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heap.cfa @ c243092

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Last change on this file since c243092 was ca7949b, checked in by Peter A. Buhr <pabuhr@…>, 4 years ago
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1	//
2	// Cforall Version 1.0.0 Copyright (C) 2017 University of Waterloo
3	//
4	// The contents of this file are covered under the licence agreement in the
5	// file "LICENCE" distributed with Cforall.
6	//
7	// heap.c --
8	//
9	// Author : Peter A. Buhr
10	// Created On : Tue Dec 19 21:58:35 2017
11	// Last Modified By : Peter A. Buhr
12	// Last Modified On : Fri Mar 6 10:14:52 2020
13	// Update Count : 650
14	//
15
16	#include <unistd.h> // sbrk, sysconf
17	#include <stdbool.h> // true, false
18	#include <stdio.h> // snprintf, fileno
19	#include <errno.h> // errno
20	#include <string.h> // memset, memcpy
21	extern "C" {
22	#include <sys/mman.h> // mmap, munmap
23	} // extern "C"
24
25	// #comment TD : Many of these should be merged into math I believe
26	#include "bits/align.hfa" // libPow2
27	#include "bits/defs.hfa" // likely, unlikely
28	#include "bits/locks.hfa" // __spinlock_t
29	#include "startup.hfa" // STARTUP_PRIORITY_MEMORY
30	//#include "stdlib.hfa" // bsearchl
31	#include "malloc.h"
32
33	#define MIN(x, y) (y > x ? x : y)
34
35	static bool traceHeap = false;
36
37	inline bool traceHeap() { return traceHeap; }
38
39	bool traceHeapOn() {
40	bool temp = traceHeap;
41	traceHeap = true;
42	return temp;
43	} // traceHeapOn
44
45	bool traceHeapOff() {
46	bool temp = traceHeap;
47	traceHeap = false;
48	return temp;
49	} // traceHeapOff
50
51	bool traceHeapTerm() { return false; }
52
53
54	static bool prtFree = false;
55
56	inline bool prtFree() {
57	return prtFree;
58	} // prtFree
59
60	bool prtFreeOn() {
61	bool temp = prtFree;
62	prtFree = true;
63	return temp;
64	} // prtFreeOn
65
66	bool prtFreeOff() {
67	bool temp = prtFree;
68	prtFree = false;
69	return temp;
70	} // prtFreeOff
71
72
73	enum {
74	// Define the default extension heap amount in units of bytes. When the uC++ supplied heap reaches the brk address,
75	// the brk address is extended by the extension amount.
76	__CFA_DEFAULT_HEAP_EXPANSION__ = (1 * 1024 * 1024),
77
78	// Define the mmap crossover point during allocation. Allocations less than this amount are allocated from buckets;
79	// values greater than or equal to this value are mmap from the operating system.
80	__CFA_DEFAULT_MMAP_START__ = (512 * 1024 + 1),
81	};
82
83	size_t default_mmap_start() __attribute__(( weak )) {
84	return __CFA_DEFAULT_MMAP_START__;
85	} // default_mmap_start
86
87	size_t default_heap_expansion() __attribute__(( weak )) {
88	return __CFA_DEFAULT_HEAP_EXPANSION__;
89	} // default_heap_expansion
90
91
92	#ifdef __CFA_DEBUG__
93	static unsigned int allocFree; // running total of allocations minus frees
94
95	static void prtUnfreed() {
96	if ( allocFree != 0 ) {
97	// DO NOT USE STREAMS AS THEY MAY BE UNAVAILABLE AT THIS POINT.
98	char helpText[512];
99	int len = snprintf( helpText, sizeof(helpText), "CFA warning (UNIX pid:%ld) : program terminating with %u(0x%x) bytes of storage allocated but not freed.\n"
100	"Possible cause is unfreed storage allocated by the program or system/library routines called from the program.\n",
101	(long int)getpid(), allocFree, allocFree ); // always print the UNIX pid
102	__cfaabi_bits_write( STDERR_FILENO, helpText, len ); // print debug/nodebug
103	} // if
104	} // prtUnfreed
105
106	extern "C" {
107	void heapAppStart() { // called by __cfaabi_appready_startup
108	allocFree = 0;
109	} // heapAppStart
110
111	void heapAppStop() { // called by __cfaabi_appready_startdown
112	fclose( stdin ); fclose( stdout );
113	prtUnfreed();
114	} // heapAppStop
115	} // extern "C"
116	#endif // __CFA_DEBUG__
117
118
119	// statically allocated variables => zero filled.
120	static size_t pageSize; // architecture pagesize
121	static size_t heapExpand; // sbrk advance
122	static size_t mmapStart; // cross over point for mmap
123	static unsigned int maxBucketsUsed; // maximum number of buckets in use
124
125
126	#define SPINLOCK 0
127	#define LOCKFREE 1
128	#define BUCKETLOCK SPINLOCK
129	#if BUCKETLOCK == LOCKFREE
130	#include <uStackLF.h>
131	#endif // LOCKFREE
132
133	// Recursive definitions: HeapManager needs size of bucket array and bucket area needs sizeof HeapManager storage.
134	// Break recusion by hardcoding number of buckets and statically checking number is correct after bucket array defined.
