Mercurial > hg > graal-compiler
comparison src/share/vm/gc_implementation/g1/heapRegionSeq.cpp @ 342:37f87013dfd8
6711316: Open source the Garbage-First garbage collector
Summary: First mercurial integration of the code for the Garbage-First garbage collector.
Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr
author | ysr |
---|---|
date | Thu, 05 Jun 2008 15:57:56 -0700 |
parents | |
children | 078b8a0d8d7c |
comparison
equal
deleted
inserted
replaced
189:0b27f3512f9e | 342:37f87013dfd8 |
---|---|
1 /* | |
2 * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved. | |
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 * | |
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 #include "incls/_precompiled.incl" | |
26 #include "incls/_heapRegionSeq.cpp.incl" | |
27 | |
28 // Local to this file. | |
29 | |
30 static int orderRegions(HeapRegion** hr1p, HeapRegion** hr2p) { | |
31 if ((*hr1p)->end() <= (*hr2p)->bottom()) return -1; | |
32 else if ((*hr2p)->end() <= (*hr1p)->bottom()) return 1; | |
33 else if (*hr1p == *hr2p) return 0; | |
34 else { | |
35 assert(false, "We should never compare distinct overlapping regions."); | |
36 } | |
37 return 0; | |
38 } | |
39 | |
40 HeapRegionSeq::HeapRegionSeq() : | |
41 _alloc_search_start(0), | |
42 // The line below is the worst bit of C++ hackery I've ever written | |
43 // (Detlefs, 11/23). You should think of it as equivalent to | |
44 // "_regions(100, true)": initialize the growable array and inform it | |
45 // that it should allocate its elem array(s) on the C heap. The first | |
46 // argument, however, is actually a comma expression (new-expr, 100). | |
47 // The purpose of the new_expr is to inform the growable array that it | |
48 // is *already* allocated on the C heap: it uses the placement syntax to | |
49 // keep it from actually doing any allocation. | |
50 _regions((ResourceObj::operator new (sizeof(GrowableArray<HeapRegion*>), | |
51 (void*)&_regions, | |
52 ResourceObj::C_HEAP), | |
53 100), | |
54 true), | |
55 _next_rr_candidate(0), | |
56 _seq_bottom(NULL) | |
57 {} | |
58 | |
59 // Private methods. | |
60 | |
61 HeapWord* | |
62 HeapRegionSeq::alloc_obj_from_region_index(int ind, size_t word_size) { | |
63 assert(G1CollectedHeap::isHumongous(word_size), | |
64 "Allocation size should be humongous"); | |
65 int cur = ind; | |
66 int first = cur; | |
67 size_t sumSizes = 0; | |
68 while (cur < _regions.length() && sumSizes < word_size) { | |
69 // Loop invariant: | |
70 // For all i in [first, cur): | |
71 // _regions.at(i)->is_empty() | |
72 // && _regions.at(i) is contiguous with its predecessor, if any | |
73 // && sumSizes is the sum of the sizes of the regions in the interval | |
74 // [first, cur) | |
75 HeapRegion* curhr = _regions.at(cur); | |
76 if (curhr->is_empty() | |
77 && !curhr->is_reserved() | |
78 && (first == cur | |
79 || (_regions.at(cur-1)->end() == | |
80 curhr->bottom()))) { | |
81 sumSizes += curhr->capacity() / HeapWordSize; | |
82 } else { | |
83 first = cur + 1; | |
84 sumSizes = 0; | |
85 } | |
86 cur++; | |
87 } | |
88 if (sumSizes >= word_size) { | |
89 _alloc_search_start = cur; | |
90 // Mark the allocated regions as allocated. | |
91 bool zf = G1CollectedHeap::heap()->allocs_are_zero_filled(); | |
92 HeapRegion* first_hr = _regions.at(first); | |
93 for (int i = first; i < cur; i++) { | |
94 HeapRegion* hr = _regions.at(i); | |
95 if (zf) | |
96 hr->ensure_zero_filled(); | |
97 { | |
98 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
99 hr->set_zero_fill_allocated(); | |
100 } | |
101 size_t sz = hr->capacity() / HeapWordSize; | |
102 HeapWord* tmp = hr->allocate(sz); | |
103 assert(tmp != NULL, "Humongous allocation failure"); | |
104 MemRegion mr = MemRegion(tmp, sz); | |
105 SharedHeap::fill_region_with_object(mr); | |
