annotate src/share/vm/runtime/virtualspace.cpp @ 1145:e018e6884bd8

6631166: CMS: better heuristics when combatting fragmentation Summary: Autonomic per-worker free block cache sizing, tunable coalition policies, fixes to per-size block statistics, retuned gain and bandwidth of some feedback loop filters to allow quicker reactivity to abrupt changes in ambient demand, and other heuristics to reduce fragmentation of the CMS old gen. Also tightened some assertions, including those related to locking. Reviewed-by: jmasa
author ysr
date Wed, 23 Dec 2009 09:23:54 -0800
parents bd02caa94611
children c18cbe5936b8
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1 /*
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2 * Copyright 1997-2009 Sun Microsystems, Inc. All Rights Reserved.
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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4 *
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5 * This code is free software; you can redistribute it and/or modify it
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6 * under the terms of the GNU General Public License version 2 only, as
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7 * published by the Free Software Foundation.
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8 *
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9 * This code is distributed in the hope that it will be useful, but WITHOUT
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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12 * version 2 for more details (a copy is included in the LICENSE file that
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13 * accompanied this code).
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14 *
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15 * You should have received a copy of the GNU General Public License version
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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18 *
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19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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20 * CA 95054 USA or visit www.sun.com if you need additional information or
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21 * have any questions.
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22 *
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23 */
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24
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25 #include "incls/_precompiled.incl"
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26 #include "incls/_virtualspace.cpp.incl"
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27
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28
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29 // ReservedSpace
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30 ReservedSpace::ReservedSpace(size_t size) {
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31 initialize(size, 0, false, NULL, 0, false);
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32 }
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33
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34 ReservedSpace::ReservedSpace(size_t size, size_t alignment,
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35 bool large,
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36 char* requested_address,
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37 const size_t noaccess_prefix) {
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38 initialize(size+noaccess_prefix, alignment, large, requested_address,
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39 noaccess_prefix, false);
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40 }
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41
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42 ReservedSpace::ReservedSpace(size_t size, size_t alignment,
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43 bool large,
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44 bool executable) {
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45 initialize(size, alignment, large, NULL, 0, executable);
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46 }
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47
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48 char *
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49 ReservedSpace::align_reserved_region(char* addr, const size_t len,
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50 const size_t prefix_size,
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51 const size_t prefix_align,
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52 const size_t suffix_size,
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53 const size_t suffix_align)
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54 {
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55 assert(addr != NULL, "sanity");
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56 const size_t required_size = prefix_size + suffix_size;
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57 assert(len >= required_size, "len too small");
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58
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59 const size_t s = size_t(addr);
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60 const size_t beg_ofs = s + prefix_size & suffix_align - 1;
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61 const size_t beg_delta = beg_ofs == 0 ? 0 : suffix_align - beg_ofs;
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62
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63 if (len < beg_delta + required_size) {
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64 return NULL; // Cannot do proper alignment.
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65 }
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66 const size_t end_delta = len - (beg_delta + required_size);
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67
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68 if (beg_delta != 0) {
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69 os::release_memory(addr, beg_delta);
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70 }
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71
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72 if (end_delta != 0) {
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73 char* release_addr = (char*) (s + beg_delta + required_size);
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74 os::release_memory(release_addr, end_delta);
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75 }
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76
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77 return (char*) (s + beg_delta);
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78 }
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79
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80 char* ReservedSpace::reserve_and_align(const size_t reserve_size,
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81 const size_t prefix_size,
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82 const size_t prefix_align,
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83 const size_t suffix_size,
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84 const size_t suffix_align)
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85 {
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86 assert(reserve_size > prefix_size + suffix_size, "should not be here");
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87
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88 char* raw_addr = os::reserve_memory(reserve_size, NULL, prefix_align);
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89 if (raw_addr == NULL) return NULL;
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90
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91 char* result = align_reserved_region(raw_addr, reserve_size, prefix_size,
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92 prefix_align, suffix_size,
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93 suffix_align);
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94 if (result == NULL && !os::release_memory(raw_addr, reserve_size)) {
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95 fatal("os::release_memory failed");
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96 }
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97
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98 #ifdef ASSERT
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99 if (result != NULL) {
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100 const size_t raw = size_t(raw_addr);
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101 const size_t res = size_t(result);
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102 assert(res >= raw, "alignment decreased start addr");
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103 assert(res + prefix_size + suffix_size <= raw + reserve_size,
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104 "alignment increased end addr");
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105 assert((res & prefix_align - 1) == 0, "bad alignment of prefix");
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106 assert((res + prefix_size & suffix_align - 1) == 0,
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107 "bad alignment of suffix");
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108 }
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109 #endif
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110
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111 return result;
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112 }
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113
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114 ReservedSpace::ReservedSpace(const size_t prefix_size,
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115 const size_t prefix_align,
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116 const size_t suffix_size,
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117 const size_t suffix_align,
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118 char* requested_address,
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119 const size_t noaccess_prefix)
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120 {
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121 assert(prefix_size != 0, "sanity");
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122 assert(prefix_align != 0, "sanity");
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123 assert(suffix_size != 0, "sanity");
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124 assert(suffix_align != 0, "sanity");
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125 assert((prefix_size & prefix_align - 1) == 0,
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126 "prefix_size not divisible by prefix_align");
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127 assert((suffix_size & suffix_align - 1) == 0,
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128 "suffix_size not divisible by suffix_align");
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129 assert((suffix_align & prefix_align - 1) == 0,
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130 "suffix_align not divisible by prefix_align");
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131
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132 // Add in noaccess_prefix to prefix_size;
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133 const size_t adjusted_prefix_size = prefix_size + noaccess_prefix;
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134 const size_t size = adjusted_prefix_size + suffix_size;
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135
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136 // On systems where the entire region has to be reserved and committed up
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137 // front, the compound alignment normally done by this method is unnecessary.
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138 const bool try_reserve_special = UseLargePages &&
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139 prefix_align == os::large_page_size();
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140 if (!os::can_commit_large_page_memory() && try_reserve_special) {
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141 initialize(size, prefix_align, true, requested_address, noaccess_prefix,
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142 false);
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143 return;
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144 }
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145
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146 _base = NULL;
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147 _size = 0;
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148 _alignment = 0;
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149 _special = false;
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150 _noaccess_prefix = 0;
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151 _executable = false;
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152
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153 // Assert that if noaccess_prefix is used, it is the same as prefix_align.
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154 assert(noaccess_prefix == 0 ||
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155 noaccess_prefix == prefix_align, "noaccess prefix wrong");
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156
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157 // Optimistically try to reserve the exact size needed.
