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comparison: build/stlport/src/allocators.cpp

build/stlport/src/allocators.cpp

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1 /*
2 *
3 * Copyright (c) 1996,1997
4 * Silicon Graphics Computer Systems, Inc.
5 *
6 * Copyright (c) 1997
7 * Moscow Center for SPARC Technology
8 *
9 * Copyright (c) 1999
10 * Boris Fomitchev
11 *
12 * This material is provided "as is", with absolutely no warranty expressed
13 * or implied. Any use is at your own risk.
14 *
15 * Permission to use or copy this software for any purpose is hereby granted
16 * without fee, provided the above notices are retained on all copies.
17 * Permission to modify the code and to distribute modified code is granted,
18 * provided the above notices are retained, and a notice that the code was
19 * modified is included with the above copyright notice.
20 *
21 */
22
23 #include "stlport_prefix.h"
24
25 #include <memory>
26
27 #if defined (__GNUC__) && (defined (__CYGWIN__) || defined (__MINGW32__))
28 # include <malloc.h>
29 #endif
30
31 #if defined (_STLP_PTHREADS) && !defined (_STLP_NO_THREADS)
32 # include <pthread_alloc>
33 # include <cerrno>
34 #endif
35
36 #include <stl/_threads.h>
37
38 #include "lock_free_slist.h"
39
40 #if defined (__WATCOMC__)
41 # pragma warning 13 9
42 # pragma warning 367 9
43 # pragma warning 368 9
44 #endif
45
46 #if defined (_STLP_SGI_THREADS)
47 // We test whether threads are in use before locking.
48 // Perhaps this should be moved into stl_threads.h, but that
49 // probably makes it harder to avoid the procedure call when
50 // it isn't needed.
51 extern "C" {
52 extern int __us_rsthread_malloc;
53 }
54 #endif
55
56 // Specialised debug form of new operator which does not provide "false"
57 // memory leaks when run with debug CRT libraries.
58 #if defined (_STLP_MSVC) && (_STLP_MSVC >= 1020 && defined (_STLP_DEBUG_ALLOC)) && !defined (_STLP_WCE)
59 # include <crtdbg.h>
60 inline char* __stlp_new_chunk(size_t __bytes) {
61 void *__chunk = _STLP_CHECK_NULL_ALLOC(::operator new(__bytes, __FILE__, __LINE__));
62 return __STATIC_CAST(char*, __chunk);
63 }
64 inline void __stlp_delete_chunck(void* __p) { ::operator delete(__p, __FILE__, __LINE__); }
65 #else
66 # ifdef _STLP_NODE_ALLOC_USE_MALLOC
67 # include <cstdlib>
68 inline char* __stlp_new_chunk(size_t __bytes) {
69 // do not use _STLP_CHECK_NULL_ALLOC, this macro is dedicated to new operator.
70 void *__chunk = _STLP_VENDOR_CSTD::malloc(__bytes);
71 if (__chunk == 0) {
72 _STLP_THROW_BAD_ALLOC;
73 }
74 return __STATIC_CAST(char*, __chunk);
75 }
76 inline void __stlp_delete_chunck(void* __p) { _STLP_VENDOR_CSTD::free(__p); }
77 # else
78 inline char* __stlp_new_chunk(size_t __bytes)
79 { return __STATIC_CAST(char*, _STLP_STD::__stl_new(__bytes)); }
80 inline void __stlp_delete_chunck(void* __p) { _STLP_STD::__stl_delete(__p); }
81 # endif
82 #endif
83
84 /* This is an additional atomic operations to the ones already defined in
85 * stl/_threads.h, platform should try to support it to improve performance.
86 * __add_atomic_t _STLP_ATOMIC_ADD(volatile __add_atomic_t* __target, __add_atomic_t __val) :
87 * does *__target = *__target + __val and returns the old *__target value */
88 typedef long __add_atomic_t;
89 typedef unsigned long __uadd_atomic_t;
90
91 #if defined (__GNUC__) && defined (__i386__)
92 inline long _STLP_atomic_add_gcc_x86(long volatile* p, long addend) {
93 long result;
94 __asm__ __volatile__
95 ("lock; xaddl %1, %0;"
96 :"=m" (*p), "=r" (result)
97 :"m" (*p), "1" (addend)
98 :"cc");
99 return result + addend;
100 }
101 # define _STLP_ATOMIC_ADD(__dst, __val) _STLP_atomic_add_gcc_x86(__dst, __val)
102 #elif defined (_STLP_WIN32THREADS)
103 // The Win32 API function InterlockedExchangeAdd is not available on Windows 95.
104 # if !defined (_STLP_WIN95_LIKE)
105 # if defined (_STLP_NEW_PLATFORM_SDK)
106 # define _STLP_ATOMIC_ADD(__dst, __val) InterlockedExchangeAdd(__dst, __val)
107 # else
108 # define _STLP_ATOMIC_ADD(__dst, __val) InterlockedExchangeAdd(__CONST_CAST(__add_atomic_t*, __dst), __val)
109 # endif
110 # endif
111 #endif
112
113 #if defined (__OS400__)
114 // dums 02/05/2007: is it really necessary ?
115 enum { _ALIGN = 16, _ALIGN_SHIFT = 4 };
116 #else
117 enum { _ALIGN = 2 * sizeof(void*), _ALIGN_SHIFT = 2 + sizeof(void*) / 4 };
118 #endif
119
120 #define _S_FREELIST_INDEX(__bytes) ((__bytes - size_t(1)) >> (int)_ALIGN_SHIFT)
121
122 _STLP_BEGIN_NAMESPACE
123
124 // malloc_alloc out-of-memory handling
125 static __oom_handler_type __oom_handler = __STATIC_CAST(__oom_handler_type, 0);
126
127 #ifdef _STLP_THREADS
128 _STLP_mutex __oom_handler_lock;
129 #endif
130
131 void* _STLP_CALL __malloc_alloc::allocate(size_t __n)
132 {
133 void *__result = malloc(__n);
134 if ( 0 == __result ) {
135 __oom_handler_type __my_malloc_handler;
136
137 for (;;) {
138 {
139 #ifdef _STLP_THREADS
140 _STLP_auto_lock _l( __oom_handler_lock );
141 #endif
142 __my_malloc_handler = __oom_handler;
143 }
144 if ( 0 == __my_malloc_handler) {
145 _STLP_THROW_BAD_ALLOC;
146 }
147 (*__my_malloc_handler)();
148 __result = malloc(__n);
149 if ( __result )
150 return __result;
151 }
152 }
153 return __result;
154 }
155
156 __oom_handler_type _STLP_CALL __malloc_alloc::set_malloc_handler(__oom_handler_type __f)
157 {
158 #ifdef _STLP_THREADS
159 _STLP_auto_lock _l( __oom_handler_lock );
160 #endif
161 __oom_handler_type __old = __oom_handler;
162 __oom_handler = __f;
163 return __old;
164 }
165
166 // *******************************************************
167 // Default node allocator.
