[apple/xnu.git] / osfmk / mach / vm_purgable.h

/*
 * Copyright (c) 2003-2007 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

/*
 * Virtual memory map purgeable object definitions.
 * Objects that will be needed in the future (forward cached objects) should be queued LIFO. 
 * Objects that have been used and are cached for reuse (backward cached) should be queued FIFO.
 * Every user of purgeable memory is entitled to using the highest volatile group (7).
 * Only if a client wants some of its objects to definitely be purged earlier, it can put those in
 * another group. This could be used to make all FIFO objects (in the lower group) go away before 
 * any LIFO objects (in the higher group) go away.
 * Objects that should not get any chance to stay around can be marked as "obsolete". They will
 * be emptied before any other objects or pages are reclaimed. Obsolete objects are not emptied
 * in any particular order.
 * 'purgeable' is recognized as the correct spelling. For historical reasons, definitions 
 * in this file are spelled 'purgable'.
 */

#ifndef	_MACH_VM_PURGABLE_H_
#define	_MACH_VM_PURGABLE_H_

/*
 *	Types defined:
 *
 *	vm_purgable_t	purgeable object control codes.
 */

typedef int	vm_purgable_t;

/*
 *	Enumeration of valid values for vm_purgable_t.
 */
#define VM_PURGABLE_SET_STATE	((vm_purgable_t) 0)	/* set state of purgeable object */
#define VM_PURGABLE_GET_STATE	((vm_purgable_t) 1)	/* get state of purgeable object */

/*
 * Volatile memory ordering groups (group zero objects are purged before group 1, etc...
 * It is implementation dependent as to whether these groups are global or per-address space.
 * (for the moment, they are global).
 */
#define VM_VOLATILE_GROUP_SHIFT		8
#define VM_VOLATILE_GROUP_MASK		(7 << VM_VOLATILE_GROUP_SHIFT)
#define VM_VOLATILE_GROUP_DEFAULT   VM_VOLATILE_GROUP_7

#define VM_VOLATILE_GROUP_0			(0 << VM_VOLATILE_GROUP_SHIFT)
#define VM_VOLATILE_GROUP_1			(1 << VM_VOLATILE_GROUP_SHIFT)
#define VM_VOLATILE_GROUP_2			(2 << VM_VOLATILE_GROUP_SHIFT)
#define VM_VOLATILE_GROUP_3			(3 << VM_VOLATILE_GROUP_SHIFT)
#define VM_VOLATILE_GROUP_4			(4 << VM_VOLATILE_GROUP_SHIFT)
#define VM_VOLATILE_GROUP_5			(5 << VM_VOLATILE_GROUP_SHIFT)
#define VM_VOLATILE_GROUP_6			(6 << VM_VOLATILE_GROUP_SHIFT)
#define VM_VOLATILE_GROUP_7			(7 << VM_VOLATILE_GROUP_SHIFT)

/*
 * Purgeable behavior
 * Within the same group, FIFO objects will be emptied before objects that are added later.
 * LIFO objects will be emptied after objects that are added later.
 * - Input only, not returned on state queries.
 */
#define VM_PURGABLE_BEHAVIOR_SHIFT  6
#define VM_PURGABLE_BEHAVIOR_MASK   (1 << VM_PURGABLE_BEHAVIOR_SHIFT)
#define VM_PURGABLE_BEHAVIOR_FIFO   (0 << VM_PURGABLE_BEHAVIOR_SHIFT)
#define VM_PURGABLE_BEHAVIOR_LIFO   (1 << VM_PURGABLE_BEHAVIOR_SHIFT)

/*
 * Obsolete object.
 * Disregard volatile group, and put object into obsolete queue instead, so it is the next object
 * to be purged.
 * - Input only, not returned on state queries.
 */
#define VM_PURGABLE_ORDERING_SHIFT		5
#define VM_PURGABLE_ORDERING_MASK		(1 << VM_PURGABLE_ORDERING_SHIFT)
#define VM_PURGABLE_ORDERING_OBSOLETE	(1 << VM_PURGABLE_ORDERING_SHIFT)
#define VM_PURGABLE_ORDERING_NORMAL		(0 << VM_PURGABLE_ORDERING_SHIFT)