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158 char* addr;
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159 if (requested_address != 0) {
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160 addr = os::attempt_reserve_memory_at(size,
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161 requested_address-noaccess_prefix);
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162 } else {
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163 addr = os::reserve_memory(size, NULL, prefix_align);
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164 }
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165 if (addr == NULL) return;
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166
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167 // Check whether the result has the needed alignment (unlikely unless
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168 // prefix_align == suffix_align).
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169 const size_t ofs = size_t(addr) + adjusted_prefix_size & suffix_align - 1;
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170 if (ofs != 0) {
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171 // Wrong alignment. Release, allocate more space and do manual alignment.
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172 //
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173 // On most operating systems, another allocation with a somewhat larger size
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174 // will return an address "close to" that of the previous allocation. The
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175 // result is often the same address (if the kernel hands out virtual
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176 // addresses from low to high), or an address that is offset by the increase
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177 // in size. Exploit that to minimize the amount of extra space requested.
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178 if (!os::release_memory(addr, size)) {
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179 fatal("os::release_memory failed");
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180 }
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181
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182 const size_t extra = MAX2(ofs, suffix_align - ofs);
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183 addr = reserve_and_align(size + extra, adjusted_prefix_size, prefix_align,
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184 suffix_size, suffix_align);
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185 if (addr == NULL) {
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186 // Try an even larger region. If this fails, address space is exhausted.
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187 addr = reserve_and_align(size + suffix_align, adjusted_prefix_size,
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188 prefix_align, suffix_size, suffix_align);
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189 }
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190 }
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191
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192 _base = addr;
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193 _size = size;
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194 _alignment = prefix_align;
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195 _noaccess_prefix = noaccess_prefix;
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196 }
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197
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198 void ReservedSpace::initialize(size_t size, size_t alignment, bool large,
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199 char* requested_address,
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200 const size_t noaccess_prefix,
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201 bool executable) {
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202 const size_t granularity = os::vm_allocation_granularity();
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203 assert((size & granularity - 1) == 0,
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204 "size not aligned to os::vm_allocation_granularity()");
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205 assert((alignment & granularity - 1) == 0,
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206 "alignment not aligned to os::vm_allocation_granularity()");
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207 assert(alignment == 0 || is_power_of_2((intptr_t)alignment),
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208 "not a power of 2");
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209
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210 _base = NULL;
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211 _size = 0;
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212 _special = false;
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213 _executable = executable;
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214 _alignment = 0;
237
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215 _noaccess_prefix = 0;
0
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216 if (size == 0) {
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217 return;
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218 }
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219
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220 // If OS doesn't support demand paging for large page memory, we need
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221 // to use reserve_memory_special() to reserve and pin the entire region.
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222 bool special = large && !os::can_commit_large_page_memory();
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223 char* base = NULL;
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224
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225 if (special) {
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226
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227 base = os::reserve_memory_special(size, requested_address, executable);
0
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228
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229 if (base != NULL) {
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230 // Check alignment constraints
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231 if (alignment > 0) {
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232 assert((uintptr_t) base % alignment == 0,
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233 "Large pages returned a non-aligned address");
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234 }
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235 _special = true;
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236 } else {
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237 // failed; try to reserve regular memory below
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238 }
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239 }
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240
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241 if (base == NULL) {
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242 // Optimistically assume that the OSes returns an aligned base pointer.
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243 // When reserving a large address range, most OSes seem to align to at
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244 // least 64K.
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245
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246 // If the memory was requested at a particular address, use
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247 // os::attempt_reserve_memory_at() to avoid over mapping something
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248 // important. If available space is not detected, return NULL.
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249
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250 if (requested_address != 0) {
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251 base = os::attempt_reserve_memory_at(size,
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252 requested_address-noaccess_prefix);
0
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253 } else {
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254 base = os::reserve_memory(size, NULL, alignment);
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255 }
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256
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257 if (base == NULL) return;
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258
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259 // Check alignment constraints
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260 if (alignment > 0 && ((size_t)base & alignment - 1) != 0) {
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261 // Base not aligned, retry
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262 if (!os::release_memory(base, size)) fatal("os::release_memory failed");
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263 // Reserve size large enough to do manual alignment and
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264 // increase size to a multiple of the desired alignment
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265 size = align_size_up(size, alignment);
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266 size_t extra_size = size + alignment;
342
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267 do {
37f87013dfd8 6711316: Open source the Garbage-First garbage collector
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268 char* extra_base = os::reserve_memory(extra_size, NULL, alignment);
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269 if (extra_base == NULL) return;
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270 // Do manual alignement
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271 base = (char*) align_size_up((uintptr_t) extra_base, alignment);
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272 assert(base >= extra_base, "just checking");
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273 // Re-reserve the region at the aligned base address.
37f87013dfd8 6711316: Open source the Garbage-First garbage collector
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274 os::release_memory(extra_base, extra_size);
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275 base = os::reserve_memory(size, base);
37f87013dfd8 6711316: Open source the Garbage-First garbage collector
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parents: 0
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276 } while (base == NULL);
0
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277 }
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278 }
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279 // Done
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280 _base = base;
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281 _size = size;
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282 _alignment = MAX2(alignment, (size_t) os::vm_page_size());
237
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283 _noaccess_prefix = noaccess_prefix;
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284
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285 // Assert that if noaccess_prefix is used, it is the same as alignment.