168 // With a reasonable compiler, this should be roughly as fast as the
169 // original STL class-specific allocators, but with less fragmentation.
170 //
171 // Important implementation properties:
172 // 1. If the client request an object of size > _MAX_BYTES, the resulting
173 // object will be obtained directly from malloc.
174 // 2. In all other cases, we allocate an object of size exactly
175 // _S_round_up(requested_size). Thus the client has enough size
176 // information that we can return the object to the proper free list
177 // without permanently losing part of the object.
178 //
179
180 #define _STLP_NFREELISTS 16
181
182 #if defined (_STLP_LEAKS_PEDANTIC) && defined (_STLP_USE_DYNAMIC_LIB)
183 /*
184 * We can only do cleanup of the node allocator memory pool if we are
185 * sure that the STLport library is used as a shared one as it guaranties
186 * the unicity of the node allocator instance. Without that guaranty node
187 * allocator instances might exchange memory blocks making the implementation
188 * of a cleaning process much more complicated.
189 */
190 # define _STLP_DO_CLEAN_NODE_ALLOC
191 #endif
192
193 /* When STLport is used without multi threaded safety we use the node allocator
194 * implementation with locks as locks becomes no-op. The lock free implementation
195 * always use system specific atomic operations which are slower than 'normal'
196 * ones.
197 */
198 #if defined (_STLP_THREADS) && \
199 defined (_STLP_HAS_ATOMIC_FREELIST) && defined (_STLP_ATOMIC_ADD)
200 /*
201 * We have an implementation of the atomic freelist (_STLP_atomic_freelist)
202 * for this architecture and compiler. That means we can use the non-blocking
203 * implementation of the node-allocation engine.*/
204 # define _STLP_USE_LOCK_FREE_IMPLEMENTATION
205 #endif
206
207 #if !defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)
208 # if defined (_STLP_THREADS)
209
210 class _Node_Alloc_Lock {
211 static _STLP_STATIC_MUTEX& _S_Mutex() {
212 static _STLP_STATIC_MUTEX mutex _STLP_MUTEX_INITIALIZER;
213 return mutex;
214 }
215 public:
216 _Node_Alloc_Lock() {
217 # if defined (_STLP_SGI_THREADS)
218 if (__us_rsthread_malloc)
219 # endif
220 _S_Mutex()._M_acquire_lock();
221 }
222
223 ~_Node_Alloc_Lock() {
224 # if defined (_STLP_SGI_THREADS)
225 if (__us_rsthread_malloc)
226 # endif
227 _S_Mutex()._M_release_lock();
228 }
229 };
230
231 # else
232
233 class _Node_Alloc_Lock {
234 public:
235 _Node_Alloc_Lock() { }
236 ~_Node_Alloc_Lock() { }
237 };
238
239 # endif
240
241 struct _Node_alloc_obj {
242 _Node_alloc_obj * _M_next;
243 };
244 #endif
245
246 class __node_alloc_impl {
247 static inline size_t _STLP_CALL _S_round_up(size_t __bytes)
248 { return (((__bytes) + (size_t)_ALIGN-1) & ~((size_t)_ALIGN - 1)); }
249
250 #if defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)
251 typedef _STLP_atomic_freelist::item _Obj;
252 typedef _STLP_atomic_freelist _Freelist;
253 typedef _STLP_atomic_freelist _ChunkList;
254
255 // Header of blocks of memory that have been allocated as part of
256 // a larger chunk but have not yet been chopped up into nodes.
257 struct _FreeBlockHeader : public _STLP_atomic_freelist::item {
258 char* _M_end; // pointer to end of free memory
259 };
260 #else
261 typedef _Node_alloc_obj _Obj;
262 typedef _Obj* _STLP_VOLATILE _Freelist;
263 typedef _Obj* _ChunkList;
264 #endif
265
266 private:
267 // Returns an object of size __n, and optionally adds to size __n free list.
268 static _Obj* _S_refill(size_t __n);
269 // Allocates a chunk for nobjs of size __p_size. nobjs may be reduced
270 // if it is inconvenient to allocate the requested number.
271 static char* _S_chunk_alloc(size_t __p_size, int& __nobjs);
272 // Chunk allocation state.
273 static _Freelist _S_free_list[_STLP_NFREELISTS];
274 // Amount of total allocated memory
275 #if defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)
276 static _STLP_VOLATILE __add_atomic_t _S_heap_size;
277 #else
278 static size_t _S_heap_size;
279 #endif
280
281 #if defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)
282 // List of blocks of free memory
283 static _STLP_atomic_freelist _S_free_mem_blocks;
284 #else
285 // Start of the current free memory buffer
286 static char* _S_start_free;
287 // End of the current free memory buffer
288 static char* _S_end_free;
289 #endif
290
291 #if defined (_STLP_DO_CLEAN_NODE_ALLOC)
292 public:
293 // Methods to report alloc/dealloc calls to the counter system.
