include/minix/endpoint.h

   1
   2 #ifndef _MINIX_ENDPOINT_H
   3 #define _MINIX_ENDPOINT_H 1
   4
   5 #include <minix/sys_config.h>
   6 #include <minix/com.h>
   7 #include <limits.h>
   8 #include <minix/type.h>
   9
  10 /* The point of the padding in 'generation size' is to
  11  * allow for certain bogus endpoint numbers such as NONE, ANY, etc.
  12  *
  13  * The _MAX_MAGIC_PROC is defined by <minix/com.h>. That include
  14  * file defines some magic process numbers such as ANY and NONE,
  15  * and must never be a valid endpoint number. Therefore we make sure
  16  * the generation size is big enough to start the next generation
  17  * above the highest magic number.
  18  */
  19 #define _ENDPOINT_GENERATION_SIZE (MAX_NR_TASKS+_MAX_MAGIC_PROC+1)
  20 #define _ENDPOINT_MAX_GENERATION  (INT_MAX/_ENDPOINT_GENERATION_SIZE-1)
  21
  22 /* Generation + Process slot number <-> endpoint. */
  23 #define _ENDPOINT(g, p) ((endpoint_t)((g) * _ENDPOINT_GENERATION_SIZE + (p)))
  24 #define _ENDPOINT_G(e) (((e)+MAX_NR_TASKS) / _ENDPOINT_GENERATION_SIZE)
  25 #define _ENDPOINT_P(e) \
  26         ((((e)+MAX_NR_TASKS) % _ENDPOINT_GENERATION_SIZE) - MAX_NR_TASKS)
  27
  28 #endif