Mercurial > hg > truffle
annotate src/share/vm/memory/heap.cpp @ 11516:20b642493616
CR-1368
author | Mick Jordan <mick.jordan@oracle.com> |
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date | Tue, 03 Sep 2013 14:09:35 -0700 |
parents | 836a62f43af9 |
children | 58fc8e2b7b6d |
rev | line source |
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0 | 1 /* |
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2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. |
0 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
1552
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #include "precompiled.hpp" |
26 #include "memory/heap.hpp" | |
27 #include "oops/oop.inline.hpp" | |
28 #include "runtime/os.hpp" | |
6197 | 29 #include "services/memTracker.hpp" |
0 | 30 |
31 size_t CodeHeap::header_size() { | |
32 return sizeof(HeapBlock); | |
33 } | |
34 | |
35 | |
36 // Implementation of Heap | |
37 | |
38 CodeHeap::CodeHeap() { | |
39 _number_of_committed_segments = 0; | |
40 _number_of_reserved_segments = 0; | |
41 _segment_size = 0; | |
42 _log2_segment_size = 0; | |
43 _next_segment = 0; | |
44 _freelist = NULL; | |
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45 _freelist_segments = 0; |
0 | 46 } |
47 | |
48 | |
49 void CodeHeap::mark_segmap_as_free(size_t beg, size_t end) { | |
50 assert(0 <= beg && beg < _number_of_committed_segments, "interval begin out of bounds"); | |
51 assert(beg < end && end <= _number_of_committed_segments, "interval end out of bounds"); | |
52 // setup _segmap pointers for faster indexing | |
53 address p = (address)_segmap.low() + beg; | |
54 address q = (address)_segmap.low() + end; | |
55 // initialize interval | |
56 while (p < q) *p++ = 0xFF; | |
57 } | |
58 | |
59 | |
60 void CodeHeap::mark_segmap_as_used(size_t beg, size_t end) { | |
61 assert(0 <= beg && beg < _number_of_committed_segments, "interval begin out of bounds"); | |
62 assert(beg < end && end <= _number_of_committed_segments, "interval end out of bounds"); | |
63 // setup _segmap pointers for faster indexing | |
64 address p = (address)_segmap.low() + beg; | |
65 address q = (address)_segmap.low() + end; | |
66 // initialize interval | |
67 int i = 0; | |
68 while (p < q) { | |
69 *p++ = i++; | |
70 if (i == 0xFF) i = 1; | |
71 } | |
72 } | |
73 | |
74 | |
75 static size_t align_to_page_size(size_t size) { | |
76 const size_t alignment = (size_t)os::vm_page_size(); | |
77 assert(is_power_of_2(alignment), "no kidding ???"); | |
78 return (size + alignment - 1) & ~(alignment - 1); | |
79 } | |
80 | |
81 | |
82 void CodeHeap::on_code_mapping(char* base, size_t size) { | |
83 #ifdef LINUX | |
84 extern void linux_wrap_code(char* base, size_t size); | |
85 linux_wrap_code(base, size); | |
86 #endif | |
87 } | |
88 | |
89 | |
90 bool CodeHeap::reserve(size_t reserved_size, size_t committed_size, | |
91 size_t segment_size) { | |
92 assert(reserved_size >= committed_size, "reserved < committed"); | |
93 assert(segment_size >= sizeof(FreeBlock), "segment size is too small"); | |
94 assert(is_power_of_2(segment_size), "segment_size must be a power of 2"); | |
95 | |
96 _segment_size = segment_size; | |
97 _log2_segment_size = exact_log2(segment_size); | |
98 | |
99 // Reserve and initialize space for _memory. | |
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100 const size_t page_size = os::can_execute_large_page_memory() ? |
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101 os::page_size_for_region(committed_size, reserved_size, 8) : |
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102 os::vm_page_size(); |
0 | 103 const size_t granularity = os::vm_allocation_granularity(); |
104 const size_t r_align = MAX2(page_size, granularity); | |
105 const size_t r_size = align_size_up(reserved_size, r_align); | |
106 const size_t c_size = align_size_up(committed_size, page_size); | |
107 | |
108 const size_t rs_align = page_size == (size_t) os::vm_page_size() ? 0 : | |
109 MAX2(page_size, granularity); | |
656 | 110 ReservedCodeSpace rs(r_size, rs_align, rs_align > 0); |
0 | 111 os::trace_page_sizes("code heap", committed_size, reserved_size, page_size, |
112 rs.base(), rs.size()); | |
113 if (!_memory.initialize(rs, c_size)) { | |