294 # if defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)
295 typedef _STLP_VOLATILE __stl_atomic_t _AllocCounter;
296 # else
297 typedef __stl_atomic_t _AllocCounter;
298 # endif
299 static _AllocCounter& _STLP_CALL _S_alloc_counter();
300 static void _S_alloc_call();
301 static void _S_dealloc_call();
302
303 private:
304 // Free all the allocated chuncks of memory
305 static void _S_chunk_dealloc();
306 // Beginning of the linked list of allocated chunks of memory
307 static _ChunkList _S_chunks;
308 #endif /* _STLP_DO_CLEAN_NODE_ALLOC */
309
310 public:
311 /* __n must be > 0 */
312 static void* _M_allocate(size_t& __n);
313 /* __p may not be 0 */
314 static void _M_deallocate(void *__p, size_t __n);
315 };
316
317 #if !defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)
318 void* __node_alloc_impl::_M_allocate(size_t& __n) {
319 __n = _S_round_up(__n);
320 _Obj * _STLP_VOLATILE * __my_free_list = _S_free_list + _S_FREELIST_INDEX(__n);
321 _Obj *__r;
322
323 // Acquire the lock here with a constructor call.
324 // This ensures that it is released in exit or during stack
325 // unwinding.
326 _Node_Alloc_Lock __lock_instance;
327
328 if ( (__r = *__my_free_list) != 0 ) {
329 *__my_free_list = __r->_M_next;
330 } else {
331 __r = _S_refill(__n);
332 }
333 # if defined (_STLP_DO_CLEAN_NODE_ALLOC)
334 _S_alloc_call();
335 # endif
336 // lock is released here
337 return __r;
338 }
339
340 void __node_alloc_impl::_M_deallocate(void *__p, size_t __n) {
341 _Obj * _STLP_VOLATILE * __my_free_list = _S_free_list + _S_FREELIST_INDEX(__n);
342 _Obj * __pobj = __STATIC_CAST(_Obj*, __p);
343
344 // acquire lock
345 _Node_Alloc_Lock __lock_instance;
346 __pobj->_M_next = *__my_free_list;
347 *__my_free_list = __pobj;
348
349 # if defined (_STLP_DO_CLEAN_NODE_ALLOC)
350 _S_dealloc_call();
351 # endif
352 // lock is released here
353 }
354
355 # if defined (_STLP_DO_CLEAN_NODE_ALLOC)
356 # define _STLP_OFFSET sizeof(_Obj)
357 # else
358 # define _STLP_OFFSET 0
359 # endif
360
361 /* We allocate memory in large chunks in order to avoid fragmenting */
362 /* the malloc heap too much. */
363 /* We assume that size is properly aligned. */
364 /* We hold the allocation lock. */
365 char* __node_alloc_impl::_S_chunk_alloc(size_t _p_size, int& __nobjs) {
366 char* __result;
367 size_t __total_bytes = _p_size * __nobjs;
368 size_t __bytes_left = _S_end_free - _S_start_free;
369
370 if (__bytes_left > 0) {
371 if (__bytes_left >= __total_bytes) {
372 __result = _S_start_free;
373 _S_start_free += __total_bytes;
374 return __result;
375 }
376
377 if (__bytes_left >= _p_size) {
378 __nobjs = (int)(__bytes_left / _p_size);
379 __total_bytes = _p_size * __nobjs;
380 __result = _S_start_free;
381 _S_start_free += __total_bytes;
382 return __result;
383 }
384
385 // Try to make use of the left-over piece.
386 _Obj* _STLP_VOLATILE* __my_free_list = _S_free_list + _S_FREELIST_INDEX(__bytes_left);
387 __REINTERPRET_CAST(_Obj*, _S_start_free)->_M_next = *__my_free_list;
388 *__my_free_list = __REINTERPRET_CAST(_Obj*, _S_start_free);
389 _S_start_free = _S_end_free = 0;
390 }
391
392 size_t __bytes_to_get = 2 * __total_bytes + _S_round_up(_S_heap_size) + _STLP_OFFSET;
393
394 _STLP_TRY {
395 _S_start_free = __stlp_new_chunk(__bytes_to_get);
396 }
397 #if defined (_STLP_USE_EXCEPTIONS)
398 catch (const _STLP_STD::bad_alloc&) {
399 _Obj* _STLP_VOLATILE* __my_free_list;
400 _Obj* __p;
401 // Try to do with what we have. That can't hurt.
402 // We do not try smaller requests, since that tends
403 // to result in disaster on multi-process machines.
404 for (size_t __i = _p_size; __i <= (size_t)_MAX_BYTES; __i += (size_t)_ALIGN) {
405 __my_free_list = _S_free_list + _S_FREELIST_INDEX(__i);
406 __p = *__my_free_list;
407 if (0 != __p) {
408 *__my_free_list = __p -> _M_next;
409 _S_start_free = __REINTERPRET_CAST(char*, __p);
410 _S_end_free = _S_start_free + __i;
411 return _S_chunk_alloc(_p_size, __nobjs);
412 // Any leftover piece will eventually make it to the
413 // right free list.
