source: libcfa/src/heap.cfa@ 029e330

ADT arm-eh ast-experimental cleanup-dtors enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 029e330 was b6830d74, checked in by Thierry Delisle <tdelisle@…>, 7 years ago

First pass of comment on heap.cfa
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1// #comment TD : this file uses both spaces and tabs for indentation
2
3//
4// Cforall Version 1.0.0 Copyright (C) 2017 University of Waterloo
5//
6// The contents of this file are covered under the licence agreement in the
7// file "LICENCE" distributed with Cforall.
8//
9// heap.c --
10//
11// Author : Peter A. Buhr
12// Created On : Tue Dec 19 21:58:35 2017
13// Last Modified By : Peter A. Buhr
14// Last Modified On : Sat Aug 11 08:22:16 2018
15// Update Count : 495
16//
17
18#include <unistd.h> // sbrk, sysconf
19#include <stdbool.h> // true, false
20#include <stdio.h> // snprintf, fileno
21#include <errno.h> // errno
22extern "C" {
23#include <sys/mman.h> // mmap, munmap
24} // extern "C"
25
26// #comment TD : Many of these should be merged into math I believe
27#include "bits/align.hfa" // libPow2
28#include "bits/defs.hfa" // likely, unlikely
29#include "bits/locks.hfa" // __spinlock_t
30#include "startup.hfa" // STARTUP_PRIORITY_MEMORY
31#include "stdlib.hfa" // bsearchl
32#include "malloc.h"
33
34
35enum {
36 __CFA_DEFAULT_MMAP_START__ = (512 * 1024 + 1),
37 __CFA_DEFAULT_HEAP_EXPANSION__ = (1 * 1024 * 1024),
38};
39
40size_t default_mmap_start() __attribute__(( weak )) {
41 return __CFA_DEFAULT_MMAP_START__;
42} // default_mmap_start
43
44size_t default_heap_expansion() __attribute__(( weak )) {
45 return __CFA_DEFAULT_HEAP_EXPANSION__;
46} // default_heap_expansion
47
48
49// supported mallopt options
50#ifndef M_MMAP_THRESHOLD
51#define M_MMAP_THRESHOLD (-1)
52#endif // M_TOP_PAD
53#ifndef M_TOP_PAD
54#define M_TOP_PAD (-2)
55#endif // M_TOP_PAD
56
57#define FASTLOOKUP
58#define __STATISTICS__
59
60#define SPINLOCK 0
61#define LOCKFREE 1
62#define BUCKETLOCK SPINLOCK
63#if BUCKETLOCK == LOCKFREE
64#include <uStackLF.h>
65#endif // LOCKFREE
66
67// #comment TD : This defined is significantly different from the __ALIGN__ define from locks.hfa
68#define ALIGN 16
69
70// enum { NoBucketSizes = 93, // number of buckets sizes
71// #ifdef FASTLOOKUP
72// LookupSizes = 65536, // number of fast lookup sizes
73// #endif // FASTLOOKUP
74// };
75#define NoBucketSizes 93 // number of buckets sizes
76#ifdef FASTLOOKUP
77#define LookupSizes 65536 // number of fast lookup sizes
78#endif // FASTLOOKUP
79
80
81static bool traceHeap = false;
82
83inline bool traceHeap() {
84 return traceHeap;
85} // traceHeap
86
87bool traceHeapOn() {
88 bool temp = traceHeap;
89 traceHeap = true;
90 return temp;
91} // traceHeapOn
92
93bool traceHeapOff() {
94 bool temp = traceHeap;
95 traceHeap = false;
96 return temp;
97} // traceHeapOff
98
99
100static bool checkFree = false;
101
102inline bool checkFree() {
103 return checkFree;
104} // checkFree
105
106bool checkFreeOn() {
107 bool temp = checkFree;
108 checkFree = true;
109 return temp;
110} // checkFreeOn
111
112bool checkFreeOff() {
113 bool temp = checkFree;
114 checkFree = false;
115 return temp;
116} // checkFreeOff
117
118
119// static bool traceHeapTerm = false;
120
121// inline bool traceHeapTerm() {
122// return traceHeapTerm;
123// } // traceHeapTerm
124
125// bool traceHeapTermOn() {
126// bool temp = traceHeapTerm;
127// traceHeapTerm = true;
128// return temp;
129// } // traceHeapTermOn
130
131// bool traceHeapTermOff() {
132// bool temp = traceHeapTerm;
133// traceHeapTerm = false;
134// return temp;
135// } // traceHeapTermOff
136
137
138#ifdef __CFA_DEBUG__
139static unsigned int allocFree; // running total of allocations minus frees
140
141static void checkUnfreed() {
142 if ( allocFree != 0 ) {
143 // DO NOT USE STREAMS AS THEY MAY BE UNAVAILABLE AT THIS POINT.
