zig

malloc.h (25622B) - Raw

---

 /*
  * Copyright (c) 1999-2023 Apple Computer, Inc. All rights reserved.
  *
  * @APPLE_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. 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_LICENSE_HEADER_END@
  */
 
 #ifndef _MALLOC_MALLOC_H_
 #define _MALLOC_MALLOC_H_
 
 #include <TargetConditionals.h>
 #include <malloc/_platform.h>
 #include <Availability.h>
 #include <os/availability.h>
 
 #include <malloc/_ptrcheck.h>
 __ptrcheck_abi_assume_single()
 
 #if __has_feature(ptrauth_calls)
 #include <ptrauth.h>
 
 // Zone function pointer, type-diversified but not address-diversified (because
 // the zone can be copied). Process-independent because the zone structure may
 // be in the shared library cache.
 #define MALLOC_ZONE_FN_PTR(fn) __ptrauth(ptrauth_key_process_independent_code, \
 		0, ptrauth_string_discriminator("malloc_zone_fn." #fn)) fn
 
 // Introspection function pointer, address- and type-diversified.
 // Process-independent because the malloc_introspection_t structure that contains
 // these pointers may be in the shared library cache.
 #define MALLOC_INTROSPECT_FN_PTR(fn) __ptrauth(ptrauth_key_process_independent_code, \
 		1, ptrauth_string_discriminator("malloc_introspect_fn." #fn)) fn
 
 // Pointer to the introspection pointer table, type-diversified but not
 // address-diversified (because the zone can be copied).
 // Process-independent because the table pointer may be in the shared library cache.
 #define MALLOC_INTROSPECT_TBL_PTR(ptr) __ptrauth(ptrauth_key_process_independent_data,\
 		0, ptrauth_string_discriminator("malloc_introspect_tbl")) ptr
 
 #endif	// __has_feature(ptrauth_calls)
 
 #ifndef MALLOC_ZONE_FN_PTR
 #define MALLOC_ZONE_FN_PTR(fn) fn
 #define MALLOC_INTROSPECT_FN_PTR(fn) fn
 #define MALLOC_INTROSPECT_TBL_PTR(ptr) ptr
 #endif // MALLOC_ZONE_FN_PTR
 
 __BEGIN_DECLS
 /*********	Type definitions	************/
 
 /*
  * Only zone implementors should depend on the layout of this structure;
  * Regular callers should use the access functions below
  */
 typedef struct _malloc_zone_t {
 	void *reserved1;	/* RESERVED FOR CFAllocator DO NOT USE */
 	void *reserved2;	/* RESERVED FOR CFAllocator DO NOT USE */
 
 	/*
 	 * Returns the size of a block or 0 if not in this zone; must be fast,
 	 * especially for negative answers.
 	 */
 	size_t (* MALLOC_ZONE_FN_PTR(size))(struct _malloc_zone_t *zone,
 			const void * __unsafe_indexable ptr);
 
 	void * __sized_by_or_null(size) (* MALLOC_ZONE_FN_PTR(malloc))(
 			struct _malloc_zone_t *zone, size_t size);
 
 	/* Same as malloc, but block returned is set to zero */
 	void * __sized_by_or_null(num_items * size) (* MALLOC_ZONE_FN_PTR(calloc))(
 			struct _malloc_zone_t *zone, size_t num_items, size_t size);
 
 	/* Same as malloc, but block returned is guaranteed to be page-aligned */
 	void * __sized_by_or_null(size) (* MALLOC_ZONE_FN_PTR(valloc))(
 			struct _malloc_zone_t *zone, size_t size);
 
 	void (* MALLOC_ZONE_FN_PTR(free))(struct _malloc_zone_t *zone,
 			void * __unsafe_indexable ptr);
 
 	void * __sized_by_or_null(size) (* MALLOC_ZONE_FN_PTR(realloc))(
 			struct _malloc_zone_t *zone, void * __unsafe_indexable ptr,
 			size_t size);
 
 	/* Zone is destroyed and all memory reclaimed */
 	void (* MALLOC_ZONE_FN_PTR(destroy))(struct _malloc_zone_t *zone);
 
 	const char * __null_terminated zone_name;
 