135	enum { NoBucketSizes = 91 }; // number of buckets sizes
136
137	struct HeapManager {
138	// struct FreeHeader; // forward declaration
139
140	struct Storage {
141	struct Header { // header
142	union Kind {
143	struct RealHeader {
144	union {
145	struct { // 4-byte word => 8-byte header, 8-byte word => 16-byte header
146	#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ && __SIZEOF_POINTER__ == 4
147	uint32_t padding; // unused, force home/blocksize to overlay alignment in fake header
148	#endif // __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ && __SIZEOF_POINTER__ == 4
149
150	union {
151	// FreeHeader * home; // allocated block points back to home locations (must overlay alignment)
152	void * home; // allocated block points back to home locations (must overlay alignment)
153	size_t blockSize; // size for munmap (must overlay alignment)
154	#if BUCKLOCK == SPINLOCK
155	Storage * next; // freed block points next freed block of same size
156	#endif // SPINLOCK
157	};
158
159	#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ && __SIZEOF_POINTER__ == 4
160	uint32_t padding; // unused, force home/blocksize to overlay alignment in fake header
161	#endif // __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ && __SIZEOF_POINTER__ == 4
162	};
163	// future code
164	#if BUCKLOCK == LOCKFREE
165	Stack<Storage>::Link next; // freed block points next freed block of same size (double-wide)
166	#endif // LOCKFREE
167	};
168	} real; // RealHeader
169	struct FakeHeader {
170	#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
171	uint32_t alignment; // low-order bits of home/blockSize used for tricks
172	#endif // __ORDER_LITTLE_ENDIAN__
173
174	uint32_t offset;
175
176	#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
177	uint32_t alignment; // low-order bits of home/blockSize used for tricks
178	#endif // __ORDER_BIG_ENDIAN__
179	} fake; // FakeHeader
180	} kind; // Kind
181	} header; // Header
182	char pad[libAlign() - sizeof( Header )];
183	char data[0]; // storage
184	}; // Storage
185
186	static_assert( libAlign() >= sizeof( Storage ), "libAlign() < sizeof( Storage )" );
187
188	struct FreeHeader {
189	#if BUCKLOCK == SPINLOCK
190	__spinlock_t lock; // must be first field for alignment
191	Storage * freeList;
192	#elif BUCKLOCK == LOCKFREE
193	// future code
194	StackLF<Storage> freeList;
195	#else
196	#error undefined lock type for bucket lock
197	#endif // SPINLOCK
198	size_t blockSize; // size of allocations on this list
199	}; // FreeHeader
200
201	// must be first fields for alignment
202	__spinlock_t extlock; // protects allocation-buffer extension
203	FreeHeader freeLists[NoBucketSizes]; // buckets for different allocation sizes
204
205	void * heapBegin; // start of heap
206	void * heapEnd; // logical end of heap
207	size_t heapRemaining; // amount of storage not allocated in the current chunk
208	}; // HeapManager
209
210	static inline size_t getKey( const HeapManager.FreeHeader & freeheader ) { return freeheader.blockSize; }
211
212
213	#define FASTLOOKUP
214	#define __STATISTICS__
215
216	// Bucket size must be multiple of 16.
217	// Powers of 2 are common allocation sizes, so make powers of 2 generate the minimum required size.
218	static const unsigned int bucketSizes[] @= { // different bucket sizes
219	16, 32, 48, 64 + sizeof(HeapManager.Storage), // 4
220	96, 112, 128 + sizeof(HeapManager.Storage), // 3
221	160, 192, 224, 256 + sizeof(HeapManager.Storage), // 4
222	320, 384, 448, 512 + sizeof(HeapManager.Storage), // 4
223	640, 768, 896, 1_024 + sizeof(HeapManager.Storage), // 4
224	1_536, 2_048 + sizeof(HeapManager.Storage), // 2
225	2_560, 3_072, 3_584, 4_096 + sizeof(HeapManager.Storage), // 4
226	6_144, 8_192 + sizeof(HeapManager.Storage), // 2
227	9_216, 10_240, 11_264, 12_288, 13_312, 14_336, 15_360, 16_384 + sizeof(HeapManager.Storage), // 8
228	18_432, 20_480, 22_528, 24_576, 26_624, 28_672, 30_720, 32_768 + sizeof(HeapManager.Storage), // 8
229	36_864, 40_960, 45_056, 49_152, 53_248, 57_344, 61_440, 65_536 + sizeof(HeapManager.Storage), // 8
230	73_728, 81_920, 90_112, 98_304, 106_496, 114_688, 122_880, 131_072 + sizeof(HeapManager.Storage), // 8
231	147_456, 163_840, 180_224, 196_608, 212_992, 229_376, 245_760, 262_144 + sizeof(HeapManager.Storage), // 8
232	294_912, 327_680, 360_448, 393_216, 425_984, 458_752, 491_520, 524_288 + sizeof(HeapManager.Storage), // 8
233	655_360, 786_432, 917_504, 1_048_576 + sizeof(HeapManager.Storage), // 4
234	1_179_648, 1_310_720, 1_441_792, 1_572_864, 1_703_936, 1_835_008, 1_966_080, 2_097_152 + sizeof(HeapManager.Storage), // 8
235	2_621_440, 3_145_728, 3_670_016, 4_194_304 + sizeof(HeapManager.Storage), // 4
236	};
237
238	static_assert( NoBucketSizes == sizeof(bucketSizes) / sizeof(bucketSizes[0]), "size of bucket array wrong" );
239
240	#ifdef FASTLOOKUP
241	enum { LookupSizes = 65_536 + sizeof(HeapManager.Storage) }; // number of fast lookup sizes
242	static unsigned char lookup[LookupSizes]; // O(1) lookup for small sizes
243	#endif // FASTLOOKUP
244
245	static int mmapFd = -1; // fake or actual fd for anonymous file
246	#ifdef __CFA_DEBUG__
247	static bool heapBoot = 0; // detect recursion during boot
248	#endif // __CFA_DEBUG__
249	static HeapManager heapManager __attribute__(( aligned (128) )) @= {}; // size of cache line to prevent false sharing
250
251
252	#ifdef __STATISTICS__
253	// Heap statistics counters.
254	static unsigned long long int mmap_storage;
255	static unsigned int mmap_calls;
256	static unsigned long long int munmap_storage;
257	static unsigned int munmap_calls;
258	static unsigned long long int sbrk_storage;
259	static unsigned int sbrk_calls;
260	static unsigned long long int malloc_storage;
261	static unsigned int malloc_calls;
262	static unsigned long long int free_storage;
263	static unsigned int free_calls;
264	static unsigned long long int calloc_storage;
265	static unsigned int calloc_calls;
266	static unsigned long long int memalign_storage;
267	static unsigned int memalign_calls;
268	static unsigned long long int cmemalign_storage;
269	static unsigned int cmemalign_calls;
270	static unsigned long long int realloc_storage;
271	static unsigned int realloc_calls;
272	// Statistics file descriptor (changed by malloc_stats_fd).
273	static int statfd = STDERR_FILENO; // default stderr
274
275	// Use "write" because streams may be shutdown when calls are made.
