Mercurial > hg > graal-compiler
annotate src/share/vm/runtime/virtualspace.cpp @ 4911:d903bf750e9f
7129514: time warp warnings after 7117303
Summary: Replace calls to os::javaTimeMillis() that are used to update the milliseconds since the last GC to an equivalent that uses a monotonically non-decreasing time source.
Reviewed-by: ysr, jmasa
author | johnc |
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date | Wed, 18 Jan 2012 09:50:16 -0800 |
parents | f08d439fab8c |
children | 7df3125953cb |
rev | line source |
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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 | |
3960 | 38 #ifdef TARGET_OS_FAMILY_bsd |
39 # include "os_bsd.inline.hpp" | |
40 #endif | |
0 | 41 |
42 | |
43 // ReservedSpace | |
44 ReservedSpace::ReservedSpace(size_t size) { | |
656 | 45 initialize(size, 0, false, NULL, 0, false); |
0 | 46 } |
47 | |
48 ReservedSpace::ReservedSpace(size_t size, size_t alignment, | |
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49 bool large, |
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50 char* requested_address, |
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51 const size_t noaccess_prefix) { |
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52 initialize(size+noaccess_prefix, alignment, large, requested_address, |
656 | 53 noaccess_prefix, false); |
54 } | |
55 | |
56 ReservedSpace::ReservedSpace(size_t size, size_t alignment, | |
57 bool large, | |
58 bool executable) { | |
59 initialize(size, alignment, large, NULL, 0, executable); | |
0 | 60 } |
61 | |
62 char * | |
63 ReservedSpace::align_reserved_region(char* addr, const size_t len, | |
64 const size_t prefix_size, | |
65 const size_t prefix_align, | |
66 const size_t suffix_size, | |
67 const size_t suffix_align) | |
68 { | |
69 assert(addr != NULL, "sanity"); | |
70 const size_t required_size = prefix_size + suffix_size; | |
71 assert(len >= required_size, "len too small"); | |
72 | |
73 const size_t s = size_t(addr); | |
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74 const size_t beg_ofs = (s + prefix_size) & (suffix_align - 1); |
0 | 75 const size_t beg_delta = beg_ofs == 0 ? 0 : suffix_align - beg_ofs; |
76 | |
77 if (len < beg_delta + required_size) { | |
78 return NULL; // Cannot do proper alignment. | |
79 } | |
80 const size_t end_delta = len - (beg_delta + required_size); | |
81 | |
82 if (beg_delta != 0) { | |
83 os::release_memory(addr, beg_delta); | |
84 } | |
85 | |
86 if (end_delta != 0) { | |
87 char* release_addr = (char*) (s + beg_delta + required_size); | |
88 os::release_memory(release_addr, end_delta); | |
89 } | |
90 | |
91 return (char*) (s + beg_delta); | |
92 } | |
93 | |
94 char* ReservedSpace::reserve_and_align(const size_t reserve_size, | |
95 const size_t prefix_size, | |
96 const size_t prefix_align, | |
97 const size_t suffix_size, | |
98 const size_t suffix_align) | |
99 { | |
100 assert(reserve_size > prefix_size + suffix_size, "should not be here"); | |
101 | |
102 char* raw_addr = os::reserve_memory(reserve_size, NULL, prefix_align); | |
103 if (raw_addr == NULL) return NULL; | |
104 | |
105 char* result = align_reserved_region(raw_addr, reserve_size, prefix_size, | |
106 prefix_align, suffix_size, | |
107 suffix_align); | |
108 if (result == NULL && !os::release_memory(raw_addr, reserve_size)) { | |
109 fatal("os::release_memory failed"); | |
110 } | |
111 | |
112 #ifdef ASSERT | |
113 if (result != NULL) { | |
114 const size_t raw = size_t(raw_addr); | |
115 const size_t res = size_t(result); | |
116 assert(res >= raw, "alignment decreased start addr"); | |
117 assert(res + prefix_size + suffix_size <= raw + reserve_size, | |
118 "alignment increased end addr"); | |
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119 assert((res & (prefix_align - 1)) == 0, "bad alignment of prefix"); |
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120 assert(((res + prefix_size) & (suffix_align - 1)) == 0, |
0 | 121 "bad alignment of suffix"); |
122 } | |
123 #endif | |
124 | |
125 return result; | |
126 } | |
127 | |
1618 | 128 // Helper method. |
129 static bool failed_to_reserve_as_requested(char* base, char* requested_address, | |
130 const size_t size, bool special) | |
131 { | |
132 if (base == requested_address || requested_address == NULL) | |
133 return false; // did not fail | |
134 | |
135 if (base != NULL) { | |
136 // Different reserve address may be acceptable in other cases | |
137 // but for compressed oops heap should be at requested address. | |
138 assert(UseCompressedOops, "currently requested address used only for compressed oops"); | |
139 if (PrintCompressedOopsMode) { | |
140 tty->cr(); | |
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141 tty->print_cr("Reserved memory not at requested address: " PTR_FORMAT " vs " PTR_FORMAT, base, requested_address); |
1618 | 142 } |
143 // OS ignored requested address. Try different address. | |
144 if (special) { | |
145 if (!os::release_memory_special(base, size)) { | |
146 fatal("os::release_memory_special failed"); | |
147 } | |
148 } else { | |
149 if (!os::release_memory(base, size)) { | |
