Mercurial > hg > graal-compiler
annotate src/share/vm/runtime/virtualspace.cpp @ 7168:73e64867adb7
8003690: Example code in JVMTI GetStackTrace documentation is broken
Summary: Fixed to minor errors in example code
Reviewed-by: sspitsyn, dholmes
author | mikael |
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date | Wed, 21 Nov 2012 09:02:13 -0800 |
parents | da91efe96a93 |
children | 730cc4ddd550 |
rev | line source |
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0 | 1 /* |
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2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. |
0 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
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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" | |
6197 | 29 #include "services/memTracker.hpp" |
1972 | 30 #ifdef TARGET_OS_FAMILY_linux |
31 # include "os_linux.inline.hpp" | |
32 #endif | |
33 #ifdef TARGET_OS_FAMILY_solaris | |
34 # include "os_solaris.inline.hpp" | |
35 #endif | |
36 #ifdef TARGET_OS_FAMILY_windows | |
37 # include "os_windows.inline.hpp" | |
38 #endif | |
3960 | 39 #ifdef TARGET_OS_FAMILY_bsd |
40 # include "os_bsd.inline.hpp" | |
41 #endif | |
0 | 42 |
43 | |
44 // ReservedSpace | |
45 ReservedSpace::ReservedSpace(size_t size) { | |
656 | 46 initialize(size, 0, false, NULL, 0, false); |
0 | 47 } |
48 | |
49 ReservedSpace::ReservedSpace(size_t size, size_t alignment, | |
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50 bool large, |
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51 char* requested_address, |
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52 const size_t noaccess_prefix) { |
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53 initialize(size+noaccess_prefix, alignment, large, requested_address, |
656 | 54 noaccess_prefix, false); |
55 } | |
56 | |
57 ReservedSpace::ReservedSpace(size_t size, size_t alignment, | |
58 bool large, | |
59 bool executable) { | |
60 initialize(size, alignment, large, NULL, 0, executable); | |
0 | 61 } |
62 | |
63 char * | |
64 ReservedSpace::align_reserved_region(char* addr, const size_t len, | |
65 const size_t prefix_size, | |
66 const size_t prefix_align, | |
67 const size_t suffix_size, | |
68 const size_t suffix_align) | |
69 { | |
70 assert(addr != NULL, "sanity"); | |
71 const size_t required_size = prefix_size + suffix_size; | |
72 assert(len >= required_size, "len too small"); | |
73 | |
74 const size_t s = size_t(addr); | |
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75 const size_t beg_ofs = (s + prefix_size) & (suffix_align - 1); |
0 | 76 const size_t beg_delta = beg_ofs == 0 ? 0 : suffix_align - beg_ofs; |
77 | |
78 if (len < beg_delta + required_size) { | |
79 return NULL; // Cannot do proper alignment. | |
80 } | |
81 const size_t end_delta = len - (beg_delta + required_size); | |
82 | |
83 if (beg_delta != 0) { | |
84 os::release_memory(addr, beg_delta); | |
85 } | |
86 | |
87 if (end_delta != 0) { | |
88 char* release_addr = (char*) (s + beg_delta + required_size); | |
89 os::release_memory(release_addr, end_delta); | |
90 } | |
91 | |
92 return (char*) (s + beg_delta); | |
93 } | |
94 | |
95 char* ReservedSpace::reserve_and_align(const size_t reserve_size, | |
96 const size_t prefix_size, | |
97 const size_t prefix_align, | |
98 const size_t suffix_size, | |
99 const size_t suffix_align) | |
100 { | |
101 assert(reserve_size > prefix_size + suffix_size, "should not be here"); | |
102 | |
103 char* raw_addr = os::reserve_memory(reserve_size, NULL, prefix_align); | |
104 if (raw_addr == NULL) return NULL; | |
105 | |
106 char* result = align_reserved_region(raw_addr, reserve_size, prefix_size, | |
107 prefix_align, suffix_size, | |
108 suffix_align); | |
109 if (result == NULL && !os::release_memory(raw_addr, reserve_size)) { | |
110 fatal("os::release_memory failed"); | |
111 } | |
112 | |
113 #ifdef ASSERT | |
114 if (result != NULL) { | |
115 const size_t raw = size_t(raw_addr); | |
116 const size_t res = size_t(result); | |
117 assert(res >= raw, "alignment decreased start addr"); | |
118 assert(res + prefix_size + suffix_size <= raw + reserve_size, | |
119 "alignment increased end addr"); | |
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120 assert((res & (prefix_align - 1)) == 0, "bad alignment of prefix"); |
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121 assert(((res + prefix_size) & (suffix_align - 1)) == 0, |
0 | 122 "bad alignment of suffix"); |
123 } | |
124 #endif | |
125 | |
126 return result; | |
127 } | |
128 | |
1618 | 129 // Helper method. |
130 static bool failed_to_reserve_as_requested(char* base, char* requested_address, | |
131 const size_t size, bool special) | |
132 { | |
133 if (base == requested_address || requested_address == NULL) | |
134 return false; // did not fail | |
135 | |
136 if (base != NULL) { | |
137 // Different reserve address may be acceptable in other cases | |
138 // but for compressed oops heap should be at requested address. | |
139 assert(UseCompressedOops, "currently requested address used only for compressed oops"); | |
140 if (PrintCompressedOopsMode) { | |
141 tty->cr(); | |