414 }
415 }
416 __bytes_to_get = __total_bytes + _STLP_OFFSET;
417 _S_start_free = __stlp_new_chunk(__bytes_to_get);
418 }
419 #endif
420
421 _S_heap_size += __bytes_to_get >> 4;
422 # if defined (_STLP_DO_CLEAN_NODE_ALLOC)
423 __REINTERPRET_CAST(_Obj*, _S_start_free)->_M_next = _S_chunks;
424 _S_chunks = __REINTERPRET_CAST(_Obj*, _S_start_free);
425 # endif
426 _S_end_free = _S_start_free + __bytes_to_get;
427 _S_start_free += _STLP_OFFSET;
428 return _S_chunk_alloc(_p_size, __nobjs);
429 }
430
431 /* Returns an object of size __n, and optionally adds to size __n free list.*/
432 /* We assume that __n is properly aligned. */
433 /* We hold the allocation lock. */
434 _Node_alloc_obj* __node_alloc_impl::_S_refill(size_t __n) {
435 int __nobjs = 20;
436 char* __chunk = _S_chunk_alloc(__n, __nobjs);
437
438 if (1 == __nobjs) return __REINTERPRET_CAST(_Obj*, __chunk);
439
440 _Obj* _STLP_VOLATILE* __my_free_list = _S_free_list + _S_FREELIST_INDEX(__n);
441 _Obj* __result;
442 _Obj* __current_obj;
443 _Obj* __next_obj;
444
445 /* Build free list in chunk */
446 __result = __REINTERPRET_CAST(_Obj*, __chunk);
447 *__my_free_list = __next_obj = __REINTERPRET_CAST(_Obj*, __chunk + __n);
448 for (--__nobjs; --__nobjs; ) {
449 __current_obj = __next_obj;
450 __next_obj = __REINTERPRET_CAST(_Obj*, __REINTERPRET_CAST(char*, __next_obj) + __n);
451 __current_obj->_M_next = __next_obj;
452 }
453 __next_obj->_M_next = 0;
454 return __result;
455 }
456
457 # if defined (_STLP_DO_CLEAN_NODE_ALLOC)
458 void __node_alloc_impl::_S_alloc_call()
459 { ++_S_alloc_counter(); }
460
461 void __node_alloc_impl::_S_dealloc_call() {
462 __stl_atomic_t &counter = _S_alloc_counter();
463 if (--counter == 0)
464 { _S_chunk_dealloc(); }
465 }
466
467 /* We deallocate all the memory chunks */
468 void __node_alloc_impl::_S_chunk_dealloc() {
469 _Obj *__pcur = _S_chunks, *__pnext;
470 while (__pcur != 0) {
471 __pnext = __pcur->_M_next;
472 __stlp_delete_chunck(__pcur);
473 __pcur = __pnext;
474 }
475 _S_chunks = 0;
476 _S_start_free = _S_end_free = 0;
477 _S_heap_size = 0;
478 memset(__REINTERPRET_CAST(char*, __CONST_CAST(_Obj**, &_S_free_list[0])), 0, _STLP_NFREELISTS * sizeof(_Obj*));
479 }
480 # endif
481
482 #else
483
484 void* __node_alloc_impl::_M_allocate(size_t& __n) {
485 __n = _S_round_up(__n);
486 _Obj* __r = _S_free_list[_S_FREELIST_INDEX(__n)].pop();
487 if (__r == 0)
488 { __r = _S_refill(__n); }
489
490 # if defined (_STLP_DO_CLEAN_NODE_ALLOC)
491 _S_alloc_call();
492 # endif
493 return __r;
494 }
495
496 void __node_alloc_impl::_M_deallocate(void *__p, size_t __n) {
497 _S_free_list[_S_FREELIST_INDEX(__n)].push(__STATIC_CAST(_Obj*, __p));
498
499 # if defined (_STLP_DO_CLEAN_NODE_ALLOC)
500 _S_dealloc_call();
501 # endif
502 }
503
504 /* Returns an object of size __n, and optionally adds additional ones to */
505 /* freelist of objects of size __n. */
506 /* We assume that __n is properly aligned. */
507 __node_alloc_impl::_Obj* __node_alloc_impl::_S_refill(size_t __n) {
508 int __nobjs = 20;
509 char* __chunk = _S_chunk_alloc(__n, __nobjs);
510
511 if (__nobjs <= 1)
512 return __REINTERPRET_CAST(_Obj*, __chunk);
513
514 // Push all new nodes (minus first one) onto freelist
515 _Obj* __result = __REINTERPRET_CAST(_Obj*, __chunk);
516 _Obj* __cur_item = __result;
517 _Freelist* __my_freelist = _S_free_list + _S_FREELIST_INDEX(__n);
518 for (--__nobjs; __nobjs != 0; --__nobjs) {
519 __cur_item = __REINTERPRET_CAST(_Obj*, __REINTERPRET_CAST(char*, __cur_item) + __n);
520 __my_freelist->push(__cur_item);
521 }
522 return __result;
523 }
524
525 # if defined (_STLP_DO_CLEAN_NODE_ALLOC)
526 # define _STLP_OFFSET _ALIGN
527 # else
528 # define _STLP_OFFSET 0
529 # endif
530
531 /* We allocate memory in large chunks in order to avoid fragmenting */
532 /* the malloc heap too much. */
533 /* We assume that size is properly aligned. */
534 char* __node_alloc_impl::_S_chunk_alloc(size_t _p_size, int& __nobjs) {
535 # if defined (_STLP_DO_CLEAN_NODE_ALLOC)
536 //We are going to add a small memory block to keep all the allocated blocks
537 //address, we need to do so respecting the memory alignment. The following
538 //static assert checks that the reserved block is big enough to store a pointer.
539 _STLP_STATIC_ASSERT(sizeof(_Obj) <= _ALIGN)
540 # endif
541 char* __result = 0;
542 __add_atomic_t __total_bytes = __STATIC_CAST(__add_atomic_t, _p_size) * __nobjs;
543
544 _FreeBlockHeader* __block = __STATIC_CAST(_FreeBlockHeader*, _S_free_mem_blocks.pop());
545 if (__block != 0) {
546 // We checked a block out and can now mess with it with impugnity.
547 // We'll put the remainder back into the list if we're done with it below.
548 char* __buf_start = __REINTERPRET_CAST(char*, __block);
549 __add_atomic_t __bytes_left = __block->_M_end - __buf_start;
550
551 if ((__bytes_left < __total_bytes) && (__bytes_left >= __STATIC_CAST(__add_atomic_t, _p_size))) {
552 // There's enough left for at least one object, but not as much as we wanted
553 __result = __buf_start;
554 __nobjs = (int)(__bytes_left/_p_size);
555 __total_bytes = __STATIC_CAST(__add_atomic_t, _p_size) * __nobjs;
556 __bytes_left -= __total_bytes;
557 __buf_start += __total_bytes;
558 }
559 else if (__bytes_left >= __total_bytes) {
560 // The block has enough left to satisfy all that was asked for
561 __result = __buf_start;
562 __bytes_left -= __total_bytes;
563 __buf_start += __total_bytes;
564 }
565
566 if (__bytes_left != 0) {
567 // There is still some memory left over in block after we satisfied our request.
568 if ((__result != 0) && (__bytes_left >= (__add_atomic_t)sizeof(_FreeBlockHeader))) {
569 // We were able to allocate at least one object and there is still enough
570 // left to put remainder back into list.