150 fatal("os::release_memory failed"); | |
151 } | |
152 } | |
153 } | |
154 return true; | |
155 } | |
156 | |
0 | 157 ReservedSpace::ReservedSpace(const size_t prefix_size, |
158 const size_t prefix_align, | |
159 const size_t suffix_size, | |
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160 const size_t suffix_align, |
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161 char* requested_address, |
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162 const size_t noaccess_prefix) |
0 | 163 { |
164 assert(prefix_size != 0, "sanity"); | |
165 assert(prefix_align != 0, "sanity"); | |
166 assert(suffix_size != 0, "sanity"); | |
167 assert(suffix_align != 0, "sanity"); | |
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168 assert((prefix_size & (prefix_align - 1)) == 0, |
0 | 169 "prefix_size not divisible by prefix_align"); |
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170 assert((suffix_size & (suffix_align - 1)) == 0, |
0 | 171 "suffix_size not divisible by suffix_align"); |
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172 assert((suffix_align & (prefix_align - 1)) == 0, |
0 | 173 "suffix_align not divisible by prefix_align"); |
174 | |
1618 | 175 // Assert that if noaccess_prefix is used, it is the same as prefix_align. |
176 assert(noaccess_prefix == 0 || | |
177 noaccess_prefix == prefix_align, "noaccess prefix wrong"); | |
178 | |
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179 // Add in noaccess_prefix to prefix_size; |
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180 const size_t adjusted_prefix_size = prefix_size + noaccess_prefix; |
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181 const size_t size = adjusted_prefix_size + suffix_size; |
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182 |
0 | 183 // On systems where the entire region has to be reserved and committed up |
184 // front, the compound alignment normally done by this method is unnecessary. | |
185 const bool try_reserve_special = UseLargePages && | |
186 prefix_align == os::large_page_size(); | |
187 if (!os::can_commit_large_page_memory() && try_reserve_special) { | |
656 | 188 initialize(size, prefix_align, true, requested_address, noaccess_prefix, |
189 false); | |
0 | 190 return; |
191 } | |
192 | |
193 _base = NULL; | |
194 _size = 0; | |
195 _alignment = 0; | |
196 _special = false; | |
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197 _noaccess_prefix = 0; |
656 | 198 _executable = false; |
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199 |
0 | 200 // Optimistically try to reserve the exact size needed. |
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201 char* addr; |
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202 if (requested_address != 0) { |
1618 | 203 requested_address -= noaccess_prefix; // adjust address |
204 assert(requested_address != NULL, "huge noaccess prefix?"); | |
205 addr = os::attempt_reserve_memory_at(size, requested_address); | |
206 if (failed_to_reserve_as_requested(addr, requested_address, size, false)) { | |
207 // OS ignored requested address. Try different address. | |
208 addr = NULL; | |
209 } | |
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210 } else { |
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211 addr = os::reserve_memory(size, NULL, prefix_align); |
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212 } |
0 | 213 if (addr == NULL) return; |
214 | |
215 // Check whether the result has the needed alignment (unlikely unless | |
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216 // prefix_align < suffix_align). |
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217 const size_t ofs = (size_t(addr) + adjusted_prefix_size) & (suffix_align - 1); |
0 | 218 if (ofs != 0) { |
219 // Wrong alignment. Release, allocate more space and do manual alignment. | |
220 // | |
221 // On most operating systems, another allocation with a somewhat larger size | |
222 // will return an address "close to" that of the previous allocation. The | |
223 // result is often the same address (if the kernel hands out virtual | |
224 // addresses from low to high), or an address that is offset by the increase | |
225 // in size. Exploit that to minimize the amount of extra space requested. | |
226 if (!os::release_memory(addr, size)) { | |
227 fatal("os::release_memory failed"); | |
228 } | |
229 | |
230 const size_t extra = MAX2(ofs, suffix_align - ofs); | |
237
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231 addr = reserve_and_align(size + extra, adjusted_prefix_size, prefix_align, |
0 | 232 suffix_size, suffix_align); |
233 if (addr == NULL) { | |
234 // Try an even larger region. If this fails, address space is exhausted. | |
237
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235 addr = reserve_and_align(size + suffix_align, adjusted_prefix_size, |
0 | 236 prefix_align, suffix_size, suffix_align); |
237 } | |
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238 |
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239 if (requested_address != 0 && |
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240 failed_to_reserve_as_requested(addr, requested_address, size, false)) { |