 	/* Optional batch callbacks; these may be NULL */
 
 	/*
 	 * Given a size, returns pointers capable of holding that size; returns the
 	 * number of pointers allocated (maybe 0 or less than num_requested)
 	 */
 	unsigned (* MALLOC_ZONE_FN_PTR(batch_malloc))(struct _malloc_zone_t *zone,
 			size_t size,
 			void * __unsafe_indexable * __counted_by(num_requested) results,
 			unsigned num_requested);
 
 	/*
 	 * Frees all the pointers in to_be_freed; note that to_be_freed may be
 	 * overwritten during the process
 	 */
 	void (* MALLOC_ZONE_FN_PTR(batch_free))(struct _malloc_zone_t *zone,
 			void * __unsafe_indexable * __counted_by(num_to_be_freed) to_be_freed,
 			unsigned num_to_be_freed);
 
 	struct malloc_introspection_t * MALLOC_INTROSPECT_TBL_PTR(introspect);
 	unsigned version;
 
 	/* Aligned memory allocation. May be NULL.  Present in version >= 5. */
 	void * __sized_by_or_null(size) (* MALLOC_ZONE_FN_PTR(memalign))(
 			struct _malloc_zone_t *zone, size_t alignment, size_t size);
 
 	/*
 	 * Free a pointer known to be in zone and known to have the given size.
 	 * May be NULL. Present in version >= 6.
 	 */
 	void (* MALLOC_ZONE_FN_PTR(free_definite_size))(struct _malloc_zone_t *zone,
 			void * __sized_by(size) ptr, size_t size);
 
 	/*
 	 * Empty out caches in the face of memory pressure. May be NULL.
 	 * Present in version >= 8.
 	 */
 	size_t (* MALLOC_ZONE_FN_PTR(pressure_relief))(struct _malloc_zone_t *zone,
 			size_t goal);
 
 	/*
 	 * Checks whether an address might belong to the zone. May be NULL. Present
 	 * in version >= 10.  False positives are allowed (e.g. the pointer was
 	 * freed, or it's in zone space that has not yet been allocated. False
 	 * negatives are not allowed.
 	 */
 	boolean_t (* MALLOC_ZONE_FN_PTR(claimed_address))(
 			struct _malloc_zone_t *zone, void * __unsafe_indexable ptr);
 
 	/*
 	 * For libmalloc-internal zone 0 implementations only: try to free ptr,
 	 * promising to call find_zone_and_free if it turns out not to belong to us.
 	 * May be present in version >= 13.
 	 */
 	void (* MALLOC_ZONE_FN_PTR(try_free_default))(struct _malloc_zone_t *zone,
 			void * __unsafe_indexable ptr);
 
 	/*
 	 * Memory allocation with an extensible binary flags option. Currently for
 	 * libmalloc-internal zone implementations only - should be NULL otherwise.
 	 * Added in version >= 15.
 	 */
 	void * __sized_by_or_null(size) (* MALLOC_ZONE_FN_PTR(malloc_with_options))(
 			struct _malloc_zone_t *zone, size_t align, size_t size,
 			uint64_t options);
 
 	/*
 	 * Typed Memory Operations versions of zone functions.  Present in
 	 * version >= 16.
 	 */
 
 	void * __sized_by_or_null(size) (* MALLOC_ZONE_FN_PTR(malloc_type_malloc))(
 			struct _malloc_zone_t *zone, size_t size, malloc_type_id_t type_id);
 
 	void * __sized_by_or_null(count * size) (* MALLOC_ZONE_FN_PTR(malloc_type_calloc))(
 			struct _malloc_zone_t *zone, size_t count, size_t size,
 			malloc_type_id_t type_id);
 
 	void * __sized_by_or_null(size) (* MALLOC_ZONE_FN_PTR(malloc_type_realloc))(
 			struct _malloc_zone_t *zone, void * __unsafe_indexable ptr,
 			size_t size, malloc_type_id_t type_id);
 
 	void * __sized_by_or_null(size) (* MALLOC_ZONE_FN_PTR(malloc_type_memalign))(
 			struct _malloc_zone_t *zone, size_t alignment, size_t size,
 			malloc_type_id_t type_id);
 
 	/* Must be NULL for non-libmalloc zone implementations */
 	void * __sized_by_or_null(size) (* MALLOC_ZONE_FN_PTR(malloc_type_malloc_with_options))(
 			struct _malloc_zone_t *zone, size_t align, size_t size, uint64_t options,
 			malloc_type_id_t type_id);
 } malloc_zone_t;
 