571 _FreeBlockHeader* __newblock = __REINTERPRET_CAST(_FreeBlockHeader*, __buf_start);
572 __newblock->_M_end = __block->_M_end;
573 _S_free_mem_blocks.push(__newblock);
574 }
575 else {
576 // We were not able to allocate enough for at least one object.
577 // Shove into freelist of nearest (rounded-down!) size.
578 size_t __rounded_down = _S_round_up(__bytes_left + 1) - (size_t)_ALIGN;
579 if (__rounded_down > 0)
580 _S_free_list[_S_FREELIST_INDEX(__rounded_down)].push((_Obj*)__buf_start);
581 }
582 }
583 if (__result != 0)
584 return __result;
585 }
586
587 // We couldn't satisfy it from the list of free blocks, get new memory.
588 __add_atomic_t __bytes_to_get = 2 * __total_bytes +
589 __STATIC_CAST(__add_atomic_t,
590 _S_round_up(__STATIC_CAST(__uadd_atomic_t, _STLP_ATOMIC_ADD(&_S_heap_size, 0)))) +
591 _STLP_OFFSET;
592 _STLP_TRY {
593 __result = __stlp_new_chunk(__bytes_to_get);
594 }
595 #if defined (_STLP_USE_EXCEPTIONS)
596 catch (const bad_alloc&) {
597 // Allocation failed; try to canibalize from freelist of a larger object size.
598 for (size_t __i = _p_size; __i <= (size_t)_MAX_BYTES; __i += (size_t)_ALIGN) {
599 _Obj* __p = _S_free_list[_S_FREELIST_INDEX(__i)].pop();
600 if (0 != __p) {
601 if (__i < sizeof(_FreeBlockHeader)) {
602 // Not enough to put into list of free blocks, divvy it up here.
603 // Use as much as possible for this request and shove remainder into freelist.
604 __nobjs = (int)(__i/_p_size);
605 __total_bytes = __nobjs * __STATIC_CAST(__add_atomic_t, _p_size);
606 size_t __bytes_left = __i - __total_bytes;
607 size_t __rounded_down = _S_round_up(__bytes_left+1) - (size_t)_ALIGN;
608 if (__rounded_down > 0) {
609 _S_free_list[_S_FREELIST_INDEX(__rounded_down)].push(__REINTERPRET_CAST(_Obj*, __REINTERPRET_CAST(char*, __p) + __total_bytes));
610 }
611 return __REINTERPRET_CAST(char*, __p);
612 }
613 else {
614 // Add node to list of available blocks and recursively allocate from it.
615 _FreeBlockHeader* __newblock = (_FreeBlockHeader*)__p;
616 __newblock->_M_end = __REINTERPRET_CAST(char*, __p) + __i;
617 _S_free_mem_blocks.push(__newblock);
618 return _S_chunk_alloc(_p_size, __nobjs);
619 }
620 }
621 }
622
623 // We were not able to find something in a freelist, try to allocate a smaller amount.
624 __bytes_to_get = __total_bytes + _STLP_OFFSET;
625 __result = __stlp_new_chunk(__bytes_to_get);
626
627 // This should either throw an exception or remedy the situation.
628 // Thus we assume it succeeded.
629 }
630 #endif
631 // Alignment check
632 _STLP_VERBOSE_ASSERT(((__REINTERPRET_CAST(size_t, __result) & __STATIC_CAST(size_t, _ALIGN - 1)) == 0),
633 _StlMsg_DBA_DELETED_TWICE)
634 _STLP_ATOMIC_ADD(&_S_heap_size, __bytes_to_get >> 4);
635
636 # if defined (_STLP_DO_CLEAN_NODE_ALLOC)
637 // We have to track the allocated memory chunks for release on exit.
638 _S_chunks.push(__REINTERPRET_CAST(_Obj*, __result));
639 __result += _ALIGN;
640 __bytes_to_get -= _ALIGN;
641 # endif
642
643 if (__bytes_to_get > __total_bytes) {
644 // Push excess memory allocated in this chunk into list of free memory blocks
645 _FreeBlockHeader* __freeblock = __REINTERPRET_CAST(_FreeBlockHeader*, __result + __total_bytes);
646 __freeblock->_M_end = __result + __bytes_to_get;
647 _S_free_mem_blocks.push(__freeblock);
648 }
649 return __result;
650 }
651
652 # if defined (_STLP_DO_CLEAN_NODE_ALLOC)
653 void __node_alloc_impl::_S_alloc_call()
654 { _STLP_ATOMIC_INCREMENT(&_S_alloc_counter()); }
655
656 void __node_alloc_impl::_S_dealloc_call() {
657 _STLP_VOLATILE __stl_atomic_t *pcounter = &_S_alloc_counter();
658 if (_STLP_ATOMIC_DECREMENT(pcounter) == 0)
659 _S_chunk_dealloc();
660 }
661
662 /* We deallocate all the memory chunks */
663 void __node_alloc_impl::_S_chunk_dealloc() {
664 // Note: The _Node_alloc_helper class ensures that this function
665 // will only be called when the (shared) library is unloaded or the
666 // process is shutdown. It's thus not possible that another thread
667 // is currently trying to allocate a node (we're not thread-safe here).
668 //
669
670 // Clear the free blocks and all freelistst. This makes sure that if
671 // for some reason more memory is allocated again during shutdown
672 // (it'd also be really nasty to leave references to deallocated memory).