276	static void printStats() {
277	char helpText[512];
278	__cfaabi_bits_print_buffer( STDERR_FILENO, helpText, sizeof(helpText),
279	"\nHeap statistics:\n"
280	" malloc: calls %u / storage %llu\n"
281	" calloc: calls %u / storage %llu\n"
282	" memalign: calls %u / storage %llu\n"
283	" cmemalign: calls %u / storage %llu\n"
284	" realloc: calls %u / storage %llu\n"
285	" free: calls %u / storage %llu\n"
286	" mmap: calls %u / storage %llu\n"
287	" munmap: calls %u / storage %llu\n"
288	" sbrk: calls %u / storage %llu\n",
289	malloc_calls, malloc_storage,
290	calloc_calls, calloc_storage,
291	memalign_calls, memalign_storage,
292	cmemalign_calls, cmemalign_storage,
293	realloc_calls, realloc_storage,
294	free_calls, free_storage,
295	mmap_calls, mmap_storage,
296	munmap_calls, munmap_storage,
297	sbrk_calls, sbrk_storage
298	);
299	} // printStats
300
301	static int printStatsXML( FILE * stream ) { // see malloc_info
302	char helpText[512];
303	int len = snprintf( helpText, sizeof(helpText),
304	"<malloc version=\"1\">\n"
305	"<heap nr=\"0\">\n"
306	"<sizes>\n"
307	"</sizes>\n"
308	"<total type=\"malloc\" count=\"%u\" size=\"%llu\"/>\n"
309	"<total type=\"calloc\" count=\"%u\" size=\"%llu\"/>\n"
310	"<total type=\"memalign\" count=\"%u\" size=\"%llu\"/>\n"
311	"<total type=\"cmemalign\" count=\"%u\" size=\"%llu\"/>\n"
312	"<total type=\"realloc\" count=\"%u\" size=\"%llu\"/>\n"
313	"<total type=\"free\" count=\"%u\" size=\"%llu\"/>\n"
314	"<total type=\"mmap\" count=\"%u\" size=\"%llu\"/>\n"
315	"<total type=\"munmap\" count=\"%u\" size=\"%llu\"/>\n"
316	"<total type=\"sbrk\" count=\"%u\" size=\"%llu\"/>\n"
317	"</malloc>",
318	malloc_calls, malloc_storage,
319	calloc_calls, calloc_storage,
320	memalign_calls, memalign_storage,
321	cmemalign_calls, cmemalign_storage,
322	realloc_calls, realloc_storage,
323	free_calls, free_storage,
324	mmap_calls, mmap_storage,
325	munmap_calls, munmap_storage,
326	sbrk_calls, sbrk_storage
327	);
328	__cfaabi_bits_write( fileno( stream ), helpText, len ); // ensures all bytes written or exit
329	return len;
330	} // printStatsXML
331	#endif // __STATISTICS__
332
333
334	// static inline void noMemory() {
335	// abort( "Heap memory exhausted at %zu bytes.\n"
336	// "Possible cause is very large memory allocation and/or large amount of unfreed storage allocated by the program or system/library routines.",
337	// ((char )(sbrk( 0 )) - (char )(heapManager.heapBegin)) );
338	// } // noMemory
339
340
341	static inline void checkAlign( size_t alignment ) {
342	if ( alignment < libAlign() \|\| ! libPow2( alignment ) ) {
343	abort( "Alignment %zu for memory allocation is less than %d and/or not a power of 2.", alignment, libAlign() );
344	} // if
345	} // checkAlign
346
347
348	static inline bool setHeapExpand( size_t value ) {
349	if ( heapExpand < pageSize ) return true;
350	heapExpand = value;
351	return false;
352	} // setHeapExpand
353
354
355	// thunk problem
356	size_t Bsearchl( unsigned int key, const unsigned int * vals, size_t dim ) {
357	size_t l = 0, m, h = dim;
358	while ( l < h ) {
359	m = (l + h) / 2;
360	if ( (unsigned int &)(vals[m]) < key ) { // cast away const
361	l = m + 1;
362	} else {
363	h = m;
364	} // if
365	} // while
366	return l;
367	} // Bsearchl
368
369
370	static inline bool setMmapStart( size_t value ) { // true => mmapped, false => sbrk
371	if ( value < pageSize \|\| bucketSizes[NoBucketSizes - 1] < value ) return true;
372	mmapStart = value; // set global
373
374	// find the closest bucket size less than or equal to the mmapStart size
375	maxBucketsUsed = Bsearchl( (unsigned int)mmapStart, bucketSizes, NoBucketSizes ); // binary search
376	assert( maxBucketsUsed < NoBucketSizes ); // subscript failure ?
377	assert( mmapStart <= bucketSizes[maxBucketsUsed] ); // search failure ?
378	return false;
379	} // setMmapStart
380
381
382	static inline void checkHeader( bool check, const char name[], void * addr ) {
383	if ( unlikely( check ) ) { // bad address ?
384	abort( "Attempt to %s storage %p with address outside the heap.\n"
385	"Possible cause is duplicate free on same block or overwriting of memory.",
386	name, addr );
387	} // if
388	} // checkHeader
389
390
391	static inline void fakeHeader( HeapManager.Storage.Header *& header, size_t & alignment ) {
392	if ( unlikely( (header->kind.fake.alignment & 1) == 1 ) ) { // fake header ?
393	size_t offset = header->kind.fake.offset;
394	alignment = header->kind.fake.alignment & -2; // remove flag from value
395	#ifdef __CFA_DEBUG__
396	checkAlign( alignment ); // check alignment
397	#endif // __CFA_DEBUG__
398	header = (HeapManager.Storage.Header )((char )header - offset);
399	} // if
400	} // fakeHeader
401
402
403	// <-------+----------------------------------------------------> bsize (bucket size)
404	// \|header \|addr
405	//==================================================================================
406	// \| alignment
407	// <-----------------<------------+-----------------------------> bsize (bucket size)
408	// \|fake-header \| addr
409	#define headerAddr( addr ) ((HeapManager.Storage.Header )( (char )addr - sizeof(HeapManager.Storage) ))
410
411	// <-------<<--------------------- dsize ---------------------->> bsize (bucket size)
412	// \|header \|addr
413	//==================================================================================
414	// \| alignment
415	// <------------------------------<<---------- dsize --------->>> bsize (bucket size)
416	// \|fake-header \|addr
417	#define dataStorage( bsize, addr, header ) (bsize - ( (char )addr - (char )header ))
418
419
420	static inline bool headers( const char name[] __attribute__(( unused )), void * addr, HeapManager.Storage.Header & header, HeapManager.FreeHeader & freeElem, size_t & size, size_t & alignment ) with ( heapManager ) {
421	header = headerAddr( addr );
422
423	if ( unlikely( heapEnd < addr ) ) { // mmapped ?
424	fakeHeader( header, alignment );
425	size = header->kind.real.blockSize & -3; // mmap size
426	return true;
427	} // if
428
429	#ifdef __CFA_DEBUG__
430	checkHeader( addr < heapBegin \|\| header < (HeapManager.Storage.Header *)heapBegin, name, addr ); // bad low address ?
431	#endif // __CFA_DEBUG__
432
433	// header may be safe to dereference
434	fakeHeader( header, alignment );
435	#ifdef __CFA_DEBUG__
436	checkHeader( header < (HeapManager.Storage.Header )heapBegin \|\| (HeapManager.Storage.Header )heapEnd < header, name, addr ); // bad address ? (offset could be + or -)
437	#endif // __CFA_DEBUG__
438
439	freeElem = (HeapManager.FreeHeader *)((size_t)header->kind.real.home & -3);
440	#ifdef __CFA_DEBUG__
441	if ( freeElem < &freeLists[0] \|\| &freeLists[NoBucketSizes] <= freeElem ) {
442	abort( "Attempt to %s storage %p with corrupted header.\n"
443	"Possible cause is duplicate free on same block or overwriting of header information.",
444	name, addr );
445	} // if
446	#endif // __CFA_DEBUG__
447	size = freeElem->blockSize;
448	return false;
449	} // headers
450
451
452	static inline void * extend( size_t size ) with ( heapManager ) {
453	lock( extlock __cfaabi_dbg_ctx2 );
454	ptrdiff_t rem = heapRemaining - size;
455	if ( rem < 0 ) {
456	// If the size requested is bigger than the current remaining storage, increase the size of the heap.
