minix/include/minix/endpoint.h
Tomas Hruby 40b1d58077 Mostly a revert of r5306. com.h defines MAX_NR_TASKS value which replaces
NR_TASKS in the endpoint macros. MAX_NR_TASKS defines the maximal number of
kernel tasks. It is unlikely that we will ever need this many tasks as the goal
is not to have such a difference in the future. For now it makes possible to
remove the limiting NR_TASKS from the endpoint code.
2009-09-29 20:13:41 +00:00

29 lines
1 KiB
C

#ifndef _MINIX_ENDPOINT_H
#define _MINIX_ENDPOINT_H 1
#include <minix/sys_config.h>
#include <minix/com.h>
#include <limits.h>
#include <minix/type.h>
/* The point of the padding in 'generation size' is to
* allow for certain bogus endpoint numbers such as NONE, ANY, etc.
*
* The _MAX_MAGIC_PROC is defined by <minix/com.h>. That include
* file defines some magic process numbers such as ANY and NONE,
* and must never be a valid endpoint number. Therefore we make sure
* the generation size is big enough to start the next generation
* above the highest magic number.
*/
#define _ENDPOINT_GENERATION_SIZE (MAX_NR_TASKS+_MAX_MAGIC_PROC+1)
#define _ENDPOINT_MAX_GENERATION (INT_MAX/_ENDPOINT_GENERATION_SIZE-1)
/* Generation + Process slot number <-> endpoint. */
#define _ENDPOINT(g, p) ((endpoint_t)((g) * _ENDPOINT_GENERATION_SIZE + (p)))
#define _ENDPOINT_G(e) (((e)+MAX_NR_TASKS) / _ENDPOINT_GENERATION_SIZE)
#define _ENDPOINT_P(e) \
((((e)+MAX_NR_TASKS) % _ENDPOINT_GENERATION_SIZE) - MAX_NR_TASKS)
#endif