144 // char helpText[512];
145 // 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"
146 // "Possible cause is unfreed storage allocated by the program or system/library routines called from the program.\n",
147 // (long int)getpid(), allocFree, allocFree ); // always print the UNIX pid
148 // __cfaabi_dbg_bits_write( helpText, len );
149 } // if
150} // checkUnfreed
151
152extern "C" {
153void heapAppStart() { // called by __cfaabi_appready_startup
154 allocFree = 0;
155} // heapAppStart
156
157void heapAppStop() { // called by __cfaabi_appready_startdown
158 fclose( stdin ); fclose( stdout );
159 checkUnfreed();
160} // heapAppStop
161} // extern "C"
162#endif // __CFA_DEBUG__
163
164
165struct HeapManager {
166// struct FreeHeader; // forward declaration
167
168 struct Storage {
169 struct Header { // header
170 union Kind {
171 struct RealHeader {
172 union {
173 // #comment TD : this code use byte size but the comment uses bit size
174
175 struct { // 32-bit word => 64-bit header, 64-bit word => 128-bit header
176 #if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ && __SIZEOF_POINTER__ == 4
177 uint32_t padding; // unused, force home/blocksize to overlay alignment in fake header
178 #endif // __ORDER_BIG_ENDIAN__ && __U_WORDSIZE__ == 32
179
180 union {
181// FreeHeader * home; // allocated block points back to home locations (must overlay alignment)
182 void * home; // allocated block points back to home locations (must overlay alignment)
183 size_t blockSize; // size for munmap (must overlay alignment)
184 #if BUCKLOCK == SPINLOCK
185 Storage * next; // freed block points next freed block of same size
186 #endif // SPINLOCK
187 };
188
189 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ && __SIZEOF_POINTER__ == 4
190 uint32_t padding; // unused, force home/blocksize to overlay alignment in fake header
191 #endif // __ORDER_LITTLE_ENDIAN__ && __U_WORDSIZE__ == 32
192
193 };
194
195 // #comment TD : C++ code
196 #if BUCKLOCK == LOCKFREE
197 Stack<Storage>::Link next; // freed block points next freed block of same size (double-wide)
198 #endif // LOCKFREE
199 };
200 } real; // RealHeader
201 struct FakeHeader {
202 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
203 uint32_t alignment; // low-order bits of home/blockSize used for tricks
204 #endif // __ORDER_LITTLE_ENDIAN__
205
206 uint32_t offset;
207
208 #if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
209 uint32_t alignment; // low-order bits of home/blockSize used for tricks
210 #endif // __ORDER_BIG_ENDIAN__
211 } fake; // FakeHeader
212 } kind; // Kind
213 } header; // Header
214 char pad[ALIGN - sizeof( Header )];
215 char data[0]; // storage
216 }; // Storage
217
218 static_assert( ALIGN >= sizeof( Storage ), "ALIGN < sizeof( Storage )" );
219
220 struct FreeHeader {
221 #if BUCKLOCK == SPINLOCK
222 __spinlock_t lock; // must be first field for alignment
223 Storage * freeList;
224 #elif BUCKLOCK == LOCKFREE
225 // #comment TD : C++ code
226 StackLF<Storage> freeList;
227 #else
228 #error undefined lock type for bucket lock
229 #endif // SPINLOCK
230 size_t blockSize; // size of allocations on this list
231 }; // FreeHeader
232
233 // must be first fields for alignment
234 __spinlock_t extlock; // protects allocation-buffer extension
235 FreeHeader freeLists[NoBucketSizes]; // buckets for different allocation sizes
236
237 void * heapBegin; // start of heap
238 void * heapEnd; // logical end of heap
239 size_t heapRemaining; // amount of storage not allocated in the current chunk
240}; // HeapManager
241
242static inline size_t getKey( const HeapManager.FreeHeader & freeheader ) { return freeheader.blockSize; }
243// statically allocated variables => zero filled.
244
245
246static size_t pageSize; // architecture pagesize
247static size_t heapExpand; // sbrk advance
248static size_t mmapStart; // cross over point for mmap
249static unsigned int maxBucketsUsed; // maximum number of buckets in use
250
251// #comment TD : This array is not const but it feels like it should be
252// Powers of 2 are common allocation sizes, so make powers of 2 generate the minimum required size.
253static unsigned int bucketSizes[NoBucketSizes] @= { // different bucket sizes
254 16, 32, 48, 64,
255 64 + sizeof(HeapManager.Storage), 96, 112, 128, 128 + sizeof(HeapManager.Storage), 160, 192, 224,
256 256 + sizeof(HeapManager.Storage), 320, 384, 448, 512 + sizeof(HeapManager.Storage), 640, 768, 896,
257 1_024 + sizeof(HeapManager.Storage), 1_536, 2_048 + sizeof(HeapManager.Storage), 2_560, 3_072, 3_584, 4_096 + sizeof(HeapManager.Storage), 6_144,
258 8_192 + sizeof(HeapManager.Storage), 9_216, 10_240, 11_264, 12_288, 13_312, 14_336, 15_360,
259 16_384 + sizeof(HeapManager.Storage), 18_432, 20_480, 22_528, 24_576, 26_624, 28_672, 30_720,
260 32_768 + sizeof(HeapManager.Storage), 36_864, 40_960, 45_056, 49_152, 53_248, 57_344, 61_440,
261 65_536 + sizeof(HeapManager.Storage), 73_728, 81_920, 90_112, 98_304, 106_496, 114_688, 122_880,
262 131_072 + sizeof(HeapManager.Storage), 147_456, 163_840, 180_224, 196_608, 212_992, 229_376, 245_760,
263 262_144 + sizeof(HeapManager.Storage), 294_912, 327_680, 360_448, 393_216, 425_984, 458_752, 491_520,
264 524_288 + sizeof(HeapManager.Storage), 655_360, 786_432, 917_504, 1_048_576 + sizeof(HeapManager.Storage), 1_179_648, 1_310_720, 1_441_792,
265 1_572_864, 1_703_936, 1_835_008, 1_966_080, 2_097_152 + sizeof(HeapManager.Storage), 2_621_440, 3_145_728, 3_670_016,
266 4_194_304 + sizeof(HeapManager.Storage)
267};
268#ifdef FASTLOOKUP
269static unsigned char lookup[LookupSizes]; // O(1) lookup for small sizes
270#endif // FASTLOOKUP
271static int mmapFd = -1; // fake or actual fd for anonymous file
272
273
274#ifdef __CFA_DEBUG__
275static bool heapBoot = 0; // detect recursion during boot
276#endif // __CFA_DEBUG__
277static HeapManager heapManager __attribute__(( aligned (128) )) @= {}; // size of cache line to prevent false sharing
278
279// #comment TD : The return type of this function should be commented
280static inline bool setMmapStart( size_t value ) {
281 if ( value < pageSize || bucketSizes[NoBucketSizes - 1] < value ) return true;
282 mmapStart = value; // set global
283
284 // find the closest bucket size less than or equal to the mmapStart size
285 maxBucketsUsed = bsearchl( (unsigned int)mmapStart, bucketSizes, NoBucketSizes ); // binary search
286 assert( maxBucketsUsed < NoBucketSizes ); // subscript failure ?