 /*!
  * @enum malloc_type_callsite_flags_v0_t
  *
  * Information about where and how malloc was called
  *
  * @constant MALLOC_TYPE_CALLSITE_FLAGS_V0_FIXED_SIZE
  * Set in malloc_type_summary_v0_t if the call to malloc was called with a fixed
  * size. Note that, at present, this bit is set in all callsites where the
  * compiler rewrites a call to malloc
  *
  * @constant MALLOC_TYPE_CALLSITE_FLAGS_V0_ARRAY
  * Set in malloc_type_summary_v0_t if the type being allocated is an array, e.g.
  * allocated via new[] or calloc(count, size)
  */
 typedef enum {
 	MALLOC_TYPE_CALLSITE_FLAGS_V0_NONE = 0,
 	MALLOC_TYPE_CALLSITE_FLAGS_V0_FIXED_SIZE = 1 << 0,
 	MALLOC_TYPE_CALLSITE_FLAGS_V0_ARRAY = 1 << 1,
 } malloc_type_callsite_flags_v0_t;
 
 /*!
  * @enum malloc_type_kind_v0_t
  *
  * @constant MALLOC_TYPE_KIND_V0_OTHER
  * Default allocation type, used for most calls to malloc
  *
  * @constant MALLOC_TYPE_KIND_V0_OBJC
  * Marks a type allocated by libobjc
  *
  * @constant MALLOC_TYPE_KIND_V0_SWIFT
  * Marks a type allocated by the Swift runtime
  *
  * @constant MALLOC_TYPE_KIND_V0_CXX
  * Marks a type allocated by the C++ runtime's operator new
  */
 typedef enum {
 	MALLOC_TYPE_KIND_V0_OTHER = 0,
 	MALLOC_TYPE_KIND_V0_OBJC = 1,
 	MALLOC_TYPE_KIND_V0_SWIFT = 2,
 	MALLOC_TYPE_KIND_V0_CXX = 3
 } malloc_type_kind_v0_t;
 
 /*!
  * @struct malloc_type_layout_semantics_v0_t
  *
  * @field contains_data_pointer
  * True if the allocated type or any of its fields is a pointer
  * to a data type (i.e. the pointee contains no pointers)
  *
  * @field contains_struct_pointer
  * True if the allocated type or any of its fields is a pointer
  * to a struct or union
  *
  * @field contains_immutable_pointer
  * True if the allocated type or any of its fields is a const pointer
  *
  * @field contains_anonymous_pointer
  * True if the allocated type or any of its fields is a pointer
  * to something other than a struct or data type
  *
  * @field is_reference_counted
  * True if the allocated type is reference counted
  *
  * @field contains_generic_data
  * True if the allocated type or any of its fields are not pointers
  */
 typedef struct {
 	bool contains_data_pointer : 1;
 	bool contains_struct_pointer : 1;
 	bool contains_immutable_pointer : 1;
 	bool contains_anonymous_pointer : 1;
 	bool is_reference_counted : 1;
 	uint16_t reserved_0 : 3;
 	bool contains_generic_data : 1;
 	uint16_t reserved_1 : 7;
 } malloc_type_layout_semantics_v0_t;
 
 /*!
  * @struct malloc_type_summary_v0_t
  *
  * @field version
  * Versioning field of the type summary. Set to 0 for the current verison. New
  * fields can be added where the reserved fields currently are without
  * incrementing the version, as long as they are non-breaking.
  *
  * @field callsite_flags
  * Details from the callsite of malloc inferred by the compiler
  *
  * @field type_kind
  * Details about the runtime making the allocation
  *
  * @field layout_semantics
  * Details about what kinds of data are contained in the type being allocated
  *
  * @discussion
  * The reserved fields should not be read from or written to, and may be
  * used for additional fields and information in future versions
  */
 typedef struct {
 	uint32_t version : 4;
 	uint32_t reserved_0 : 2;
 	malloc_type_callsite_flags_v0_t callsite_flags : 4;
 	malloc_type_kind_v0_t type_kind : 2;
 	uint32_t reserved_1 : 4;
 	malloc_type_layout_semantics_v0_t layout_semantics;
 } malloc_type_summary_v0_t;
 
