;
; heap.sh
;
; A resizing, nonshifting heap
;
; © 1994-1998 Straylight
;

;----- Licensing note -------------------------------------------------------
;
; This file is part of Straylight's Sapphire library.
;
; Sapphire is free software; you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation; either version 2, or (at your option)
; any later version.
;
; Sapphire is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
; GNU General Public License for more details.
;
; You should have received a copy of the GNU General Public License
; along with Sapphire.  If not, write to the Free Software Foundation,
; 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

;----- Overview -------------------------------------------------------------
;
; Functions provided:
;
;  heap_init
;  heap_useHeap
;  heap_info
;  heap_alloc
;  heap_free
;  heap_reAlloc

		[	:LNOT::DEF:heap__dfn
		GBLL	heap__dfn

; --- heap_init ---
;
; On entry:	--
;
; On exit:	--
;
; Use:		Initialises the heap system for use.

		IMPORT	heap_init

; --- heap_useHeap ---
;
; On entry:	--
;
; On exit:	--
;
; Use:		Registers the resizing heap as the current allocator.

		IMPORT	heap_useHeap

; --- heap_info ---
;
; On entry:	--
;
; On exit:	R0 == current heap size
;		R1 == amount of memory free in the heap
;		R2 == size of the largest block free
;
; Use:		Describes the heap's current status.

		IMPORT	heap_info

; --- heap_alloc ---
;
; On entry:	R0 == size of block wanted
;
; On exit:	CC if enough memory was found and
;		  R0 == pointer to the block allocated
;		else CS and
;		  R0 corrupted
;
; Use:		Allocates a block of at least a given size from a heap.  If
;		the heap is not big enough, more is claimed from the
;		operating system.

		IMPORT	heap_alloc

; --- heap_free ---
;
; On entry:	R0 == pointer to a block created with heap_alloc
;
; On exit:	--
;
; Use:		Frees a block allocated using heap_alloc.  It tries to
;		shrink the heap as much as possible afterwards.

		IMPORT	heap_free

; --- heap_reAlloc ---
;
; On entry:	R0 == pointer to block whose size we want to change
;		R1 == the new size of the block
;
; On exit:	CC if block was resized, and
;		  R0 == pointer to the block (which may have moved)
;		else CS and
;		  R0 corrupted
;
; Use:		Changes the size of a heap block.  If possible, the block's
;		position is unchanged, but this may not always be the case.
;
;		Note that changing a block's size to 0 is permitted.

		IMPORT	heap_reAlloc

		]

;----- That's all, folks ----------------------------------------------------

		END