457
458	size_t increase = libCeiling( size > heapExpand ? size : heapExpand, libAlign() );
459	if ( sbrk( increase ) == (void *)-1 ) {
460	unlock( extlock );
461	errno = ENOMEM;
462	return 0p;
463	} // if
464	#ifdef __STATISTICS__
465	sbrk_calls += 1;
466	sbrk_storage += increase;
467	#endif // __STATISTICS__
468	#ifdef __CFA_DEBUG__
469	// Set new memory to garbage so subsequent uninitialized usages might fail.
470	memset( (char *)heapEnd + heapRemaining, '\377', increase );
471	#endif // __CFA_DEBUG__
472	rem = heapRemaining + increase - size;
473	} // if
474
475	HeapManager.Storage * block = (HeapManager.Storage *)heapEnd;
476	heapRemaining = rem;
477	heapEnd = (char *)heapEnd + size;
478	unlock( extlock );
479	return block;
480	} // extend
481
482
483	static inline void * doMalloc( size_t size ) with ( heapManager ) {
484	HeapManager.Storage * block; // pointer to new block of storage
485
486	// Look up size in the size list. Make sure the user request includes space for the header that must be allocated
487	// along with the block and is a multiple of the alignment size.
488
489	if ( unlikely( size > ~0ul - sizeof(HeapManager.Storage) ) ) return 0p;
490	size_t tsize = size + sizeof(HeapManager.Storage);
491	if ( likely( tsize < mmapStart ) ) { // small size => sbrk
492	size_t posn;
493	#ifdef FASTLOOKUP
494	if ( tsize < LookupSizes ) posn = lookup[tsize];
495	else
496	#endif // FASTLOOKUP
497	posn = Bsearchl( (unsigned int)tsize, bucketSizes, (size_t)maxBucketsUsed );
498	HeapManager.FreeHeader * freeElem = &freeLists[posn];
499	// #ifdef FASTLOOKUP
500	// if ( tsize < LookupSizes )
501	// freeElem = &freeLists[lookup[tsize]];
502	// else
503	// #endif // FASTLOOKUP
504	// freeElem = bsearchl( tsize, freeLists, (size_t)maxBucketsUsed ); // binary search
505	// HeapManager.FreeHeader * freeElem =
506	// #ifdef FASTLOOKUP
507	// tsize < LookupSizes ? &freeLists[lookup[tsize]] :
508	// #endif // FASTLOOKUP
509	// bsearchl( tsize, freeLists, (size_t)maxBucketsUsed ); // binary search
510	assert( freeElem <= &freeLists[maxBucketsUsed] ); // subscripting error ?
511	assert( tsize <= freeElem->blockSize ); // search failure ?
512	tsize = freeElem->blockSize; // total space needed for request
513
514	// Spin until the lock is acquired for this particular size of block.
515
516	#if defined( SPINLOCK )
517	lock( freeElem->lock __cfaabi_dbg_ctx2 );
518	block = freeElem->freeList; // remove node from stack
519	#else
520	block = freeElem->freeList.pop();
521	#endif // SPINLOCK
522	if ( unlikely( block == 0p ) ) { // no free block ?
523	#if defined( SPINLOCK )
524	unlock( freeElem->lock );
525	#endif // SPINLOCK
526
527	// Freelist for that size was empty, so carve it out of the heap if there's enough left, or get some more
528	// and then carve it off.
529
530	block = (HeapManager.Storage *)extend( tsize ); // mutual exclusion on call
531	if ( unlikely( block == 0p ) ) return 0p;
532	#if defined( SPINLOCK )
533	} else {
534	freeElem->freeList = block->header.kind.real.next;
535	unlock( freeElem->lock );
536	#endif // SPINLOCK
537	} // if
538
539	block->header.kind.real.home = freeElem; // pointer back to free list of apropriate size
540	} else { // large size => mmap
541	if ( unlikely( size > ~0ul - pageSize ) ) return 0p;
542	tsize = libCeiling( tsize, pageSize ); // must be multiple of page size
543	#ifdef __STATISTICS__
544	__atomic_add_fetch( &mmap_calls, 1, __ATOMIC_SEQ_CST );
545	__atomic_add_fetch( &mmap_storage, tsize, __ATOMIC_SEQ_CST );
546	#endif // __STATISTICS__
547	block = (HeapManager.Storage *)mmap( 0, tsize, PROT_READ \| PROT_WRITE, MAP_PRIVATE \| MAP_ANONYMOUS, mmapFd, 0 );
548	if ( block == (HeapManager.Storage *)MAP_FAILED ) {
549	// Do not call strerror( errno ) as it may call malloc.
550	abort( "(HeapManager &)0x%p.doMalloc() : internal error, mmap failure, size:%zu error:%d.", &heapManager, tsize, errno );
551	} // if
552	#ifdef __CFA_DEBUG__
553	// Set new memory to garbage so subsequent uninitialized usages might fail.
554	memset( block, '\377', tsize );
555	#endif // __CFA_DEBUG__
556	block->header.kind.real.blockSize = tsize; // storage size for munmap
557	} // if
558
559	void * addr = &(block->data); // adjust off header to user bytes
560
561	#ifdef __CFA_DEBUG__
562	assert( ((uintptr_t)addr & (libAlign() - 1)) == 0 ); // minimum alignment ?
563	__atomic_add_fetch( &allocFree, tsize, __ATOMIC_SEQ_CST );
564	if ( traceHeap() ) {
565	enum { BufferSize = 64 };
566	char helpText[BufferSize];
567	int len = snprintf( helpText, BufferSize, "%p = Malloc( %zu ) (allocated %zu)\n", addr, size, tsize );
568	// int len = snprintf( helpText, BufferSize, "Malloc %p %zu\n", addr, size );
569	__cfaabi_bits_write( STDERR_FILENO, helpText, len ); // print debug/nodebug
570	} // if
571	#endif // __CFA_DEBUG__
572
573	return addr;
574	} // doMalloc
575
576
577	static inline void doFree( void * addr ) with ( heapManager ) {
578	#ifdef __CFA_DEBUG__
579	if ( unlikely( heapManager.heapBegin == 0p ) ) {
580	abort( "doFree( %p ) : internal error, called before heap is initialized.", addr );
581	} // if
582	#endif // __CFA_DEBUG__
583
584	HeapManager.Storage.Header * header;
585	HeapManager.FreeHeader * freeElem;
586	size_t size, alignment; // not used (see realloc)
587
588	if ( headers( "free", addr, header, freeElem, size, alignment ) ) { // mmapped ?
