Mercurial > hg > graal-jvmci-8
annotate src/share/vm/runtime/virtualspace.cpp @ 3910:d968f546734e
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author | iveresov |
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date | Wed, 07 Sep 2011 11:52:00 -0700 |
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0 | 1 /* |
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2 * Copyright (c) 1997, 2011, 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 * | |
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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 "oops/markOop.hpp" | |
27 #include "oops/oop.inline.hpp" | |
28 #include "runtime/virtualspace.hpp" | |
29 #ifdef TARGET_OS_FAMILY_linux | |
30 # include "os_linux.inline.hpp" | |
31 #endif | |
32 #ifdef TARGET_OS_FAMILY_solaris | |
33 # include "os_solaris.inline.hpp" | |
34 #endif | |
35 #ifdef TARGET_OS_FAMILY_windows | |
36 # include "os_windows.inline.hpp" | |
37 #endif | |
0 | 38 |
39 | |
40 // ReservedSpace | |
41 ReservedSpace::ReservedSpace(size_t size) { | |
656 | 42 initialize(size, 0, false, NULL, 0, false); |
0 | 43 } |
44 | |
45 ReservedSpace::ReservedSpace(size_t size, size_t alignment, | |
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46 bool large, |
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47 char* requested_address, |
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48 const size_t noaccess_prefix) { |
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49 initialize(size+noaccess_prefix, alignment, large, requested_address, |
656 | 50 noaccess_prefix, false); |
51 } | |
52 | |
53 ReservedSpace::ReservedSpace(size_t size, size_t alignment, | |
54 bool large, | |
55 bool executable) { | |
56 initialize(size, alignment, large, NULL, 0, executable); | |
0 | 57 } |
58 | |
59 char * | |
60 ReservedSpace::align_reserved_region(char* addr, const size_t len, | |
61 const size_t prefix_size, | |
62 const size_t prefix_align, | |
63 const size_t suffix_size, | |
64 const size_t suffix_align) | |
65 { | |
66 assert(addr != NULL, "sanity"); | |
67 const size_t required_size = prefix_size + suffix_size; | |
68 assert(len >= required_size, "len too small"); | |
69 | |
70 const size_t s = size_t(addr); | |
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71 const size_t beg_ofs = (s + prefix_size) & (suffix_align - 1); |
0 | 72 const size_t beg_delta = beg_ofs == 0 ? 0 : suffix_align - beg_ofs; |
73 | |
74 if (len < beg_delta + required_size) { | |
75 return NULL; // Cannot do proper alignment. | |
76 } | |
77 const size_t end_delta = len - (beg_delta + required_size); | |
78 | |
79 if (beg_delta != 0) { | |
80 os::release_memory(addr, beg_delta); | |
81 } | |
82 | |
83 if (end_delta != 0) { | |
84 char* release_addr = (char*) (s + beg_delta + required_size); | |
85 os::release_memory(release_addr, end_delta); | |
86 } | |
87 | |
88 return (char*) (s + beg_delta); | |
89 } | |
90 | |
91 char* ReservedSpace::reserve_and_align(const size_t reserve_size, | |
92 const size_t prefix_size, | |
93 const size_t prefix_align, | |
94 const size_t suffix_size, | |
95 const size_t suffix_align) | |
96 { | |
97 assert(reserve_size > prefix_size + suffix_size, "should not be here"); | |
98 | |
99 char* raw_addr = os::reserve_memory(reserve_size, NULL, prefix_align); | |
100 if (raw_addr == NULL) return NULL; | |
101 | |
102 char* result = align_reserved_region(raw_addr, reserve_size, prefix_size, | |
103 prefix_align, suffix_size, | |
104 suffix_align); | |
105 if (result == NULL && !os::release_memory(raw_addr, reserve_size)) { | |
106 fatal("os::release_memory failed"); | |
107 } | |
108 | |
109 #ifdef ASSERT | |
110 if (result != NULL) { | |
111 const size_t raw = size_t(raw_addr); | |
112 const size_t res = size_t(result); | |
113 assert(res >= raw, "alignment decreased start addr"); | |
114 assert(res + prefix_size + suffix_size <= raw + reserve_size, | |
115 "alignment increased end addr"); | |
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116 assert((res & (prefix_align - 1)) == 0, "bad alignment of prefix"); |
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117 assert(((res + prefix_size) & (suffix_align - 1)) == 0, |
0 | 118 "bad alignment of suffix"); |
119 } | |
120 #endif | |
121 | |
122 return result; | |
123 } | |
124 | |
1618 | 125 // Helper method. |
126 static bool failed_to_reserve_as_requested(char* base, char* requested_address, | |
127 const size_t size, bool special) | |
128 { | |
129 if (base == requested_address || requested_address == NULL) | |
130 return false; // did not fail | |
131 | |
132 if (base != NULL) { | |
133 // Different reserve address may be acceptable in other cases | |
134 // but for compressed oops heap should be at requested address. | |
135 assert(UseCompressedOops, "currently requested address used only for compressed oops"); | |
136 if (PrintCompressedOopsMode) { | |
137 tty->cr(); | |
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138 tty->print_cr("Reserved memory not at requested address: " PTR_FORMAT " vs " PTR_FORMAT, base, requested_address); |
1618 | 139 } |
140 // OS ignored requested address. Try different address. | |
141 if (special) { | |
