Annotation of 42BSD/sys/h/cmap.h, revision 1.1.1.1

1.1       root        1: /*     cmap.h  6.1     83/07/29        */
                      2: 
                      3: /*
                      4:  * core map entry
                      5:  */
                      6: struct cmap
                      7: {
                      8: unsigned int   c_next:13,      /* index of next free list entry */
                      9:                c_prev:13,      /* index of previous free list entry */
                     10:                c_mdev:4,       /* which mounted dev this is from */
                     11:                c_lock:1,       /* locked for raw i/o or pagein */
                     12:                c_want:1,       /* wanted */
                     13:                c_page:16,      /* virtual page number in segment */
                     14:                c_hlink:13,     /* hash link for <blkno,mdev> */
                     15:                c_intrans:1,    /* intransit bit */
                     16:                c_free:1,       /* on the free list */
                     17:                c_gone:1,       /* associated page has been released */
                     18:                c_type:2,       /* type CSYS or CTEXT or CSTACK or CDATA */
                     19:                c_blkno:20,     /* disk block this is a copy of */
                     20:                c_ndx:10;       /* index of owner proc or text */
                     21: };
                     22: 
                     23: #define        CMHEAD  0
                     24: 
                     25: /*
                     26:  * Shared text pages are not totally abandoned when a process
                     27:  * exits, but are remembered while in the free list hashed by <mdev,blkno>
                     28:  * off the cmhash structure so that they can be reattached
                     29:  * if another instance of the program runs again soon.
                     30:  */
                     31: #define        CMHSIZ  512             /* SHOULD BE DYNAMIC */
                     32: #define        CMHASH(bn)      ((bn)&(CMHSIZ-1))
                     33: 
                     34: #ifdef KERNEL
                     35: struct cmap *cmap;
                     36: struct cmap *ecmap;
                     37: int    ncmap;
                     38: struct cmap *mfind();
                     39: int    firstfree, maxfree;
                     40: int    ecmx;                   /* cmap index of ecmap */
                     41: short  cmhash[CMHSIZ];
                     42: #endif
                     43: 
                     44: /* bits defined in c_type */
                     45: 
                     46: #define        CSYS            0               /* none of below */
                     47: #define        CTEXT           1               /* belongs to shared text segment */
                     48: #define        CDATA           2               /* belongs to data segment */
                     49: #define        CSTACK          3               /* belongs to stack segment */
                     50: 
                     51: #define        pgtocm(x)       ((((x)-firstfree) / CLSIZE) + 1)
                     52: #define        cmtopg(x)       ((((x)-1) * CLSIZE) + firstfree)

unix.superglobalmegacorp.com

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