589	#ifdef __STATISTICS__
590	__atomic_add_fetch( &munmap_calls, 1, __ATOMIC_SEQ_CST );
591	__atomic_add_fetch( &munmap_storage, size, __ATOMIC_SEQ_CST );
592	#endif // __STATISTICS__
593	if ( munmap( header, size ) == -1 ) {
594	#ifdef __CFA_DEBUG__
595	abort( "Attempt to deallocate storage %p not allocated or with corrupt header.\n"
596	"Possible cause is invalid pointer.",
597	addr );
598	#endif // __CFA_DEBUG__
599	} // if
600	} else {
601	#ifdef __CFA_DEBUG__
602	// Set free memory to garbage so subsequent usages might fail.
603	memset( ((HeapManager.Storage *)header)->data, '\377', freeElem->blockSize - sizeof( HeapManager.Storage ) );
604	#endif // __CFA_DEBUG__
605
606	#ifdef __STATISTICS__
607	free_storage += size;
608	#endif // __STATISTICS__
609	#if defined( SPINLOCK )
610	lock( freeElem->lock __cfaabi_dbg_ctx2 ); // acquire spin lock
611	header->kind.real.next = freeElem->freeList; // push on stack
612	freeElem->freeList = (HeapManager.Storage *)header;
613	unlock( freeElem->lock ); // release spin lock
614	#else
615	freeElem->freeList.push( (HeapManager.Storage )header );
616	#endif // SPINLOCK
617	} // if
618
619	#ifdef __CFA_DEBUG__
620	__atomic_add_fetch( &allocFree, -size, __ATOMIC_SEQ_CST );
621	if ( traceHeap() ) {
622	enum { BufferSize = 64 };
623	char helpText[BufferSize];
624	int len = snprintf( helpText, sizeof(helpText), "Free( %p ) size:%zu\n", addr, size );
625	__cfaabi_bits_write( STDERR_FILENO, helpText, len ); // print debug/nodebug
626	} // if
627	#endif // __CFA_DEBUG__
628	} // doFree
629
630
631	size_t prtFree( HeapManager & manager ) with ( manager ) {
632	size_t total = 0;
633	#ifdef __STATISTICS__
634	__cfaabi_bits_acquire();
635	__cfaabi_bits_print_nolock( STDERR_FILENO, "\nBin lists (bin size : free blocks on list)\n" );
636	#endif // __STATISTICS__
637	for ( unsigned int i = 0; i < maxBucketsUsed; i += 1 ) {
638	size_t size = freeLists[i].blockSize;
639	#ifdef __STATISTICS__
640	unsigned int N = 0;
641	#endif // __STATISTICS__
642
643	#if defined( SPINLOCK )
644	for ( HeapManager.Storage * p = freeLists[i].freeList; p != 0p; p = p->header.kind.real.next ) {
645	#else
646	for ( HeapManager.Storage * p = freeLists[i].freeList.top(); p != 0p; p = p->header.kind.real.next.top ) {
647	#endif // SPINLOCK
648	total += size;
649	#ifdef __STATISTICS__
650	N += 1;
651	#endif // __STATISTICS__
652	} // for
653
654	#ifdef __STATISTICS__
655	__cfaabi_bits_print_nolock( STDERR_FILENO, "%7zu, %-7u ", size, N );
656	if ( (i + 1) % 8 == 0 ) __cfaabi_bits_print_nolock( STDERR_FILENO, "\n" );
657	#endif // __STATISTICS__
658	} // for
659	#ifdef __STATISTICS__
660	__cfaabi_bits_print_nolock( STDERR_FILENO, "\ntotal free blocks:%zu\n", total );
661	__cfaabi_bits_release();
662	#endif // __STATISTICS__
663	return (char )heapEnd - (char )heapBegin - total;
664	} // prtFree
665
666
667	static void ?{}( HeapManager & manager ) with ( manager ) {
668	pageSize = sysconf( _SC_PAGESIZE );
669
670	for ( unsigned int i = 0; i < NoBucketSizes; i += 1 ) { // initialize the free lists
671	freeLists[i].blockSize = bucketSizes[i];
672	} // for
673
674	#ifdef FASTLOOKUP
675	unsigned int idx = 0;
676	for ( unsigned int i = 0; i < LookupSizes; i += 1 ) {
677	if ( i > bucketSizes[idx] ) idx += 1;
678	lookup[i] = idx;
679	} // for
680	#endif // FASTLOOKUP
681
682	if ( setMmapStart( default_mmap_start() ) ) {
683	abort( "HeapManager : internal error, mmap start initialization failure." );
684	} // if
685	heapExpand = default_heap_expansion();
686
687	char * end = (char *)sbrk( 0 );
688	sbrk( (char *)libCeiling( (long unsigned int)end, libAlign() ) - end ); // move start of heap to multiple of alignment
689	heapBegin = heapEnd = sbrk( 0 ); // get new start point
690	} // HeapManager
691
692
693	static void ^?{}( HeapManager & ) {
694	#ifdef __STATISTICS__
695	if ( traceHeapTerm() ) {
696	printStats();
697	// if ( prtfree() ) prtFree( heapManager, true );
698	} // if
699	#endif // __STATISTICS__
700	} // ~HeapManager
701
702
703	static void memory_startup( void ) __attribute__(( constructor( STARTUP_PRIORITY_MEMORY ) ));
704	void memory_startup( void ) {
705	#ifdef __CFA_DEBUG__
706	if ( unlikely( heapBoot ) ) { // check for recursion during system boot
707	// DO NOT USE STREAMS AS THEY MAY BE UNAVAILABLE AT THIS POINT.
708	abort( "boot() : internal error, recursively invoked during system boot." );
709	} // if
710	heapBoot = true;
711	#endif // __CFA_DEBUG__
712
713	//assert( heapManager.heapBegin != 0 );
714	//heapManager{};
715	if ( heapManager.heapBegin == 0p ) heapManager{};
716	} // memory_startup
717
718	static void memory_shutdown( void ) __attribute__(( destructor( STARTUP_PRIORITY_MEMORY ) ));
719	void memory_shutdown( void ) {
720	^heapManager{};
721	} // memory_shutdown
722
723
724	static inline void * mallocNoStats( size_t size ) { // necessary for malloc statistics
725	//assert( heapManager.heapBegin != 0 );
726	if ( unlikely( heapManager.heapBegin == 0p ) ) heapManager{}; // called before memory_startup ?