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142 tty->print_cr("Reserved memory not at requested address: " PTR_FORMAT " vs " PTR_FORMAT, base, requested_address); |
1618 | 143 } |
144 // OS ignored requested address. Try different address. | |
145 if (special) { | |
146 if (!os::release_memory_special(base, size)) { | |
147 fatal("os::release_memory_special failed"); | |
148 } | |
149 } else { | |
150 if (!os::release_memory(base, size)) { | |
151 fatal("os::release_memory failed"); | |
152 } | |
153 } | |
154 } | |
155 return true; | |
156 } | |
157 | |
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158 ReservedSpace::ReservedSpace(const size_t suffix_size, |
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159 const size_t suffix_align, |
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160 char* requested_address, |
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161 const size_t noaccess_prefix) |
0 | 162 { |
163 assert(suffix_size != 0, "sanity"); | |
164 assert(suffix_align != 0, "sanity"); | |
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165 assert((suffix_size & (suffix_align - 1)) == 0, |
0 | 166 "suffix_size not divisible by suffix_align"); |
167 | |
1618 | 168 // Assert that if noaccess_prefix is used, it is the same as prefix_align. |
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169 // Add in noaccess_prefix to prefix |
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170 const size_t adjusted_prefix_size = noaccess_prefix; |
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171 const size_t size = adjusted_prefix_size + suffix_size; |
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172 |
0 | 173 // On systems where the entire region has to be reserved and committed up |
174 // front, the compound alignment normally done by this method is unnecessary. | |
175 const bool try_reserve_special = UseLargePages && | |
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176 suffix_align == os::large_page_size(); |
0 | 177 if (!os::can_commit_large_page_memory() && try_reserve_special) { |
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178 initialize(size, suffix_align, true, requested_address, noaccess_prefix, |
656 | 179 false); |
0 | 180 return; |
181 } | |
182 | |
183 _base = NULL; | |
184 _size = 0; | |
185 _alignment = 0; | |
186 _special = false; | |
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187 _noaccess_prefix = 0; |
656 | 188 _executable = false; |
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189 |
0 | 190 // Optimistically try to reserve the exact size needed. |
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191 char* addr; |
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192 if (requested_address != 0) { |
1618 | 193 requested_address -= noaccess_prefix; // adjust address |
194 assert(requested_address != NULL, "huge noaccess prefix?"); | |
195 addr = os::attempt_reserve_memory_at(size, requested_address); | |
196 if (failed_to_reserve_as_requested(addr, requested_address, size, false)) { | |
197 // OS ignored requested address. Try different address. | |
198 addr = NULL; | |
199 } | |
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200 } else { |
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201 addr = os::reserve_memory(size, NULL, suffix_align); |
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202 } |
0 | 203 if (addr == NULL) return; |
204 | |
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205 // Check whether the result has the needed alignment |
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206 const size_t ofs = (size_t(addr) + adjusted_prefix_size) & (suffix_align - 1); |
0 | 207 if (ofs != 0) { |
208 // Wrong alignment. Release, allocate more space and do manual alignment. | |
209 // | |
210 // On most operating systems, another allocation with a somewhat larger size | |
211 // will return an address "close to" that of the previous allocation. The | |
212 // result is often the same address (if the kernel hands out virtual | |
213 // addresses from low to high), or an address that is offset by the increase | |
214 // in size. Exploit that to minimize the amount of extra space requested. | |
215 if (!os::release_memory(addr, size)) { | |
216 fatal("os::release_memory failed"); | |
217 } | |
218 | |
219 const size_t extra = MAX2(ofs, suffix_align - ofs); | |
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220 addr = reserve_and_align(size + extra, adjusted_prefix_size, suffix_align, |
0 | 221 suffix_size, suffix_align); |
222 if (addr == NULL) { | |
223 // Try an even larger region. If this fails, address space is exhausted. | |
237
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224 addr = reserve_and_align(size + suffix_align, adjusted_prefix_size, |
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225 suffix_align, suffix_size, suffix_align); |
0 | 226 } |
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227 |
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228 if (requested_address != 0 && |
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229 failed_to_reserve_as_requested(addr, requested_address, size, false)) { |