142 if (!os::release_memory_special(base, size)) { | |
143 fatal("os::release_memory_special failed"); | |
144 } | |
145 } else { | |
146 if (!os::release_memory(base, size)) { | |
147 fatal("os::release_memory failed"); | |
148 } | |
149 } | |
150 } | |
151 return true; | |
152 } | |
153 | |
0 | 154 ReservedSpace::ReservedSpace(const size_t prefix_size, |
155 const size_t prefix_align, | |
156 const size_t suffix_size, | |
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157 const size_t suffix_align, |
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158 char* requested_address, |
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159 const size_t noaccess_prefix) |
0 | 160 { |
161 assert(prefix_size != 0, "sanity"); | |
162 assert(prefix_align != 0, "sanity"); | |
163 assert(suffix_size != 0, "sanity"); | |
164 assert(suffix_align != 0, "sanity"); | |
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165 assert((prefix_size & (prefix_align - 1)) == 0, |
0 | 166 "prefix_size not divisible by prefix_align"); |
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167 assert((suffix_size & (suffix_align - 1)) == 0, |
0 | 168 "suffix_size not divisible by suffix_align"); |
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169 assert((suffix_align & (prefix_align - 1)) == 0, |
0 | 170 "suffix_align not divisible by prefix_align"); |
171 | |
1618 | 172 // Assert that if noaccess_prefix is used, it is the same as prefix_align. |
173 assert(noaccess_prefix == 0 || | |
174 noaccess_prefix == prefix_align, "noaccess prefix wrong"); | |
175 | |
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176 // Add in noaccess_prefix to prefix_size; |
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177 const size_t adjusted_prefix_size = prefix_size + noaccess_prefix; |
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178 const size_t size = adjusted_prefix_size + suffix_size; |
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179 |
0 | 180 // On systems where the entire region has to be reserved and committed up |
181 // front, the compound alignment normally done by this method is unnecessary. | |
182 const bool try_reserve_special = UseLargePages && | |
183 prefix_align == os::large_page_size(); | |
184 if (!os::can_commit_large_page_memory() && try_reserve_special) { | |
656 | 185 initialize(size, prefix_align, true, requested_address, noaccess_prefix, |
186 false); | |
0 | 187 return; |
188 } | |
189 | |
190 _base = NULL; | |
191 _size = 0; | |
192 _alignment = 0; | |
193 _special = false; | |
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194 _noaccess_prefix = 0; |
656 | 195 _executable = false; |
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196 |
0 | 197 // Optimistically try to reserve the exact size needed. |
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198 char* addr; |
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199 if (requested_address != 0) { |
1618 | 200 requested_address -= noaccess_prefix; // adjust address |
201 assert(requested_address != NULL, "huge noaccess prefix?"); | |
202 addr = os::attempt_reserve_memory_at(size, requested_address); | |
203 if (failed_to_reserve_as_requested(addr, requested_address, size, false)) { | |
204 // OS ignored requested address. Try different address. | |
205 addr = NULL; | |
206 } | |
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207 } else { |
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208 addr = os::reserve_memory(size, NULL, prefix_align); |
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209 } |
0 | 210 if (addr == NULL) return; |
211 | |
212 // Check whether the result has the needed alignment (unlikely unless | |
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213 // prefix_align < suffix_align). |
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214 const size_t ofs = (size_t(addr) + adjusted_prefix_size) & (suffix_align - 1); |
0 | 215 if (ofs != 0) { |
216 // Wrong alignment. Release, allocate more space and do manual alignment. | |
217 // | |
218 // On most operating systems, another allocation with a somewhat larger size | |
219 // will return an address "close to" that of the previous allocation. The | |
220 // result is often the same address (if the kernel hands out virtual | |
221 // addresses from low to high), or an address that is offset by the increase | |
222 // in size. Exploit that to minimize the amount of extra space requested. | |
223 if (!os::release_memory(addr, size)) { | |
224 fatal("os::release_memory failed"); | |
225 } | |
226 | |
227 const size_t extra = MAX2(ofs, suffix_align - ofs); | |
237
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228 addr = reserve_and_align(size + extra, adjusted_prefix_size, prefix_align, |
0 | 229 suffix_size, suffix_align); |
230 if (addr == NULL) { | |
231 // Try an even larger region. If this fails, address space is exhausted. | |
237
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232 addr = reserve_and_align(size + suffix_align, adjusted_prefix_size, |
0 | 233 prefix_align, suffix_size, suffix_align); |
234 } | |
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235 |