114 return false; | |
115 } | |
116 | |
117 on_code_mapping(_memory.low(), _memory.committed_size()); | |
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118 _number_of_committed_segments = size_to_segments(_memory.committed_size()); |
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119 _number_of_reserved_segments = size_to_segments(_memory.reserved_size()); |
0 | 120 assert(_number_of_reserved_segments >= _number_of_committed_segments, "just checking"); |
121 | |
122 // reserve space for _segmap | |
123 if (!_segmap.initialize(align_to_page_size(_number_of_reserved_segments), align_to_page_size(_number_of_committed_segments))) { | |
124 return false; | |
125 } | |
6197 | 126 |
127 MemTracker::record_virtual_memory_type((address)_segmap.low_boundary(), mtCode); | |
128 | |
0 | 129 assert(_segmap.committed_size() >= (size_t) _number_of_committed_segments, "could not commit enough space for segment map"); |
130 assert(_segmap.reserved_size() >= (size_t) _number_of_reserved_segments , "could not reserve enough space for segment map"); | |
131 assert(_segmap.reserved_size() >= _segmap.committed_size() , "just checking"); | |
132 | |
133 // initialize remaining instance variables | |
134 clear(); | |
135 return true; | |
136 } | |
137 | |
138 | |
139 void CodeHeap::release() { | |
140 Unimplemented(); | |
141 } | |
142 | |
143 | |
144 bool CodeHeap::expand_by(size_t size) { | |
145 // expand _memory space | |
146 size_t dm = align_to_page_size(_memory.committed_size() + size) - _memory.committed_size(); | |
147 if (dm > 0) { | |
148 char* base = _memory.low() + _memory.committed_size(); | |
149 if (!_memory.expand_by(dm)) return false; | |
150 on_code_mapping(base, dm); | |
151 size_t i = _number_of_committed_segments; | |
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152 _number_of_committed_segments = size_to_segments(_memory.committed_size()); |
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153 assert(_number_of_reserved_segments == size_to_segments(_memory.reserved_size()), "number of reserved segments should not change"); |
0 | 154 assert(_number_of_reserved_segments >= _number_of_committed_segments, "just checking"); |
155 // expand _segmap space | |
156 size_t ds = align_to_page_size(_number_of_committed_segments) - _segmap.committed_size(); | |
157 if (ds > 0) { | |
158 if (!_segmap.expand_by(ds)) return false; | |
159 } | |
160 assert(_segmap.committed_size() >= (size_t) _number_of_committed_segments, "just checking"); | |
161 // initialize additional segmap entries | |
162 mark_segmap_as_free(i, _number_of_committed_segments); | |
163 } | |
164 return true; | |
165 } | |
166 | |
167 | |
168 void CodeHeap::shrink_by(size_t size) { | |
169 Unimplemented(); | |
170 } | |
171 | |
172 | |
173 void CodeHeap::clear() { | |
174 _next_segment = 0; | |
175 mark_segmap_as_free(0, _number_of_committed_segments); | |
176 } | |
177 | |
178 | |
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179 void* CodeHeap::allocate(size_t instance_size, bool is_critical) { |
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180 size_t number_of_segments = size_to_segments(instance_size + sizeof(HeapBlock)); |
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181 assert(segments_to_size(number_of_segments) >= sizeof(FreeBlock), "not enough room for FreeList"); |
0 | 182 |
183 // First check if we can satify request from freelist | |
184 debug_only(verify()); | |
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185 HeapBlock* block = search_freelist(number_of_segments, is_critical); |
0 | 186 debug_only(if (VerifyCodeCacheOften) verify()); |
187 if (block != NULL) { | |
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188 assert(block->length() >= number_of_segments && block->length() < number_of_segments + CodeCacheMinBlockLength, "sanity check"); |
0 | 189 assert(!block->free(), "must be marked free"); |
190 #ifdef ASSERT | |
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191 memset((void *)block->allocated_space(), badCodeHeapNewVal, instance_size); |
0 | 192 #endif |
193 return block->allocated_space(); | |
194 } | |
195 | |
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196 // Ensure minimum size for allocation to the heap. |
