perm filename HMAP.H[11,HE] blob
sn#690530 filedate 1982-12-08 generic text, type T, neo UTF8
/* map.h 4.6 81/05/12 */
/*
**********************************************************************
* HISTORY
* 04-Dec-81 Mike Accetta (mja) at Carnegie-Mellon University
* Inserted BBNNET TCP/IP 3.0 changes from Rob Gurwitz
* at BBN (V3.04a).
*
**********************************************************************
*
* Resource Allocation Maps.
*
* Associated routines manage sub-allocation of an address space using
* an array of segment descriptors. The first element of this array
* is a map structure, describing the arrays extent and the name
* of the controlled object. Each additional structure represents
* a free segment of the address space.
*
* A call to rminit initializes a resource map and may also be used
* to free some address space for the map. Subsequent calls to rmalloc
* and rmfree allocate and free space in 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(). The routines
* could use linked lists and call a memory allocator when they run
* out of space, but that would not solve the out of space problem when
* called at interrupt time.
*
* 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_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
{
int m_size; /* size of this segment of the map */
int m_addr; /* resource-space addr of start of segment */
};
#ifdef KERNEL
struct map *swapmap;
int nswapmap;
struct map *argmap;
#define ARGMAPSIZE 16
struct map *kernelmap;
#if NBBNNET > 0
struct map *netmap;
#endif NBBNNET
#endif