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236 if (requested_address != 0 && |
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237 failed_to_reserve_as_requested(addr, requested_address, size, false)) { |
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238 // As a result of the alignment constraints, the allocated addr differs |
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239 // from the requested address. Return back to the caller who can |
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240 // take remedial action (like try again without a requested address). |
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241 assert(_base == NULL, "should be"); |
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242 return; |
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243 } |
0 | 244 } |
245 | |
246 _base = addr; | |
247 _size = size; | |
248 _alignment = prefix_align; | |
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249 _noaccess_prefix = noaccess_prefix; |
0 | 250 } |
251 | |
252 void ReservedSpace::initialize(size_t size, size_t alignment, bool large, | |
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253 char* requested_address, |
656 | 254 const size_t noaccess_prefix, |
255 bool executable) { | |
0 | 256 const size_t granularity = os::vm_allocation_granularity(); |
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257 assert((size & (granularity - 1)) == 0, |
0 | 258 "size not aligned to os::vm_allocation_granularity()"); |
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259 assert((alignment & (granularity - 1)) == 0, |
0 | 260 "alignment not aligned to os::vm_allocation_granularity()"); |
261 assert(alignment == 0 || is_power_of_2((intptr_t)alignment), | |
262 "not a power of 2"); | |
263 | |
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264 alignment = MAX2(alignment, (size_t)os::vm_page_size()); |
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265 |
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266 // Assert that if noaccess_prefix is used, it is the same as alignment. |
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267 assert(noaccess_prefix == 0 || |
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268 noaccess_prefix == alignment, "noaccess prefix wrong"); |
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269 |
0 | 270 _base = NULL; |
271 _size = 0; | |
272 _special = false; | |
656 | 273 _executable = executable; |
0 | 274 _alignment = 0; |
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275 _noaccess_prefix = 0; |
0 | 276 if (size == 0) { |
277 return; | |
278 } | |
279 | |
280 // If OS doesn't support demand paging for large page memory, we need | |
281 // to use reserve_memory_special() to reserve and pin the entire region. | |
282 bool special = large && !os::can_commit_large_page_memory(); | |
283 char* base = NULL; | |
284 | |
1618 | 285 if (requested_address != 0) { |
286 requested_address -= noaccess_prefix; // adjust requested address | |
287 assert(requested_address != NULL, "huge noaccess prefix?"); | |
288 } | |
289 | |
0 | 290 if (special) { |
291 | |
656 | 292 base = os::reserve_memory_special(size, requested_address, executable); |
0 | 293 |
294 if (base != NULL) { | |
1618 | 295 if (failed_to_reserve_as_requested(base, requested_address, size, true)) { |
296 // OS ignored requested address. Try different address. | |
297 return; | |
298 } | |
0 | 299 // Check alignment constraints |
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300 assert((uintptr_t) base % alignment == 0, |
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301 "Large pages returned a non-aligned address"); |
0 | 302 _special = true; |
303 } else { | |
304 // failed; try to reserve regular memory below | |
1618 | 305 if (UseLargePages && (!FLAG_IS_DEFAULT(UseLargePages) || |
306 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { | |
307 if (PrintCompressedOopsMode) { | |
308 tty->cr(); | |
309 tty->print_cr("Reserve regular memory without large pages."); | |
310 } | |
311 } | |
0 | 312 } |
313 } | |
314 | |
315 if (base == NULL) { | |
316 // Optimistically assume that the OSes returns an aligned base pointer. | |
317 // When reserving a large address range, most OSes seem to align to at | |
318 // least 64K. | |
319 | |
320 // If the memory was requested at a particular address, use | |
321 // os::attempt_reserve_memory_at() to avoid over mapping something | |
322 // important. If available space is not detected, return NULL. | |
323 | |
324 if (requested_address != 0) { | |
1618 | 325 base = os::attempt_reserve_memory_at(size, requested_address); |
326 if (failed_to_reserve_as_requested(base, requested_address, size, false)) { | |
327 // OS ignored requested address. Try different address. | |
328 base = NULL; | |
329 } | |
0 | 330 } else { |
331 base = os::reserve_memory(size, NULL, alignment); | |
332 } | |
333 | |
334 if (base == NULL) return; | |
335 | |
336 // Check alignment constraints | |
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337 if ((((size_t)base + noaccess_prefix) & (alignment - 1)) != 0) { |
0 | 338 // Base not aligned, retry |