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241 // As a result of the alignment constraints, the allocated addr differs |
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242 // from the requested address. Return back to the caller who can |
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243 // take remedial action (like try again without a requested address). |
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244 assert(_base == NULL, "should be"); |
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245 return; |
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246 } |
0 | 247 } |
248 | |
249 _base = addr; | |
250 _size = size; | |
251 _alignment = prefix_align; | |
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252 _noaccess_prefix = noaccess_prefix; |
0 | 253 } |
254 | |
255 void ReservedSpace::initialize(size_t size, size_t alignment, bool large, | |
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256 char* requested_address, |
656 | 257 const size_t noaccess_prefix, |
258 bool executable) { | |
0 | 259 const size_t granularity = os::vm_allocation_granularity(); |
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260 assert((size & (granularity - 1)) == 0, |
0 | 261 "size not aligned to os::vm_allocation_granularity()"); |
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262 assert((alignment & (granularity - 1)) == 0, |
0 | 263 "alignment not aligned to os::vm_allocation_granularity()"); |
264 assert(alignment == 0 || is_power_of_2((intptr_t)alignment), | |
265 "not a power of 2"); | |
266 | |
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267 alignment = MAX2(alignment, (size_t)os::vm_page_size()); |
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268 |
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269 // Assert that if noaccess_prefix is used, it is the same as alignment. |
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270 assert(noaccess_prefix == 0 || |
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271 noaccess_prefix == alignment, "noaccess prefix wrong"); |
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272 |
0 | 273 _base = NULL; |
274 _size = 0; | |
275 _special = false; | |
656 | 276 _executable = executable; |
0 | 277 _alignment = 0; |
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278 _noaccess_prefix = 0; |
0 | 279 if (size == 0) { |
280 return; | |
281 } | |
282 | |
283 // If OS doesn't support demand paging for large page memory, we need | |
284 // to use reserve_memory_special() to reserve and pin the entire region. | |
285 bool special = large && !os::can_commit_large_page_memory(); | |
286 char* base = NULL; | |
287 | |
1618 | 288 if (requested_address != 0) { |
289 requested_address -= noaccess_prefix; // adjust requested address | |
290 assert(requested_address != NULL, "huge noaccess prefix?"); | |
291 } | |
292 | |
0 | 293 if (special) { |
294 | |
656 | 295 base = os::reserve_memory_special(size, requested_address, executable); |
0 | 296 |
297 if (base != NULL) { | |
1618 | 298 if (failed_to_reserve_as_requested(base, requested_address, size, true)) { |
299 // OS ignored requested address. Try different address. | |
300 return; | |
301 } | |
0 | 302 // Check alignment constraints |
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303 assert((uintptr_t) base % alignment == 0, |
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304 "Large pages returned a non-aligned address"); |
0 | 305 _special = true; |
306 } else { | |
307 // failed; try to reserve regular memory below | |
1618 | 308 if (UseLargePages && (!FLAG_IS_DEFAULT(UseLargePages) || |
309 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { | |
310 if (PrintCompressedOopsMode) { | |
311 tty->cr(); | |
312 tty->print_cr("Reserve regular memory without large pages."); | |
313 } | |
314 } | |
0 | 315 } |
316 } | |
317 | |
318 if (base == NULL) { | |
319 // Optimistically assume that the OSes returns an aligned base pointer. | |
320 // When reserving a large address range, most OSes seem to align to at | |
321 // least 64K. | |
322 | |
323 // If the memory was requested at a particular address, use | |
324 // os::attempt_reserve_memory_at() to avoid over mapping something | |
325 // important. If available space is not detected, return NULL. | |
326 | |
327 if (requested_address != 0) { | |
1618 | 328 base = os::attempt_reserve_memory_at(size, requested_address); |
329 if (failed_to_reserve_as_requested(base, requested_address, size, false)) { | |
330 // OS ignored requested address. Try different address. | |
331 base = NULL; | |
332 } | |
0 | 333 } else { |
334 base = os::reserve_memory(size, NULL, alignment); | |
335 } | |
336 | |
337 if (base == NULL) return; | |
338 | |
339 // Check alignment constraints | |
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340 if ((((size_t)base + noaccess_prefix) & (alignment - 1)) != 0) { |
0 | 341 // Base not aligned, retry |
342 if (!os::release_memory(base, size)) fatal("os::release_memory failed"); | |
343 // Reserve size large enough to do manual alignment and | |