 /*!
  * @union malloc_type_descriptor_v0_t
  *
  * @field hash
  * Hash of the type layout of the allocated type, or if type inference failed,
  * the hash of the callsite's file, line and column. The hash allows the
  * allocator to disambiguate between different types with the same summary, e.g.
  * types that have the same fields in different orders.
  *
  * @field summary
  * Details of the type being allocated
  *
  * @field type_id
  * opaque type used for punning
  *
  * @discussion
  * Use malloc_type_descriptor_v0_t to decode the opaque malloc_type_id_t with
  * version == 0 into a malloc_type_summary_v0_t:
  *
  * <code>
  * malloc_type_descriptor_v0_t desc = (malloc_type_descriptor_v0_t){ .type_id = id };
  * </code>
  *
  * See LLVM documentation for more details
  */
 typedef union {
 	struct {
 		uint32_t hash;
 		malloc_type_summary_v0_t summary;
 	};
 	malloc_type_id_t type_id;
 } malloc_type_descriptor_v0_t;
 
 /*********	Creation and destruction	************/
 
 extern malloc_zone_t *malloc_default_zone(void);
 	/* The initial zone */
 
 #if !0 && !0
 extern malloc_zone_t *malloc_create_zone(vm_size_t start_size, unsigned flags);
 	/* Creates a new zone with default behavior and registers it */
 
 extern void malloc_destroy_zone(malloc_zone_t *zone);
 	/* Destroys zone and everything it allocated */
 #endif 
 
 /*********	Block creation and manipulation	************/
 
 extern void * __sized_by_or_null(size) malloc_zone_malloc(malloc_zone_t *zone, size_t size) __alloc_size(2) _MALLOC_TYPED(malloc_type_zone_malloc, 2);
 	/* Allocates a new pointer of size size; zone must be non-NULL */
 
 extern void * __sized_by_or_null(num_items * size) malloc_zone_calloc(malloc_zone_t *zone, size_t num_items, size_t size) __alloc_size(2,3) _MALLOC_TYPED(malloc_type_zone_calloc, 3);
 	/* Allocates a new pointer of size num_items * size; block is cleared; zone must be non-NULL */
 
 extern void * __sized_by_or_null(size) malloc_zone_valloc(malloc_zone_t *zone, size_t size) __alloc_size(2) _MALLOC_TYPED(malloc_type_zone_valloc, 2);
 	/* Allocates a new pointer of size size; zone must be non-NULL; Pointer is guaranteed to be page-aligned and block is cleared */
 
 extern void malloc_zone_free(malloc_zone_t *zone, void * __unsafe_indexable ptr);
 	/* Frees pointer in zone; zone must be non-NULL */
 
 extern void * __sized_by_or_null(size) malloc_zone_realloc(malloc_zone_t *zone, void * __unsafe_indexable ptr, size_t size) __alloc_size(3) _MALLOC_TYPED(malloc_type_zone_realloc, 3);
 	/* Enlarges block if necessary; zone must be non-NULL */
 
 extern malloc_zone_t *malloc_zone_from_ptr(const void * __unsafe_indexable ptr);
 	/* Returns the zone for a pointer, or NULL if not in any zone.
 	The ptr must have been returned from a malloc or realloc call. */
 
 extern size_t malloc_size(const void * __unsafe_indexable ptr);
 	/* Returns size of given ptr, including any padding inserted by the allocator */
 
 extern size_t malloc_good_size(size_t size);
 	/* Returns number of bytes greater than or equal to size that can be allocated without padding */
 
 extern void * __sized_by_or_null(size) malloc_zone_memalign(malloc_zone_t *zone, size_t alignment, size_t size) __alloc_align(2) __alloc_size(3) _MALLOC_TYPED(malloc_type_zone_memalign, 3) __OSX_AVAILABLE_STARTING(__MAC_10_6, __IPHONE_3_0);
 	/*
 	 * Allocates a new pointer of size size whose address is an exact multiple of alignment.
 	 * alignment must be a power of two and at least as large as sizeof(void *).
 	 * zone must be non-NULL.
 	 */
 