673 _S_free_mem_blocks.clear();
674 _S_heap_size = 0;
675
676 for (size_t __i = 0; __i < _STLP_NFREELISTS; ++__i) {
677 _S_free_list[__i].clear();
678 }
679
680 // Detach list of chunks and free them all
681 _Obj* __chunk = _S_chunks.clear();
682 while (__chunk != 0) {
683 _Obj* __next = __chunk->_M_next;
684 __stlp_delete_chunck(__chunk);
685 __chunk = __next;
686 }
687 }
688 # endif
689
690 #endif
691
692 #if defined (_STLP_DO_CLEAN_NODE_ALLOC)
693 struct __node_alloc_cleaner {
694 ~__node_alloc_cleaner()
695 { __node_alloc_impl::_S_dealloc_call(); }
696 };
697
698 # if defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)
699 _STLP_VOLATILE __stl_atomic_t& _STLP_CALL
700 # else
701 __stl_atomic_t& _STLP_CALL
702 # endif
703 __node_alloc_impl::_S_alloc_counter() {
704 static _AllocCounter _S_counter = 1;
705 static __node_alloc_cleaner _S_node_alloc_cleaner;
706 return _S_counter;
707 }
708 #endif
709
710 #if !defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)
711 _Node_alloc_obj * _STLP_VOLATILE
712 __node_alloc_impl::_S_free_list[_STLP_NFREELISTS]
713 = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
714 // The 16 zeros are necessary to make version 4.1 of the SunPro
715 // compiler happy. Otherwise it appears to allocate too little
716 // space for the array.
717 #else
718 _STLP_atomic_freelist __node_alloc_impl::_S_free_list[_STLP_NFREELISTS];
719 _STLP_atomic_freelist __node_alloc_impl::_S_free_mem_blocks;
720 #endif
721
722 #if !defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)
723 char *__node_alloc_impl::_S_start_free = 0;
724 char *__node_alloc_impl::_S_end_free = 0;
725 #endif
726
727 #if defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)
728 _STLP_VOLATILE __add_atomic_t
729 #else
730 size_t
731 #endif
732 __node_alloc_impl::_S_heap_size = 0;
733
734 #if defined (_STLP_DO_CLEAN_NODE_ALLOC)
735 # if defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)
736 _STLP_atomic_freelist __node_alloc_impl::_S_chunks;
737 # else
738 _Node_alloc_obj* __node_alloc_impl::_S_chunks = 0;
739 # endif
740 #endif
741
742 void * _STLP_CALL __node_alloc::_M_allocate(size_t& __n)
743 { return __node_alloc_impl::_M_allocate(__n); }
744
745 void _STLP_CALL __node_alloc::_M_deallocate(void *__p, size_t __n)
746 { __node_alloc_impl::_M_deallocate(__p, __n); }
747
748 #if defined (_STLP_PTHREADS) && !defined (_STLP_NO_THREADS)
749
750 # define _STLP_DATA_ALIGNMENT 8
751
752 _STLP_MOVE_TO_PRIV_NAMESPACE
753
754 // *******************************************************
755 // __perthread_alloc implementation
756 union _Pthread_alloc_obj {
757 union _Pthread_alloc_obj * __free_list_link;
758 char __client_data[_STLP_DATA_ALIGNMENT]; /* The client sees this. */
759 };
760
761 // Pthread allocators don't appear to the client to have meaningful
762 // instances. We do in fact need to associate some state with each
763 // thread. That state is represented by _Pthread_alloc_per_thread_state.
764
765 struct _Pthread_alloc_per_thread_state {
766 typedef _Pthread_alloc_obj __obj;
767 enum { _S_NFREELISTS = _MAX_BYTES / _STLP_DATA_ALIGNMENT };
768
769 // Free list link for list of available per thread structures.
770 // When one of these becomes available for reuse due to thread
771 // termination, any objects in its free list remain associated
772 // with it. The whole structure may then be used by a newly
773 // created thread.
774 _Pthread_alloc_per_thread_state() : __next(0)
775 { memset((void *)__CONST_CAST(_Pthread_alloc_obj**, __free_list), 0, (size_t)_S_NFREELISTS * sizeof(__obj *)); }
776 // Returns an object of size __n, and possibly adds to size n free list.
777 void *_M_refill(size_t __n);
778
779 _Pthread_alloc_obj* volatile __free_list[_S_NFREELISTS];
780 _Pthread_alloc_per_thread_state *__next;
781 // this data member is only to be used by per_thread_allocator, which returns memory to the originating thread.
782 _STLP_mutex _M_lock;
783 };
784
785 // Pthread-specific allocator.
786 class _Pthread_alloc_impl {
787 public: // but only for internal use:
788 typedef _Pthread_alloc_per_thread_state __state_type;
789 typedef char value_type;
790
791 // Allocates a chunk for nobjs of size size. nobjs may be reduced
792 // if it is inconvenient to allocate the requested number.
793 static char *_S_chunk_alloc(size_t __size, size_t &__nobjs, __state_type*);
794
795 enum {_S_ALIGN = _STLP_DATA_ALIGNMENT};
796
797 static size_t _S_round_up(size_t __bytes)
798 { return (((__bytes) + (int)_S_ALIGN - 1) & ~((int)_S_ALIGN - 1)); }
799 static size_t _S_freelist_index(size_t __bytes)
800 { return (((__bytes) + (int)_S_ALIGN - 1) / (int)_S_ALIGN - 1); }
801
802 private:
803 // Chunk allocation state. And other shared state.
804 // Protected by _S_chunk_allocator_lock.
805 static _STLP_STATIC_MUTEX _S_chunk_allocator_lock;
806 static char *_S_start_free;
807 static char *_S_end_free;
808 static size_t _S_heap_size;
809 static __state_type *_S_free_per_thread_states;
810 static pthread_key_t _S_key;
811 static bool _S_key_initialized;
812 // Pthread key under which per thread state is stored.
813 // Allocator instances that are currently unclaimed by any thread.
814 static void _S_destructor(void *instance);
815 // Function to be called on thread exit to reclaim per thread
816 // state.
817 static __state_type *_S_new_per_thread_state();
818 public:
819 // Return a recycled or new per thread state.
820 static __state_type *_S_get_per_thread_state();
821 private:
822 // ensure that the current thread has an associated
823 // per thread state.