287 assert( mmapStart <= bucketSizes[maxBucketsUsed] ); // search failure ?
288 return false;
289} // setMmapStart
290
291
292static void ?{}( HeapManager & manager ) with ( manager ) {
293 pageSize = sysconf( _SC_PAGESIZE );
294
295 for ( unsigned int i = 0; i < NoBucketSizes; i += 1 ) { // initialize the free lists
296 freeLists[i].blockSize = bucketSizes[i];
297 } // for
298
299 #ifdef FASTLOOKUP
300 unsigned int idx = 0;
301 for ( unsigned int i = 0; i < LookupSizes; i += 1 ) {
302 if ( i > bucketSizes[idx] ) idx += 1;
303 lookup[i] = idx;
304 } // for
305 #endif // FASTLOOKUP
306
307 if ( setMmapStart( default_mmap_start() ) ) {
308 abort( "HeapManager : internal error, mmap start initialization failure." );
309 } // if
310 heapExpand = default_heap_expansion();
311
312 char * End = (char *)sbrk( 0 );
313 sbrk( (char *)libCeiling( (long unsigned int)End, libAlign() ) - End ); // move start of heap to multiple of alignment
314 heapBegin = heapEnd = sbrk( 0 ); // get new start point
315} // HeapManager
316
317
318static void ^?{}( HeapManager & ) {
319 #ifdef __STATISTICS__
320 // if ( traceHeapTerm() ) {
321 // printStats();
322 // if ( checkfree() ) checkFree( heapManager, true );
323 // } // if
324 #endif // __STATISTICS__
325} // ~HeapManager
326
327
328static void memory_startup( void ) __attribute__(( constructor( STARTUP_PRIORITY_MEMORY ) ));
329void memory_startup( void ) {
330 #ifdef __CFA_DEBUG__
331 if ( unlikely( heapBoot ) ) { // check for recursion during system boot
332 // DO NOT USE STREAMS AS THEY MAY BE UNAVAILABLE AT THIS POINT.
333 abort( "boot() : internal error, recursively invoked during system boot." );
334 } // if
335 heapBoot = true;
336 #endif // __CFA_DEBUG__
337
338 // #comment TD : This assertion seems redundent with the above code
339 assert( heapManager.heapBegin == 0 );
340 heapManager{};
341} // memory_startup
342
343static void memory_shutdown( void ) __attribute__(( destructor( STARTUP_PRIORITY_MEMORY ) ));
344void memory_shutdown( void ) {
345 ^heapManager{};
346} // memory_shutdown
347
348
349#ifdef __STATISTICS__
350static unsigned long long int mmap_storage; // heap statistics counters
351static unsigned int mmap_calls;
352static unsigned long long int munmap_storage;
353static unsigned int munmap_calls;
354static unsigned long long int sbrk_storage;
355static unsigned int sbrk_calls;
356static unsigned long long int malloc_storage;
357static unsigned int malloc_calls;
358static unsigned long long int free_storage;
359static unsigned int free_calls;
360static unsigned long long int calloc_storage;
361static unsigned int calloc_calls;
362static unsigned long long int memalign_storage;
363static unsigned int memalign_calls;
364static unsigned long long int cmemalign_storage;
365static unsigned int cmemalign_calls;
366static unsigned long long int realloc_storage;
367static unsigned int realloc_calls;
368
369static int statfd; // statistics file descriptor (changed by malloc_stats_fd)
370
371
372// Use "write" because streams may be shutdown when calls are made.
373static void printStats() {
374 char helpText[512];
375 __cfaabi_dbg_bits_print_buffer( helpText, sizeof(helpText),
376 "\nHeap statistics:\n"
377 " malloc: calls %u / storage %llu\n"
378 " calloc: calls %u / storage %llu\n"
379 " memalign: calls %u / storage %llu\n"
380 " cmemalign: calls %u / storage %llu\n"
381 " realloc: calls %u / storage %llu\n"
382 " free: calls %u / storage %llu\n"
383 " mmap: calls %u / storage %llu\n"
384 " munmap: calls %u / storage %llu\n"
385 " sbrk: calls %u / storage %llu\n",
386 malloc_calls, malloc_storage,
387 calloc_calls, calloc_storage,
388 memalign_calls, memalign_storage,
389 cmemalign_calls, cmemalign_storage,
390 realloc_calls, realloc_storage,
391 free_calls, free_storage,
392 mmap_calls, mmap_storage,
393 munmap_calls, munmap_storage,
394 sbrk_calls, sbrk_storage
395 );
396} // printStats
397
398// #comment TD : Why do we have this?
399static int printStatsXML( FILE * stream ) {
400 char helpText[512];
401 int len = snprintf( helpText, sizeof(helpText),
402 "<malloc version=\"1\">\n"
403 "<heap nr=\"0\">\n"
404 "<sizes>\n"
405 "</sizes>\n"
406 "<total type=\"malloc\" count=\"%u\" size=\"%llu\"/>\n"
407 "<total type=\"calloc\" count=\"%u\" size=\"%llu\"/>\n"
408 "<total type=\"memalign\" count=\"%u\" size=\"%llu\"/>\n"
409 "<total type=\"cmemalign\" count=\"%u\" size=\"%llu\"/>\n"
410 "<total type=\"realloc\" count=\"%u\" size=\"%llu\"/>\n"
411 "<total type=\"free\" count=\"%u\" size=\"%llu\"/>\n"
412 "<total type=\"mmap\" count=\"%u\" size=\"%llu\"/>\n"
413 "<total type=\"munmap\" count=\"%u\" size=\"%llu\"/>\n"
414 "<total type=\"sbrk\" count=\"%u\" size=\"%llu\"/>\n"
415 "</malloc>",
416 malloc_calls, malloc_storage,
417 calloc_calls, calloc_storage,
418 memalign_calls, memalign_storage,
419 cmemalign_calls, cmemalign_storage,
420 realloc_calls, realloc_storage,
421 free_calls, free_storage,
422 mmap_calls, mmap_storage,
423 munmap_calls, munmap_storage,
424 sbrk_calls, sbrk_storage
425 );
426 return write( fileno( stream ), helpText, len ); // -1 => error
427} // printStatsXML
428#endif // __STATISTICS__
429
430// #comment TD : Is this the samething as Out-of-Memory?