344 // increase size to a multiple of the desired alignment | |
345 size = align_size_up(size, alignment); | |
346 size_t extra_size = size + alignment; | |
342 | 347 do { |
348 char* extra_base = os::reserve_memory(extra_size, NULL, alignment); | |
349 if (extra_base == NULL) return; | |
350 // Do manual alignement | |
351 base = (char*) align_size_up((uintptr_t) extra_base, alignment); | |
352 assert(base >= extra_base, "just checking"); | |
353 // Re-reserve the region at the aligned base address. | |
354 os::release_memory(extra_base, extra_size); | |
355 base = os::reserve_memory(size, base); | |
356 } while (base == NULL); | |
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357 |
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358 if (requested_address != 0 && |
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359 failed_to_reserve_as_requested(base, requested_address, size, false)) { |
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360 // As a result of the alignment constraints, the allocated base differs |
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361 // from the requested address. Return back to the caller who can |
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362 // take remedial action (like try again without a requested address). |
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363 assert(_base == NULL, "should be"); |
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364 return; |
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365 } |
0 | 366 } |
367 } | |
368 // Done | |
369 _base = base; | |
370 _size = size; | |
3824
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371 _alignment = alignment; |
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372 _noaccess_prefix = noaccess_prefix; |
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373 |
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374 // Assert that if noaccess_prefix is used, it is the same as alignment. |
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375 assert(noaccess_prefix == 0 || |
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376 noaccess_prefix == _alignment, "noaccess prefix wrong"); |
0 | 377 |
378 assert(markOopDesc::encode_pointer_as_mark(_base)->decode_pointer() == _base, | |
379 "area must be distinguisable from marks for mark-sweep"); | |
380 assert(markOopDesc::encode_pointer_as_mark(&_base[size])->decode_pointer() == &_base[size], | |
381 "area must be distinguisable from marks for mark-sweep"); | |
382 } | |
383 | |
384 | |
385 ReservedSpace::ReservedSpace(char* base, size_t size, size_t alignment, | |
656 | 386 bool special, bool executable) { |
0 | 387 assert((size % os::vm_allocation_granularity()) == 0, |
388 "size not allocation aligned"); | |
389 _base = base; | |
390 _size = size; | |
391 _alignment = alignment; | |
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392 _noaccess_prefix = 0; |
0 | 393 _special = special; |
656 | 394 _executable = executable; |
0 | 395 } |
396 | |
397 | |
398 ReservedSpace ReservedSpace::first_part(size_t partition_size, size_t alignment, | |
399 bool split, bool realloc) { | |
400 assert(partition_size <= size(), "partition failed"); | |
401 if (split) { | |
656 | 402 os::split_reserved_memory(base(), size(), partition_size, realloc); |
0 | 403 } |
656 | 404 ReservedSpace result(base(), partition_size, alignment, special(), |
405 executable()); | |
0 | 406 return result; |
407 } | |
408 | |
409 | |
410 ReservedSpace | |
411 ReservedSpace::last_part(size_t partition_size, size_t alignment) { | |
412 assert(partition_size <= size(), "partition failed"); | |
413 ReservedSpace result(base() + partition_size, size() - partition_size, | |
656 | 414 alignment, special(), executable()); |
0 | 415 return result; |
416 } | |
417 | |
418 | |
419 size_t ReservedSpace::page_align_size_up(size_t size) { | |
420 return align_size_up(size, os::vm_page_size()); | |
421 } | |
422 | |
423 | |
424 size_t ReservedSpace::page_align_size_down(size_t size) { | |
425 return align_size_down(size, os::vm_page_size()); | |
426 } | |
427 | |
428 | |
429 size_t ReservedSpace::allocation_align_size_up(size_t size) { | |
430 return align_size_up(size, os::vm_allocation_granularity()); | |
431 } | |
432 | |
433 | |
434 size_t ReservedSpace::allocation_align_size_down(size_t size) { | |
435 return align_size_down(size, os::vm_allocation_granularity()); | |
436 } | |
437 | |
438 | |
439 void ReservedSpace::release() { | |
440 if (is_reserved()) { | |
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441 char *real_base = _base - _noaccess_prefix; |
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442 const size_t real_size = _size + _noaccess_prefix; |
0 | 443 if (special()) { |
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444 os::release_memory_special(real_base, real_size); |
0 | 445 } else{ |
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446 os::release_memory(real_base, real_size); |
0 | 447 } |
448 _base = NULL; | |
449 _size = 0; | |
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450 _noaccess_prefix = 0; |
0 | 451 _special = false; |
656 | 452 _executable = false; |
0 | 453 } |