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197 if (number_of_segments < CodeCacheMinBlockLength) { |
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198 number_of_segments = CodeCacheMinBlockLength; |
0 | 199 } |
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200 |
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201 if (!is_critical) { |
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202 // Make sure the allocation fits in the unallocated heap without using |
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203 // the CodeCacheMimimumFreeSpace that is reserved for critical allocations. |
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204 if (segments_to_size(number_of_segments) > (heap_unallocated_capacity() - CodeCacheMinimumFreeSpace)) { |
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205 // Fail allocation |
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206 return NULL; |
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207 } |
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208 } |
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209 |
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210 if (_next_segment + number_of_segments <= _number_of_committed_segments) { |
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211 mark_segmap_as_used(_next_segment, _next_segment + number_of_segments); |
0 | 212 HeapBlock* b = block_at(_next_segment); |
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213 b->initialize(number_of_segments); |
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214 _next_segment += number_of_segments; |
0 | 215 #ifdef ASSERT |
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216 memset((void *)b->allocated_space(), badCodeHeapNewVal, instance_size); |
0 | 217 #endif |
218 return b->allocated_space(); | |
219 } else { | |
220 return NULL; | |
221 } | |
222 } | |
223 | |
224 | |
225 void CodeHeap::deallocate(void* p) { | |
226 assert(p == find_start(p), "illegal deallocation"); | |
227 // Find start of HeapBlock | |
228 HeapBlock* b = (((HeapBlock *)p) - 1); | |
229 assert(b->allocated_space() == p, "sanity check"); | |
230 #ifdef ASSERT | |
231 memset((void *)b->allocated_space(), | |
232 badCodeHeapFreeVal, | |
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233 segments_to_size(b->length()) - sizeof(HeapBlock)); |
0 | 234 #endif |
235 add_to_freelist(b); | |
236 | |
237 debug_only(if (VerifyCodeCacheOften) verify()); | |
238 } | |
239 | |
240 | |
241 void* CodeHeap::find_start(void* p) const { | |
242 if (!contains(p)) { | |
243 return NULL; | |
244 } | |
245 size_t i = segment_for(p); | |
246 address b = (address)_segmap.low(); | |
247 if (b[i] == 0xFF) { | |
248 return NULL; | |
249 } | |
250 while (b[i] > 0) i -= (int)b[i]; | |
251 HeapBlock* h = block_at(i); | |
252 if (h->free()) { | |
253 return NULL; | |
254 } | |
255 return h->allocated_space(); | |
256 } | |
257 | |
258 | |
259 size_t CodeHeap::alignment_unit() const { | |
260 // this will be a power of two | |
261 return _segment_size; | |
262 } | |
263 | |
264 | |
265 size_t CodeHeap::alignment_offset() const { | |
266 // The lowest address in any allocated block will be | |
267 // equal to alignment_offset (mod alignment_unit). | |
268 return sizeof(HeapBlock) & (_segment_size - 1); | |
269 } | |
270 | |
271 // Finds the next free heapblock. If the current one is free, that it returned | |
272 void* CodeHeap::next_free(HeapBlock *b) const { | |
273 // Since free blocks are merged, there is max. on free block | |
274 // between two used ones | |
275 if (b != NULL && b->free()) b = next_block(b); | |
276 assert(b == NULL || !b->free(), "must be in use or at end of heap"); | |
277 return (b == NULL) ? NULL : b->allocated_space(); | |
278 } | |
279 | |
280 // Returns the first used HeapBlock | |
281 HeapBlock* CodeHeap::first_block() const { | |
282 if (_next_segment > 0) | |
283 return block_at(0); | |
284 return NULL; | |
285 } | |
286 | |
287 HeapBlock *CodeHeap::block_start(void *q) const { | |
288 HeapBlock* b = (HeapBlock*)find_start(q); | |
289 if (b == NULL) return NULL; | |
290 return b - 1; | |
291 } | |
292 | |