339 if (!os::release_memory(base, size)) fatal("os::release_memory failed"); | |
340 // Reserve size large enough to do manual alignment and | |
341 // increase size to a multiple of the desired alignment | |
342 size = align_size_up(size, alignment); | |
343 size_t extra_size = size + alignment; | |
342 | 344 do { |
345 char* extra_base = os::reserve_memory(extra_size, NULL, alignment); | |
346 if (extra_base == NULL) return; | |
347 // Do manual alignement | |
348 base = (char*) align_size_up((uintptr_t) extra_base, alignment); | |
349 assert(base >= extra_base, "just checking"); | |
350 // Re-reserve the region at the aligned base address. | |
351 os::release_memory(extra_base, extra_size); | |
352 base = os::reserve_memory(size, base); | |
353 } while (base == NULL); | |
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354 |
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355 if (requested_address != 0 && |
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356 failed_to_reserve_as_requested(base, requested_address, size, false)) { |
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357 // As a result of the alignment constraints, the allocated base differs |
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358 // from the requested address. Return back to the caller who can |
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359 // take remedial action (like try again without a requested address). |
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360 assert(_base == NULL, "should be"); |
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361 return; |
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362 } |
0 | 363 } |
364 } | |
365 // Done | |
366 _base = base; | |
367 _size = size; | |
3824
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368 _alignment = alignment; |
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369 _noaccess_prefix = noaccess_prefix; |
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370 |
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371 // Assert that if noaccess_prefix is used, it is the same as alignment. |
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372 assert(noaccess_prefix == 0 || |
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373 noaccess_prefix == _alignment, "noaccess prefix wrong"); |
0 | 374 |
375 assert(markOopDesc::encode_pointer_as_mark(_base)->decode_pointer() == _base, | |
376 "area must be distinguisable from marks for mark-sweep"); | |
377 assert(markOopDesc::encode_pointer_as_mark(&_base[size])->decode_pointer() == &_base[size], | |
378 "area must be distinguisable from marks for mark-sweep"); | |
379 } | |
380 | |
381 | |
382 ReservedSpace::ReservedSpace(char* base, size_t size, size_t alignment, | |
656 | 383 bool special, bool executable) { |
0 | 384 assert((size % os::vm_allocation_granularity()) == 0, |
385 "size not allocation aligned"); | |
386 _base = base; | |
387 _size = size; | |
388 _alignment = alignment; | |
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389 _noaccess_prefix = 0; |
0 | 390 _special = special; |
656 | 391 _executable = executable; |
0 | 392 } |
393 | |
394 | |
395 ReservedSpace ReservedSpace::first_part(size_t partition_size, size_t alignment, | |
396 bool split, bool realloc) { | |
397 assert(partition_size <= size(), "partition failed"); | |
398 if (split) { | |
656 | 399 os::split_reserved_memory(base(), size(), partition_size, realloc); |
0 | 400 } |
656 | 401 ReservedSpace result(base(), partition_size, alignment, special(), |
402 executable()); | |
0 | 403 return result; |
404 } | |
405 | |
406 | |
407 ReservedSpace | |
408 ReservedSpace::last_part(size_t partition_size, size_t alignment) { | |
409 assert(partition_size <= size(), "partition failed"); | |
410 ReservedSpace result(base() + partition_size, size() - partition_size, | |
656 | 411 alignment, special(), executable()); |
0 | 412 return result; |
413 } | |
414 | |
415 | |
416 size_t ReservedSpace::page_align_size_up(size_t size) { | |
417 return align_size_up(size, os::vm_page_size()); | |
418 } | |
419 | |
420 | |
421 size_t ReservedSpace::page_align_size_down(size_t size) { | |
422 return align_size_down(size, os::vm_page_size()); | |
423 } | |
424 | |
425 | |
426 size_t ReservedSpace::allocation_align_size_up(size_t size) { | |
427 return align_size_up(size, os::vm_allocation_granularity()); | |
428 } | |
429 | |
430 | |
431 size_t ReservedSpace::allocation_align_size_down(size_t size) { | |
432 return align_size_down(size, os::vm_allocation_granularity()); | |
433 } | |
434 | |
435 | |
436 void ReservedSpace::release() { | |
437 if (is_reserved()) { | |
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438 char *real_base = _base - _noaccess_prefix; |
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439 const size_t real_size = _size + _noaccess_prefix; |
0 | 440 if (special()) { |
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441 os::release_memory_special(real_base, real_size); |
0 | 442 } else{ |
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443 os::release_memory(real_base, real_size); |
0 | 444 } |
445 _base = NULL; | |
446 _size = 0; | |