454 } | |
455 | |
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456 void ReservedSpace::protect_noaccess_prefix(const size_t size) { |
1618 | 457 assert( (_noaccess_prefix != 0) == (UseCompressedOops && _base != NULL && |
458 (size_t(_base + _size) > OopEncodingHeapMax) && | |
459 Universe::narrow_oop_use_implicit_null_checks()), | |
460 "noaccess_prefix should be used only with non zero based compressed oops"); | |
461 | |
462 // If there is no noaccess prefix, return. | |
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463 if (_noaccess_prefix == 0) return; |
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464 |
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465 assert(_noaccess_prefix >= (size_t)os::vm_page_size(), |
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466 "must be at least page size big"); |
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467 |
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468 // Protect memory at the base of the allocated region. |
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469 // If special, the page was committed (only matters on windows) |
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470 if (!os::protect_memory(_base, _noaccess_prefix, os::MEM_PROT_NONE, |
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471 _special)) { |
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472 fatal("cannot protect protection page"); |
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473 } |
1618 | 474 if (PrintCompressedOopsMode) { |
475 tty->cr(); | |
476 tty->print_cr("Protected page at the reserved heap base: " PTR_FORMAT " / " INTX_FORMAT " bytes", _base, _noaccess_prefix); | |
477 } | |
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478 |
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479 _base += _noaccess_prefix; |
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480 _size -= _noaccess_prefix; |
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481 assert((size == _size) && ((uintptr_t)_base % _alignment == 0), |
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482 "must be exactly of required size and alignment"); |
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483 } |
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484 |
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485 ReservedHeapSpace::ReservedHeapSpace(size_t size, size_t alignment, |
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486 bool large, char* requested_address) : |
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487 ReservedSpace(size, alignment, large, |
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488 requested_address, |
642
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489 (UseCompressedOops && (Universe::narrow_oop_base() != NULL) && |
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490 Universe::narrow_oop_use_implicit_null_checks()) ? |
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491 lcm(os::vm_page_size(), alignment) : 0) { |
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492 // Only reserved space for the java heap should have a noaccess_prefix |
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493 // if using compressed oops. |
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494 protect_noaccess_prefix(size); |
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495 } |
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496 |
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497 ReservedHeapSpace::ReservedHeapSpace(const size_t prefix_size, |
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498 const size_t prefix_align, |
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499 const size_t suffix_size, |
642
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500 const size_t suffix_align, |
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501 char* requested_address) : |
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502 ReservedSpace(prefix_size, prefix_align, suffix_size, suffix_align, |
642
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503 requested_address, |
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504 (UseCompressedOops && (Universe::narrow_oop_base() != NULL) && |
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505 Universe::narrow_oop_use_implicit_null_checks()) ? |
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506 lcm(os::vm_page_size(), prefix_align) : 0) { |
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507 protect_noaccess_prefix(prefix_size+suffix_size); |
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508 } |
0 | 509 |
656 | 510 // Reserve space for code segment. Same as Java heap only we mark this as |
511 // executable. | |
512 ReservedCodeSpace::ReservedCodeSpace(size_t r_size, | |
513 size_t rs_align, | |
514 bool large) : | |
515 ReservedSpace(r_size, rs_align, large, /*executable*/ true) { | |
516 } | |
517 | |
0 | 518 // VirtualSpace |
519 | |
520 VirtualSpace::VirtualSpace() { | |
521 _low_boundary = NULL; | |
522 _high_boundary = NULL; | |
523 _low = NULL; | |
524 _high = NULL; | |
525 _lower_high = NULL; | |