824 class _M_lock;
825 friend class _M_lock;
826 class _M_lock {
827 public:
828 _M_lock () { _S_chunk_allocator_lock._M_acquire_lock(); }
829 ~_M_lock () { _S_chunk_allocator_lock._M_release_lock(); }
830 };
831
832 public:
833
834 /* n must be > 0 */
835 static void * allocate(size_t& __n);
836
837 /* p may not be 0 */
838 static void deallocate(void *__p, size_t __n);
839
840 // boris : versions for per_thread_allocator
841 /* n must be > 0 */
842 static void * allocate(size_t& __n, __state_type* __a);
843
844 /* p may not be 0 */
845 static void deallocate(void *__p, size_t __n, __state_type* __a);
846
847 static void * reallocate(void *__p, size_t __old_sz, size_t& __new_sz);
848 };
849
850 /* Returns an object of size n, and optionally adds to size n free list.*/
851 /* We assume that n is properly aligned. */
852 /* We hold the allocation lock. */
853 void *_Pthread_alloc_per_thread_state::_M_refill(size_t __n) {
854 typedef _Pthread_alloc_obj __obj;
855 size_t __nobjs = 128;
856 char * __chunk = _Pthread_alloc_impl::_S_chunk_alloc(__n, __nobjs, this);
857 __obj * volatile * __my_free_list;
858 __obj * __result;
859 __obj * __current_obj, * __next_obj;
860 size_t __i;
861
862 if (1 == __nobjs) {
863 return __chunk;
864 }
865
866 __my_free_list = __free_list + _Pthread_alloc_impl::_S_freelist_index(__n);
867
868 /* Build free list in chunk */
869 __result = (__obj *)__chunk;
870 *__my_free_list = __next_obj = (__obj *)(__chunk + __n);
871 for (__i = 1; ; ++__i) {
872 __current_obj = __next_obj;
873 __next_obj = (__obj *)((char *)__next_obj + __n);
874 if (__nobjs - 1 == __i) {
875 __current_obj -> __free_list_link = 0;
876 break;
877 } else {
878 __current_obj -> __free_list_link = __next_obj;
879 }
880 }
881 return __result;
882 }
883
884 void _Pthread_alloc_impl::_S_destructor(void *__instance) {
885 _M_lock __lock_instance; // Need to acquire lock here.
886 _Pthread_alloc_per_thread_state* __s = (_Pthread_alloc_per_thread_state*)__instance;
887 __s -> __next = _S_free_per_thread_states;
888 _S_free_per_thread_states = __s;
889 }
890
891 _Pthread_alloc_per_thread_state* _Pthread_alloc_impl::_S_new_per_thread_state() {
892 /* lock already held here. */
893 if (0 != _S_free_per_thread_states) {
894 _Pthread_alloc_per_thread_state *__result = _S_free_per_thread_states;
895 _S_free_per_thread_states = _S_free_per_thread_states -> __next;
896 return __result;
897 }
898 else {
899 return new _Pthread_alloc_per_thread_state;
900 }
901 }
902
903 _Pthread_alloc_per_thread_state* _Pthread_alloc_impl::_S_get_per_thread_state() {
904 int __ret_code;
905 __state_type* __result;
906
907 if (_S_key_initialized && (__result = (__state_type*) pthread_getspecific(_S_key)))
908 return __result;
909
910 /*REFERENCED*/
911 _M_lock __lock_instance; // Need to acquire lock here.
912 if (!_S_key_initialized) {
913 if (pthread_key_create(&_S_key, _S_destructor)) {
914 _STLP_THROW_BAD_ALLOC; // failed
915 }
916 _S_key_initialized = true;
917 }
918
919 __result = _S_new_per_thread_state();
920 __ret_code = pthread_setspecific(_S_key, __result);
921 if (__ret_code) {
922 if (__ret_code == ENOMEM) {
923 _STLP_THROW_BAD_ALLOC;
924 } else {
925 // EINVAL
926 _STLP_ABORT();
927 }
928 }
929 return __result;
930 }
931
932 /* We allocate memory in large chunks in order to avoid fragmenting */
933 /* the malloc heap too much. */
934 /* We assume that size is properly aligned. */
935 char *_Pthread_alloc_impl::_S_chunk_alloc(size_t __p_size, size_t &__nobjs, _Pthread_alloc_per_thread_state *__a) {
936 typedef _Pthread_alloc_obj __obj;
937 {
938 char * __result;
939 size_t __total_bytes;
940 size_t __bytes_left;
941 /*REFERENCED*/
942 _M_lock __lock_instance; // Acquire lock for this routine
943
944 __total_bytes = __p_size * __nobjs;
945 __bytes_left = _S_end_free - _S_start_free;
946 if (__bytes_left >= __total_bytes) {
947 __result = _S_start_free;
948 _S_start_free += __total_bytes;
949 return __result;
950 } else if (__bytes_left >= __p_size) {
951 __nobjs = __bytes_left/__p_size;
952 __total_bytes = __p_size * __nobjs;
953 __result = _S_start_free;
954 _S_start_free += __total_bytes;
955 return __result;
956 } else {
957 size_t __bytes_to_get = 2 * __total_bytes + _S_round_up(_S_heap_size);
958 // Try to make use of the left-over piece.
959 if (__bytes_left > 0) {
960 __obj * volatile * __my_free_list = __a->__free_list + _S_freelist_index(__bytes_left);
961 ((__obj *)_S_start_free) -> __free_list_link = *__my_free_list;
962 *__my_free_list = (__obj *)_S_start_free;
963 }
964 # ifdef _SGI_SOURCE
965 // Try to get memory that's aligned on something like a
966 // cache line boundary, so as to avoid parceling out
967 // parts of the same line to different threads and thus
968 // possibly different processors.