293 // Returns the next Heap block an offset into one | |
294 HeapBlock* CodeHeap::next_block(HeapBlock *b) const { | |
295 if (b == NULL) return NULL; | |
296 size_t i = segment_for(b) + b->length(); | |
297 if (i < _next_segment) | |
298 return block_at(i); | |
299 return NULL; | |
300 } | |
301 | |
302 | |
303 // Returns current capacity | |
304 size_t CodeHeap::capacity() const { | |
305 return _memory.committed_size(); | |
306 } | |
307 | |
308 size_t CodeHeap::max_capacity() const { | |
309 return _memory.reserved_size(); | |
310 } | |
311 | |
312 size_t CodeHeap::allocated_capacity() const { | |
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313 // size of used heap - size on freelist |
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314 return segments_to_size(_next_segment - _freelist_segments); |
0 | 315 } |
316 | |
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317 // Returns size of the unallocated heap block |
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318 size_t CodeHeap::heap_unallocated_capacity() const { |
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319 // Total number of segments - number currently used |
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320 return segments_to_size(_number_of_reserved_segments - _next_segment); |
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321 } |
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322 |
0 | 323 // Free list management |
324 | |
325 FreeBlock *CodeHeap::following_block(FreeBlock *b) { | |
326 return (FreeBlock*)(((address)b) + _segment_size * b->length()); | |
327 } | |
328 | |
329 // Inserts block b after a | |
330 void CodeHeap::insert_after(FreeBlock* a, FreeBlock* b) { | |
331 assert(a != NULL && b != NULL, "must be real pointers"); | |
332 | |
333 // Link b into the list after a | |
334 b->set_link(a->link()); | |
335 a->set_link(b); | |
336 | |
337 // See if we can merge blocks | |
338 merge_right(b); // Try to make b bigger | |
339 merge_right(a); // Try to make a include b | |
340 } | |
341 | |
342 // Try to merge this block with the following block | |
343 void CodeHeap::merge_right(FreeBlock *a) { | |
344 assert(a->free(), "must be a free block"); | |
345 if (following_block(a) == a->link()) { | |
346 assert(a->link() != NULL && a->link()->free(), "must be free too"); | |
347 // Update block a to include the following block | |
348 a->set_length(a->length() + a->link()->length()); | |
349 a->set_link(a->link()->link()); | |
350 // Update find_start map | |
351 size_t beg = segment_for(a); | |
352 mark_segmap_as_used(beg, beg + a->length()); | |
353 } | |
354 } | |
355 | |
356 void CodeHeap::add_to_freelist(HeapBlock *a) { | |
357 FreeBlock* b = (FreeBlock*)a; | |
358 assert(b != _freelist, "cannot be removed twice"); | |
359 | |
360 // Mark as free and update free space count | |
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361 _freelist_segments += b->length(); |
0 | 362 b->set_free(); |
363 | |
364 // First element in list? | |
365 if (_freelist == NULL) { | |
366 _freelist = b; | |
367 b->set_link(NULL); | |
368 return; | |
369 } | |
370 | |
371 // Scan for right place to put into list. List | |
372 // is sorted by increasing addresseses | |
373 FreeBlock* prev = NULL; | |
374 FreeBlock* cur = _freelist; | |
375 while(cur != NULL && cur < b) { | |
376 assert(prev == NULL || prev < cur, "must be ordered"); | |
377 prev = cur; | |
378 cur = cur->link(); | |
379 } | |
380 | |
381 assert( (prev == NULL && b < _freelist) || | |
382 (prev < b && (cur == NULL || b < cur)), "list must be ordered"); | |
383 | |
384 if (prev == NULL) { | |
385 // Insert first in list | |
386 b->set_link(_freelist); | |
387 _freelist = b; | |
388 merge_right(_freelist); | |
389 } else { | |
390 insert_after(prev, b); | |
391 } | |
392 } | |
393 | |
394 // Search freelist for an entry on the list with the best fit | |
395 // Return NULL if no one was found | |
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396 FreeBlock* CodeHeap::search_freelist(size_t length, bool is_critical) { |
0 | 397 FreeBlock *best_block = NULL; |
398 FreeBlock *best_prev = NULL; | |
399 size_t best_length = 0; | |
400 | |
401 // Search for smallest block which is bigger than length | |