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286 assert(noaccess_prefix == 0 ||
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287 noaccess_prefix == _alignment, "noaccess prefix wrong");
0
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288
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289 assert(markOopDesc::encode_pointer_as_mark(_base)->decode_pointer() == _base,
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290 "area must be distinguisable from marks for mark-sweep");
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291 assert(markOopDesc::encode_pointer_as_mark(&_base[size])->decode_pointer() == &_base[size],
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292 "area must be distinguisable from marks for mark-sweep");
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293 }
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294
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295
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296 ReservedSpace::ReservedSpace(char* base, size_t size, size_t alignment,
656
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297 bool special, bool executable) {
0
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298 assert((size % os::vm_allocation_granularity()) == 0,
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299 "size not allocation aligned");
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300 _base = base;
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301 _size = size;
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302 _alignment = alignment;
237
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303 _noaccess_prefix = 0;
0
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304 _special = special;
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305 _executable = executable;
0
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306 }
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307
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308
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309 ReservedSpace ReservedSpace::first_part(size_t partition_size, size_t alignment,
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310 bool split, bool realloc) {
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311 assert(partition_size <= size(), "partition failed");
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312 if (split) {
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313 os::split_reserved_memory(base(), size(), partition_size, realloc);
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314 }
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315 ReservedSpace result(base(), partition_size, alignment, special(),
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316 executable());
0
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317 return result;
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318 }
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319
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320
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321 ReservedSpace
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322 ReservedSpace::last_part(size_t partition_size, size_t alignment) {
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323 assert(partition_size <= size(), "partition failed");
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324 ReservedSpace result(base() + partition_size, size() - partition_size,
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325 alignment, special(), executable());
0
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326 return result;
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327 }
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328
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329
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330 size_t ReservedSpace::page_align_size_up(size_t size) {
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331 return align_size_up(size, os::vm_page_size());
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332 }
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333
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334
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335 size_t ReservedSpace::page_align_size_down(size_t size) {
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336 return align_size_down(size, os::vm_page_size());
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337 }
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338
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339
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340 size_t ReservedSpace::allocation_align_size_up(size_t size) {
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341 return align_size_up(size, os::vm_allocation_granularity());
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342 }
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343
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344
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345 size_t ReservedSpace::allocation_align_size_down(size_t size) {
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346 return align_size_down(size, os::vm_allocation_granularity());
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347 }
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348
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349
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350 void ReservedSpace::release() {
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351 if (is_reserved()) {
237
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352 char *real_base = _base - _noaccess_prefix;
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353 const size_t real_size = _size + _noaccess_prefix;
0
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354 if (special()) {
237
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diff changeset
355 os::release_memory_special(real_base, real_size);
0
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356 } else{
237
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diff changeset
357 os::release_memory(real_base, real_size);
0
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358 }
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359 _base = NULL;
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360 _size = 0;
237
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diff changeset
361 _noaccess_prefix = 0;
0
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362 _special = false;
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363 _executable = false;
0
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364 }
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365 }
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366
237
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diff changeset
367 void ReservedSpace::protect_noaccess_prefix(const size_t size) {
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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diff changeset
368 // If there is noaccess prefix, return.
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
369 if (_noaccess_prefix == 0) return;
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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parents: 0
diff changeset
370
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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diff changeset
371 assert(_noaccess_prefix >= (size_t)os::vm_page_size(),
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
372 "must be at least page size big");
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parents: 0
diff changeset
373
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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diff changeset
374 // Protect memory at the base of the allocated region.
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
375 // If special, the page was committed (only matters on windows)
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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parents: 0
diff changeset
376 if (!os::protect_memory(_base, _noaccess_prefix, os::MEM_PROT_NONE,
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
377 _special)) {
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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parents: 0
diff changeset
378 fatal("cannot protect protection page");
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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parents: 0
diff changeset
379 }
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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parents: 0
diff changeset
380
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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diff changeset
381 _base += _noaccess_prefix;
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
382 _size -= _noaccess_prefix;
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
383 assert((size == _size) && ((uintptr_t)_base % _alignment == 0),
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
384 "must be exactly of required size and alignment");
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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parents: 0
diff changeset
385 }
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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parents: 0
diff changeset
386
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
387 ReservedHeapSpace::ReservedHeapSpace(size_t size, size_t alignment,
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
388 bool large, char* requested_address) :
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
389 ReservedSpace(size, alignment, large,
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
390 requested_address,
642
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kvn
parents: 380
diff changeset
391 (UseCompressedOops && (Universe::narrow_oop_base() != NULL) &&
660978a2a31a 6791178: Specialize for zero as the compressed oop vm heap base
kvn
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diff changeset
392 Universe::narrow_oop_use_implicit_null_checks()) ?
325
93befa083681 6741004: UseLargePages + UseCompressedOops breaks implicit null checking guard page
coleenp
parents: 237
diff changeset
393 lcm(os::vm_page_size(), alignment) : 0) {
237
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parents: 0
diff changeset
394 // Only reserved space for the java heap should have a noaccess_prefix
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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parents: 0
diff changeset
395 // if using compressed oops.
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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diff changeset
396 protect_noaccess_prefix(size);
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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parents: 0
diff changeset
397 }
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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parents: 0
diff changeset
398
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parents: 0
diff changeset
399 ReservedHeapSpace::ReservedHeapSpace(const size_t prefix_size,
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
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parents: 0
diff changeset
400 const size_t prefix_align,
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
401 const size_t suffix_size,
642
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parents: 380
diff changeset
402 const size_t suffix_align,
660978a2a31a 6791178: Specialize for zero as the compressed oop vm heap base
kvn
parents: 380
diff changeset
403 char* requested_address) :
237
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
404 ReservedSpace(prefix_size, prefix_align, suffix_size, suffix_align,
642
660978a2a31a 6791178: Specialize for zero as the compressed oop vm heap base
kvn
parents: 380
diff changeset
405 requested_address,
660978a2a31a 6791178: Specialize for zero as the compressed oop vm heap base
kvn
parents: 380
diff changeset
406 (UseCompressedOops && (Universe::narrow_oop_base() != NULL) &&
660978a2a31a 6791178: Specialize for zero as the compressed oop vm heap base
kvn
parents: 380
diff changeset
407 Universe::narrow_oop_use_implicit_null_checks()) ?
325
93befa083681 6741004: UseLargePages + UseCompressedOops breaks implicit null checking guard page
coleenp
parents: 237
diff changeset
408 lcm(os::vm_page_size(), prefix_align) : 0) {
237
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
409 protect_noaccess_prefix(prefix_size+suffix_size);
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
410 }
0
a61af66fc99e Initial load
duke
parents:
diff changeset
411
656
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
412 // Reserve space for code segment. Same as Java heap only we mark this as
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
413 // executable.
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
414 ReservedCodeSpace::ReservedCodeSpace(size_t r_size,
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
415 size_t rs_align,
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
416 bool large) :
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
417 ReservedSpace(r_size, rs_align, large, /*executable*/ true) {
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
418 }
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
419
0
a61af66fc99e Initial load
duke
parents:
diff changeset
420 // VirtualSpace
a61af66fc99e Initial load
duke
parents:
diff changeset
421
a61af66fc99e Initial load
duke
parents:
diff changeset
422 VirtualSpace::VirtualSpace() {
a61af66fc99e Initial load
duke
parents:
diff changeset
423 _low_boundary = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
424 _high_boundary = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
425 _low = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
426 _high = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
427 _lower_high = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
428 _middle_high = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
429 _upper_high = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
430 _lower_high_boundary = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
431 _middle_high_boundary = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
432 _upper_high_boundary = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
433 _lower_alignment = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
434 _middle_alignment = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
435 _upper_alignment = 0;
237
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
436 _special = false;
656
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
437 _executable = false;
0
a61af66fc99e Initial load
duke
parents:
diff changeset
438 }
a61af66fc99e Initial load
duke
parents:
diff changeset
439
a61af66fc99e Initial load
duke
parents:
diff changeset
440
a61af66fc99e Initial load
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parents:
diff changeset
441 bool VirtualSpace::initialize(ReservedSpace rs, size_t committed_size) {
a61af66fc99e Initial load
duke
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442 if(!rs.is_reserved()) return false; // allocation failed.