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447 _noaccess_prefix = 0; |
0 | 448 _special = false; |
656 | 449 _executable = false; |
0 | 450 } |
451 } | |
452 | |
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453 void ReservedSpace::protect_noaccess_prefix(const size_t size) { |
1618 | 454 assert( (_noaccess_prefix != 0) == (UseCompressedOops && _base != NULL && |
455 (size_t(_base + _size) > OopEncodingHeapMax) && | |
456 Universe::narrow_oop_use_implicit_null_checks()), | |
457 "noaccess_prefix should be used only with non zero based compressed oops"); | |
458 | |
459 // If there is no noaccess prefix, return. | |
237
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460 if (_noaccess_prefix == 0) return; |
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461 |
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462 assert(_noaccess_prefix >= (size_t)os::vm_page_size(), |
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463 "must be at least page size big"); |
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464 |
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465 // Protect memory at the base of the allocated region. |
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466 // If special, the page was committed (only matters on windows) |
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467 if (!os::protect_memory(_base, _noaccess_prefix, os::MEM_PROT_NONE, |
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468 _special)) { |
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469 fatal("cannot protect protection page"); |
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470 } |
1618 | 471 if (PrintCompressedOopsMode) { |
472 tty->cr(); | |
473 tty->print_cr("Protected page at the reserved heap base: " PTR_FORMAT " / " INTX_FORMAT " bytes", _base, _noaccess_prefix); | |
474 } | |
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475 |
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476 _base += _noaccess_prefix; |
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477 _size -= _noaccess_prefix; |
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478 assert((size == _size) && ((uintptr_t)_base % _alignment == 0), |
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479 "must be exactly of required size and alignment"); |
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480 } |
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481 |
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482 ReservedHeapSpace::ReservedHeapSpace(size_t size, size_t alignment, |
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483 bool large, char* requested_address) : |
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484 ReservedSpace(size, alignment, large, |
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485 requested_address, |
642
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486 (UseCompressedOops && (Universe::narrow_oop_base() != NULL) && |
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487 Universe::narrow_oop_use_implicit_null_checks()) ? |
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488 lcm(os::vm_page_size(), alignment) : 0) { |
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489 // Only reserved space for the java heap should have a noaccess_prefix |
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490 // if using compressed oops. |
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491 protect_noaccess_prefix(size); |
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492 } |
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493 |
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494 ReservedHeapSpace::ReservedHeapSpace(const size_t prefix_size, |
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495 const size_t prefix_align, |
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496 const size_t suffix_size, |
642
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497 const size_t suffix_align, |
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498 char* requested_address) : |
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499 ReservedSpace(prefix_size, prefix_align, suffix_size, suffix_align, |
642
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500 requested_address, |
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501 (UseCompressedOops && (Universe::narrow_oop_base() != NULL) && |
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502 Universe::narrow_oop_use_implicit_null_checks()) ? |
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503 lcm(os::vm_page_size(), prefix_align) : 0) { |
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504 protect_noaccess_prefix(prefix_size+suffix_size); |
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505 } |
0 | 506 |
656 | 507 // Reserve space for code segment. Same as Java heap only we mark this as |
508 // executable. | |
509 ReservedCodeSpace::ReservedCodeSpace(size_t r_size, | |
510 size_t rs_align, | |
511 bool large) : | |
512 ReservedSpace(r_size, rs_align, large, /*executable*/ true) { | |
513 } | |
514 | |
0 | 515 // VirtualSpace |
516 | |
517 VirtualSpace::VirtualSpace() { | |
518 _low_boundary = NULL; | |