431static inline void noMemory() {
432 abort( "Heap memory exhausted at %zu bytes.\n"
433 "Possible cause is very large memory allocation and/or large amount of unfreed storage allocated by the program or system/library routines.",
434 ((char *)(sbrk( 0 )) - (char *)(heapManager.heapBegin)) );
435} // noMemory
436
437
438static inline void checkAlign( size_t alignment ) {
439 if ( alignment < sizeof(void *) || ! libPow2( alignment ) ) {
440 abort( "Alignment %zu for memory allocation is less than sizeof(void *) and/or not a power of 2.", alignment );
441 } // if
442} // checkAlign
443
444
445static inline bool setHeapExpand( size_t value ) {
446 if ( heapExpand < pageSize ) return true;
447 heapExpand = value;
448 return false;
449} // setHeapExpand
450
451
452static inline void checkHeader( bool check, const char * name, void * addr ) {
453 if ( unlikely( check ) ) { // bad address ?
454 abort( "Attempt to %s storage %p with address outside the heap.\n"
455 "Possible cause is duplicate free on same block or overwriting of memory.",
456 name, addr );
457 } // if
458} // checkHeader
459
460// #comment TD : function should be commented and/or have a more evocative name
461// this isn't either a check or a constructor which is what I would expect this function to be
462static inline void fakeHeader( HeapManager.Storage.Header *& header, size_t & size, size_t & alignment ) {
463 if ( unlikely( (header->kind.fake.alignment & 1) == 1 ) ) { // fake header ?
464 size_t offset = header->kind.fake.offset;
465 alignment = header->kind.fake.alignment & -2; // remove flag from value
466 #ifdef __CFA_DEBUG__
467 checkAlign( alignment ); // check alignment
468 #endif // __CFA_DEBUG__
469 header = (HeapManager.Storage.Header *)((char *)header - offset);
470 } // if
471} // fakeHeader
472
473// #comment TD : Why is this a define
474#define headerAddr( addr ) ((HeapManager.Storage.Header *)( (char *)addr - sizeof(HeapManager.Storage) ))
475
476static inline bool headers( const char * name, void * addr, HeapManager.Storage.Header *& header, HeapManager.FreeHeader *& freeElem, size_t & size, size_t & alignment ) with ( heapManager ) {
477 header = headerAddr( addr );
478
479 if ( unlikely( heapEnd < addr ) ) { // mmapped ?
480 fakeHeader( header, size, alignment );
481 size = header->kind.real.blockSize & -3; // mmap size
482 return true;
483 } // if
484
485 #ifdef __CFA_DEBUG__
486 checkHeader( addr < heapBegin || header < (HeapManager.Storage.Header *)heapBegin, name, addr ); // bad low address ?
487 #endif // __CFA_DEBUG__
488
489 // #comment TD : This code looks weird...
490 // It's called as the first statement of both branches of the last if, with the same parameters in all cases
491
492 // header may be safe to dereference
493 fakeHeader( header, size, alignment );
494 #ifdef __CFA_DEBUG__
495 checkHeader( header < (HeapManager.Storage.Header *)heapBegin || (HeapManager.Storage.Header *)heapEnd < header, name, addr ); // bad address ? (offset could be + or -)
496 #endif // __CFA_DEBUG__
497
498 freeElem = (HeapManager.FreeHeader *)((size_t)header->kind.real.home & -3);
499 #ifdef __CFA_DEBUG__
500 if ( freeElem < &freeLists[0] || &freeLists[NoBucketSizes] <= freeElem ) {
501 abort( "Attempt to %s storage %p with corrupted header.\n"
502 "Possible cause is duplicate free on same block or overwriting of header information.",
503 name, addr );
504 } // if
505 #endif // __CFA_DEBUG__
506 size = freeElem->blockSize;
507 return false;
508} // headers
509
510
511static inline void * extend( size_t size ) with ( heapManager ) {
512 lock( extlock __cfaabi_dbg_ctx2 );
513 ptrdiff_t rem = heapRemaining - size;
514 if ( rem < 0 ) {
515 // If the size requested is bigger than the current remaining storage, increase the size of the heap.
516
517 size_t increase = libCeiling( size > heapExpand ? size : heapExpand, libAlign() );
518 if ( sbrk( increase ) == (void *)-1 ) {
519 unlock( extlock );
520 errno = ENOMEM;
521 return 0;
522 } // if
523#ifdef __STATISTICS__
524 sbrk_calls += 1;
525 sbrk_storage += increase;
526#endif // __STATISTICS__
527#ifdef __CFA_DEBUG__
528 // Set new memory to garbage so subsequent uninitialized usages might fail.
529 memset( (char *)heapEnd + heapRemaining, '\377', increase );
530#endif // __CFA_DEBUG__
531 rem = heapRemaining + increase - size;
532 } // if
533
534 HeapManager.Storage * block = (HeapManager.Storage *)heapEnd;
535 heapRemaining = rem;
536 heapEnd = (char *)heapEnd + size;
537 unlock( extlock );
538 return block;
539} // extend
540
541
542static inline void * doMalloc( size_t size ) with ( heapManager ) {
543 HeapManager.Storage * block;
544
545 // Look up size in the size list. Make sure the user request includes space for the header that must be allocated
546 // along with the block and is a multiple of the alignment size.