a61af66fc99e Initial load
duke
parents:
diff changeset
443 assert(_low_boundary == NULL, "VirtualSpace already initialized");
a61af66fc99e Initial load
duke
parents:
diff changeset
444 _low_boundary = rs.base();
a61af66fc99e Initial load
duke
parents:
diff changeset
445 _high_boundary = low_boundary() + rs.size();
a61af66fc99e Initial load
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parents:
diff changeset
446
a61af66fc99e Initial load
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parents:
diff changeset
447 _low = low_boundary();
a61af66fc99e Initial load
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parents:
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448 _high = low();
a61af66fc99e Initial load
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parents:
diff changeset
449
a61af66fc99e Initial load
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parents:
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450 _special = rs.special();
656
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
451 _executable = rs.executable();
0
a61af66fc99e Initial load
duke
parents:
diff changeset
452
a61af66fc99e Initial load
duke
parents:
diff changeset
453 // When a VirtualSpace begins life at a large size, make all future expansion
a61af66fc99e Initial load
duke
parents:
diff changeset
454 // and shrinking occur aligned to a granularity of large pages. This avoids
a61af66fc99e Initial load
duke
parents:
diff changeset
455 // fragmentation of physical addresses that inhibits the use of large pages
a61af66fc99e Initial load
duke
parents:
diff changeset
456 // by the OS virtual memory system. Empirically, we see that with a 4MB
a61af66fc99e Initial load
duke
parents:
diff changeset
457 // page size, the only spaces that get handled this way are codecache and
a61af66fc99e Initial load
duke
parents:
diff changeset
458 // the heap itself, both of which provide a substantial performance
a61af66fc99e Initial load
duke
parents:
diff changeset
459 // boost in many benchmarks when covered by large pages.
a61af66fc99e Initial load
duke
parents:
diff changeset
460 //
a61af66fc99e Initial load
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parents:
diff changeset
461 // No attempt is made to force large page alignment at the very top and
a61af66fc99e Initial load
duke
parents:
diff changeset
462 // bottom of the space if they are not aligned so already.
a61af66fc99e Initial load
duke
parents:
diff changeset
463 _lower_alignment = os::vm_page_size();
a61af66fc99e Initial load
duke
parents:
diff changeset
464 _middle_alignment = os::page_size_for_region(rs.size(), rs.size(), 1);
a61af66fc99e Initial load
duke
parents:
diff changeset
465 _upper_alignment = os::vm_page_size();
a61af66fc99e Initial load
duke
parents:
diff changeset
466
a61af66fc99e Initial load
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parents:
diff changeset
467 // End of each region
a61af66fc99e Initial load
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parents:
diff changeset
468 _lower_high_boundary = (char*) round_to((intptr_t) low_boundary(), middle_alignment());
a61af66fc99e Initial load
duke
parents:
diff changeset
469 _middle_high_boundary = (char*) round_down((intptr_t) high_boundary(), middle_alignment());
a61af66fc99e Initial load
duke
parents:
diff changeset
470 _upper_high_boundary = high_boundary();
a61af66fc99e Initial load
duke
parents:
diff changeset
471
a61af66fc99e Initial load
duke
parents:
diff changeset
472 // High address of each region
a61af66fc99e Initial load
duke
parents:
diff changeset
473 _lower_high = low_boundary();
a61af66fc99e Initial load
duke
parents:
diff changeset
474 _middle_high = lower_high_boundary();
a61af66fc99e Initial load
duke
parents:
diff changeset
475 _upper_high = middle_high_boundary();
a61af66fc99e Initial load
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parents:
diff changeset
476
a61af66fc99e Initial load
duke
parents:
diff changeset
477 // commit to initial size
a61af66fc99e Initial load
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parents:
diff changeset
478 if (committed_size > 0) {
a61af66fc99e Initial load
duke
parents:
diff changeset
479 if (!expand_by(committed_size)) {
a61af66fc99e Initial load
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parents:
diff changeset
480 return false;
a61af66fc99e Initial load
duke
parents:
diff changeset
481 }
a61af66fc99e Initial load
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parents:
diff changeset
482 }
a61af66fc99e Initial load
duke
parents:
diff changeset
483 return true;
a61af66fc99e Initial load
duke
parents:
diff changeset
484 }
a61af66fc99e Initial load
duke
parents:
diff changeset
485
a61af66fc99e Initial load
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parents:
diff changeset
486
a61af66fc99e Initial load
duke
parents:
diff changeset
487 VirtualSpace::~VirtualSpace() {
a61af66fc99e Initial load
duke
parents:
diff changeset
488 release();
a61af66fc99e Initial load
duke
parents:
diff changeset
489 }
a61af66fc99e Initial load
duke
parents:
diff changeset
490
a61af66fc99e Initial load
duke
parents:
diff changeset
491
a61af66fc99e Initial load
duke
parents:
diff changeset
492 void VirtualSpace::release() {
237
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
493 // This does not release memory it never reserved.