402 FreeBlock *prev = NULL; | |
403 FreeBlock *cur = _freelist; | |
404 while(cur != NULL) { | |
405 size_t l = cur->length(); | |
406 if (l >= length && (best_block == NULL || best_length > l)) { | |
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407 |
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408 // Non critical allocations are not allowed to use the last part of the code heap. |
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409 if (!is_critical) { |
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410 // Make sure the end of the allocation doesn't cross into the last part of the code heap |
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411 if (((size_t)cur + length) > ((size_t)high_boundary() - CodeCacheMinimumFreeSpace)) { |
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412 // the freelist is sorted by address - if one fails, all consecutive will also fail. |
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413 break; |
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414 } |
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415 } |
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416 |
0 | 417 // Remember best block, its previous element, and its length |
418 best_block = cur; | |
419 best_prev = prev; | |
420 best_length = best_block->length(); | |
421 } | |
422 | |
423 // Next element in list | |
424 prev = cur; | |
425 cur = cur->link(); | |
426 } | |
427 | |
428 if (best_block == NULL) { | |
429 // None found | |
430 return NULL; | |
431 } | |
432 | |
433 assert((best_prev == NULL && _freelist == best_block ) || | |
434 (best_prev != NULL && best_prev->link() == best_block), "sanity check"); | |
435 | |
436 // Exact (or at least good enough) fit. Remove from list. | |
437 // Don't leave anything on the freelist smaller than CodeCacheMinBlockLength. | |
438 if (best_length < length + CodeCacheMinBlockLength) { | |
439 length = best_length; | |
440 if (best_prev == NULL) { | |
441 assert(_freelist == best_block, "sanity check"); | |
442 _freelist = _freelist->link(); | |
443 } else { | |
444 // Unmap element | |
445 best_prev->set_link(best_block->link()); | |
446 } | |
447 } else { | |
448 // Truncate block and return a pointer to the following block | |
449 best_block->set_length(best_length - length); | |
450 best_block = following_block(best_block); | |
451 // Set used bit and length on new block | |
452 size_t beg = segment_for(best_block); | |
453 mark_segmap_as_used(beg, beg + length); | |
454 best_block->set_length(length); | |
455 } | |
456 | |
457 best_block->set_used(); | |
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458 _freelist_segments -= length; |
0 | 459 return best_block; |
460 } | |
461 | |
462 //---------------------------------------------------------------------------- | |
463 // Non-product code | |
464 | |
465 #ifndef PRODUCT | |
466 | |
467 void CodeHeap::print() { | |
468 tty->print_cr("The Heap"); | |
469 } | |
470 | |
471 #endif | |
472 | |
473 void CodeHeap::verify() { | |
474 // Count the number of blocks on the freelist, and the amount of space | |
475 // represented. | |
476 int count = 0; | |
477 size_t len = 0; | |
478 for(FreeBlock* b = _freelist; b != NULL; b = b->link()) { | |
479 len += b->length(); | |
480 count++; | |
481 } | |
482 | |
483 // Verify that freelist contains the right amount of free space | |
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484 // guarantee(len == _freelist_segments, "wrong freelist"); |
0 | 485 |
486 // Verify that the number of free blocks is not out of hand. | |
487 static int free_block_threshold = 10000; | |
488 if (count > free_block_threshold) { | |
489 warning("CodeHeap: # of free blocks > %d", free_block_threshold); | |
490 // Double the warning limit | |
491 free_block_threshold *= 2; | |
492 } | |
493 | |
494 // Verify that the freelist contains the same number of free blocks that is | |
495 // found on the full list. | |
496 for(HeapBlock *h = first_block(); h != NULL; h = next_block(h)) { | |
497 if (h->free()) count--; | |
498 } | |
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499 // guarantee(count == 0, "missing free blocks"); |
0 | 500 } |