547
548 size_t tsize = size + sizeof(HeapManager.Storage);
549 if ( likely( tsize < mmapStart ) ) { // small size => sbrk
550 HeapManager.FreeHeader * freeElem =
551 #ifdef FASTLOOKUP
552 tsize < LookupSizes ? &freeLists[lookup[tsize]] :
553 #endif // FASTLOOKUP
554 bsearchl( tsize, freeLists, (size_t)maxBucketsUsed ); // binary search
555 assert( freeElem <= &freeLists[maxBucketsUsed] ); // subscripting error ?
556 assert( tsize <= freeElem->blockSize ); // search failure ?
557 tsize = freeElem->blockSize; // total space needed for request
558
559 // Spin until the lock is acquired for this particular size of block.
560
561 #if defined( SPINLOCK )
562 lock( freeElem->lock __cfaabi_dbg_ctx2 );
563 block = freeElem->freeList; // remove node from stack
564 #else
565 block = freeElem->freeList.pop();
566 #endif // SPINLOCK
567 if ( unlikely( block == 0 ) ) { // no free block ?
568 #if defined( SPINLOCK )
569 unlock( freeElem->lock );
570 #endif // SPINLOCK
571 // Freelist for that size was empty, so carve it out of the heap if there's enough left, or get some more
572 // and then carve it off.
573
574 block = (HeapManager.Storage *)extend( tsize ); // mutual exclusion on call
575 if ( unlikely( block == 0 ) ) return 0;
576 #if defined( SPINLOCK )
577 } else {
578 freeElem->freeList = block->header.kind.real.next;
579 unlock( freeElem->lock );
580 #endif // SPINLOCK
581 } // if
582
583 block->header.kind.real.home = freeElem; // pointer back to free list of apropriate size
584 } else { // large size => mmap
585 tsize = libCeiling( tsize, pageSize ); // must be multiple of page size
586 #ifdef __STATISTICS__
587 __atomic_add_fetch( &mmap_calls, 1, __ATOMIC_SEQ_CST );
588 __atomic_add_fetch( &mmap_storage, tsize, __ATOMIC_SEQ_CST );
589 #endif // __STATISTICS__
590 block = (HeapManager.Storage *)mmap( 0, tsize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, mmapFd, 0 );
591 if ( block == (HeapManager.Storage *)MAP_FAILED ) {
592 // Do not call strerror( errno ) as it may call malloc.
593 abort( "(HeapManager &)0x%p.doMalloc() : internal error, mmap failure, size:%zu error:%d.", &heapManager, tsize, errno );
594 } // if
595#ifdef __CFA_DEBUG__
596 // Set new memory to garbage so subsequent uninitialized usages might fail.
597 memset( block, '\377', tsize );
598#endif // __CFA_DEBUG__
599 block->header.kind.real.blockSize = tsize; // storage size for munmap
600 } // if
601
602 void * area = &(block->data); // adjust off header to user bytes
603
604 #ifdef __CFA_DEBUG__
605 assert( ((uintptr_t)area & (libAlign() - 1)) == 0 ); // minimum alignment ?
606 __atomic_add_fetch( &allocFree, tsize, __ATOMIC_SEQ_CST );
607 if ( traceHeap() ) {
608 enum { BufferSize = 64 };
609 char helpText[BufferSize];
610 int len = snprintf( helpText, BufferSize, "%p = Malloc( %zu ) (allocated %zu)\n", area, size, tsize );
611 // int len = snprintf( helpText, BufferSize, "Malloc %p %zu\n", area, size );
612 __cfaabi_dbg_bits_write( helpText, len );
613 } // if
614 #endif // __CFA_DEBUG__
615
616 return area;
617} // doMalloc
618
619
620static inline void doFree( void * addr ) with ( heapManager ) {
621 #ifdef __CFA_DEBUG__
622 if ( unlikely( heapManager.heapBegin == 0 ) ) {
623 abort( "doFree( %p ) : internal error, called before heap is initialized.", addr );
624 } // if
625 #endif // __CFA_DEBUG__
626
627 HeapManager.Storage.Header * header;
628 HeapManager.FreeHeader * freeElem;
629 size_t size, alignment; // not used (see realloc)
630
631 if ( headers( "free", addr, header, freeElem, size, alignment ) ) { // mmapped ?
632 #ifdef __STATISTICS__
633 __atomic_add_fetch( &munmap_calls, 1, __ATOMIC_SEQ_CST );
634 __atomic_add_fetch( &munmap_storage, size, __ATOMIC_SEQ_CST );
635 #endif // __STATISTICS__
636 if ( munmap( header, size ) == -1 ) {
637 #ifdef __CFA_DEBUG__
638 abort( "Attempt to deallocate storage %p not allocated or with corrupt header.\n"
639 "Possible cause is invalid pointer.",
640 addr );
641 #endif // __CFA_DEBUG__
642 } // if
643 } else {
644 #ifdef __CFA_DEBUG__
645 // Set free memory to garbage so subsequent usages might fail.