1fdb98a17101 6716785: implicit null checks not triggering with CompressedOops
coleenp
parents: 0
diff changeset
494 // Caller must release via rs.release();
0
a61af66fc99e Initial load
duke
parents:
diff changeset
495 _low_boundary = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
496 _high_boundary = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
497 _low = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
498 _high = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
499 _lower_high = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
500 _middle_high = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
501 _upper_high = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
502 _lower_high_boundary = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
503 _middle_high_boundary = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
504 _upper_high_boundary = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
505 _lower_alignment = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
506 _middle_alignment = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
507 _upper_alignment = 0;
a61af66fc99e Initial load
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parents:
diff changeset
508 _special = false;
656
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
509 _executable = false;
0
a61af66fc99e Initial load
duke
parents:
diff changeset
510 }
a61af66fc99e Initial load
duke
parents:
diff changeset
511
a61af66fc99e Initial load
duke
parents:
diff changeset
512
a61af66fc99e Initial load
duke
parents:
diff changeset
513 size_t VirtualSpace::committed_size() const {
a61af66fc99e Initial load
duke
parents:
diff changeset
514 return pointer_delta(high(), low(), sizeof(char));
a61af66fc99e Initial load
duke
parents:
diff changeset
515 }
a61af66fc99e Initial load
duke
parents:
diff changeset
516
a61af66fc99e Initial load
duke
parents:
diff changeset
517
a61af66fc99e Initial load
duke
parents:
diff changeset
518 size_t VirtualSpace::reserved_size() const {
a61af66fc99e Initial load
duke
parents:
diff changeset
519 return pointer_delta(high_boundary(), low_boundary(), sizeof(char));
a61af66fc99e Initial load
duke
parents:
diff changeset
520 }
a61af66fc99e Initial load
duke
parents:
diff changeset
521
a61af66fc99e Initial load
duke
parents:
diff changeset
522
a61af66fc99e Initial load
duke
parents:
diff changeset
523 size_t VirtualSpace::uncommitted_size() const {
a61af66fc99e Initial load
duke
parents:
diff changeset
524 return reserved_size() - committed_size();
a61af66fc99e Initial load
duke
parents:
diff changeset
525 }
a61af66fc99e Initial load
duke
parents:
diff changeset
526
a61af66fc99e Initial load
duke
parents:
diff changeset
527
a61af66fc99e Initial load
duke
parents:
diff changeset
528 bool VirtualSpace::contains(const void* p) const {
a61af66fc99e Initial load
duke
parents:
diff changeset
529 return low() <= (const char*) p && (const char*) p < high();
a61af66fc99e Initial load
duke
parents:
diff changeset
530 }
a61af66fc99e Initial load
duke
parents:
diff changeset
531
a61af66fc99e Initial load
duke
parents:
diff changeset
532 /*
a61af66fc99e Initial load
duke
parents:
diff changeset
533 First we need to determine if a particular virtual space is using large
a61af66fc99e Initial load
duke
parents:
diff changeset
534 pages. This is done at the initialize function and only virtual spaces
a61af66fc99e Initial load
duke
parents:
diff changeset
535 that are larger than LargePageSizeInBytes use large pages. Once we
a61af66fc99e Initial load
duke
parents:
diff changeset
536 have determined this, all expand_by and shrink_by calls must grow and
a61af66fc99e Initial load
duke
parents:
diff changeset
537 shrink by large page size chunks. If a particular request
a61af66fc99e Initial load
duke
parents:
diff changeset
538 is within the current large page, the call to commit and uncommit memory
a61af66fc99e Initial load
duke
parents:
diff changeset
539 can be ignored. In the case that the low and high boundaries of this
a61af66fc99e Initial load
duke
parents:
diff changeset
540 space is not large page aligned, the pages leading to the first large
a61af66fc99e Initial load
duke
parents:
diff changeset
541 page address and the pages after the last large page address must be
a61af66fc99e Initial load
duke
parents:
diff changeset
542 allocated with default pages.
a61af66fc99e Initial load
duke
parents:
diff changeset
543 */
a61af66fc99e Initial load
duke
parents:
diff changeset
544 bool VirtualSpace::expand_by(size_t bytes, bool pre_touch) {
a61af66fc99e Initial load
duke
parents:
diff changeset
545 if (uncommitted_size() < bytes) return false;
a61af66fc99e Initial load
duke
parents:
diff changeset
546
a61af66fc99e Initial load
duke
parents:
diff changeset
547 if (special()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
548 // don't commit memory if the entire space is pinned in memory
a61af66fc99e Initial load
duke
parents:
diff changeset
549 _high += bytes;
a61af66fc99e Initial load
duke
parents:
diff changeset
550 return true;
a61af66fc99e Initial load
duke
parents:
diff changeset
551 }
a61af66fc99e Initial load
duke
parents:
diff changeset
552
a61af66fc99e Initial load
duke
parents:
diff changeset
553 char* previous_high = high();
a61af66fc99e Initial load
duke
parents:
diff changeset
554 char* unaligned_new_high = high() + bytes;
a61af66fc99e Initial load
duke
parents:
diff changeset
555 assert(unaligned_new_high <= high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
556 "cannot expand by more than upper boundary");
a61af66fc99e Initial load
duke
parents:
diff changeset
557
a61af66fc99e Initial load
duke
parents:
diff changeset
558 // Calculate where the new high for each of the regions should be. If
a61af66fc99e Initial load
duke
parents:
diff changeset
559 // the low_boundary() and high_boundary() are LargePageSizeInBytes aligned
a61af66fc99e Initial load
duke
parents:
diff changeset
560 // then the unaligned lower and upper new highs would be the
a61af66fc99e Initial load
duke
parents:
diff changeset
561 // lower_high() and upper_high() respectively.
a61af66fc99e Initial load
duke
parents:
diff changeset
562 char* unaligned_lower_new_high =
a61af66fc99e Initial load
duke
parents:
diff changeset
563 MIN2(unaligned_new_high, lower_high_boundary());
a61af66fc99e Initial load
duke
parents:
diff changeset
564 char* unaligned_middle_new_high =
a61af66fc99e Initial load
duke
parents:
diff changeset
565 MIN2(unaligned_new_high, middle_high_boundary());
a61af66fc99e Initial load
duke
parents:
diff changeset
566 char* unaligned_upper_new_high =
a61af66fc99e Initial load
duke
parents:
diff changeset
567 MIN2(unaligned_new_high, upper_high_boundary());
a61af66fc99e Initial load
duke
parents:
diff changeset
568
a61af66fc99e Initial load
duke
parents:
diff changeset
569 // Align the new highs based on the regions alignment. lower and upper
a61af66fc99e Initial load
duke
parents:
diff changeset
570 // alignment will always be default page size. middle alignment will be
a61af66fc99e Initial load
duke
parents:
diff changeset
571 // LargePageSizeInBytes if the actual size of the virtual space is in
a61af66fc99e Initial load
duke
parents:
diff changeset
572 // fact larger than LargePageSizeInBytes.
a61af66fc99e Initial load
duke
parents:
diff changeset
573 char* aligned_lower_new_high =
a61af66fc99e Initial load
duke
parents:
diff changeset
574 (char*) round_to((intptr_t) unaligned_lower_new_high, lower_alignment());
a61af66fc99e Initial load
duke
parents:
diff changeset
575 char* aligned_middle_new_high =
a61af66fc99e Initial load
duke
parents:
diff changeset
576 (char*) round_to((intptr_t) unaligned_middle_new_high, middle_alignment());
a61af66fc99e Initial load
duke
parents:
diff changeset
577 char* aligned_upper_new_high =
a61af66fc99e Initial load
duke
parents:
diff changeset
578 (char*) round_to((intptr_t) unaligned_upper_new_high, upper_alignment());
a61af66fc99e Initial load
duke
parents:
diff changeset
579
a61af66fc99e Initial load
duke
parents:
diff changeset
580 // Determine which regions need to grow in this expand_by call.