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230 // As a result of the alignment constraints, the allocated addr differs |
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231 // from the requested address. Return back to the caller who can |
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232 // take remedial action (like try again without a requested address). |
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233 assert(_base == NULL, "should be"); |
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234 return; |
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235 } |
0 | 236 } |
237 | |
238 _base = addr; | |
239 _size = size; | |
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240 _alignment = suffix_align; |
237
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241 _noaccess_prefix = noaccess_prefix; |
0 | 242 } |
243 | |
244 void ReservedSpace::initialize(size_t size, size_t alignment, bool large, | |
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245 char* requested_address, |
656 | 246 const size_t noaccess_prefix, |
247 bool executable) { | |
0 | 248 const size_t granularity = os::vm_allocation_granularity(); |
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249 assert((size & (granularity - 1)) == 0, |
0 | 250 "size not aligned to os::vm_allocation_granularity()"); |
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251 assert((alignment & (granularity - 1)) == 0, |
0 | 252 "alignment not aligned to os::vm_allocation_granularity()"); |
253 assert(alignment == 0 || is_power_of_2((intptr_t)alignment), | |
254 "not a power of 2"); | |
255 | |
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256 alignment = MAX2(alignment, (size_t)os::vm_page_size()); |
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257 |
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258 // Assert that if noaccess_prefix is used, it is the same as alignment. |
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259 assert(noaccess_prefix == 0 || |
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260 noaccess_prefix == alignment, "noaccess prefix wrong"); |
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261 |
0 | 262 _base = NULL; |
263 _size = 0; | |
264 _special = false; | |
656 | 265 _executable = executable; |
0 | 266 _alignment = 0; |
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267 _noaccess_prefix = 0; |
0 | 268 if (size == 0) { |
269 return; | |
270 } | |
271 | |
272 // If OS doesn't support demand paging for large page memory, we need | |
273 // to use reserve_memory_special() to reserve and pin the entire region. | |
274 bool special = large && !os::can_commit_large_page_memory(); | |
275 char* base = NULL; | |
276 | |
1618 | 277 if (requested_address != 0) { |
278 requested_address -= noaccess_prefix; // adjust requested address | |
279 assert(requested_address != NULL, "huge noaccess prefix?"); | |
280 } | |
281 | |
0 | 282 if (special) { |
283 | |
656 | 284 base = os::reserve_memory_special(size, requested_address, executable); |
0 | 285 |
286 if (base != NULL) { | |
1618 | 287 if (failed_to_reserve_as_requested(base, requested_address, size, true)) { |
288 // OS ignored requested address. Try different address. | |
289 return; | |
290 } | |
0 | 291 // Check alignment constraints |
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292 assert((uintptr_t) base % alignment == 0, |
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293 "Large pages returned a non-aligned address"); |
0 | 294 _special = true; |
295 } else { | |
296 // failed; try to reserve regular memory below | |
1618 | 297 if (UseLargePages && (!FLAG_IS_DEFAULT(UseLargePages) || |
298 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { | |
299 if (PrintCompressedOopsMode) { | |
300 tty->cr(); | |
301 tty->print_cr("Reserve regular memory without large pages."); | |
302 } | |
303 } | |
0 | 304 } |
305 } | |
306 | |
307 if (base == NULL) { | |
308 // Optimistically assume that the OSes returns an aligned base pointer. | |
309 // When reserving a large address range, most OSes seem to align to at | |
310 // least 64K. | |
311 | |
312 // If the memory was requested at a particular address, use | |
313 // os::attempt_reserve_memory_at() to avoid over mapping something | |
314 // important. If available space is not detected, return NULL. | |
315 | |
316 if (requested_address != 0) { | |
1618 | 317 base = os::attempt_reserve_memory_at(size, requested_address); |
318 if (failed_to_reserve_as_requested(base, requested_address, size, false)) { | |
319 // OS ignored requested address. Try different address. | |
320 base = NULL; | |
321 } | |
0 | 322 } else { |
323 base = os::reserve_memory(size, NULL, alignment); | |
324 } | |
325 | |
326 if (base == NULL) return; | |
327 | |
328 // Check alignment constraints | |
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329 if ((((size_t)base + noaccess_prefix) & (alignment - 1)) != 0) { |
0 | 330 // Base not aligned, retry |
331 if (!os::release_memory(base, size)) fatal("os::release_memory failed"); | |
332 // Reserve size large enough to do manual alignment and | |
333 // increase size to a multiple of the desired alignment | |