519 _high_boundary = NULL; | |
520 _low = NULL; | |
521 _high = NULL; | |
522 _lower_high = NULL; | |
523 _middle_high = NULL; | |
524 _upper_high = NULL; | |
525 _lower_high_boundary = NULL; | |
526 _middle_high_boundary = NULL; | |
527 _upper_high_boundary = NULL; | |
528 _lower_alignment = 0; | |
529 _middle_alignment = 0; | |
530 _upper_alignment = 0; | |
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531 _special = false; |
656 | 532 _executable = false; |
0 | 533 } |
534 | |
535 | |
536 bool VirtualSpace::initialize(ReservedSpace rs, size_t committed_size) { | |
537 if(!rs.is_reserved()) return false; // allocation failed. | |
538 assert(_low_boundary == NULL, "VirtualSpace already initialized"); | |
539 _low_boundary = rs.base(); | |
540 _high_boundary = low_boundary() + rs.size(); | |
541 | |
542 _low = low_boundary(); | |
543 _high = low(); | |
544 | |
545 _special = rs.special(); | |
656 | 546 _executable = rs.executable(); |
0 | 547 |
548 // When a VirtualSpace begins life at a large size, make all future expansion | |
549 // and shrinking occur aligned to a granularity of large pages. This avoids | |
550 // fragmentation of physical addresses that inhibits the use of large pages | |
551 // by the OS virtual memory system. Empirically, we see that with a 4MB | |
552 // page size, the only spaces that get handled this way are codecache and | |
553 // the heap itself, both of which provide a substantial performance | |
554 // boost in many benchmarks when covered by large pages. | |
555 // | |
556 // No attempt is made to force large page alignment at the very top and | |
557 // bottom of the space if they are not aligned so already. | |
558 _lower_alignment = os::vm_page_size(); | |
559 _middle_alignment = os::page_size_for_region(rs.size(), rs.size(), 1); | |
560 _upper_alignment = os::vm_page_size(); | |
561 | |
562 // End of each region | |
563 _lower_high_boundary = (char*) round_to((intptr_t) low_boundary(), middle_alignment()); | |
564 _middle_high_boundary = (char*) round_down((intptr_t) high_boundary(), middle_alignment()); | |
565 _upper_high_boundary = high_boundary(); | |
566 | |
567 // High address of each region | |
568 _lower_high = low_boundary(); | |
569 _middle_high = lower_high_boundary(); | |
570 _upper_high = middle_high_boundary(); | |
571 | |
572 // commit to initial size | |
573 if (committed_size > 0) { | |
574 if (!expand_by(committed_size)) { | |
575 return false; | |
576 } | |
577 } | |
578 return true; | |
579 } | |
580 | |
581 | |
582 VirtualSpace::~VirtualSpace() { | |
583 release(); | |
584 } | |
585 | |
586 | |
587 void VirtualSpace::release() { | |
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588 // This does not release memory it never reserved. |
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589 // Caller must release via rs.release(); |
0 | 590 _low_boundary = NULL; |
591 _high_boundary = NULL; | |
592 _low = NULL; | |
593 _high = NULL; | |
594 _lower_high = NULL; | |
595 _middle_high = NULL; | |
596 _upper_high = NULL; | |
597 _lower_high_boundary = NULL; | |
598 _middle_high_boundary = NULL; | |
599 _upper_high_boundary = NULL; | |
600 _lower_alignment = 0; | |
601 _middle_alignment = 0; | |
602 _upper_alignment = 0; | |
603 _special = false; | |
656 | 604 _executable = false; |
0 | 605 } |
606 | |
607 | |
608 size_t VirtualSpace::committed_size() const { | |
609 return pointer_delta(high(), low(), sizeof(char)); | |
610 } | |
611 | |
612 | |
613 size_t VirtualSpace::reserved_size() const { | |
614 return pointer_delta(high_boundary(), low_boundary(), sizeof(char)); | |
615 } | |
616 | |
617 | |
618 size_t VirtualSpace::uncommitted_size() const { | |
619 return reserved_size() - committed_size(); | |
620 } | |
621 | |
622 | |
623 bool VirtualSpace::contains(const void* p) const { | |
624 return low() <= (const char*) p && (const char*) p < high(); | |
625 } | |
626 | |
627 /* | |
628 First we need to determine if a particular virtual space is using large | |
629 pages. This is done at the initialize function and only virtual spaces | |
630 that are larger than LargePageSizeInBytes use large pages. Once we | |
631 have determined this, all expand_by and shrink_by calls must grow and | |
632 shrink by large page size chunks. If a particular request | |
633 is within the current large page, the call to commit and uncommit memory | |
634 can be ignored. In the case that the low and high boundaries of this | |
635 space is not large page aligned, the pages leading to the first large | |
636 page address and the pages after the last large page address must be | |
637 allocated with default pages. | |
638 */ | |
639 bool VirtualSpace::expand_by(size_t bytes, bool pre_touch) { | |
640 if (uncommitted_size() < bytes) return false; | |
641 | |
642 if (special()) { | |
643 // don't commit memory if the entire space is pinned in memory | |
644 _high += bytes; | |
645 return true; | |
646 } | |
647 | |
648 char* previous_high = high(); | |
649 char* unaligned_new_high = high() + bytes; | |
650 assert(unaligned_new_high <= high_boundary(), | |
651 "cannot expand by more than upper boundary"); | |
652 | |
653 // Calculate where the new high for each of the regions should be. If | |