a61af66fc99e Initial load
duke
parents:
diff changeset
581 // If you are growing in the lower region, high() must be in that
a61af66fc99e Initial load
duke
parents:
diff changeset
582 // region so calcuate the size based on high(). For the middle and
a61af66fc99e Initial load
duke
parents:
diff changeset
583 // upper regions, determine the starting point of growth based on the
a61af66fc99e Initial load
duke
parents:
diff changeset
584 // location of high(). By getting the MAX of the region's low address
a61af66fc99e Initial load
duke
parents:
diff changeset
585 // (or the prevoius region's high address) and high(), we can tell if it
a61af66fc99e Initial load
duke
parents:
diff changeset
586 // is an intra or inter region growth.
a61af66fc99e Initial load
duke
parents:
diff changeset
587 size_t lower_needs = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
588 if (aligned_lower_new_high > lower_high()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
589 lower_needs =
a61af66fc99e Initial load
duke
parents:
diff changeset
590 pointer_delta(aligned_lower_new_high, lower_high(), sizeof(char));
a61af66fc99e Initial load
duke
parents:
diff changeset
591 }
a61af66fc99e Initial load
duke
parents:
diff changeset
592 size_t middle_needs = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
593 if (aligned_middle_new_high > middle_high()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
594 middle_needs =
a61af66fc99e Initial load
duke
parents:
diff changeset
595 pointer_delta(aligned_middle_new_high, middle_high(), sizeof(char));
a61af66fc99e Initial load
duke
parents:
diff changeset
596 }
a61af66fc99e Initial load
duke
parents:
diff changeset
597 size_t upper_needs = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
598 if (aligned_upper_new_high > upper_high()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
599 upper_needs =
a61af66fc99e Initial load
duke
parents:
diff changeset
600 pointer_delta(aligned_upper_new_high, upper_high(), sizeof(char));
a61af66fc99e Initial load
duke
parents:
diff changeset
601 }
a61af66fc99e Initial load
duke
parents:
diff changeset
602
a61af66fc99e Initial load
duke
parents:
diff changeset
603 // Check contiguity.
a61af66fc99e Initial load
duke
parents:
diff changeset
604 assert(low_boundary() <= lower_high() &&
a61af66fc99e Initial load
duke
parents:
diff changeset
605 lower_high() <= lower_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
606 "high address must be contained within the region");
a61af66fc99e Initial load
duke
parents:
diff changeset
607 assert(lower_high_boundary() <= middle_high() &&
a61af66fc99e Initial load
duke
parents:
diff changeset
608 middle_high() <= middle_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
609 "high address must be contained within the region");
a61af66fc99e Initial load
duke
parents:
diff changeset
610 assert(middle_high_boundary() <= upper_high() &&
a61af66fc99e Initial load
duke
parents:
diff changeset
611 upper_high() <= upper_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
612 "high address must be contained within the region");
a61af66fc99e Initial load
duke
parents:
diff changeset
613
a61af66fc99e Initial load
duke
parents:
diff changeset
614 // Commit regions
a61af66fc99e Initial load
duke
parents:
diff changeset
615 if (lower_needs > 0) {
a61af66fc99e Initial load
duke
parents:
diff changeset
616 assert(low_boundary() <= lower_high() &&
a61af66fc99e Initial load
duke
parents:
diff changeset
617 lower_high() + lower_needs <= lower_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
618 "must not expand beyond region");
656
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
619 if (!os::commit_memory(lower_high(), lower_needs, _executable)) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
620 debug_only(warning("os::commit_memory failed"));
a61af66fc99e Initial load
duke
parents:
diff changeset
621 return false;
a61af66fc99e Initial load
duke
parents:
diff changeset
622 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
623 _lower_high += lower_needs;
a61af66fc99e Initial load
duke
parents:
diff changeset
624 }
a61af66fc99e Initial load
duke
parents:
diff changeset
625 }
a61af66fc99e Initial load
duke
parents:
diff changeset
626 if (middle_needs > 0) {
a61af66fc99e Initial load
duke
parents:
diff changeset
627 assert(lower_high_boundary() <= middle_high() &&
a61af66fc99e Initial load
duke
parents:
diff changeset
628 middle_high() + middle_needs <= middle_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
629 "must not expand beyond region");
656
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
630 if (!os::commit_memory(middle_high(), middle_needs, middle_alignment(),
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
631 _executable)) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
632 debug_only(warning("os::commit_memory failed"));
a61af66fc99e Initial load
duke
parents:
diff changeset
633 return false;
a61af66fc99e Initial load
duke
parents:
diff changeset
634 }
a61af66fc99e Initial load
duke
parents:
diff changeset
635 _middle_high += middle_needs;
a61af66fc99e Initial load
duke
parents:
diff changeset
636 }
a61af66fc99e Initial load
duke
parents:
diff changeset
637 if (upper_needs > 0) {
a61af66fc99e Initial load
duke
parents:
diff changeset
638 assert(middle_high_boundary() <= upper_high() &&
a61af66fc99e Initial load
duke
parents:
diff changeset
639 upper_high() + upper_needs <= upper_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
640 "must not expand beyond region");
656
6bdd6923ba16 6541756: Reduce executable C-heap
coleenp
parents: 642
diff changeset
641 if (!os::commit_memory(upper_high(), upper_needs, _executable)) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
642 debug_only(warning("os::commit_memory failed"));
a61af66fc99e Initial load
duke
parents:
diff changeset
643 return false;
a61af66fc99e Initial load
duke
parents:
diff changeset
644 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
645 _upper_high += upper_needs;
a61af66fc99e Initial load
duke
parents:
diff changeset
646 }
a61af66fc99e Initial load
duke
parents:
diff changeset
647 }
a61af66fc99e Initial load
duke
parents:
diff changeset
648
a61af66fc99e Initial load
duke
parents:
diff changeset
649 if (pre_touch || AlwaysPreTouch) {
a61af66fc99e Initial load
duke
parents:
diff changeset
650 int vm_ps = os::vm_page_size();
a61af66fc99e Initial load
duke
parents:
diff changeset
651 for (char* curr = previous_high;
a61af66fc99e Initial load
duke
parents:
diff changeset
652 curr < unaligned_new_high;
a61af66fc99e Initial load
duke
parents:
diff changeset
653 curr += vm_ps) {
a61af66fc99e Initial load
duke
parents:
diff changeset
654 // Note the use of a write here; originally we tried just a read, but
a61af66fc99e Initial load
duke
parents:
diff changeset
655 // since the value read was unused, the optimizer removed the read.