106 hr->declare_filled_region_to_BOT(mr); | |
107 if (i == first) { | |
108 first_hr->set_startsHumongous(); | |
109 } else { | |
110 assert(i > first, "sanity"); | |
111 hr->set_continuesHumongous(first_hr); | |
112 } | |
113 } | |
114 HeapWord* first_hr_bot = first_hr->bottom(); | |
115 HeapWord* obj_end = first_hr_bot + word_size; | |
116 first_hr->set_top(obj_end); | |
117 return first_hr_bot; | |
118 } else { | |
119 // If we started from the beginning, we want to know why we can't alloc. | |
120 return NULL; | |
121 } | |
122 } | |
123 | |
124 void HeapRegionSeq::print_empty_runs(bool reserved_are_empty) { | |
125 int empty_run = 0; | |
126 int n_empty = 0; | |
127 bool at_least_one_reserved = false; | |
128 int empty_run_start; | |
129 for (int i = 0; i < _regions.length(); i++) { | |
130 HeapRegion* r = _regions.at(i); | |
131 if (r->continuesHumongous()) continue; | |
132 if (r->is_empty() && (reserved_are_empty || !r->is_reserved())) { | |
133 assert(!r->isHumongous(), "H regions should not be empty."); | |
134 if (empty_run == 0) empty_run_start = i; | |
135 empty_run++; | |
136 n_empty++; | |
137 if (r->is_reserved()) { | |
138 at_least_one_reserved = true; | |
139 } | |
140 } else { | |
141 if (empty_run > 0) { | |
142 gclog_or_tty->print(" %d:%d", empty_run_start, empty_run); | |
143 if (reserved_are_empty && at_least_one_reserved) | |
144 gclog_or_tty->print("(R)"); | |
145 empty_run = 0; | |
146 at_least_one_reserved = false; | |
147 } | |
148 } | |
149 } | |
150 if (empty_run > 0) { | |
151 gclog_or_tty->print(" %d:%d", empty_run_start, empty_run); | |
152 if (reserved_are_empty && at_least_one_reserved) gclog_or_tty->print("(R)"); | |
153 } | |
154 gclog_or_tty->print_cr(" [tot = %d]", n_empty); | |
155 } | |
156 | |
157 int HeapRegionSeq::find(HeapRegion* hr) { | |
158 // FIXME: optimized for adjacent regions of fixed size. | |
159 int ind = hr->hrs_index(); | |
160 if (ind != -1) { | |
161 assert(_regions.at(ind) == hr, "Mismatch"); | |
162 } | |
163 return ind; | |
164 } | |
165 | |
166 | |
167 // Public methods. | |
168 | |
169 void HeapRegionSeq::insert(HeapRegion* hr) { | |
170 if (_regions.length() == 0 | |
171 || _regions.top()->end() <= hr->bottom()) { | |
172 hr->set_hrs_index(_regions.length()); | |
173 _regions.append(hr); | |
174 } else { | |
175 _regions.append(hr); | |
176 _regions.sort(orderRegions); | |
177 for (int i = 0; i < _regions.length(); i++) { | |
178 _regions.at(i)->set_hrs_index(i); | |
179 } | |
180 } | |
181 char* bot = (char*)_regions.at(0)->bottom(); | |
182 if (_seq_bottom == NULL || bot < _seq_bottom) _seq_bottom = bot; | |
183 } | |
184 | |
185 size_t HeapRegionSeq::length() { | |
186 return _regions.length(); | |
187 } | |
188 | |
189 size_t HeapRegionSeq::free_suffix() { | |
190 size_t res = 0; | |
191 int first = _regions.length() - 1; | |
192 int cur = first; | |
193 while (cur >= 0 && | |
194 (_regions.at(cur)->is_empty() | |
195 && !_regions.at(cur)->is_reserved() | |
196 && (first == cur | |
197 || (_regions.at(cur+1)->bottom() == | |
198 _regions.at(cur)->end())))) { | |
199 res++; | |
200 cur--; | |
201 } | |
202 return res; | |
203 } | |
204 | |
205 HeapWord* HeapRegionSeq::obj_allocate(size_t word_size) { | |
206 int cur = _alloc_search_start; | |
207 // Make sure "cur" is a valid index. | |
208 assert(cur >= 0, "Invariant."); | |
209 HeapWord* res = alloc_obj_from_region_index(cur, word_size); | |
210 if (res == NULL) | |
211 res = alloc_obj_from_region_index(0, word_size); | |
212 return res; | |
213 } | |
214 | |
215 void HeapRegionSeq::iterate(HeapRegionClosure* blk) { | |
216 iterate_from((HeapRegion*)NULL, blk); | |
217 } | |
218 | |
219 // The first argument r is the heap region at which iteration begins. | |
220 // This operation runs fastest when r is NULL, or the heap region for | |