 /*********	Batch methods	************/
 
 #if !0 && !0
 extern unsigned malloc_zone_batch_malloc(malloc_zone_t *zone, size_t size, void * __unsafe_indexable * __counted_by(num_requested) results, unsigned num_requested);
 	/* Allocates num blocks of the same size; Returns the number truly allocated (may be 0) */
 
 extern void malloc_zone_batch_free(malloc_zone_t *zone, void * __unsafe_indexable * __counted_by(num) to_be_freed, unsigned num);
 	/* frees all the pointers in to_be_freed; note that to_be_freed may be overwritten during the process; This function will always free even if the zone has no batch callback */
 #endif 
 
 /*********	Functions for libcache	************/
 
 #if !0 && !0
 extern malloc_zone_t *malloc_default_purgeable_zone(void) __OSX_AVAILABLE_STARTING(__MAC_10_6, __IPHONE_3_0);
 	/* Returns a pointer to the default purgeable_zone. */
 
 extern void malloc_make_purgeable(void * __unsafe_indexable ptr) __OSX_AVAILABLE_STARTING(__MAC_10_6, __IPHONE_3_0);
 	/* Make an allocation from the purgeable zone purgeable if possible.  */
 
 extern int malloc_make_nonpurgeable(void * __unsafe_indexable ptr) __OSX_AVAILABLE_STARTING(__MAC_10_6, __IPHONE_3_0);
 	/* Makes an allocation from the purgeable zone nonpurgeable.
 	 * Returns zero if the contents were not purged since the last
 	 * call to malloc_make_purgeable, else returns non-zero. */
 #endif 
 
 /*********	Functions for zone implementors	************/
 
 #if !0 && !0
 extern void malloc_zone_register(malloc_zone_t *zone);
 	/* Registers a custom malloc zone; Should typically be called after a
 	 * malloc_zone_t has been filled in with custom methods by a client.  See
 	 * malloc_create_zone for creating additional malloc zones with the
 	 * default allocation and free behavior. */
 
 extern void malloc_zone_unregister(malloc_zone_t *zone);
 	/* De-registers a zone
 	Should typically be called before calling the zone destruction routine */
 #endif 
 
 extern void malloc_set_zone_name(malloc_zone_t *zone, const char * __null_terminated name);
 	/* Sets the name of a zone */
 
 extern const char *malloc_get_zone_name(malloc_zone_t *zone);
 	/* Returns the name of a zone */
 
 #if !0 && !0
 size_t malloc_zone_pressure_relief(malloc_zone_t *zone, size_t goal) __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_4_3);
 	/* malloc_zone_pressure_relief() advises the malloc subsystem that the process is under memory pressure and
 	 * that the subsystem should make its best effort towards releasing (i.e. munmap()-ing) "goal" bytes from "zone".
 	 * If "goal" is passed as zero, the malloc subsystem will attempt to achieve maximal pressure relief in "zone".
 	 * If "zone" is passed as NULL, all zones are examined for pressure relief opportunities.
 	 * malloc_zone_pressure_relief() returns the number of bytes released.
 	 */
 #endif 
 
 typedef struct {
 	vm_address_t	address;
 	vm_size_t		size;
 } vm_range_t;
 
 typedef struct malloc_statistics_t {
 	unsigned	blocks_in_use;
 	size_t	size_in_use;
 	size_t	max_size_in_use;	/* high water mark of touched memory */
 	size_t	size_allocated;		/* reserved in memory */
 } malloc_statistics_t;
 
 typedef kern_return_t memory_reader_t(task_t remote_task, vm_address_t remote_address, vm_size_t size, void * __sized_by(size) *local_memory);
 	/* given a task, "reads" the memory at the given address and size
 	local_memory: set to a contiguous chunk of memory; validity of local_memory is assumed to be limited (until next call) */
 
 #define MALLOC_PTR_IN_USE_RANGE_TYPE	1	/* for allocated pointers */
 #define MALLOC_PTR_REGION_RANGE_TYPE	2	/* for region containing pointers */
 #define MALLOC_ADMIN_REGION_RANGE_TYPE	4	/* for region used internally */
 #define MALLOC_ZONE_SPECIFIC_FLAGS	0xff00	/* bits reserved for zone-specific purposes */
 
 typedef void vm_range_recorder_t(task_t, void *, unsigned type, vm_range_t *, unsigned);
 /* given a task and context, "records" the specified addresses */
 