334 size = align_size_up(size, alignment); | |
335 size_t extra_size = size + alignment; | |
342 | 336 do { |
337 char* extra_base = os::reserve_memory(extra_size, NULL, alignment); | |
338 if (extra_base == NULL) return; | |
339 // Do manual alignement | |
340 base = (char*) align_size_up((uintptr_t) extra_base, alignment); | |
341 assert(base >= extra_base, "just checking"); | |
342 // Re-reserve the region at the aligned base address. | |
343 os::release_memory(extra_base, extra_size); | |
344 base = os::reserve_memory(size, base); | |
345 } while (base == NULL); | |
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346 |
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347 if (requested_address != 0 && |
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348 failed_to_reserve_as_requested(base, requested_address, size, false)) { |
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349 // As a result of the alignment constraints, the allocated base differs |
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350 // from the requested address. Return back to the caller who can |
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351 // take remedial action (like try again without a requested address). |
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352 assert(_base == NULL, "should be"); |
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353 return; |
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354 } |
0 | 355 } |
356 } | |
357 // Done | |
358 _base = base; | |
359 _size = size; | |
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360 _alignment = alignment; |
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361 _noaccess_prefix = noaccess_prefix; |
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362 |
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363 // Assert that if noaccess_prefix is used, it is the same as alignment. |
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364 assert(noaccess_prefix == 0 || |
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365 noaccess_prefix == _alignment, "noaccess prefix wrong"); |
0 | 366 |
367 assert(markOopDesc::encode_pointer_as_mark(_base)->decode_pointer() == _base, | |
368 "area must be distinguisable from marks for mark-sweep"); | |
369 assert(markOopDesc::encode_pointer_as_mark(&_base[size])->decode_pointer() == &_base[size], | |
370 "area must be distinguisable from marks for mark-sweep"); | |
371 } | |
372 | |
373 | |
374 ReservedSpace::ReservedSpace(char* base, size_t size, size_t alignment, | |
656 | 375 bool special, bool executable) { |
0 | 376 assert((size % os::vm_allocation_granularity()) == 0, |
377 "size not allocation aligned"); | |
378 _base = base; | |
379 _size = size; | |
380 _alignment = alignment; | |
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381 _noaccess_prefix = 0; |
0 | 382 _special = special; |
656 | 383 _executable = executable; |
0 | 384 } |
385 | |
386 | |
387 ReservedSpace ReservedSpace::first_part(size_t partition_size, size_t alignment, | |
388 bool split, bool realloc) { | |
389 assert(partition_size <= size(), "partition failed"); | |
390 if (split) { | |
656 | 391 os::split_reserved_memory(base(), size(), partition_size, realloc); |
0 | 392 } |
656 | 393 ReservedSpace result(base(), partition_size, alignment, special(), |
394 executable()); | |
0 | 395 return result; |
396 } | |
397 | |
398 | |
399 ReservedSpace | |
400 ReservedSpace::last_part(size_t partition_size, size_t alignment) { | |
401 assert(partition_size <= size(), "partition failed"); | |
402 ReservedSpace result(base() + partition_size, size() - partition_size, | |
656 | 403 alignment, special(), executable()); |
0 | 404 return result; |
405 } | |
406 | |
407 | |
408 size_t ReservedSpace::page_align_size_up(size_t size) { | |
409 return align_size_up(size, os::vm_page_size()); | |
410 } | |
411 | |
412 | |
413 size_t ReservedSpace::page_align_size_down(size_t size) { | |
414 return align_size_down(size, os::vm_page_size()); | |
415 } | |
416 | |
417 | |
418 size_t ReservedSpace::allocation_align_size_up(size_t size) { | |
419 return align_size_up(size, os::vm_allocation_granularity()); | |
420 } | |
421 | |
422 | |
423 size_t ReservedSpace::allocation_align_size_down(size_t size) { | |
424 return align_size_down(size, os::vm_allocation_granularity()); | |
425 } | |
426 | |
427 | |
428 void ReservedSpace::release() { | |
429 if (is_reserved()) { | |
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430 char *real_base = _base - _noaccess_prefix; |
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431 const size_t real_size = _size + _noaccess_prefix; |
0 | 432 if (special()) { |
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433 os::release_memory_special(real_base, real_size); |
0 | 434 } else{ |
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435 os::release_memory(real_base, real_size); |
0 | 436 } |
437 _base = NULL; | |
438 _size = 0; | |
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439 _noaccess_prefix = 0; |
0 | 440 _special = false; |
656 | 441 _executable = false; |
0 | 442 } |
443 } | |
444 | |