646 memset( ((HeapManager.Storage *)header)->data, '\377', freeElem->blockSize - sizeof( HeapManager.Storage ) );
647 #endif // __CFA_DEBUG__
648
649 #ifdef __STATISTICS__
650 free_storage += size;
651 #endif // __STATISTICS__
652 #if defined( SPINLOCK )
653 lock( freeElem->lock __cfaabi_dbg_ctx2 ); // acquire spin lock
654 header->kind.real.next = freeElem->freeList; // push on stack
655 freeElem->freeList = (HeapManager.Storage *)header;
656 unlock( freeElem->lock ); // release spin lock
657 #else
658 freeElem->freeList.push( *(HeapManager.Storage *)header );
659 #endif // SPINLOCK
660 } // if
661
662 #ifdef __CFA_DEBUG__
663 __atomic_add_fetch( &allocFree, -size, __ATOMIC_SEQ_CST );
664 if ( traceHeap() ) {
665 char helpText[64];
666 int len = snprintf( helpText, sizeof(helpText), "Free( %p ) size:%zu\n", addr, size );
667 __cfaabi_dbg_bits_write( helpText, len );
668 } // if
669 #endif // __CFA_DEBUG__
670} // doFree
671
672
673size_t checkFree( HeapManager & manager ) with ( manager ) {
674 size_t total = 0;
675 #ifdef __STATISTICS__
676 __cfaabi_dbg_bits_acquire();
677 __cfaabi_dbg_bits_print_nolock( "\nBin lists (bin size : free blocks on list)\n" );
678 #endif // __STATISTICS__
679 for ( unsigned int i = 0; i < maxBucketsUsed; i += 1 ) {
680 size_t size = freeLists[i].blockSize;
681 #ifdef __STATISTICS__
682 unsigned int N = 0;
683 #endif // __STATISTICS__
684
685 #if defined( SPINLOCK )
686 for ( HeapManager.Storage * p = freeLists[i].freeList; p != 0; p = p->header.kind.real.next ) {
687 #else
688 for ( HeapManager.Storage * p = freeLists[i].freeList.top(); p != 0; p = p->header.kind.real.next.top ) {
689 #endif // SPINLOCK
690 total += size;
691 #ifdef __STATISTICS__
692 N += 1;
693 #endif // __STATISTICS__
694 } // for
695
696 #ifdef __STATISTICS__
697 __cfaabi_dbg_bits_print_nolock( "%7zu, %-7u ", size, N );
698 if ( (i + 1) % 8 == 0 ) __cfaabi_dbg_bits_print_nolock( "\n" );
699 #endif // __STATISTICS__
700 } // for
701 #ifdef __STATISTICS__
702 __cfaabi_dbg_bits_print_nolock( "\ntotal free blocks:%zu\n", total );
703 __cfaabi_dbg_bits_release();
704 #endif // __STATISTICS__
705 return (char *)heapEnd - (char *)heapBegin - total;
706} // checkFree
707
708// #comment TD : This is not a good name, plus this feels like it could easily be folded into doMalloc
709static inline void * malloc2( size_t size ) { // necessary for malloc statistics
710 assert( heapManager.heapBegin != 0 );
711 void * area = doMalloc( size );
712 if ( unlikely( area == 0 ) ) errno = ENOMEM; // POSIX
713 return area;
714} // malloc2
715
716
717static inline void * memalign2( size_t alignment, size_t size ) { // necessary for malloc statistics
718#ifdef __CFA_DEBUG__
719 checkAlign( alignment ); // check alignment
720#endif // __CFA_DEBUG__
721
722 // if alignment <= default alignment, do normal malloc as two headers are unnecessary
723 if ( unlikely( alignment <= libAlign() ) ) return malloc2( size );
724
725 // Allocate enough storage to guarantee an address on the alignment boundary, and sufficient space before it for
726 // administrative storage. NOTE, WHILE THERE ARE 2 HEADERS, THE FIRST ONE IS IMPLICITLY CREATED BY DOMALLOC.
727 // .-------------v-----------------v----------------v----------,
728 // | Real Header | ... padding ... | Fake Header | data ... |
729 // `-------------^-----------------^-+--------------^----------'
730 // |<--------------------------------' offset/align |<-- alignment boundary
731
732 // subtract libAlign() because it is already the minimum alignment
733 // add sizeof(Storage) for fake header
734 // #comment TD : this is the only place that calls doMalloc without calling malloc2, why ?
735 char * area = (char *)doMalloc( size + alignment - libAlign() + sizeof(HeapManager.Storage) );
736 if ( unlikely( area == 0 ) ) return area;
737
738 // address in the block of the "next" alignment address
739 char * user = (char *)libCeiling( (uintptr_t)(area + sizeof(HeapManager.Storage)), alignment );
740
741 // address of header from malloc
742 HeapManager.Storage.Header * realHeader = headerAddr( area );
743 // address of fake header * before* the alignment location
744 HeapManager.Storage.Header * fakeHeader = headerAddr( user );
745 // SKULLDUGGERY: insert the offset to the start of the actual storage block and remember alignment
746 fakeHeader->kind.fake.offset = (char *)fakeHeader - (char *)realHeader;
747 // SKULLDUGGERY: odd alignment imples fake header
748 fakeHeader->kind.fake.alignment = alignment | 1;
749
750 return user;
751} // memalign2
752
753
754extern "C" {
755 // The malloc() function allocates size bytes and returns a pointer to the
756 // allocated memory. The memory is not initialized. If size is 0, then malloc()
757 // returns either NULL, or a unique pointer value that can later be successfully
758 // passed to free().
759 void * malloc( size_t size ) {
760 #ifdef __STATISTICS__
761 __atomic_add_fetch( &malloc_calls, 1, __ATOMIC_SEQ_CST );
762 __atomic_add_fetch( &malloc_storage, size, __ATOMIC_SEQ_CST );
763 #endif // __STATISTICS__
764
765 return malloc2( size );
766 } // malloc
767
768 // The calloc() function allocates memory for an array of nmemb elements of
769 // size bytes each and returns a pointer to the allocated memory. The memory
770 // is set to zero. If nmemb or size is 0, then calloc() returns either NULL,
771 // or a unique pointer value that can later be successfully passed to free().
772 void * calloc( size_t noOfElems, size_t elemSize ) {
773 size_t size = noOfElems * elemSize;
774 #ifdef __STATISTICS__
775 __atomic_add_fetch( &calloc_calls, 1, __ATOMIC_SEQ_CST );
776 __atomic_add_fetch( &calloc_storage, size, __ATOMIC_SEQ_CST );
777 #endif // __STATISTICS__
778
779 char * area = (char *)malloc2( size );
780 if ( unlikely( area == 0 ) ) return 0;
781
782 HeapManager.Storage.Header * header;
783 HeapManager.FreeHeader * freeElem;
784 size_t asize, alignment;
785 bool mapped __attribute__(( unused )) = headers( "calloc", area, header, freeElem, asize, alignment );
786 #ifndef __CFA_DEBUG__
787 // Mapped storage is zero filled, but in debug mode mapped memory is scrubbed in doMalloc, so it has to be reset to zero.