654 // the low_boundary() and high_boundary() are LargePageSizeInBytes aligned | |
655 // then the unaligned lower and upper new highs would be the | |
656 // lower_high() and upper_high() respectively. | |
657 char* unaligned_lower_new_high = | |
658 MIN2(unaligned_new_high, lower_high_boundary()); | |
659 char* unaligned_middle_new_high = | |
660 MIN2(unaligned_new_high, middle_high_boundary()); | |
661 char* unaligned_upper_new_high = | |
662 MIN2(unaligned_new_high, upper_high_boundary()); | |
663 | |
664 // Align the new highs based on the regions alignment. lower and upper | |
665 // alignment will always be default page size. middle alignment will be | |
666 // LargePageSizeInBytes if the actual size of the virtual space is in | |
667 // fact larger than LargePageSizeInBytes. | |
668 char* aligned_lower_new_high = | |
669 (char*) round_to((intptr_t) unaligned_lower_new_high, lower_alignment()); | |
670 char* aligned_middle_new_high = | |
671 (char*) round_to((intptr_t) unaligned_middle_new_high, middle_alignment()); | |
672 char* aligned_upper_new_high = | |
673 (char*) round_to((intptr_t) unaligned_upper_new_high, upper_alignment()); | |
674 | |
675 // Determine which regions need to grow in this expand_by call. | |
676 // If you are growing in the lower region, high() must be in that | |
677 // region so calcuate the size based on high(). For the middle and | |
678 // upper regions, determine the starting point of growth based on the | |
679 // location of high(). By getting the MAX of the region's low address | |
680 // (or the prevoius region's high address) and high(), we can tell if it | |
681 // is an intra or inter region growth. | |
682 size_t lower_needs = 0; | |
683 if (aligned_lower_new_high > lower_high()) { | |
684 lower_needs = | |
685 pointer_delta(aligned_lower_new_high, lower_high(), sizeof(char)); | |
686 } | |
687 size_t middle_needs = 0; | |
688 if (aligned_middle_new_high > middle_high()) { | |
689 middle_needs = | |
690 pointer_delta(aligned_middle_new_high, middle_high(), sizeof(char)); | |
691 } | |
692 size_t upper_needs = 0; | |
693 if (aligned_upper_new_high > upper_high()) { | |
694 upper_needs = | |
695 pointer_delta(aligned_upper_new_high, upper_high(), sizeof(char)); | |
696 } | |
697 | |
698 // Check contiguity. | |
699 assert(low_boundary() <= lower_high() && | |
700 lower_high() <= lower_high_boundary(), | |
701 "high address must be contained within the region"); | |
702 assert(lower_high_boundary() <= middle_high() && | |
703 middle_high() <= middle_high_boundary(), | |
704 "high address must be contained within the region"); | |
705 assert(middle_high_boundary() <= upper_high() && | |
706 upper_high() <= upper_high_boundary(), | |
707 "high address must be contained within the region"); | |
708 | |
709 // Commit regions | |
710 if (lower_needs > 0) { | |
711 assert(low_boundary() <= lower_high() && | |
712 lower_high() + lower_needs <= lower_high_boundary(), | |
713 "must not expand beyond region"); | |
656 | 714 if (!os::commit_memory(lower_high(), lower_needs, _executable)) { |
0 | 715 debug_only(warning("os::commit_memory failed")); |
716 return false; | |
717 } else { | |
718 _lower_high += lower_needs; | |
719 } | |
720 } | |
721 if (middle_needs > 0) { | |
722 assert(lower_high_boundary() <= middle_high() && | |
723 middle_high() + middle_needs <= middle_high_boundary(), | |
724 "must not expand beyond region"); | |
656 | 725 if (!os::commit_memory(middle_high(), middle_needs, middle_alignment(), |
726 _executable)) { | |
0 | 727 debug_only(warning("os::commit_memory failed")); |
728 return false; | |
729 } | |
730 _middle_high += middle_needs; | |
731 } | |
732 if (upper_needs > 0) { | |
733 assert(middle_high_boundary() <= upper_high() && | |
734 upper_high() + upper_needs <= upper_high_boundary(), | |
735 "must not expand beyond region"); | |
656 | 736 if (!os::commit_memory(upper_high(), upper_needs, _executable)) { |
0 | 737 debug_only(warning("os::commit_memory failed")); |
738 return false; | |
739 } else { | |
740 _upper_high += upper_needs; | |
741 } | |
742 } | |
743 | |
744 if (pre_touch || AlwaysPreTouch) { | |
745 int vm_ps = os::vm_page_size(); | |
746 for (char* curr = previous_high; | |
747 curr < unaligned_new_high; | |
748 curr += vm_ps) { | |
749 // Note the use of a write here; originally we tried just a read, but | |
750 // since the value read was unused, the optimizer removed the read. | |
751 // If we ever have a concurrent touchahead thread, we'll want to use | |
752 // a read, to avoid the potential of overwriting data (if a mutator | |
753 // thread beats the touchahead thread to a page). There are various | |
754 // ways of making sure this read is not optimized away: for example, | |
755 // generating the code for a read procedure at runtime. | |
756 *curr = 0; | |
757 } | |
758 } | |
759 | |
760 _high += bytes; | |
761 return true; | |
762 } | |
763 | |
764 // A page is uncommitted if the contents of the entire page is deemed unusable. | |
765 // Continue to decrement the high() pointer until it reaches a page boundary | |
766 // in which case that particular page can now be uncommitted. | |
