54 lines
1.7 KiB
C
54 lines
1.7 KiB
C
/*
|
|
* Resource Allocation Maps.
|
|
*
|
|
* Copyright (c) 1986 Regents of the University of California.
|
|
* All rights reserved. The Berkeley software License Agreement
|
|
* specifies the terms and conditions for redistribution.
|
|
*/
|
|
|
|
/*
|
|
* Associated routines manage allocation of an address space using
|
|
* an array of segment descriptors.
|
|
*
|
|
* Malloc and mfree allocate and free the resource described
|
|
* by the resource map. If the resource map becomes too fragmented
|
|
* to be described in the available space, then some of the resource
|
|
* is discarded. This may lead to critical shortages,
|
|
* but is better than not checking (as the previous versions of
|
|
* these routines did) or giving up and calling panic().
|
|
*
|
|
* N.B.: The address 0 in the resource address space is not available
|
|
* as it is used internally by the resource map routines.
|
|
*/
|
|
struct map {
|
|
struct mapent *m_map; /* start of the map */
|
|
struct mapent *m_limit; /* address of last slot in map */
|
|
char *m_name; /* name of resource */
|
|
/* we use m_name when the map overflows, in warning messages */
|
|
};
|
|
|
|
struct mapent {
|
|
size_t m_size; /* size of this segment of the map */
|
|
size_t m_addr; /* resource-space addr of start of segment */
|
|
};
|
|
|
|
#ifdef KERNEL
|
|
extern struct map swapmap[]; /* space for swap allocation */
|
|
|
|
/*
|
|
* Allocate units from the given map.
|
|
*/
|
|
size_t malloc (struct map *mp, size_t nbytes);
|
|
|
|
/*
|
|
* Free the previously allocated units at addr into the specified map.
|
|
*/
|
|
void mfree (struct map *mp, size_t nbytes, size_t addr);
|
|
|
|
/*
|
|
* Allocate resources for the three segments of a process.
|
|
*/
|
|
size_t malloc3 (struct map *mp, size_t d_size, size_t s_size, size_t u_size, size_t a[3]);
|
|
|
|
#endif
|