788 if ( ! mapped )
789 #endif // __CFA_DEBUG__
790 memset( area, '\0', asize - sizeof(HeapManager.Storage) ); // set to zeros
791
792 header->kind.real.blockSize |= 2; // mark as zero filled
793 return area;
794 } // calloc
795
796 // #comment TD : Document this function
797 void * cmemalign( size_t alignment, size_t noOfElems, size_t elemSize ) {
798 size_t size = noOfElems * elemSize;
799 #ifdef __STATISTICS__
800 __atomic_add_fetch( &cmemalign_calls, 1, __ATOMIC_SEQ_CST );
801 __atomic_add_fetch( &cmemalign_storage, size, __ATOMIC_SEQ_CST );
802 #endif // __STATISTICS__
803
804 char * area = (char *)memalign2( alignment, size );
805 if ( unlikely( area == 0 ) ) return 0;
806 HeapManager.Storage.Header * header;
807 HeapManager.FreeHeader * freeElem;
808 size_t asize;
809 bool mapped __attribute__(( unused )) = headers( "cmemalign", area, header, freeElem, asize, alignment );
810 #ifndef __CFA_DEBUG__
811 // Mapped storage is zero filled, but in debug mode mapped memory is scrubbed in doMalloc, so it has to be reset to zero.
812 if ( ! mapped )
813 #endif // __CFA_DEBUG__
814 memset( area, '\0', asize - ( (char *)area - (char *)header ) ); // set to zeros
815 header->kind.real.blockSize |= 2; // mark as zero filled
816
817 return area;
818 } // cmemalign
819
820 // The realloc() function changes the size of the memory block pointed to by
821 // ptr to size bytes. The contents will be unchanged in the range from the
822 // start of the region up to the minimum of the old and new sizes. If the new
823 // size is larger than the old size, the added memory will not be initialized.
824 // If ptr is NULL, then the call is equivalent to malloc(size), for all values
825 // of size; if size is equal to zero, and ptr is not NULL, then the call is
826 // equivalent to free(ptr). Unless ptr is NULL, it must have been returned by
827 // an earlier call to malloc(), calloc() or realloc(). If the area pointed to
828 // was moved, a free(ptr) is done.
829 void * realloc( void * addr, size_t size ) {
830 #ifdef __STATISTICS__
831 __atomic_add_fetch( &realloc_calls, 1, __ATOMIC_SEQ_CST );
832 #endif // __STATISTICS__
833
834 if ( unlikely( addr == 0 ) ) return malloc2( size ); // special cases
835 if ( unlikely( size == 0 ) ) { free( addr ); return 0; }
836
837 HeapManager.Storage.Header * header;
838 HeapManager.FreeHeader * freeElem;
839 size_t asize, alignment = 0;
840 headers( "realloc", addr, header, freeElem, asize, alignment );
841
842 size_t usize = asize - ( (char *)addr - (char *)header ); // compute the amount of user storage in the block
843 if ( usize >= size ) { // already sufficient storage
844 // This case does not result in a new profiler entry because the previous one still exists and it must match with
845 // the free for this memory. Hence, this realloc does not appear in the profiler output.
846 return addr;
847 } // if
848
849 #ifdef __STATISTICS__
850 __atomic_add_fetch( &realloc_storage, size, __ATOMIC_SEQ_CST );
851 #endif // __STATISTICS__
852
853 void * area;
854 if ( unlikely( alignment != 0 ) ) { // previous request memalign?
855 area = memalign( alignment, size ); // create new area
856 } else {
857 area = malloc2( size ); // create new area
858 } // if
859 if ( unlikely( area == 0 ) ) return 0;
860 if ( unlikely( header->kind.real.blockSize & 2 ) ) { // previous request zero fill (calloc/cmemalign) ?
861 assert( (header->kind.real.blockSize & 1) == 0 );
862 bool mapped __attribute__(( unused )) = headers( "realloc", area, header, freeElem, asize, alignment );
863 #ifndef __CFA_DEBUG__
864 // Mapped storage is zero filled, but in debug mode mapped memory is scrubbed in doMalloc, so it has to be reset to zero.
865 if ( ! mapped )
866 #endif // __CFA_DEBUG__
867 memset( (char *)area + usize, '\0', asize - ( (char *)area - (char *)header ) - usize ); // zero-fill back part
868 header->kind.real.blockSize |= 2; // mark new request as zero fill
869 } // if
870 memcpy( area, addr, usize ); // copy bytes
871 free( addr );
872 return area;
873 } // realloc
874
875
876 // The obsolete function memalign() allocates size bytes and returns
877 // a pointer to the allocated memory. The memory address will be a
878 // multiple of alignment, which must be a power of two.
879 void * memalign( size_t alignment, size_t size ) __attribute__ ((deprecated));
880 void * memalign( size_t alignment, size_t size ) {
881 #ifdef __STATISTICS__
882 __atomic_add_fetch( &memalign_calls, 1, __ATOMIC_SEQ_CST );
883 __atomic_add_fetch( &memalign_storage, size, __ATOMIC_SEQ_CST );
884 #endif // __STATISTICS__
885
886 void * area = memalign2( alignment, size );
887
888 return area;
889 } // memalign
890
891 // The function aligned_alloc() is the same as memalign(), except for
892 // the added restriction that size should be a multiple of alignment.
893 void * aligned_alloc( size_t alignment, size_t size ) {
894 return memalign( alignment, size );
895 } // aligned_alloc
896
897
898 // The function posix_memalign() allocates size bytes and places the address
899 // of the allocated memory in *memptr. The address of the allocated memory
900 // will be a multiple of alignment, which must be a power of two and a multiple
901 // of sizeof(void *). If size is 0, then posix_memalign() returns either NULL,
902 // or a unique pointer value that can later be successfully passed to free(3).