727	void * addr = doMalloc( size );
728	if ( unlikely( addr == 0p ) ) errno = ENOMEM; // POSIX
729	return addr;
730	} // mallocNoStats
731
732
733	static inline void * callocNoStats( size_t noOfElems, size_t elemSize ) {
734	size_t size = noOfElems * elemSize;
735	char * addr = (char *)mallocNoStats( size );
736	if ( unlikely( addr == 0p ) ) return 0p;
737
738	HeapManager.Storage.Header * header;
739	HeapManager.FreeHeader * freeElem;
740	size_t bsize, alignment;
741	bool mapped __attribute__(( unused )) = headers( "calloc", addr, header, freeElem, bsize, alignment );
742	#ifndef __CFA_DEBUG__
743	// Mapped storage is zero filled, but in debug mode mapped memory is scrubbed in doMalloc, so it has to be reset to zero.
744	if ( ! mapped )
745	#endif // __CFA_DEBUG__
746	// Zero entire data space even when > than size => realloc without a new allocation and zero fill works.
747	// <-------00000000000000000000000000000000000000000000000000000> bsize (bucket size)
748	// `-header`-addr `-size
749	memset( addr, '\0', bsize - sizeof(HeapManager.Storage) ); // set to zeros
750
751	header->kind.real.blockSize \|= 2; // mark as zero filled
752	return addr;
753	} // callocNoStats
754
755
756	static inline void * memalignNoStats( size_t alignment, size_t size ) { // necessary for malloc statistics
757	#ifdef __CFA_DEBUG__
758	checkAlign( alignment ); // check alignment
759	#endif // __CFA_DEBUG__
760
761	// if alignment <= default alignment, do normal malloc as two headers are unnecessary
762	if ( unlikely( alignment <= libAlign() ) ) return mallocNoStats( size );
763
764	// Allocate enough storage to guarantee an address on the alignment boundary, and sufficient space before it for
765	// administrative storage. NOTE, WHILE THERE ARE 2 HEADERS, THE FIRST ONE IS IMPLICITLY CREATED BY DOMALLOC.
766	// .-------------v-----------------v----------------v----------,
767	// \| Real Header \| ... padding ... \| Fake Header \| data ... \|
768	// `-------------^-----------------^-+--------------^----------'
769	// \|<--------------------------------' offset/align \|<-- alignment boundary
770
771	// subtract libAlign() because it is already the minimum alignment
772	// add sizeof(Storage) for fake header
773	char * addr = (char *)mallocNoStats( size + alignment - libAlign() + sizeof(HeapManager.Storage) );
774	if ( unlikely( addr == 0p ) ) return addr;
775
776	// address in the block of the "next" alignment address
777	char * user = (char *)libCeiling( (uintptr_t)(addr + sizeof(HeapManager.Storage)), alignment );
778
779	// address of header from malloc
780	HeapManager.Storage.Header * realHeader = headerAddr( addr );
781	// address of fake header * before* the alignment location
782	HeapManager.Storage.Header * fakeHeader = headerAddr( user );
783	// SKULLDUGGERY: insert the offset to the start of the actual storage block and remember alignment
784	fakeHeader->kind.fake.offset = (char )fakeHeader - (char )realHeader;
785	// SKULLDUGGERY: odd alignment imples fake header
786	fakeHeader->kind.fake.alignment = alignment \| 1;
787
788	return user;
789	} // memalignNoStats
790
791
792	static inline void * cmemalignNoStats( size_t alignment, size_t noOfElems, size_t elemSize ) {
793	size_t size = noOfElems * elemSize;
794	char * addr = (char *)memalignNoStats( alignment, size );
795	if ( unlikely( addr == 0p ) ) return 0p;
796	HeapManager.Storage.Header * header;
797	HeapManager.FreeHeader * freeElem;
798	size_t bsize;
799	bool mapped __attribute__(( unused )) = headers( "cmemalign", addr, header, freeElem, bsize, alignment );
800	#ifndef __CFA_DEBUG__
801	// Mapped storage is zero filled, but in debug mode mapped memory is scrubbed in doMalloc, so it has to be reset to zero.
802	if ( ! mapped )
803	#endif // __CFA_DEBUG__
804	memset( addr, '\0', dataStorage( bsize, addr, header ) ); // set to zeros
805	header->kind.real.blockSize \|= 2; // mark as zero filled
806
807	return addr;
808	} // cmemalignNoStats
809
810
811	// supported mallopt options
812	#ifndef M_MMAP_THRESHOLD
813	#define M_MMAP_THRESHOLD (-1)
814	#endif // M_TOP_PAD
815	#ifndef M_TOP_PAD
816	#define M_TOP_PAD (-2)
817	#endif // M_TOP_PAD
818
819
820	extern "C" {
821	// Allocates size bytes and returns a pointer to the allocated memory. The memory is not initialized. If size is 0,
822	// then malloc() returns either 0p, or a unique pointer value that can later be successfully passed to free().
823	void * malloc( size_t size ) {
824	#ifdef __STATISTICS__
825	__atomic_add_fetch( &malloc_calls, 1, __ATOMIC_SEQ_CST );
826	__atomic_add_fetch( &malloc_storage, size, __ATOMIC_SEQ_CST );
827	#endif // __STATISTICS__
828
829	return mallocNoStats( size );
830	} // malloc
831
832	// Allocate memory for an array of nmemb elements of size bytes each and returns a pointer to the allocated
833	// memory. The memory is set to zero. If nmemb or size is 0, then calloc() returns either 0p, or a unique pointer
834	// value that can later be successfully passed to free().
835	void * calloc( size_t noOfElems, size_t elemSize ) {
836	#ifdef __STATISTICS__
837	__atomic_add_fetch( &calloc_calls, 1, __ATOMIC_SEQ_CST );
838	__atomic_add_fetch( &calloc_storage, noOfElems * elemSize, __ATOMIC_SEQ_CST );
839	#endif // __STATISTICS__
840
841	return callocNoStats( noOfElems, elemSize );
842	} // calloc
843
844	// Change the size of the memory block pointed to by ptr to size bytes. The contents shall be unchanged in the range
845	// from the start of the region up to the minimum of the old and new sizes. If the new size is larger than the old
846	// size, the added memory shall not be initialized. If ptr is 0p, then the call is equivalent to malloc(size), for
847	// all values of size; if size is equal to zero, and ptr is not 0p, then the call is equivalent to free(ptr). Unless
848	// ptr is 0p, it must have been returned by an earlier call to malloc(), calloc() or realloc(). If the area pointed
849	// to was moved, a free(ptr) is done.
