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Annotation of 41BSD/sys/h/cmap.h, revision 1.1.1.1

1.1       root        1: /*     cmap.h  4.1     11/9/80 */
                      2: 
                      3: /*
                      4:  * core map entry
                      5:  *
                      6:  * NB: THE SIZE OF THIS STRUCTURE IS WELL KNOWN IN cmap.m
                      7:  */
                      8: struct cmap
                      9: {
                     10: unsigned int   c_next:13,      /* index of next free list entry */
                     11:                c_prev:13,      /* index of previous free list entry */
                     12:                c_mdev:4,       /* which mounted dev this is from */
                     13:                c_lock:1,       /* locked for raw i/o or pagein */
                     14:                c_want:1,       /* wanted */
                     15:                c_page:16,      /* virtual page number in segment */
                     16:                c_hlink:13,     /* hash link for <blkno,mdev> */
                     17:                c_intrans:1,    /* intransit bit */
                     18:                c_free:1,       /* on the free list */
                     19:                c_gone:1,       /* associated page has been released */
                     20:                c_type:2,       /* type CSYS or CTEXT or CSTACK or CDATA */
                     21:                c_blkno:20,     /* disk block this is a copy of */
                     22:                c_ndx:10;       /* index of owner proc or text */
                     23: };
                     24: 
                     25: #define        CMHEAD  0
                     26: 
                     27: /*
                     28:  * Shared text pages are not totally abandoned when a process
                     29:  * exits, but are remembered while in the free list hashed by <mdev,blkno>
                     30:  * off the cmhash structure so that they can be reattached
                     31:  * if another instance of the program runs again soon.
                     32:  */
                     33: #define        CMHSIZ  512             /* SHOULD BE DYNAMIC */
                     34: #define        CMHASH(bn)      ((bn)&(CMHSIZ-1))
                     35: 
                     36: #ifdef KERNEL
                     37: extern struct cmap *cmap;
                     38: extern struct cmap *ecmap;
                     39: struct cmap *mfind();
                     40: struct cmap zcmap;
                     41: int    firstfree, maxfree;
                     42: int    ecmx;                   /* cmap index of ecmap */
                     43: short  cmhash[CMHSIZ];
                     44: #endif
                     45: 
                     46: /* bits defined in c_type */
                     47: 
                     48: #define        CSYS            0               /* none of below */
                     49: #define        CTEXT           1               /* belongs to shared text segment */
                     50: #define        CDATA           2               /* belongs to data segment */
                     51: #define        CSTACK          3               /* belongs to stack segment */
                     52: 
                     53: #define        pgtocm(x)       ((((x)-firstfree) / CLSIZE) + 1)
                     54: #define        cmtopg(x)       ((((x)-1) * CLSIZE) + firstfree)

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