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445 void ReservedSpace::protect_noaccess_prefix(const size_t size) { |
1618 | 446 assert( (_noaccess_prefix != 0) == (UseCompressedOops && _base != NULL && |
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447 (Universe::narrow_oop_base() != NULL) && |
1618 | 448 Universe::narrow_oop_use_implicit_null_checks()), |
449 "noaccess_prefix should be used only with non zero based compressed oops"); | |
450 | |
451 // If there is no noaccess prefix, return. | |
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452 if (_noaccess_prefix == 0) return; |
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453 |
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454 assert(_noaccess_prefix >= (size_t)os::vm_page_size(), |
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455 "must be at least page size big"); |
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456 |
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457 // Protect memory at the base of the allocated region. |
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458 // If special, the page was committed (only matters on windows) |
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459 if (!os::protect_memory(_base, _noaccess_prefix, os::MEM_PROT_NONE, |
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460 _special)) { |
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461 fatal("cannot protect protection page"); |
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462 } |
1618 | 463 if (PrintCompressedOopsMode) { |
464 tty->cr(); | |
465 tty->print_cr("Protected page at the reserved heap base: " PTR_FORMAT " / " INTX_FORMAT " bytes", _base, _noaccess_prefix); | |
466 } | |
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467 |
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468 _base += _noaccess_prefix; |
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469 _size -= _noaccess_prefix; |
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470 assert((size == _size) && ((uintptr_t)_base % _alignment == 0), |
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471 "must be exactly of required size and alignment"); |
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472 } |
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473 |
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474 ReservedHeapSpace::ReservedHeapSpace(size_t size, size_t alignment, |
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475 bool large, char* requested_address) : |
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476 ReservedSpace(size, alignment, large, |
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477 requested_address, |
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478 (UseCompressedOops && (Universe::narrow_oop_base() != NULL) && |
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479 Universe::narrow_oop_use_implicit_null_checks()) ? |
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480 lcm(os::vm_page_size(), alignment) : 0) { |
6197 | 481 if (base() > 0) { |
482 MemTracker::record_virtual_memory_type((address)base(), mtJavaHeap); | |
483 } | |
484 | |
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485 // Only reserved space for the java heap should have a noaccess_prefix |
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486 // if using compressed oops. |
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487 protect_noaccess_prefix(size); |
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488 } |
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489 |
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490 ReservedHeapSpace::ReservedHeapSpace(const size_t heap_space_size, |
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491 const size_t alignment, |
642
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492 char* requested_address) : |
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493 ReservedSpace(heap_space_size, alignment, |
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494 requested_address, |
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495 (UseCompressedOops && (Universe::narrow_oop_base() != NULL) && |
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496 Universe::narrow_oop_use_implicit_null_checks()) ? |
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497 lcm(os::vm_page_size(), alignment) : 0) { |
6197 | 498 if (base() > 0) { |
499 MemTracker::record_virtual_memory_type((address)base(), mtJavaHeap); | |
500 } | |
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501 protect_noaccess_prefix(heap_space_size); |
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502 } |
0 | 503 |
656 | 504 // Reserve space for code segment. Same as Java heap only we mark this as |
505 // executable. | |
506 ReservedCodeSpace::ReservedCodeSpace(size_t r_size, | |
507 size_t rs_align, | |
508 bool large) : | |
509 ReservedSpace(r_size, rs_align, large, /*executable*/ true) { | |
6197 | 510 MemTracker::record_virtual_memory_type((address)base(), mtCode); |
656 | 511 } |
512 | |
0 | 513 // VirtualSpace |
514 | |
515 VirtualSpace::VirtualSpace() { | |
516 _low_boundary = NULL; | |
517 _high_boundary = NULL; | |