850	void * realloc( void * oaddr, size_t size ) {
851	#ifdef __STATISTICS__
852	__atomic_add_fetch( &realloc_calls, 1, __ATOMIC_SEQ_CST );
853	#endif // __STATISTICS__
854
855	// If size is equal to 0, either NULL or a pointer suitable to be passed to free() is returned.
856	if ( unlikely( size == 0 ) ) { free( oaddr ); return mallocNoStats( size ); } // special cases
857	if ( unlikely( oaddr == 0p ) ) return mallocNoStats( size );
858
859	HeapManager.Storage.Header * header;
860	HeapManager.FreeHeader * freeElem;
861	size_t bsize, oalign = 0;
862	headers( "realloc", oaddr, header, freeElem, bsize, oalign );
863
864	size_t odsize = dataStorage( bsize, oaddr, header ); // data storage available in bucket
865	if ( size <= odsize && odsize <= size * 2 ) { // allow up to 50% wasted storage in smaller size
866	// Do not know size of original allocation => cannot do 0 fill for any additional space because do not know
867	// where to start filling, i.e., do not overwrite existing values in space.
868	//
869	// This case does not result in a new profiler entry because the previous one still exists and it must match with
870	// the free for this memory. Hence, this realloc does not appear in the profiler output.
871	return oaddr;
872	} // if
873
874	#ifdef __STATISTICS__
875	__atomic_add_fetch( &realloc_storage, size, __ATOMIC_SEQ_CST );
876	#endif // __STATISTICS__
877
878	// change size and copy old content to new storage
879
880	void * naddr;
881	if ( unlikely( oalign != 0 ) ) { // previous request memalign?
882	if ( unlikely( header->kind.real.blockSize & 2 ) ) { // previous request zero fill
883	naddr = cmemalignNoStats( oalign, 1, size ); // create new aligned area
884	} else {
885	naddr = memalignNoStats( oalign, size ); // create new aligned area
886	} // if
887	} else {
888	if ( unlikely( header->kind.real.blockSize & 2 ) ) { // previous request zero fill
889	naddr = callocNoStats( 1, size ); // create new area
890	} else {
891	naddr = mallocNoStats( size ); // create new area
892	} // if
893	} // if
894	if ( unlikely( naddr == 0p ) ) return 0p;
895
896	headers( "realloc", naddr, header, freeElem, bsize, oalign );
897	size_t ndsize = dataStorage( bsize, naddr, header ); // data storage avilable in bucket
898	// To preserve prior fill, the entire bucket must be copied versus the size.
899	memcpy( naddr, oaddr, MIN( odsize, ndsize ) ); // copy bytes
900	free( oaddr );
901	return naddr;
902	} // realloc
903
904	// Allocates size bytes and returns a pointer to the allocated memory. The memory address shall be a multiple of
905	// alignment, which must be a power of two. (obsolete)
906	void * memalign( size_t alignment, size_t size ) {
907	#ifdef __STATISTICS__
908	__atomic_add_fetch( &memalign_calls, 1, __ATOMIC_SEQ_CST );
909	__atomic_add_fetch( &memalign_storage, size, __ATOMIC_SEQ_CST );
910	#endif // __STATISTICS__
911
912	return memalignNoStats( alignment, size );
913	} // memalign
914
915
916	// Same as calloc() with memory alignment.
917	void * cmemalign( size_t alignment, size_t noOfElems, size_t elemSize ) {
918	#ifdef __STATISTICS__
919	__atomic_add_fetch( &cmemalign_calls, 1, __ATOMIC_SEQ_CST );
920	__atomic_add_fetch( &cmemalign_storage, noOfElems * elemSize, __ATOMIC_SEQ_CST );
921	#endif // __STATISTICS__
922
923	return cmemalignNoStats( alignment, noOfElems, elemSize );
924	} // cmemalign
925
926	// Same as memalign(), but ISO/IEC 2011 C11 Section 7.22.2 states: the value of size shall be an integral multiple
927	// of alignment. This requirement is universally ignored.
928	void * aligned_alloc( size_t alignment, size_t size ) {
929	return memalign( alignment, size );
930	} // aligned_alloc
931
932
933	// Allocates size bytes and places the address of the allocated memory in *memptr. The address of the allocated
934	// memory shall be a multiple of alignment, which must be a power of two and a multiple of sizeof(void *). If size
935	// is 0, then posix_memalign() returns either 0p, or a unique pointer value that can later be successfully passed to
936	// free(3).
937	int posix_memalign( void ** memptr, size_t alignment, size_t size ) {
938	if ( alignment < sizeof(void *) \|\| ! libPow2( alignment ) ) return EINVAL; // check alignment
939	* memptr = memalign( alignment, size );
940	if ( unlikely( * memptr == 0p ) ) return ENOMEM;
941	return 0;
942	} // posix_memalign
943
944	// Allocates size bytes and returns a pointer to the allocated memory. The memory address shall be a multiple of the
945	// page size. It is equivalent to memalign(sysconf(_SC_PAGESIZE),size).
946	void * valloc( size_t size ) {
947	return memalign( pageSize, size );
948	} // valloc
949
950
951	// Same as valloc but rounds size to multiple of page size.
952	void * pvalloc( size_t size ) {
953	return memalign( pageSize, libCeiling( size, pageSize ) );
954	} // pvalloc
955
956
957	// Frees the memory space pointed to by ptr, which must have been returned by a previous call to malloc(), calloc()
958	// or realloc(). Otherwise, or if free(ptr) has already been called before, undefined behavior occurs. If ptr is
959	// 0p, no operation is performed.
960	void free( void * addr ) {
961	#ifdef __STATISTICS__
962	__atomic_add_fetch( &free_calls, 1, __ATOMIC_SEQ_CST );
963	#endif // __STATISTICS__
964
965	if ( unlikely( addr == 0p ) ) { // special case
966	// #ifdef __CFA_DEBUG__
967	// if ( traceHeap() ) {
968	// #define nullmsg "Free( 0x0 ) size:0\n"
969	// // Do not debug print free( 0p ), as it can cause recursive entry from sprintf.
970	// __cfaabi_dbg_write( nullmsg, sizeof(nullmsg) - 1 );
971	// } // if
972	// #endif // __CFA_DEBUG__
973	return;
974	} // exit
975
976	doFree( addr );
977	} // free
978
979
980	// Returns the alignment of the allocation.
981	size_t malloc_alignment( void * addr ) {
982	if ( unlikely( addr == 0p ) ) return libAlign(); // minimum alignment
983	HeapManager.Storage.Header * header = headerAddr( addr );
984	if ( (header->kind.fake.alignment & 1) == 1 ) { // fake header ?