526 _middle_high = NULL; | |
527 _upper_high = NULL; | |
528 _lower_high_boundary = NULL; | |
529 _middle_high_boundary = NULL; | |
530 _upper_high_boundary = NULL; | |
531 _lower_alignment = 0; | |
532 _middle_alignment = 0; | |
533 _upper_alignment = 0; | |
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534 _special = false; |
656 | 535 _executable = false; |
0 | 536 } |
537 | |
538 | |
539 bool VirtualSpace::initialize(ReservedSpace rs, size_t committed_size) { | |
540 if(!rs.is_reserved()) return false; // allocation failed. | |
541 assert(_low_boundary == NULL, "VirtualSpace already initialized"); | |
542 _low_boundary = rs.base(); | |
543 _high_boundary = low_boundary() + rs.size(); | |
544 | |
545 _low = low_boundary(); | |
546 _high = low(); | |
547 | |
548 _special = rs.special(); | |
656 | 549 _executable = rs.executable(); |
0 | 550 |
551 // When a VirtualSpace begins life at a large size, make all future expansion | |
552 // and shrinking occur aligned to a granularity of large pages. This avoids | |
553 // fragmentation of physical addresses that inhibits the use of large pages | |
554 // by the OS virtual memory system. Empirically, we see that with a 4MB | |
555 // page size, the only spaces that get handled this way are codecache and | |
556 // the heap itself, both of which provide a substantial performance | |
557 // boost in many benchmarks when covered by large pages. | |
558 // | |
559 // No attempt is made to force large page alignment at the very top and | |
560 // bottom of the space if they are not aligned so already. | |
561 _lower_alignment = os::vm_page_size(); | |
562 _middle_alignment = os::page_size_for_region(rs.size(), rs.size(), 1); | |
563 _upper_alignment = os::vm_page_size(); | |
564 | |
565 // End of each region | |
566 _lower_high_boundary = (char*) round_to((intptr_t) low_boundary(), middle_alignment()); | |
567 _middle_high_boundary = (char*) round_down((intptr_t) high_boundary(), middle_alignment()); | |
568 _upper_high_boundary = high_boundary(); | |
569 | |
570 // High address of each region | |
571 _lower_high = low_boundary(); | |
572 _middle_high = lower_high_boundary(); | |
573 _upper_high = middle_high_boundary(); | |
574 | |
575 // commit to initial size | |
576 if (committed_size > 0) { | |
577 if (!expand_by(committed_size)) { | |
578 return false; | |
579 } | |
580 } | |
581 return true; | |
582 } | |
583 | |
584 | |
585 VirtualSpace::~VirtualSpace() { | |
586 release(); | |
587 } | |
588 | |
589 | |
590 void VirtualSpace::release() { | |
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591 // This does not release memory it never reserved. |
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592 // Caller must release via rs.release(); |
0 | 593 _low_boundary = NULL; |
594 _high_boundary = NULL; | |
595 _low = NULL; | |
596 _high = NULL; | |
597 _lower_high = NULL; | |
598 _middle_high = NULL; | |
599 _upper_high = NULL; | |
600 _lower_high_boundary = NULL; | |
601 _middle_high_boundary = NULL; | |
602 _upper_high_boundary = NULL; | |
603 _lower_alignment = 0; | |
604 _middle_alignment = 0; | |
605 _upper_alignment = 0; | |
606 _special = false; | |
656 | 607 _executable = false; |
0 | 608 } |
609 | |
610 | |
611 size_t VirtualSpace::committed_size() const { | |
612 return pointer_delta(high(), low(), sizeof(char)); | |
613 } | |
614 | |
615 | |
616 size_t VirtualSpace::reserved_size() const { | |
617 return pointer_delta(high_boundary(), low_boundary(), sizeof(char)); | |
618 } | |
619 | |
620 | |
621 size_t VirtualSpace::uncommitted_size() const { | |
622 return reserved_size() - committed_size(); | |
623 } | |
624 | |
625 | |
626 bool VirtualSpace::contains(const void* p) const { | |
627 return low() <= (const char*) p && (const char*) p < high(); | |
628 } | |
629 | |
630 /* | |
631 First we need to determine if a particular virtual space is using large | |
632 pages. This is done at the initialize function and only virtual spaces | |
633 that are larger than LargePageSizeInBytes use large pages. Once we | |
634 have determined this, all expand_by and shrink_by calls must grow and | |
635 shrink by large page size chunks. If a particular request | |
636 is within the current large page, the call to commit and uncommit memory | |
637 can be ignored. In the case that the low and high boundaries of this | |
638 space is not large page aligned, the pages leading to the first large | |
639 page address and the pages after the last large page address must be | |
640 allocated with default pages. | |
641 */ | |
642 bool VirtualSpace::expand_by(size_t bytes, bool pre_touch) { | |
643 if (uncommitted_size() < bytes) return false; | |
644 | |
645 if (special()) { | |
646 // don't commit memory if the entire space is pinned in memory | |
647 _high += bytes; | |
648 return true; | |
649 } | |
650 | |
651 char* previous_high = high(); | |
652 char* unaligned_new_high = high() + bytes; | |
653 assert(unaligned_new_high <= high_boundary(), | |
654 "cannot expand by more than upper boundary"); | |
655 | |
656 // Calculate where the new high for each of the regions should be. If | |