518 _low = NULL; | |
519 _high = NULL; | |
520 _lower_high = NULL; | |
521 _middle_high = NULL; | |
522 _upper_high = NULL; | |
523 _lower_high_boundary = NULL; | |
524 _middle_high_boundary = NULL; | |
525 _upper_high_boundary = NULL; | |
526 _lower_alignment = 0; | |
527 _middle_alignment = 0; | |
528 _upper_alignment = 0; | |
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529 _special = false; |
656 | 530 _executable = false; |
0 | 531 } |
532 | |
533 | |
534 bool VirtualSpace::initialize(ReservedSpace rs, size_t committed_size) { | |
535 if(!rs.is_reserved()) return false; // allocation failed. | |
536 assert(_low_boundary == NULL, "VirtualSpace already initialized"); | |
537 _low_boundary = rs.base(); | |
538 _high_boundary = low_boundary() + rs.size(); | |
539 | |
540 _low = low_boundary(); | |
541 _high = low(); | |
542 | |
543 _special = rs.special(); | |
656 | 544 _executable = rs.executable(); |
0 | 545 |
546 // When a VirtualSpace begins life at a large size, make all future expansion | |
547 // and shrinking occur aligned to a granularity of large pages. This avoids | |
548 // fragmentation of physical addresses that inhibits the use of large pages | |
549 // by the OS virtual memory system. Empirically, we see that with a 4MB | |
550 // page size, the only spaces that get handled this way are codecache and | |
551 // the heap itself, both of which provide a substantial performance | |
552 // boost in many benchmarks when covered by large pages. | |
553 // | |
554 // No attempt is made to force large page alignment at the very top and | |
555 // bottom of the space if they are not aligned so already. | |
556 _lower_alignment = os::vm_page_size(); | |
557 _middle_alignment = os::page_size_for_region(rs.size(), rs.size(), 1); | |
558 _upper_alignment = os::vm_page_size(); | |
559 | |
560 // End of each region | |
561 _lower_high_boundary = (char*) round_to((intptr_t) low_boundary(), middle_alignment()); | |
562 _middle_high_boundary = (char*) round_down((intptr_t) high_boundary(), middle_alignment()); | |
563 _upper_high_boundary = high_boundary(); | |
564 | |
565 // High address of each region | |
566 _lower_high = low_boundary(); | |
567 _middle_high = lower_high_boundary(); | |
568 _upper_high = middle_high_boundary(); | |
569 | |
570 // commit to initial size | |
571 if (committed_size > 0) { | |
572 if (!expand_by(committed_size)) { | |
573 return false; | |
574 } | |
575 } | |
576 return true; | |
577 } | |
578 | |
579 | |
580 VirtualSpace::~VirtualSpace() { | |
581 release(); | |
582 } | |
583 | |
584 | |
585 void VirtualSpace::release() { | |
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586 // This does not release memory it never reserved. |
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587 // Caller must release via rs.release(); |
0 | 588 _low_boundary = NULL; |
589 _high_boundary = NULL; | |
590 _low = NULL; | |
591 _high = NULL; | |
592 _lower_high = NULL; | |
593 _middle_high = NULL; | |
594 _upper_high = NULL; | |
595 _lower_high_boundary = NULL; | |
596 _middle_high_boundary = NULL; | |
597 _upper_high_boundary = NULL; | |
598 _lower_alignment = 0; | |
599 _middle_alignment = 0; | |
600 _upper_alignment = 0; | |
601 _special = false; | |
656 | 602 _executable = false; |
0 | 603 } |
604 | |
605 | |
606 size_t VirtualSpace::committed_size() const { | |
607 return pointer_delta(high(), low(), sizeof(char)); | |
608 } | |
609 | |
610 | |
611 size_t VirtualSpace::reserved_size() const { | |
612 return pointer_delta(high_boundary(), low_boundary(), sizeof(char)); | |
613 } | |
614 | |
615 | |
616 size_t VirtualSpace::uncommitted_size() const { | |
617 return reserved_size() - committed_size(); | |
618 } | |
619 | |
620 | |
621 bool VirtualSpace::contains(const void* p) const { | |
622 return low() <= (const char*) p && (const char*) p < high(); | |
623 } | |
624 | |
625 /* | |
626 First we need to determine if a particular virtual space is using large | |
627 pages. This is done at the initialize function and only virtual spaces | |
628 that are larger than LargePageSizeInBytes use large pages. Once we | |
629 have determined this, all expand_by and shrink_by calls must grow and | |
630 shrink by large page size chunks. If a particular request | |
631 is within the current large page, the call to commit and uncommit memory | |
632 can be ignored. In the case that the low and high boundaries of this | |
633 space is not large page aligned, the pages leading to the first large | |
634 page address and the pages after the last large page address must be | |
635 allocated with default pages. | |
636 */ | |
637 bool VirtualSpace::expand_by(size_t bytes, bool pre_touch) { | |
638 if (uncommitted_size() < bytes) return false; | |
639 | |
640 if (special()) { | |
641 // don't commit memory if the entire space is pinned in memory | |
642 _high += bytes; | |
643 return true; | |
644 } | |
645 | |
646 char* previous_high = high(); | |
647 char* unaligned_new_high = high() + bytes; | |
648 assert(unaligned_new_high <= high_boundary(), | |
649 "cannot expand by more than upper boundary"); | |
650 | |
651 // Calculate where the new high for each of the regions should be. If | |