985	return header->kind.fake.alignment & -2; // remove flag from value
986	} else {
987	return libAlign (); // minimum alignment
988	} // if
989	} // malloc_alignment
990
991
992	// Returns true if the allocation is zero filled, i.e., initially allocated by calloc().
993	bool malloc_zero_fill( void * addr ) {
994	if ( unlikely( addr == 0p ) ) return false; // null allocation is not zero fill
995	HeapManager.Storage.Header * header = headerAddr( addr );
996	if ( (header->kind.fake.alignment & 1) == 1 ) { // fake header ?
997	header = (HeapManager.Storage.Header )((char )header - header->kind.fake.offset);
998	} // if
999	return (header->kind.real.blockSize & 2) != 0; // zero filled (calloc/cmemalign) ?
1000	} // malloc_zero_fill
1001
1002
1003	// Returns the number of usable bytes in the block pointed to by ptr, a pointer to a block of memory allocated by
1004	// malloc or a related function.
1005	size_t malloc_usable_size( void * addr ) {
1006	if ( unlikely( addr == 0p ) ) return 0; // null allocation has 0 size
1007	HeapManager.Storage.Header * header;
1008	HeapManager.FreeHeader * freeElem;
1009	size_t bsize, alignment;
1010
1011	headers( "malloc_usable_size", addr, header, freeElem, bsize, alignment );
1012	return dataStorage( bsize, addr, header ); // data storage in bucket
1013	} // malloc_usable_size
1014
1015
1016	// Prints (on default standard error) statistics about memory allocated by malloc and related functions.
1017	void malloc_stats( void ) {
1018	#ifdef __STATISTICS__
1019	printStats();
1020	if ( prtFree() ) prtFree( heapManager );
1021	#endif // __STATISTICS__
1022	} // malloc_stats
1023
1024	// Changes the file descripter where malloc_stats() writes statistics.
1025	int malloc_stats_fd( int fd __attribute__(( unused )) ) {
1026	#ifdef __STATISTICS__
1027	int temp = statfd;
1028	statfd = fd;
1029	return temp;
1030	#else
1031	return -1;
1032	#endif // __STATISTICS__
1033	} // malloc_stats_fd
1034
1035
1036	// Adjusts parameters that control the behavior of the memory-allocation functions (see malloc). The param argument
1037	// specifies the parameter to be modified, and value specifies the new value for that parameter.
1038	int mallopt( int option, int value ) {
1039	choose( option ) {
1040	case M_TOP_PAD:
1041	if ( setHeapExpand( value ) ) return 1;
1042	case M_MMAP_THRESHOLD:
1043	if ( setMmapStart( value ) ) return 1;
1044	} // switch
1045	return 0; // error, unsupported
1046	} // mallopt
1047
1048	// Attempt to release free memory at the top of the heap (by calling sbrk with a suitable argument).
1049	int malloc_trim( size_t ) {
1050	return 0; // => impossible to release memory
1051	} // malloc_trim
1052
1053
1054	// Exports an XML string that describes the current state of the memory-allocation implementation in the caller.
1055	// The string is printed on the file stream stream. The exported string includes information about all arenas (see
1056	// malloc).
1057	int malloc_info( int options, FILE * stream ) {
1058	if ( options != 0 ) { errno = EINVAL; return -1; }
1059	return printStatsXML( stream );
1060	} // malloc_info
1061
1062
1063	// Records the current state of all malloc internal bookkeeping variables (but not the actual contents of the heap
1064	// or the state of malloc_hook functions pointers). The state is recorded in a system-dependent opaque data
1065	// structure dynamically allocated via malloc, and a pointer to that data structure is returned as the function
1066	// result. (The caller must free this memory.)
1067	void * malloc_get_state( void ) {
1068	return 0p; // unsupported
1069	} // malloc_get_state
1070
1071
1072	// Restores the state of all malloc internal bookkeeping variables to the values recorded in the opaque data
1073	// structure pointed to by state.
1074	int malloc_set_state( void * ptr ) {
1075	return 0; // unsupported
1076	} // malloc_set_state
1077	} // extern "C"
1078
1079
1080	// Must have CFA linkage to overload with C linkage realloc.
1081	void * realloc( void * oaddr, size_t nalign, size_t size ) {
1082	#ifdef __STATISTICS__
1083	__atomic_add_fetch( &realloc_calls, 1, __ATOMIC_SEQ_CST );
1084	#endif // __STATISTICS__
1085
1086	// If size is equal to 0, either NULL or a pointer suitable to be passed to free() is returned.
1087	if ( unlikely( size == 0 ) ) { free( oaddr ); return mallocNoStats( size ); } // special cases
1088	if ( unlikely( oaddr == 0p ) ) return mallocNoStats( size );
1089
1090	if ( unlikely( nalign == 0 ) ) nalign = libAlign(); // reset alignment to minimum
1091	#ifdef __CFA_DEBUG__
1092	else
1093	checkAlign( nalign ); // check alignment
1094	#endif // __CFA_DEBUG__
1095
1096	HeapManager.Storage.Header * header;
1097	HeapManager.FreeHeader * freeElem;
1098	size_t bsize, oalign = 0;
1099	headers( "realloc", oaddr, header, freeElem, bsize, oalign );
1100	size_t odsize = dataStorage( bsize, oaddr, header ); // data storage available in bucket
1101
1102	if ( oalign != 0 && (uintptr_t)oaddr % nalign == 0 ) { // has alignment and just happens to work out
1103	headerAddr( oaddr )->kind.fake.alignment = nalign \| 1; // update alignment (could be the same)
1104	return realloc( oaddr, size );
1105	} // if
1106
1107	#ifdef __STATISTICS__
1108	__atomic_add_fetch( &realloc_storage, size, __ATOMIC_SEQ_CST );
1109	#endif // __STATISTICS__
1110
1111	// change size and copy old content to new storage
1112
1113	void * naddr;
1114	if ( unlikely( header->kind.real.blockSize & 2 ) ) { // previous request zero fill
1115	naddr = cmemalignNoStats( nalign, 1, size ); // create new aligned area
1116	} else {
1117	naddr = memalignNoStats( nalign, size ); // create new aligned area
1118	} // if
1119
1120	headers( "realloc", naddr, header, freeElem, bsize, oalign );
1121	size_t ndsize = dataStorage( bsize, naddr, header ); // data storage avilable in bucket
1122	// To preserve prior fill, the entire bucket must be copied versus the size.
1123	memcpy( naddr, oaddr, MIN( odsize, ndsize ) ); // copy bytes
1124	free( oaddr );
1125	return naddr;
1126	} // realloc
1127
1128
1129	// Local Variables: //
1130	// tab-width: 4 //
1131	// compile-command: "cfa -nodebug -O2 heap.cfa" //
1132	// End: //

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