969 {
970 const int __cache_line_size = 128; // probable upper bound
971 __bytes_to_get &= ~(__cache_line_size-1);
972 _S_start_free = (char *)memalign(__cache_line_size, __bytes_to_get);
973 if (0 == _S_start_free) {
974 _S_start_free = (char *)__malloc_alloc::allocate(__bytes_to_get);
975 }
976 }
977 # else /* !SGI_SOURCE */
978 _S_start_free = (char *)__malloc_alloc::allocate(__bytes_to_get);
979 # endif
980 _S_heap_size += __bytes_to_get >> 4;
981 _S_end_free = _S_start_free + __bytes_to_get;
982 }
983 }
984 // lock is released here
985 return _S_chunk_alloc(__p_size, __nobjs, __a);
986 }
987
988
989 /* n must be > 0 */
990 void *_Pthread_alloc_impl::allocate(size_t& __n) {
991 typedef _Pthread_alloc_obj __obj;
992 __obj * volatile * __my_free_list;
993 __obj * __result;
994 __state_type* __a;
995
996 if (__n > _MAX_BYTES) {
997 return __malloc_alloc::allocate(__n);
998 }
999
1000 __n = _S_round_up(__n);
1001 __a = _S_get_per_thread_state();
1002
1003 __my_free_list = __a->__free_list + _S_freelist_index(__n);
1004 __result = *__my_free_list;
1005 if (__result == 0) {
1006 void *__r = __a->_M_refill(__n);
1007 return __r;
1008 }
1009 *__my_free_list = __result->__free_list_link;
1010 return __result;
1011 };
1012
1013 /* p may not be 0 */
1014 void _Pthread_alloc_impl::deallocate(void *__p, size_t __n) {
1015 typedef _Pthread_alloc_obj __obj;
1016 __obj *__q = (__obj *)__p;
1017 __obj * volatile * __my_free_list;
1018 __state_type* __a;
1019
1020 if (__n > _MAX_BYTES) {
1021 __malloc_alloc::deallocate(__p, __n);
1022 return;
1023 }
1024
1025 __a = _S_get_per_thread_state();
1026
1027 __my_free_list = __a->__free_list + _S_freelist_index(__n);
1028 __q -> __free_list_link = *__my_free_list;
1029 *__my_free_list = __q;
1030 }
1031
1032 // boris : versions for per_thread_allocator
1033 /* n must be > 0 */
1034 void *_Pthread_alloc_impl::allocate(size_t& __n, __state_type* __a) {
1035 typedef _Pthread_alloc_obj __obj;
1036 __obj * volatile * __my_free_list;
1037 __obj * __result;
1038
1039 if (__n > _MAX_BYTES) {
1040 return __malloc_alloc::allocate(__n);
1041 }
1042 __n = _S_round_up(__n);
1043
1044 // boris : here, we have to lock per thread state, as we may be getting memory from
1045 // different thread pool.
1046 _STLP_auto_lock __lock(__a->_M_lock);
1047
1048 __my_free_list = __a->__free_list + _S_freelist_index(__n);
1049 __result = *__my_free_list;
1050 if (__result == 0) {
1051 void *__r = __a->_M_refill(__n);
1052 return __r;
1053 }
1054 *__my_free_list = __result->__free_list_link;
1055 return __result;
1056 };
1057
1058 /* p may not be 0 */
1059 void _Pthread_alloc_impl::deallocate(void *__p, size_t __n, __state_type* __a) {
1060 typedef _Pthread_alloc_obj __obj;
1061 __obj *__q = (__obj *)__p;
1062 __obj * volatile * __my_free_list;
1063
1064 if (__n > _MAX_BYTES) {
1065 __malloc_alloc::deallocate(__p, __n);
1066 return;
1067 }
1068
1069 // boris : here, we have to lock per thread state, as we may be returning memory from
1070 // different thread.
1071 _STLP_auto_lock __lock(__a->_M_lock);
1072
1073 __my_free_list = __a->__free_list + _S_freelist_index(__n);
1074 __q -> __free_list_link = *__my_free_list;
1075 *__my_free_list = __q;
1076 }
1077
1078 void *_Pthread_alloc_impl::reallocate(void *__p, size_t __old_sz, size_t& __new_sz) {
1079 void * __result;
1080 size_t __copy_sz;
1081
1082 if (__old_sz > _MAX_BYTES && __new_sz > _MAX_BYTES) {
1083 return realloc(__p, __new_sz);
1084 }
1085
1086 if (_S_round_up(__old_sz) == _S_round_up(__new_sz)) return __p;
1087 __result = allocate(__new_sz);
1088 __copy_sz = __new_sz > __old_sz? __old_sz : __new_sz;
1089 memcpy(__result, __p, __copy_sz);
1090 deallocate(__p, __old_sz);
1091 return __result;
1092 }
1093
1094 _Pthread_alloc_per_thread_state* _Pthread_alloc_impl::_S_free_per_thread_states = 0;
1095 pthread_key_t _Pthread_alloc_impl::_S_key = 0;
1096 _STLP_STATIC_MUTEX _Pthread_alloc_impl::_S_chunk_allocator_lock _STLP_MUTEX_INITIALIZER;
1097 bool _Pthread_alloc_impl::_S_key_initialized = false;
1098 char *_Pthread_alloc_impl::_S_start_free = 0;
1099 char *_Pthread_alloc_impl::_S_end_free = 0;
1100 size_t _Pthread_alloc_impl::_S_heap_size = 0;
1101
1102 void * _STLP_CALL _Pthread_alloc::allocate(size_t& __n)
1103 { return _Pthread_alloc_impl::allocate(__n); }
1104 void _STLP_CALL _Pthread_alloc::deallocate(void *__p, size_t __n)
1105 { _Pthread_alloc_impl::deallocate(__p, __n); }
1106 void * _STLP_CALL _Pthread_alloc::allocate(size_t& __n, __state_type* __a)
1107 { return _Pthread_alloc_impl::allocate(__n, __a); }
1108 void _STLP_CALL _Pthread_alloc::deallocate(void *__p, size_t __n, __state_type* __a)
1109 { _Pthread_alloc_impl::deallocate(__p, __n, __a); }
1110 void * _STLP_CALL _Pthread_alloc::reallocate(void *__p, size_t __old_sz, size_t& __new_sz)
1111 { return _Pthread_alloc_impl::reallocate(__p, __old_sz, __new_sz); }
1112 _Pthread_alloc_per_thread_state* _STLP_CALL _Pthread_alloc::_S_get_per_thread_state()
1113 { return _Pthread_alloc_impl::_S_get_per_thread_state(); }
1114
1115 _STLP_MOVE_TO_STD_NAMESPACE
1116
1117 #endif
1118
1119 _STLP_END_NAMESPACE
1120
1121 #undef _S_FREELIST_INDEX

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