657 // the low_boundary() and high_boundary() are LargePageSizeInBytes aligned | |
658 // then the unaligned lower and upper new highs would be the | |
659 // lower_high() and upper_high() respectively. | |
660 char* unaligned_lower_new_high = | |
661 MIN2(unaligned_new_high, lower_high_boundary()); | |
662 char* unaligned_middle_new_high = | |
663 MIN2(unaligned_new_high, middle_high_boundary()); | |
664 char* unaligned_upper_new_high = | |
665 MIN2(unaligned_new_high, upper_high_boundary()); | |
666 | |
667 // Align the new highs based on the regions alignment. lower and upper | |
668 // alignment will always be default page size. middle alignment will be | |
669 // LargePageSizeInBytes if the actual size of the virtual space is in | |
670 // fact larger than LargePageSizeInBytes. | |
671 char* aligned_lower_new_high = | |
672 (char*) round_to((intptr_t) unaligned_lower_new_high, lower_alignment()); | |
673 char* aligned_middle_new_high = | |
674 (char*) round_to((intptr_t) unaligned_middle_new_high, middle_alignment()); | |
675 char* aligned_upper_new_high = | |
676 (char*) round_to((intptr_t) unaligned_upper_new_high, upper_alignment()); | |
677 | |
678 // Determine which regions need to grow in this expand_by call. | |
679 // If you are growing in the lower region, high() must be in that | |
680 // region so calcuate the size based on high(). For the middle and | |
681 // upper regions, determine the starting point of growth based on the | |
682 // location of high(). By getting the MAX of the region's low address | |
683 // (or the prevoius region's high address) and high(), we can tell if it | |
684 // is an intra or inter region growth. | |
685 size_t lower_needs = 0; | |
686 if (aligned_lower_new_high > lower_high()) { | |
687 lower_needs = | |
688 pointer_delta(aligned_lower_new_high, lower_high(), sizeof(char)); | |
689 } | |
690 size_t middle_needs = 0; | |
691 if (aligned_middle_new_high > middle_high()) { | |
692 middle_needs = | |
693 pointer_delta(aligned_middle_new_high, middle_high(), sizeof(char)); | |
694 } | |
695 size_t upper_needs = 0; | |
696 if (aligned_upper_new_high > upper_high()) { | |
697 upper_needs = | |
698 pointer_delta(aligned_upper_new_high, upper_high(), sizeof(char)); | |
699 } | |
700 | |
701 // Check contiguity. | |
702 assert(low_boundary() <= lower_high() && | |
703 lower_high() <= lower_high_boundary(), | |
704 "high address must be contained within the region"); | |
705 assert(lower_high_boundary() <= middle_high() && | |
706 middle_high() <= middle_high_boundary(), | |
707 "high address must be contained within the region"); | |
708 assert(middle_high_boundary() <= upper_high() && | |
709 upper_high() <= upper_high_boundary(), | |
710 "high address must be contained within the region"); | |
711 | |
712 // Commit regions | |
713 if (lower_needs > 0) { | |
714 assert(low_boundary() <= lower_high() && | |
715 lower_high() + lower_needs <= lower_high_boundary(), | |
716 "must not expand beyond region"); | |
656 | 717 if (!os::commit_memory(lower_high(), lower_needs, _executable)) { |
0 | 718 debug_only(warning("os::commit_memory failed")); |
719 return false; | |
720 } else { | |
721 _lower_high += lower_needs; | |
722 } | |
723 } | |
724 if (middle_needs > 0) { | |
725 assert(lower_high_boundary() <= middle_high() && | |
726 middle_high() + middle_needs <= middle_high_boundary(), | |
727 "must not expand beyond region"); | |
656 | 728 if (!os::commit_memory(middle_high(), middle_needs, middle_alignment(), |
729 _executable)) { | |
0 | 730 debug_only(warning("os::commit_memory failed")); |
731 return false; | |
732 } | |
733 _middle_high += middle_needs; | |
734 } | |
735 if (upper_needs > 0) { | |
736 assert(middle_high_boundary() <= upper_high() && | |
737 upper_high() + upper_needs <= upper_high_boundary(), | |
738 "must not expand beyond region"); | |
656 | 739 if (!os::commit_memory(upper_high(), upper_needs, _executable)) { |
0 | 740 debug_only(warning("os::commit_memory failed")); |
741 return false; | |
742 } else { | |
743 _upper_high += upper_needs; | |
744 } | |
745 } | |
746 | |
747 if (pre_touch || AlwaysPreTouch) { | |
748 int vm_ps = os::vm_page_size(); | |
749 for (char* curr = previous_high; | |
750 curr < unaligned_new_high; | |
751 curr += vm_ps) { | |
752 // Note the use of a write here; originally we tried just a read, but | |
753 // since the value read was unused, the optimizer removed the read. | |
754 // If we ever have a concurrent touchahead thread, we'll want to use | |
755 // a read, to avoid the potential of overwriting data (if a mutator | |
756 // thread beats the touchahead thread to a page). There are various | |
757 // ways of making sure this read is not optimized away: for example, | |
758 // generating the code for a read procedure at runtime. | |
759 *curr = 0; | |
760 } | |
761 } | |
762 | |
763 _high += bytes; | |
764 return true; | |
765 } | |
766 | |
767 // A page is uncommitted if the contents of the entire page is deemed unusable. | |
768 // Continue to decrement the high() pointer until it reaches a page boundary | |
769 // in which case that particular page can now be uncommitted. | |