 /* Print function for the print_task() operation. */
 typedef void print_task_printer_t(const char * __null_terminated fmt, ...) __printflike(1,2);
 
 typedef struct malloc_introspection_t {
 	kern_return_t (* MALLOC_INTROSPECT_FN_PTR(enumerator))(task_t task, void *, unsigned type_mask, vm_address_t zone_address, memory_reader_t reader, vm_range_recorder_t recorder); /* enumerates all the malloc pointers in use */
 	size_t	(* MALLOC_INTROSPECT_FN_PTR(good_size))(malloc_zone_t *zone, size_t size);
 	boolean_t 	(* MALLOC_INTROSPECT_FN_PTR(check))(malloc_zone_t *zone); /* Consistency checker */
 	void	(* MALLOC_INTROSPECT_FN_PTR(print))(malloc_zone_t *zone, boolean_t verbose); /* Prints zone  */
 	void	(* MALLOC_INTROSPECT_FN_PTR(log))(malloc_zone_t *zone, void * __unsafe_indexable address); /* Enables logging of activity */
 	void	(* MALLOC_INTROSPECT_FN_PTR(force_lock))(malloc_zone_t *zone); /* Forces locking zone */
 	void	(* MALLOC_INTROSPECT_FN_PTR(force_unlock))(malloc_zone_t *zone); /* Forces unlocking zone */
 	void	(* MALLOC_INTROSPECT_FN_PTR(statistics))(malloc_zone_t *zone, malloc_statistics_t *stats); /* Fills statistics */
 	boolean_t	(* MALLOC_INTROSPECT_FN_PTR(zone_locked))(malloc_zone_t *zone); /* Are any zone locks held */
 
 	/* Discharge checking. Present in version >= 7. */
 	boolean_t	(* MALLOC_INTROSPECT_FN_PTR(enable_discharge_checking))(malloc_zone_t *zone);
 	void	(* MALLOC_INTROSPECT_FN_PTR(disable_discharge_checking))(malloc_zone_t *zone);
 	void	(* MALLOC_INTROSPECT_FN_PTR(discharge))(malloc_zone_t *zone, void * __unsafe_indexable memory);
 #ifdef __BLOCKS__
 	void	(* MALLOC_INTROSPECT_FN_PTR(enumerate_discharged_pointers))(malloc_zone_t *zone, void (^report_discharged)(void *memory, void *info));
 	#else
 	void	*enumerate_unavailable_without_blocks;
 #endif /* __BLOCKS__ */
 	void	(* MALLOC_INTROSPECT_FN_PTR(reinit_lock))(malloc_zone_t *zone); /* Reinitialize zone locks, called only from atfork_child handler. Present in version >= 9. */
 	void	(* MALLOC_INTROSPECT_FN_PTR(print_task))(task_t task, unsigned level, vm_address_t zone_address, memory_reader_t reader, print_task_printer_t printer); /* debug print for another process. Present in version >= 11. */
 	void	(* MALLOC_INTROSPECT_FN_PTR(task_statistics))(task_t task, vm_address_t zone_address, memory_reader_t reader, malloc_statistics_t *stats); /* Present in version >= 12. */
 	unsigned	zone_type; /* Identifies the zone type.  0 means unknown/undefined zone type.  Present in version >= 14. */
 } malloc_introspection_t;
 
 // The value of "level" when passed to print_task() that corresponds to
 // verbose passed to print()
 #define MALLOC_VERBOSE_PRINT_LEVEL	2
 
 #if !0 && !0
 extern void malloc_printf(const char * __null_terminated format, ...) __printflike(1,2);
 	/* Convenience for logging errors and warnings;
 	No allocation is performed during execution of this function;
 	Only understands usual %p %d %s formats, and %y that expresses a number of bytes (5b,10KB,1MB...)
 	*/
 #endif 
 
 /*********	Functions for performance tools	************/
 
 #if !0 && !0
 extern kern_return_t malloc_get_all_zones(task_t task, memory_reader_t reader, vm_address_t * __single * __counted_by(*count) addresses, unsigned *count);
 	/* Fills addresses and count with the addresses of the zones in task;
 	Note that the validity of the addresses returned correspond to the validity reader */
 #endif 
 