a61af66fc99e Initial load
duke
parents:
diff changeset
656 // If we ever have a concurrent touchahead thread, we'll want to use
a61af66fc99e Initial load
duke
parents:
diff changeset
657 // a read, to avoid the potential of overwriting data (if a mutator
a61af66fc99e Initial load
duke
parents:
diff changeset
658 // thread beats the touchahead thread to a page). There are various
a61af66fc99e Initial load
duke
parents:
diff changeset
659 // ways of making sure this read is not optimized away: for example,
a61af66fc99e Initial load
duke
parents:
diff changeset
660 // generating the code for a read procedure at runtime.
a61af66fc99e Initial load
duke
parents:
diff changeset
661 *curr = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
662 }
a61af66fc99e Initial load
duke
parents:
diff changeset
663 }
a61af66fc99e Initial load
duke
parents:
diff changeset
664
a61af66fc99e Initial load
duke
parents:
diff changeset
665 _high += bytes;
a61af66fc99e Initial load
duke
parents:
diff changeset
666 return true;
a61af66fc99e Initial load
duke
parents:
diff changeset
667 }
a61af66fc99e Initial load
duke
parents:
diff changeset
668
a61af66fc99e Initial load
duke
parents:
diff changeset
669 // A page is uncommitted if the contents of the entire page is deemed unusable.
a61af66fc99e Initial load
duke
parents:
diff changeset
670 // Continue to decrement the high() pointer until it reaches a page boundary
a61af66fc99e Initial load
duke
parents:
diff changeset
671 // in which case that particular page can now be uncommitted.
a61af66fc99e Initial load
duke
parents:
diff changeset
672 void VirtualSpace::shrink_by(size_t size) {
a61af66fc99e Initial load
duke
parents:
diff changeset
673 if (committed_size() < size)
a61af66fc99e Initial load
duke
parents:
diff changeset
674 fatal("Cannot shrink virtual space to negative size");
a61af66fc99e Initial load
duke
parents:
diff changeset
675
a61af66fc99e Initial load
duke
parents:
diff changeset
676 if (special()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
677 // don't uncommit if the entire space is pinned in memory
a61af66fc99e Initial load
duke
parents:
diff changeset
678 _high -= size;
a61af66fc99e Initial load
duke
parents:
diff changeset
679 return;
a61af66fc99e Initial load
duke
parents:
diff changeset
680 }
a61af66fc99e Initial load
duke
parents:
diff changeset
681
a61af66fc99e Initial load
duke
parents:
diff changeset
682 char* unaligned_new_high = high() - size;
a61af66fc99e Initial load
duke
parents:
diff changeset
683 assert(unaligned_new_high >= low_boundary(), "cannot shrink past lower boundary");
a61af66fc99e Initial load
duke
parents:
diff changeset
684
a61af66fc99e Initial load
duke
parents:
diff changeset
685 // Calculate new unaligned address
a61af66fc99e Initial load
duke
parents:
diff changeset
686 char* unaligned_upper_new_high =
a61af66fc99e Initial load
duke
parents:
diff changeset
687 MAX2(unaligned_new_high, middle_high_boundary());
a61af66fc99e Initial load
duke
parents:
diff changeset
688 char* unaligned_middle_new_high =
a61af66fc99e Initial load
duke
parents:
diff changeset
689 MAX2(unaligned_new_high, lower_high_boundary());
a61af66fc99e Initial load
duke
parents:
diff changeset
690 char* unaligned_lower_new_high =
a61af66fc99e Initial load
duke
parents:
diff changeset
691 MAX2(unaligned_new_high, low_boundary());
a61af66fc99e Initial load
duke
parents:
diff changeset
692
a61af66fc99e Initial load
duke
parents:
diff changeset
693 // Align address to region's alignment
a61af66fc99e Initial load
duke
parents:
diff changeset
694 char* aligned_upper_new_high =
a61af66fc99e Initial load
duke
parents:
diff changeset
695 (char*) round_to((intptr_t) unaligned_upper_new_high, upper_alignment());
a61af66fc99e Initial load
duke
parents:
diff changeset
696 char* aligned_middle_new_high =
a61af66fc99e Initial load
duke
parents:
diff changeset
697 (char*) round_to((intptr_t) unaligned_middle_new_high, middle_alignment());
a61af66fc99e Initial load
duke
parents:
diff changeset
698 char* aligned_lower_new_high =
a61af66fc99e Initial load
duke
parents:
diff changeset
699 (char*) round_to((intptr_t) unaligned_lower_new_high, lower_alignment());
a61af66fc99e Initial load
duke
parents:
diff changeset
700
a61af66fc99e Initial load
duke
parents:
diff changeset
701 // Determine which regions need to shrink
a61af66fc99e Initial load
duke
parents:
diff changeset
702 size_t upper_needs = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
703 if (aligned_upper_new_high < upper_high()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
704 upper_needs =
a61af66fc99e Initial load
duke
parents:
diff changeset
705 pointer_delta(upper_high(), aligned_upper_new_high, sizeof(char));
a61af66fc99e Initial load
duke
parents:
diff changeset
706 }
a61af66fc99e Initial load
duke
parents:
diff changeset
707 size_t middle_needs = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
708 if (aligned_middle_new_high < middle_high()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
709 middle_needs =
a61af66fc99e Initial load
duke
parents:
diff changeset
710 pointer_delta(middle_high(), aligned_middle_new_high, sizeof(char));
a61af66fc99e Initial load
duke
parents:
diff changeset
711 }
a61af66fc99e Initial load
duke
parents:
diff changeset
712 size_t lower_needs = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
713 if (aligned_lower_new_high < lower_high()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
714 lower_needs =
a61af66fc99e Initial load
duke
parents:
diff changeset
715 pointer_delta(lower_high(), aligned_lower_new_high, sizeof(char));
a61af66fc99e Initial load
duke
parents:
diff changeset
716 }
a61af66fc99e Initial load
duke
parents:
diff changeset
717
a61af66fc99e Initial load
duke
parents:
diff changeset
718 // Check contiguity.