767 void VirtualSpace::shrink_by(size_t size) { | |
768 if (committed_size() < size) | |
769 fatal("Cannot shrink virtual space to negative size"); | |
770 | |
771 if (special()) { | |
772 // don't uncommit if the entire space is pinned in memory | |
773 _high -= size; | |
774 return; | |
775 } | |
776 | |
777 char* unaligned_new_high = high() - size; | |
778 assert(unaligned_new_high >= low_boundary(), "cannot shrink past lower boundary"); | |
779 | |
780 // Calculate new unaligned address | |
781 char* unaligned_upper_new_high = | |
782 MAX2(unaligned_new_high, middle_high_boundary()); | |
783 char* unaligned_middle_new_high = | |
784 MAX2(unaligned_new_high, lower_high_boundary()); | |
785 char* unaligned_lower_new_high = | |
786 MAX2(unaligned_new_high, low_boundary()); | |
787 | |
788 // Align address to region's alignment | |
789 char* aligned_upper_new_high = | |
790 (char*) round_to((intptr_t) unaligned_upper_new_high, upper_alignment()); | |
791 char* aligned_middle_new_high = | |
792 (char*) round_to((intptr_t) unaligned_middle_new_high, middle_alignment()); | |
793 char* aligned_lower_new_high = | |
794 (char*) round_to((intptr_t) unaligned_lower_new_high, lower_alignment()); | |
795 | |
796 // Determine which regions need to shrink | |
797 size_t upper_needs = 0; | |
798 if (aligned_upper_new_high < upper_high()) { | |
799 upper_needs = | |
800 pointer_delta(upper_high(), aligned_upper_new_high, sizeof(char)); | |
801 } | |
802 size_t middle_needs = 0; | |
803 if (aligned_middle_new_high < middle_high()) { | |
804 middle_needs = | |
805 pointer_delta(middle_high(), aligned_middle_new_high, sizeof(char)); | |
806 } | |
807 size_t lower_needs = 0; | |
808 if (aligned_lower_new_high < lower_high()) { | |
809 lower_needs = | |
810 pointer_delta(lower_high(), aligned_lower_new_high, sizeof(char)); | |
811 } | |
812 | |
813 // Check contiguity. | |
814 assert(middle_high_boundary() <= upper_high() && | |
815 upper_high() <= upper_high_boundary(), | |
816 "high address must be contained within the region"); | |
817 assert(lower_high_boundary() <= middle_high() && | |
818 middle_high() <= middle_high_boundary(), | |
819 "high address must be contained within the region"); | |
820 assert(low_boundary() <= lower_high() && | |
821 lower_high() <= lower_high_boundary(), | |
822 "high address must be contained within the region"); | |
823 | |
824 // Uncommit | |
825 if (upper_needs > 0) { | |
826 assert(middle_high_boundary() <= aligned_upper_new_high && | |
827 aligned_upper_new_high + upper_needs <= upper_high_boundary(), | |
828 "must not shrink beyond region"); | |
829 if (!os::uncommit_memory(aligned_upper_new_high, upper_needs)) { | |
830 debug_only(warning("os::uncommit_memory failed")); | |
831 return; | |
832 } else { | |
833 _upper_high -= upper_needs; | |
834 } | |
835 } | |
836 if (middle_needs > 0) { | |
837 assert(lower_high_boundary() <= aligned_middle_new_high && | |
838 aligned_middle_new_high + middle_needs <= middle_high_boundary(), | |
839 "must not shrink beyond region"); | |
840 if (!os::uncommit_memory(aligned_middle_new_high, middle_needs)) { | |
841 debug_only(warning("os::uncommit_memory failed")); | |
842 return; | |
843 } else { | |
844 _middle_high -= middle_needs; | |
845 } | |
846 } | |
847 if (lower_needs > 0) { | |
848 assert(low_boundary() <= aligned_lower_new_high && | |
849 aligned_lower_new_high + lower_needs <= lower_high_boundary(), | |
850 "must not shrink beyond region"); | |
851 if (!os::uncommit_memory(aligned_lower_new_high, lower_needs)) { | |
852 debug_only(warning("os::uncommit_memory failed")); | |
853 return; | |
854 } else { | |
855 _lower_high -= lower_needs; | |
856 } | |
857 } | |
858 | |
859 _high -= size; | |
860 } | |
861 | |
862 #ifndef PRODUCT | |
863 void VirtualSpace::check_for_contiguity() { | |
864 // Check contiguity. | |
865 assert(low_boundary() <= lower_high() && | |
866 lower_high() <= lower_high_boundary(), | |
867 "high address must be contained within the region"); | |
868 assert(lower_high_boundary() <= middle_high() && | |
869 middle_high() <= middle_high_boundary(), | |
870 "high address must be contained within the region"); | |
871 assert(middle_high_boundary() <= upper_high() && | |
872 upper_high() <= upper_high_boundary(), | |
873 "high address must be contained within the region"); | |
874 assert(low() >= low_boundary(), "low"); | |
875 assert(low_boundary() <= lower_high_boundary(), "lower high boundary"); | |
876 assert(upper_high_boundary() <= high_boundary(), "upper high boundary"); | |
877 assert(high() <= upper_high(), "upper high"); | |
878 } | |
879 | |
880 void VirtualSpace::print() { | |
881 tty->print ("Virtual space:"); | |
882 if (special()) tty->print(" (pinned in memory)"); | |
883 tty->cr(); | |
884 tty->print_cr(" - committed: %ld", committed_size()); | |
885 tty->print_cr(" - reserved: %ld", reserved_size()); | |
886 tty->print_cr(" - [low, high]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", low(), high()); | |
887 tty->print_cr(" - [low_b, high_b]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", low_boundary(), high_boundary()); | |
888 } | |
889 | |
890 #endif |