 /*********	Debug helpers	************/
 
 extern void malloc_zone_print_ptr_info(void * __unsafe_indexable ptr);
 	/* print to stdout if this pointer is in the malloc heap, free status, and size */
 
 extern boolean_t malloc_zone_check(malloc_zone_t *zone);
 	/* Checks zone is well formed; if !zone, checks all zones */
 
 extern void malloc_zone_print(malloc_zone_t *zone, boolean_t verbose);
 	/* Prints summary on zone; if !zone, prints all zones */
 
 #if !0 && !0
 extern void malloc_zone_statistics(malloc_zone_t *zone, malloc_statistics_t *stats);
 	/* Fills statistics for zone; if !zone, sums up all zones */
 
 extern void malloc_zone_log(malloc_zone_t *zone, void * __unsafe_indexable address);
 	/* Controls logging of all activity; if !zone, for all zones;
 	If address==0 nothing is logged;
 	If address==-1 all activity is logged;
 	Else only the activity regarding address is logged */
 #endif 
 
 struct mstats {
 	size_t	bytes_total;
 	size_t	chunks_used;
 	size_t	bytes_used;
 	size_t	chunks_free;
 	size_t	bytes_free;
 };
 
 #if !0 && !0
 extern struct mstats mstats(void);
 
 extern boolean_t malloc_zone_enable_discharge_checking(malloc_zone_t *zone) __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_4_3);
 	/* Increment the discharge checking enabled counter for a zone. Returns true if the zone supports checking, false if it does not. */
 
 extern void malloc_zone_disable_discharge_checking(malloc_zone_t *zone) __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_4_3);
 /* Decrement the discharge checking enabled counter for a zone. */
 
 extern void malloc_zone_discharge(malloc_zone_t *zone, void * __unsafe_indexable memory) __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_4_3);
 	/* Register memory that the programmer expects to be freed soon.
 	zone may be NULL in which case the zone is determined using malloc_zone_from_ptr().
 	If discharge checking is off for the zone this function is a no-op. */
 #endif 
 
 #if !0 && !0
 #ifdef __BLOCKS__
 extern void malloc_zone_enumerate_discharged_pointers(malloc_zone_t *zone, void (^report_discharged)(void *memory, void *info)) __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_4_3);
 	/* Calls report_discharged for each block that was registered using malloc_zone_discharge() but has not yet been freed.
 	info is used to provide zone defined information about the memory block.
 	If zone is NULL then the enumeration covers all zones. */
 #else
 extern void malloc_zone_enumerate_discharged_pointers(malloc_zone_t *zone, void *) __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_4_3);
 #endif /* __BLOCKS__ */
 #endif 
 
 /*********  Zone version summary ************/
 // Version 0, but optional:
 //   malloc_zone_t::batch_malloc
 //   malloc_zone_t::batch_free
 // Version 5:
 //   malloc_zone_t::memalign
 // Version 6:
 //   malloc_zone_t::free_definite_size
 // Version 7:
 //   malloc_introspection_t::enable_discharge_checking
 //   malloc_introspection_t::disable_discharge_checking
 //   malloc_introspection_t::discharge
 // Version 8:
 //   malloc_zone_t::pressure_relief
 // Version 9:
 //   malloc_introspection_t::reinit_lock
 // Version 10:
 //   malloc_zone_t::claimed_address
 // Version 11:
 //   malloc_introspection_t::print_task
 // Version 12:
 //   malloc_introspection_t::task_statistics
 // Version 13:
 //   - malloc_zone_t::malloc and malloc_zone_t::calloc assume responsibility for
 //     setting errno to ENOMEM on failure
 //   - malloc_zone_t::try_free_default
 // Version 14:
 //   malloc_introspection_t::zone_type
 // Version 15:
 //   malloc_zone_t::malloc_with_options
 // Version 16:
 //   malloc_zone_t::malloc_type_malloc
 //   malloc_zone_t::malloc_type_calloc
 //   malloc_zone_t::malloc_type_realloc
 //   malloc_zone_t::malloc_type_memalign
 //   malloc_zone_t::malloc_type_malloc_with_options
 
 // These functions are optional and calling them requires two checks:
 //  * Check zone version to ensure zone struct is large enough to include the member.
 //  * Check that the function pointer is not null.
 
 __END_DECLS
 
 #endif /* _MALLOC_MALLOC_H_ */