770 void VirtualSpace::shrink_by(size_t size) { | |
771 if (committed_size() < size) | |
772 fatal("Cannot shrink virtual space to negative size"); | |
773 | |
774 if (special()) { | |
775 // don't uncommit if the entire space is pinned in memory | |
776 _high -= size; | |
777 return; | |
778 } | |
779 | |
780 char* unaligned_new_high = high() - size; | |
781 assert(unaligned_new_high >= low_boundary(), "cannot shrink past lower boundary"); | |
782 | |
783 // Calculate new unaligned address | |
784 char* unaligned_upper_new_high = | |
785 MAX2(unaligned_new_high, middle_high_boundary()); | |
786 char* unaligned_middle_new_high = | |
787 MAX2(unaligned_new_high, lower_high_boundary()); | |
788 char* unaligned_lower_new_high = | |
789 MAX2(unaligned_new_high, low_boundary()); | |
790 | |
791 // Align address to region's alignment | |
792 char* aligned_upper_new_high = | |
793 (char*) round_to((intptr_t) unaligned_upper_new_high, upper_alignment()); | |
794 char* aligned_middle_new_high = | |
795 (char*) round_to((intptr_t) unaligned_middle_new_high, middle_alignment()); | |
796 char* aligned_lower_new_high = | |
797 (char*) round_to((intptr_t) unaligned_lower_new_high, lower_alignment()); | |
798 | |
799 // Determine which regions need to shrink | |
800 size_t upper_needs = 0; | |
801 if (aligned_upper_new_high < upper_high()) { | |
802 upper_needs = | |
803 pointer_delta(upper_high(), aligned_upper_new_high, sizeof(char)); | |
804 } | |
805 size_t middle_needs = 0; | |
806 if (aligned_middle_new_high < middle_high()) { | |
807 middle_needs = | |
808 pointer_delta(middle_high(), aligned_middle_new_high, sizeof(char)); | |
809 } | |
810 size_t lower_needs = 0; | |
811 if (aligned_lower_new_high < lower_high()) { | |
812 lower_needs = | |
813 pointer_delta(lower_high(), aligned_lower_new_high, sizeof(char)); | |
814 } | |
815 | |
816 // Check contiguity. | |
817 assert(middle_high_boundary() <= upper_high() && | |
818 upper_high() <= upper_high_boundary(), | |
819 "high address must be contained within the region"); | |
820 assert(lower_high_boundary() <= middle_high() && | |
821 middle_high() <= middle_high_boundary(), | |
822 "high address must be contained within the region"); | |
823 assert(low_boundary() <= lower_high() && | |
824 lower_high() <= lower_high_boundary(), | |
825 "high address must be contained within the region"); | |
826 | |
827 // Uncommit | |
828 if (upper_needs > 0) { | |
829 assert(middle_high_boundary() <= aligned_upper_new_high && | |
830 aligned_upper_new_high + upper_needs <= upper_high_boundary(), | |
831 "must not shrink beyond region"); | |
832 if (!os::uncommit_memory(aligned_upper_new_high, upper_needs)) { | |
833 debug_only(warning("os::uncommit_memory failed")); | |
834 return; | |
835 } else { | |
836 _upper_high -= upper_needs; | |
837 } | |
838 } | |
839 if (middle_needs > 0) { | |
840 assert(lower_high_boundary() <= aligned_middle_new_high && | |
841 aligned_middle_new_high + middle_needs <= middle_high_boundary(), | |
842 "must not shrink beyond region"); | |
843 if (!os::uncommit_memory(aligned_middle_new_high, middle_needs)) { | |
844 debug_only(warning("os::uncommit_memory failed")); | |
845 return; | |
846 } else { | |
847 _middle_high -= middle_needs; | |
848 } | |
849 } | |
850 if (lower_needs > 0) { | |
851 assert(low_boundary() <= aligned_lower_new_high && | |
852 aligned_lower_new_high + lower_needs <= lower_high_boundary(), | |
853 "must not shrink beyond region"); | |
854 if (!os::uncommit_memory(aligned_lower_new_high, lower_needs)) { | |
855 debug_only(warning("os::uncommit_memory failed")); | |
856 return; | |
857 } else { | |
858 _lower_high -= lower_needs; | |
859 } | |
860 } | |
861 | |
862 _high -= size; | |
863 } | |
864 | |
865 #ifndef PRODUCT | |
866 void VirtualSpace::check_for_contiguity() { | |
867 // Check contiguity. | |
868 assert(low_boundary() <= lower_high() && | |
869 lower_high() <= lower_high_boundary(), | |
870 "high address must be contained within the region"); | |
871 assert(lower_high_boundary() <= middle_high() && | |
872 middle_high() <= middle_high_boundary(), | |
873 "high address must be contained within the region"); | |
874 assert(middle_high_boundary() <= upper_high() && | |
875 upper_high() <= upper_high_boundary(), | |
876 "high address must be contained within the region"); | |
877 assert(low() >= low_boundary(), "low"); | |
878 assert(low_boundary() <= lower_high_boundary(), "lower high boundary"); | |
879 assert(upper_high_boundary() <= high_boundary(), "upper high boundary"); | |
880 assert(high() <= upper_high(), "upper high"); | |
881 } | |
882 | |
883 void VirtualSpace::print() { | |
884 tty->print ("Virtual space:"); | |
885 if (special()) tty->print(" (pinned in memory)"); | |
886 tty->cr(); | |
887 tty->print_cr(" - committed: %ld", committed_size()); | |
888 tty->print_cr(" - reserved: %ld", reserved_size()); | |
889 tty->print_cr(" - [low, high]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", low(), high()); | |
890 tty->print_cr(" - [low_b, high_b]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", low_boundary(), high_boundary()); | |
891 } | |
892 | |
893 #endif |