903 int posix_memalign( void ** memptr, size_t alignment, size_t size ) {
904 if ( alignment < sizeof(void *) || ! libPow2( alignment ) ) return EINVAL; // check alignment
905 * memptr = memalign( alignment, size );
906 if ( unlikely( * memptr == 0 ) ) return ENOMEM;
907 return 0;
908 } // posix_memalign
909
910 // The obsolete function valloc() allocates size bytes and returns a pointer
911 // to the allocated memory. The memory address will be a multiple of the page size.
912 // It is equivalent to memalign(sysconf(_SC_PAGESIZE),size).
913 void * valloc( size_t size ) __attribute__ ((deprecated));
914 void * valloc( size_t size ) {
915 return memalign( pageSize, size );
916 } // valloc
917
918
919 // The free() function frees the memory space pointed to by ptr, which must
920 // have been returned by a previous call to malloc(), calloc() or realloc().
921 // Otherwise, or if free(ptr) has already been called before, undefined
922 // behavior occurs. If ptr is NULL, no operation is performed.
923 void free( void * addr ) {
924 #ifdef __STATISTICS__
925 __atomic_add_fetch( &free_calls, 1, __ATOMIC_SEQ_CST );
926 #endif // __STATISTICS__
927
928 // #comment TD : To decrease nesting I would but the special case in the
929 // else instead, plus it reads more naturally to have the
930 // short / normal case instead
931 if ( unlikely( addr == 0 ) ) { // special case
932 #ifdef __CFA_DEBUG__
933 if ( traceHeap() ) {
934 #define nullmsg "Free( 0x0 ) size:0\n"
935 // Do not debug print free( 0 ), as it can cause recursive entry from sprintf.
936 __cfaabi_dbg_bits_write( nullmsg, sizeof(nullmsg) - 1 );
937 } // if
938 #endif // __CFA_DEBUG__
939 return;
940 } // exit
941
942 doFree( addr );
943 } // free
944
945 // The mallopt() function adjusts parameters that control the behavior of the
946 // memory-allocation functions (see malloc(3)). The param argument specifies
947 // the parameter to be modified, and value specifies the new value for that
948 // parameter.
949 int mallopt( int option, int value ) {
950 choose( option ) {
951 case M_TOP_PAD:
952 if ( setHeapExpand( value ) ) fallthru default;
953 case M_MMAP_THRESHOLD:
954 if ( setMmapStart( value ) ) fallthru default;
955 default:
956 // #comment TD : 1 for unsopported feels wrong
957 return 1; // success, or unsupported
958 } // switch
959 return 0; // error
960 } // mallopt
961
962 // The malloc_trim() function attempts to release free memory at the top
963 // of the heap (by calling sbrk(2) with a suitable argument).
964 int malloc_trim( size_t ) {
965 return 0; // => impossible to release memory
966 } // malloc_trim
967
968 // The malloc_usable_size() function returns the number of usable bytes in the
969 // block pointed to by ptr, a pointer to a block of memory allocated by
970 // malloc(3) or a related function.
971 size_t malloc_usable_size( void * addr ) {
972 if ( unlikely( addr == 0 ) ) return 0; // null allocation has 0 size
973
974 HeapManager.Storage.Header * header;
975 HeapManager.FreeHeader * freeElem;
976 size_t size, alignment;
977
978 headers( "malloc_usable_size", addr, header, freeElem, size, alignment );
979 size_t usize = size - ( (char *)addr - (char *)header ); // compute the amount of user storage in the block
980 return usize;
981 } // malloc_usable_size
982
983
984 // #comment TD : Document this function
985 size_t malloc_alignment( void * addr ) {
986 if ( unlikely( addr == 0 ) ) return libAlign(); // minimum alignment
987 HeapManager.Storage.Header * header = (HeapManager.Storage.Header *)( (char *)addr - sizeof(HeapManager.Storage) );
988 if ( (header->kind.fake.alignment & 1) == 1 ) { // fake header ?
989 return header->kind.fake.alignment & -2; // remove flag from value
990 } else {
991 return libAlign (); // minimum alignment
992 } // if
993 } // malloc_alignment
994
995
996 // #comment TD : Document this function
997 bool malloc_zero_fill( void * addr ) {
998 if ( unlikely( addr == 0 ) ) return false; // null allocation is not zero fill
999
1000 HeapManager.Storage.Header * header = (HeapManager.Storage.Header *)( (char *)addr - sizeof(HeapManager.Storage) );
1001 if ( (header->kind.fake.alignment & 1) == 1 ) { // fake header ?
1002 header = (HeapManager.Storage.Header *)((char *)header - header->kind.fake.offset);
1003 } // if
1004 return (header->kind.real.blockSize & 2) != 0; // zero filled (calloc/cmemalign) ?
1005 } // malloc_zero_fill
1006
1007
1008 // #comment TD : Document this function
1009 void malloc_stats( void ) {
1010 #ifdef __STATISTICS__
1011 printStats();
1012 if ( checkFree() ) checkFree( heapManager );
1013 #endif // __STATISTICS__
1014 } // malloc_stats
1015
1016 // #comment TD : Document this function
1017 int malloc_stats_fd( int fd ) {
1018 #ifdef __STATISTICS__
1019 int temp = statfd;
1020 statfd = fd;
1021 return temp;
1022 #else
1023 return -1;
1024 #endif // __STATISTICS__
1025 } // malloc_stats_fd
1026
1027
1028 // #comment TD : Document this function
1029 int malloc_info( int options, FILE * stream ) {
1030 return printStatsXML( stream );
1031 } // malloc_info
1032
1033
1034 // #comment TD : What are these two functions for?
1035 void * malloc_get_state( void ) {
1036 return 0;
1037 } // malloc_get_state
1038
1039 int malloc_set_state( void * ptr ) {
1040 return 0;
1041 } // malloc_set_state
1042} // extern "C"
1043
1044
1045// Local Variables: //
1046// tab-width: 4 //
1047// compile-command: "cfa -nodebug -O2 heap.c" //
1048// End: //
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