/*
 * Obsolete parameter - do not use
 */
#define VM_VOLATILE_ORDER_SHIFT			4
#define VM_VOLATILE_ORDER_MASK			(1 << VM_VOLATILE_ORDER_SHIFT)
#define VM_VOLATILE_MAKE_FIRST_IN_GROUP	(1 << VM_VOLATILE_ORDER_SHIFT)
#define VM_VOLATILE_MAKE_LAST_IN_GROUP	(0 << VM_VOLATILE_ORDER_SHIFT)

/*
 * Valid states of a purgeable object.
 */
#define VM_PURGABLE_STATE_MIN	0		/* minimum purgeable object state value */
#define VM_PURGABLE_STATE_MAX	3		/* maximum purgeable object state value */
#define VM_PURGABLE_STATE_MASK	3		/* mask to separate state from group */

#define VM_PURGABLE_NONVOLATILE	0		/* purgeable object is non-volatile */
#define VM_PURGABLE_VOLATILE	1		/* purgeable object is volatile */
#define VM_PURGABLE_EMPTY		2		/* purgeable object is volatile and empty */
#define VM_PURGABLE_DENY		3		/* (mark) object not purgeable */

#endif	/* _MACH_VM_PURGABLE_H_ */
Commit	Line	Data
91447636	1	/*
2d21ac55	2	* Copyright (c) 2003-2007 Apple Inc. All rights reserved.
91447636	3	*
2d21ac55	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
91447636	5	*
2d21ac55 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
8f6c56a5	14	*
2d21ac55 A	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
8f6c56a5 A	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
8f6c56a5 A	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55 A	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
8f6c56a5	25	*
2d21ac55	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
91447636 A	27	*/
	28
	29	/*
2d21ac55 A	30	* Virtual memory map purgeable object definitions.
	31	* Objects that will be needed in the future (forward cached objects) should be queued LIFO.
	32	* Objects that have been used and are cached for reuse (backward cached) should be queued FIFO.
	33	* Every user of purgeable memory is entitled to using the highest volatile group (7).
	34	* Only if a client wants some of its objects to definitely be purged earlier, it can put those in
	35	* another group. This could be used to make all FIFO objects (in the lower group) go away before
	36	* any LIFO objects (in the higher group) go away.
	37	* Objects that should not get any chance to stay around can be marked as "obsolete". They will
	38	* be emptied before any other objects or pages are reclaimed. Obsolete objects are not emptied
	39	* in any particular order.
	40	* 'purgeable' is recognized as the correct spelling. For historical reasons, definitions
	41	* in this file are spelled 'purgable'.
91447636 A	42	*/
	43
	44	#ifndef _MACH_VM_PURGABLE_H_
	45	#define _MACH_VM_PURGABLE_H_
	46
	47	/*
	48	* Types defined:
	49	*
2d21ac55	50	* vm_purgable_t purgeable object control codes.
91447636 A	51	*/
	52
	53	typedef int vm_purgable_t;
	54
	55	/*
	56	* Enumeration of valid values for vm_purgable_t.
	57	*/
2d21ac55 A	58	#define VM_PURGABLE_SET_STATE ((vm_purgable_t) 0) /* set state of purgeable object */
	59	#define VM_PURGABLE_GET_STATE ((vm_purgable_t) 1) /* get state of purgeable object */