a61af66fc99e Initial load
duke
parents:
diff changeset
719 assert(middle_high_boundary() <= upper_high() &&
a61af66fc99e Initial load
duke
parents:
diff changeset
720 upper_high() <= upper_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
721 "high address must be contained within the region");
a61af66fc99e Initial load
duke
parents:
diff changeset
722 assert(lower_high_boundary() <= middle_high() &&
a61af66fc99e Initial load
duke
parents:
diff changeset
723 middle_high() <= middle_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
724 "high address must be contained within the region");
a61af66fc99e Initial load
duke
parents:
diff changeset
725 assert(low_boundary() <= lower_high() &&
a61af66fc99e Initial load
duke
parents:
diff changeset
726 lower_high() <= lower_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
727 "high address must be contained within the region");
a61af66fc99e Initial load
duke
parents:
diff changeset
728
a61af66fc99e Initial load
duke
parents:
diff changeset
729 // Uncommit
a61af66fc99e Initial load
duke
parents:
diff changeset
730 if (upper_needs > 0) {
a61af66fc99e Initial load
duke
parents:
diff changeset
731 assert(middle_high_boundary() <= aligned_upper_new_high &&
a61af66fc99e Initial load
duke
parents:
diff changeset
732 aligned_upper_new_high + upper_needs <= upper_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
733 "must not shrink beyond region");
a61af66fc99e Initial load
duke
parents:
diff changeset
734 if (!os::uncommit_memory(aligned_upper_new_high, upper_needs)) {
a61af66fc99e Initial load
duke
parents:
diff changeset
735 debug_only(warning("os::uncommit_memory failed"));
a61af66fc99e Initial load
duke
parents:
diff changeset
736 return;
a61af66fc99e Initial load
duke
parents:
diff changeset
737 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
738 _upper_high -= upper_needs;
a61af66fc99e Initial load
duke
parents:
diff changeset
739 }
a61af66fc99e Initial load
duke
parents:
diff changeset
740 }
a61af66fc99e Initial load
duke
parents:
diff changeset
741 if (middle_needs > 0) {
a61af66fc99e Initial load
duke
parents:
diff changeset
742 assert(lower_high_boundary() <= aligned_middle_new_high &&
a61af66fc99e Initial load
duke
parents:
diff changeset
743 aligned_middle_new_high + middle_needs <= middle_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
744 "must not shrink beyond region");
a61af66fc99e Initial load
duke
parents:
diff changeset
745 if (!os::uncommit_memory(aligned_middle_new_high, middle_needs)) {
a61af66fc99e Initial load
duke
parents:
diff changeset
746 debug_only(warning("os::uncommit_memory failed"));
a61af66fc99e Initial load
duke
parents:
diff changeset
747 return;
a61af66fc99e Initial load
duke
parents:
diff changeset
748 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
749 _middle_high -= middle_needs;
a61af66fc99e Initial load
duke
parents:
diff changeset
750 }
a61af66fc99e Initial load
duke
parents:
diff changeset
751 }
a61af66fc99e Initial load
duke
parents:
diff changeset
752 if (lower_needs > 0) {
a61af66fc99e Initial load
duke
parents:
diff changeset
753 assert(low_boundary() <= aligned_lower_new_high &&
a61af66fc99e Initial load
duke
parents:
diff changeset
754 aligned_lower_new_high + lower_needs <= lower_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
755 "must not shrink beyond region");
a61af66fc99e Initial load
duke
parents:
diff changeset
756 if (!os::uncommit_memory(aligned_lower_new_high, lower_needs)) {
a61af66fc99e Initial load
duke
parents:
diff changeset
757 debug_only(warning("os::uncommit_memory failed"));
a61af66fc99e Initial load
duke
parents:
diff changeset
758 return;
a61af66fc99e Initial load
duke
parents:
diff changeset
759 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
760 _lower_high -= lower_needs;
a61af66fc99e Initial load
duke
parents:
diff changeset
761 }
a61af66fc99e Initial load
duke
parents:
diff changeset
762 }
a61af66fc99e Initial load
duke
parents:
diff changeset
763
a61af66fc99e Initial load
duke
parents:
diff changeset
764 _high -= size;
a61af66fc99e Initial load
duke
parents:
diff changeset
765 }
a61af66fc99e Initial load
duke
parents:
diff changeset
766
a61af66fc99e Initial load
duke
parents:
diff changeset
767 #ifndef PRODUCT
a61af66fc99e Initial load
duke
parents:
diff changeset
768 void VirtualSpace::check_for_contiguity() {
a61af66fc99e Initial load
duke
parents:
diff changeset
769 // Check contiguity.
a61af66fc99e Initial load
duke
parents:
diff changeset
770 assert(low_boundary() <= lower_high() &&
a61af66fc99e Initial load
duke
parents:
diff changeset
771 lower_high() <= lower_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
772 "high address must be contained within the region");
a61af66fc99e Initial load
duke
parents:
diff changeset
773 assert(lower_high_boundary() <= middle_high() &&
a61af66fc99e Initial load
duke
parents:
diff changeset
774 middle_high() <= middle_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
775 "high address must be contained within the region");
a61af66fc99e Initial load
duke
parents:
diff changeset
776 assert(middle_high_boundary() <= upper_high() &&
a61af66fc99e Initial load
duke
parents:
diff changeset
777 upper_high() <= upper_high_boundary(),
a61af66fc99e Initial load
duke
parents:
diff changeset
778 "high address must be contained within the region");
a61af66fc99e Initial load
duke
parents:
diff changeset
779 assert(low() >= low_boundary(), "low");
a61af66fc99e Initial load
duke
parents:
diff changeset
780 assert(low_boundary() <= lower_high_boundary(), "lower high boundary");
a61af66fc99e Initial load
duke
parents:
diff changeset
781 assert(upper_high_boundary() <= high_boundary(), "upper high boundary");
a61af66fc99e Initial load
duke
parents:
diff changeset
782 assert(high() <= upper_high(), "upper high");
a61af66fc99e Initial load
duke
parents:
diff changeset
783 }
a61af66fc99e Initial load
duke
parents:
diff changeset
784
a61af66fc99e Initial load
duke
parents:
diff changeset
785 void VirtualSpace::print() {
a61af66fc99e Initial load
duke
parents:
diff changeset
786 tty->print ("Virtual space:");
a61af66fc99e Initial load
duke
parents:
diff changeset
787 if (special()) tty->print(" (pinned in memory)");
a61af66fc99e Initial load
duke
parents:
diff changeset
788 tty->cr();
a61af66fc99e Initial load
duke
parents:
diff changeset
789 tty->print_cr(" - committed: %ld", committed_size());
a61af66fc99e Initial load
duke
parents:
diff changeset
790 tty->print_cr(" - reserved: %ld", reserved_size());
a61af66fc99e Initial load
duke
parents:
diff changeset
791 tty->print_cr(" - [low, high]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", low(), high());
a61af66fc99e Initial load
duke
parents:
diff changeset
792 tty->print_cr(" - [low_b, high_b]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", low_boundary(), high_boundary());
a61af66fc99e Initial load
duke
parents:
diff changeset
793 }
a61af66fc99e Initial load
duke
parents:
diff changeset
794
a61af66fc99e Initial load
duke
parents:
diff changeset
795 #endif