652 // the low_boundary() and high_boundary() are LargePageSizeInBytes aligned | |
653 // then the unaligned lower and upper new highs would be the | |
654 // lower_high() and upper_high() respectively. | |
655 char* unaligned_lower_new_high = | |
656 MIN2(unaligned_new_high, lower_high_boundary()); | |
657 char* unaligned_middle_new_high = | |
658 MIN2(unaligned_new_high, middle_high_boundary()); | |
659 char* unaligned_upper_new_high = | |
660 MIN2(unaligned_new_high, upper_high_boundary()); | |
661 | |
662 // Align the new highs based on the regions alignment. lower and upper | |
663 // alignment will always be default page size. middle alignment will be | |
664 // LargePageSizeInBytes if the actual size of the virtual space is in | |
665 // fact larger than LargePageSizeInBytes. | |
666 char* aligned_lower_new_high = | |
667 (char*) round_to((intptr_t) unaligned_lower_new_high, lower_alignment()); | |
668 char* aligned_middle_new_high = | |
669 (char*) round_to((intptr_t) unaligned_middle_new_high, middle_alignment()); | |
670 char* aligned_upper_new_high = | |
671 (char*) round_to((intptr_t) unaligned_upper_new_high, upper_alignment()); | |
672 | |
673 // Determine which regions need to grow in this expand_by call. | |
674 // If you are growing in the lower region, high() must be in that | |
675 // region so calcuate the size based on high(). For the middle and | |
676 // upper regions, determine the starting point of growth based on the | |
677 // location of high(). By getting the MAX of the region's low address | |
678 // (or the prevoius region's high address) and high(), we can tell if it | |
679 // is an intra or inter region growth. | |
680 size_t lower_needs = 0; | |
681 if (aligned_lower_new_high > lower_high()) { | |
682 lower_needs = | |
683 pointer_delta(aligned_lower_new_high, lower_high(), sizeof(char)); | |
684 } | |
685 size_t middle_needs = 0; | |
686 if (aligned_middle_new_high > middle_high()) { | |
687 middle_needs = | |
688 pointer_delta(aligned_middle_new_high, middle_high(), sizeof(char)); | |
689 } | |
690 size_t upper_needs = 0; | |
691 if (aligned_upper_new_high > upper_high()) { | |
692 upper_needs = | |
693 pointer_delta(aligned_upper_new_high, upper_high(), sizeof(char)); | |
694 } | |
695 | |
696 // Check contiguity. | |
697 assert(low_boundary() <= lower_high() && | |
698 lower_high() <= lower_high_boundary(), | |
699 "high address must be contained within the region"); | |
700 assert(lower_high_boundary() <= middle_high() && | |
701 middle_high() <= middle_high_boundary(), | |
702 "high address must be contained within the region"); | |
703 assert(middle_high_boundary() <= upper_high() && | |
704 upper_high() <= upper_high_boundary(), | |
705 "high address must be contained within the region"); | |
706 | |
707 // Commit regions | |
708 if (lower_needs > 0) { | |
709 assert(low_boundary() <= lower_high() && | |
710 lower_high() + lower_needs <= lower_high_boundary(), | |
711 "must not expand beyond region"); | |
656 | 712 if (!os::commit_memory(lower_high(), lower_needs, _executable)) { |
0 | 713 debug_only(warning("os::commit_memory failed")); |
714 return false; | |
715 } else { | |
716 _lower_high += lower_needs; | |
717 } | |
718 } | |
719 if (middle_needs > 0) { | |
720 assert(lower_high_boundary() <= middle_high() && | |
721 middle_high() + middle_needs <= middle_high_boundary(), | |
722 "must not expand beyond region"); | |
656 | 723 if (!os::commit_memory(middle_high(), middle_needs, middle_alignment(), |
724 _executable)) { | |
0 | 725 debug_only(warning("os::commit_memory failed")); |
726 return false; | |
727 } | |
728 _middle_high += middle_needs; | |
729 } | |
730 if (upper_needs > 0) { | |
731 assert(middle_high_boundary() <= upper_high() && | |
732 upper_high() + upper_needs <= upper_high_boundary(), | |
733 "must not expand beyond region"); | |
656 | 734 if (!os::commit_memory(upper_high(), upper_needs, _executable)) { |
0 | 735 debug_only(warning("os::commit_memory failed")); |
736 return false; | |
737 } else { | |
738 _upper_high += upper_needs; | |
739 } | |
740 } | |
741 | |
742 if (pre_touch || AlwaysPreTouch) { | |
743 int vm_ps = os::vm_page_size(); | |
744 for (char* curr = previous_high; | |
745 curr < unaligned_new_high; | |
746 curr += vm_ps) { | |
747 // Note the use of a write here; originally we tried just a read, but | |
748 // since the value read was unused, the optimizer removed the read. | |
749 // If we ever have a concurrent touchahead thread, we'll want to use | |
750 // a read, to avoid the potential of overwriting data (if a mutator | |
751 // thread beats the touchahead thread to a page). There are various | |
752 // ways of making sure this read is not optimized away: for example, | |
753 // generating the code for a read procedure at runtime. | |
754 *curr = 0; | |
755 } | |
756 } | |
757 | |
758 _high += bytes; | |
759 return true; | |
760 } | |
761 | |
762 // A page is uncommitted if the contents of the entire page is deemed unusable. | |
763 // Continue to decrement the high() pointer until it reaches a page boundary | |
764 // in which case that particular page can now be uncommitted. | |