	60
	61	/*
	62	* Volatile memory ordering groups (group zero objects are purged before group 1, etc...
	63	* It is implementation dependent as to whether these groups are global or per-address space.
	64	* (for the moment, they are global).
	65	*/
	66	#define VM_VOLATILE_GROUP_SHIFT 8
	67	#define VM_VOLATILE_GROUP_MASK (7 << VM_VOLATILE_GROUP_SHIFT)
	68	#define VM_VOLATILE_GROUP_DEFAULT VM_VOLATILE_GROUP_7
	69
	70	#define VM_VOLATILE_GROUP_0 (0 << VM_VOLATILE_GROUP_SHIFT)
	71	#define VM_VOLATILE_GROUP_1 (1 << VM_VOLATILE_GROUP_SHIFT)
	72	#define VM_VOLATILE_GROUP_2 (2 << VM_VOLATILE_GROUP_SHIFT)
	73	#define VM_VOLATILE_GROUP_3 (3 << VM_VOLATILE_GROUP_SHIFT)
	74	#define VM_VOLATILE_GROUP_4 (4 << VM_VOLATILE_GROUP_SHIFT)
	75	#define VM_VOLATILE_GROUP_5 (5 << VM_VOLATILE_GROUP_SHIFT)
	76	#define VM_VOLATILE_GROUP_6 (6 << VM_VOLATILE_GROUP_SHIFT)
	77	#define VM_VOLATILE_GROUP_7 (7 << VM_VOLATILE_GROUP_SHIFT)
	78
	79	/*
	80	* Purgeable behavior
	81	* Within the same group, FIFO objects will be emptied before objects that are added later.
	82	* LIFO objects will be emptied after objects that are added later.
	83	* - Input only, not returned on state queries.
	84	*/
	85	#define VM_PURGABLE_BEHAVIOR_SHIFT 6
	86	#define VM_PURGABLE_BEHAVIOR_MASK (1 << VM_PURGABLE_BEHAVIOR_SHIFT)
	87	#define VM_PURGABLE_BEHAVIOR_FIFO (0 << VM_PURGABLE_BEHAVIOR_SHIFT)
	88	#define VM_PURGABLE_BEHAVIOR_LIFO (1 << VM_PURGABLE_BEHAVIOR_SHIFT)
	89
	90	/*
	91	* Obsolete object.
	92	* Disregard volatile group, and put object into obsolete queue instead, so it is the next object
	93	* to be purged.
	94	* - Input only, not returned on state queries.
	95	*/
	96	#define VM_PURGABLE_ORDERING_SHIFT 5
	97	#define VM_PURGABLE_ORDERING_MASK (1 << VM_PURGABLE_ORDERING_SHIFT)
	98	#define VM_PURGABLE_ORDERING_OBSOLETE (1 << VM_PURGABLE_ORDERING_SHIFT)
	99	#define VM_PURGABLE_ORDERING_NORMAL (0 << VM_PURGABLE_ORDERING_SHIFT)
	100
	101
	102	/*
	103	* Obsolete parameter - do not use
	104	*/
	105	#define VM_VOLATILE_ORDER_SHIFT 4
	106	#define VM_VOLATILE_ORDER_MASK (1 << VM_VOLATILE_ORDER_SHIFT)
	107	#define VM_VOLATILE_MAKE_FIRST_IN_GROUP (1 << VM_VOLATILE_ORDER_SHIFT)
	108	#define VM_VOLATILE_MAKE_LAST_IN_GROUP (0 << VM_VOLATILE_ORDER_SHIFT)
91447636 A	109
91447636 A	110	/*
2d21ac55	111	* Valid states of a purgeable object.
91447636	112	*/
2d21ac55 A	113	#define VM_PURGABLE_STATE_MIN 0 /* minimum purgeable object state value */
	114	#define VM_PURGABLE_STATE_MAX 3 /* maximum purgeable object state value */
	115	#define VM_PURGABLE_STATE_MASK 3 /* mask to separate state from group */
91447636	116
2d21ac55 A	117	#define VM_PURGABLE_NONVOLATILE 0 /* purgeable object is non-volatile */
	118	#define VM_PURGABLE_VOLATILE 1 /* purgeable object is volatile */
	119	#define VM_PURGABLE_EMPTY 2 /* purgeable object is volatile and empty */
	120	#define VM_PURGABLE_DENY 3 /* (mark) object not purgeable */
91447636 A	121
91447636 A	122	#endif /* _MACH_VM_PURGABLE_H_ */