221 // which a HeapRegionClosure most recently returned true, or the | |
222 // heap region immediately to its right in the sequence. In all | |
223 // other cases a linear search is required to find the index of r. | |
224 | |
225 void HeapRegionSeq::iterate_from(HeapRegion* r, HeapRegionClosure* blk) { | |
226 | |
227 // :::: FIXME :::: | |
228 // Static cache value is bad, especially when we start doing parallel | |
229 // remembered set update. For now just don't cache anything (the | |
230 // code in the def'd out blocks). | |
231 | |
232 #if 0 | |
233 static int cached_j = 0; | |
234 #endif | |
235 int len = _regions.length(); | |
236 int j = 0; | |
237 // Find the index of r. | |
238 if (r != NULL) { | |
239 #if 0 | |
240 assert(cached_j >= 0, "Invariant."); | |
241 if ((cached_j < len) && (r == _regions.at(cached_j))) { | |
242 j = cached_j; | |
243 } else if ((cached_j + 1 < len) && (r == _regions.at(cached_j + 1))) { | |
244 j = cached_j + 1; | |
245 } else { | |
246 j = find(r); | |
247 #endif | |
248 if (j < 0) { | |
249 j = 0; | |
250 } | |
251 #if 0 | |
252 } | |
253 #endif | |
254 } | |
255 int i; | |
256 for (i = j; i < len; i += 1) { | |
257 int res = blk->doHeapRegion(_regions.at(i)); | |
258 if (res) { | |
259 #if 0 | |
260 cached_j = i; | |
261 #endif | |
262 blk->incomplete(); | |
263 return; | |
264 } | |
265 } | |
266 for (i = 0; i < j; i += 1) { | |
267 int res = blk->doHeapRegion(_regions.at(i)); | |
268 if (res) { | |
269 #if 0 | |
270 cached_j = i; | |
271 #endif | |
272 blk->incomplete(); | |
273 return; | |
274 } | |
275 } | |
276 } | |
277 | |
278 void HeapRegionSeq::iterate_from(int idx, HeapRegionClosure* blk) { | |
279 int len = _regions.length(); | |
280 int i; | |
281 for (i = idx; i < len; i++) { | |
282 if (blk->doHeapRegion(_regions.at(i))) { | |
283 blk->incomplete(); | |
284 return; | |
285 } | |
286 } | |
287 for (i = 0; i < idx; i++) { | |
288 if (blk->doHeapRegion(_regions.at(i))) { | |
289 blk->incomplete(); | |
290 return; | |
291 } | |
292 } | |
293 } | |
294 | |
295 MemRegion HeapRegionSeq::shrink_by(size_t shrink_bytes, | |
296 size_t& num_regions_deleted) { | |
297 assert(shrink_bytes % os::vm_page_size() == 0, "unaligned"); | |
298 assert(shrink_bytes % HeapRegion::GrainBytes == 0, "unaligned"); | |
299 | |
300 if (_regions.length() == 0) { | |
301 num_regions_deleted = 0; | |
302 return MemRegion(); | |
303 } | |
304 int j = _regions.length() - 1; | |
305 HeapWord* end = _regions.at(j)->end(); | |
306 HeapWord* last_start = end; | |
307 while (j >= 0 && shrink_bytes > 0) { | |
308 HeapRegion* cur = _regions.at(j); | |
309 // We have to leave humongous regions where they are, | |
310 // and work around them. | |
311 if (cur->isHumongous()) { | |
312 return MemRegion(last_start, end); | |
313 } | |
314 cur->reset_zero_fill(); | |
315 assert(cur == _regions.top(), "Should be top"); | |
316 if (!cur->is_empty()) break; | |
317 shrink_bytes -= cur->capacity(); | |
318 num_regions_deleted++; | |
319 _regions.pop(); | |
320 last_start = cur->bottom(); | |
321 // We need to delete these somehow, but can't currently do so here: if | |
322 // we do, the ZF thread may still access the deleted region. We'll | |
323 // leave this here as a reminder that we have to do something about | |
324 // this. | |
325 // delete cur; | |
326 j--; | |
327 } | |
328 return MemRegion(last_start, end); | |
329 } | |
330 | |
331 | |
332 class PrintHeapRegionClosure : public HeapRegionClosure { | |
333 public: | |
334 bool doHeapRegion(HeapRegion* r) { | |
335 gclog_or_tty->print(PTR_FORMAT ":", r); | |
336 r->print(); | |
337 return false; | |
338 } | |
339 }; | |
340 | |
341 void HeapRegionSeq::print() { | |
342 PrintHeapRegionClosure cl; | |
343 iterate(&cl); | |
344 } |