765 void VirtualSpace::shrink_by(size_t size) { | |
766 if (committed_size() < size) | |
767 fatal("Cannot shrink virtual space to negative size"); | |
768 | |
769 if (special()) { | |
770 // don't uncommit if the entire space is pinned in memory | |
771 _high -= size; | |
772 return; | |
773 } | |
774 | |
775 char* unaligned_new_high = high() - size; | |
776 assert(unaligned_new_high >= low_boundary(), "cannot shrink past lower boundary"); | |
777 | |
778 // Calculate new unaligned address | |
779 char* unaligned_upper_new_high = | |
780 MAX2(unaligned_new_high, middle_high_boundary()); | |
781 char* unaligned_middle_new_high = | |
782 MAX2(unaligned_new_high, lower_high_boundary()); | |
783 char* unaligned_lower_new_high = | |
784 MAX2(unaligned_new_high, low_boundary()); | |
785 | |
786 // Align address to region's alignment | |
787 char* aligned_upper_new_high = | |
788 (char*) round_to((intptr_t) unaligned_upper_new_high, upper_alignment()); | |
789 char* aligned_middle_new_high = | |
790 (char*) round_to((intptr_t) unaligned_middle_new_high, middle_alignment()); | |
791 char* aligned_lower_new_high = | |
792 (char*) round_to((intptr_t) unaligned_lower_new_high, lower_alignment()); | |
793 | |
794 // Determine which regions need to shrink | |
795 size_t upper_needs = 0; | |
796 if (aligned_upper_new_high < upper_high()) { | |
797 upper_needs = | |
798 pointer_delta(upper_high(), aligned_upper_new_high, sizeof(char)); | |
799 } | |
800 size_t middle_needs = 0; | |
801 if (aligned_middle_new_high < middle_high()) { | |
802 middle_needs = | |
803 pointer_delta(middle_high(), aligned_middle_new_high, sizeof(char)); | |
804 } | |
805 size_t lower_needs = 0; | |
806 if (aligned_lower_new_high < lower_high()) { | |
807 lower_needs = | |
808 pointer_delta(lower_high(), aligned_lower_new_high, sizeof(char)); | |
809 } | |
810 | |
811 // Check contiguity. | |
812 assert(middle_high_boundary() <= upper_high() && | |
813 upper_high() <= upper_high_boundary(), | |
814 "high address must be contained within the region"); | |
815 assert(lower_high_boundary() <= middle_high() && | |
816 middle_high() <= middle_high_boundary(), | |
817 "high address must be contained within the region"); | |
818 assert(low_boundary() <= lower_high() && | |
819 lower_high() <= lower_high_boundary(), | |
820 "high address must be contained within the region"); | |
821 | |
822 // Uncommit | |
823 if (upper_needs > 0) { | |
824 assert(middle_high_boundary() <= aligned_upper_new_high && | |
825 aligned_upper_new_high + upper_needs <= upper_high_boundary(), | |
826 "must not shrink beyond region"); | |
827 if (!os::uncommit_memory(aligned_upper_new_high, upper_needs)) { | |
828 debug_only(warning("os::uncommit_memory failed")); | |
829 return; | |
830 } else { | |
831 _upper_high -= upper_needs; | |
832 } | |
833 } | |
834 if (middle_needs > 0) { | |
835 assert(lower_high_boundary() <= aligned_middle_new_high && | |
836 aligned_middle_new_high + middle_needs <= middle_high_boundary(), | |
837 "must not shrink beyond region"); | |
838 if (!os::uncommit_memory(aligned_middle_new_high, middle_needs)) { | |
839 debug_only(warning("os::uncommit_memory failed")); | |
840 return; | |
841 } else { | |
842 _middle_high -= middle_needs; | |
843 } | |
844 } | |
845 if (lower_needs > 0) { | |
846 assert(low_boundary() <= aligned_lower_new_high && | |
847 aligned_lower_new_high + lower_needs <= lower_high_boundary(), | |
848 "must not shrink beyond region"); | |
849 if (!os::uncommit_memory(aligned_lower_new_high, lower_needs)) { | |
850 debug_only(warning("os::uncommit_memory failed")); | |
851 return; | |
852 } else { | |
853 _lower_high -= lower_needs; | |
854 } | |
855 } | |
856 | |
857 _high -= size; | |
858 } | |
859 | |
860 #ifndef PRODUCT | |
861 void VirtualSpace::check_for_contiguity() { | |
862 // Check contiguity. | |
863 assert(low_boundary() <= lower_high() && | |
864 lower_high() <= lower_high_boundary(), | |
865 "high address must be contained within the region"); | |
866 assert(lower_high_boundary() <= middle_high() && | |
867 middle_high() <= middle_high_boundary(), | |
868 "high address must be contained within the region"); | |
869 assert(middle_high_boundary() <= upper_high() && | |
870 upper_high() <= upper_high_boundary(), | |
871 "high address must be contained within the region"); | |
872 assert(low() >= low_boundary(), "low"); | |
873 assert(low_boundary() <= lower_high_boundary(), "lower high boundary"); | |
874 assert(upper_high_boundary() <= high_boundary(), "upper high boundary"); | |
875 assert(high() <= upper_high(), "upper high"); | |
876 } | |
877 | |
878 void VirtualSpace::print() { | |
879 tty->print ("Virtual space:"); | |
880 if (special()) tty->print(" (pinned in memory)"); | |
881 tty->cr(); | |
882 tty->print_cr(" - committed: %ld", committed_size()); | |
883 tty->print_cr(" - reserved: %ld", reserved_size()); | |
884 tty->print_cr(" - [low, high]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", low(), high()); | |
885 tty->print_cr(" - [low_b, high_b]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", low_boundary(), high_boundary()); | |
886 } | |
887 | |
888 #endif |