---|
| 19 | struct wordq *qp queue structure pointer
|
---|
| 20 | unsigned short *qadr queue buffer pointer
|
---|
| 21 | unsigned short qsiz maximum length of queue
|
---|
| 22 | unsigned short hi high water mark count
|
---|
| 23 | unsigned short lo low water mark count
|
---|
| 24 |
|
---|
| 25 | Return value:
|
---|
| 26 |
|
---|
| 27 | unsigned short qsiz size of queue
|
---|
| 28 | ============================================================================
|
---|
| 29 | */
|
---|
| 30 |
|
---|
[0580615] | 31 | unsigned short setwq(struct wordq *qp, unsigned short *qadr, unsigned short qsiz, unsigned short hi, unsigned short lo)
|
---|
[f40a309] | 32 | {
|
---|
| 33 | if ((unsigned short *)0L EQ qadr)
|
---|
| 34 | qsiz = 0;
|
---|
| 35 |
|
---|
| 36 | qp->qbuf = qadr;
|
---|
| 37 | qp->qsize = qsiz;
|
---|
| 38 | qp->qlen = 0;
|
---|
| 39 | qp->qin = 0;
|
---|
| 40 | qp->qout = 0;
|
---|
| 41 | qp->qhi = hi;
|
---|
| 42 | qp->qlo = lo;
|
---|
| 43 |
|
---|
| 44 | return(qsiz);
|
---|
| 45 | }
|
---|
| 46 |
|
---|
| 47 | /* |
---|
| 48 |
|
---|
| 49 | */
|
---|
| 50 |
|
---|
| 51 | /*
|
---|
| 52 | ============================================================================
|
---|
| 53 | putwq(qp, c) -- put a word in a word queue
|
---|
| 54 |
|
---|
| 55 | Where:
|
---|
| 56 |
|
---|
| 57 | qp queue structure pointer
|
---|
| 58 | c word to put in the queue
|
---|
| 59 |
|
---|
| 60 | Return values:
|
---|
| 61 |
|
---|
| 62 | -2 error, queue size was 0
|
---|
| 63 | -1 queue was full, word not added to queue
|
---|
| 64 | 0 word added to queue
|
---|
| 65 | 1 at high water mark, word added to queue
|
---|
| 66 | ============================================================================
|
---|
| 67 | */
|
---|
[0580615] | 68 |
|
---|
[f40a309] | 69 | short putwq(struct wordq *qp, unsigned short c)
|
---|
| 70 | {
|
---|
| 71 | if (0 NE qp->qsize) { /* verify queue is ok */
|
---|
| 72 |
|
---|
| 73 | if (qp->qlen EQ qp->qsize) /* check queue length */
|
---|
| 74 | return(-1); /* -1 = full */
|
---|
| 75 |
|
---|
| 76 | qp->qbuf[qp->qin++] = c; /* put word in queue */
|
---|
| 77 |
|
---|
| 78 | if (qp->qin GE qp->qsize) /* update input index */
|
---|
| 79 | qp->qin = 0; /* wrap around */
|
---|
| 80 |
|
---|
| 81 | if (++qp->qlen EQ qp->qhi) /* check length again */
|
---|
| 82 | return(1); /* 1 = at hi water */
|
---|
| 83 | else
|
---|
| 84 | return(0); /* 0 = OK */
|
---|
| 85 |
|
---|
| 86 | } else {
|
---|
| 87 |
|
---|
| 88 | return(-2); /* -2 = error */
|
---|
| 89 | }
|
---|
| 90 | }
|
---|
| 91 |
|
---|
| 92 | /* |
---|
| 93 |
|
---|
| 94 | */
|
---|
| 95 |
|
---|
| 96 | /*
|
---|
| 97 | ============================================================================
|
---|
| 98 | getwq(qp, p) -- get a word from a word queue
|
---|
| 99 |
|
---|
| 100 | Where:
|
---|
| 101 |
|
---|
| 102 | qp queue structure pointer
|
---|
| 103 | p word pointer for returned word
|
---|
| 104 |
|
---|
| 105 | Return values:
|
---|
| 106 |
|
---|
| 107 | -2 error, queue size was 0
|
---|
| 108 | -1 queue was empty, no word returned
|
---|
| 109 | 0 word returned
|
---|
| 110 | 1 at low water, word returned
|
---|
| 111 | ============================================================================
|
---|
[0580615] | 112 | */
|
---|
[f40a309] | 113 |
|
---|
| 114 | short getwq(struct wordq *qp, unsigned short *p)
|
---|
| 115 | {
|
---|
| 116 | if (0 NE qp->qsize) { /* check queue is ok */
|
---|
| 117 |
|
---|
| 118 | if (0 NE qp->qlen) { /* check queue length */
|
---|
| 119 |
|
---|
| 120 | *p = qp->qbuf[qp->qout++]; /* get word from queue */
|
---|
| 121 |
|
---|
| 122 | if (qp->qout GE qp->qsize) /* check out pointer */
|
---|
| 123 | qp->qout = 0; /* wrap around */
|
---|
| 124 |
|
---|
| 125 | if (--qp->qlen EQ qp->qlo) /* check length again */
|
---|
| 126 | return(1); /* 1 = at low water */
|
---|
| 127 | else
|
---|
| 128 | return(0); /* 0 = OK */
|
---|
| 129 |
|
---|
| 130 | } else {
|
---|
| 131 |
|
---|
| 132 | return(-1); /* -1 = emtpy */
|
---|
| 133 | }
|
---|
| 134 |
|
---|
| 135 | } else {
|
---|
| 136 |
|
---|
| 137 | return(-2); /* -2 = error */
|
---|
| 138 | }
|
---|
| 139 | }
|
---|