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1 /* |
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2 * Copyright (c) 2019, SAP SE. All rights reserved. |
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3 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. |
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4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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5 * |
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6 * This code is free software; you can redistribute it and/or modify it |
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7 * under the terms of the GNU General Public License version 2 only, as |
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8 * published by the Free Software Foundation. |
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9 * |
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10 * This code is distributed in the hope that it will be useful, but WITHOUT |
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11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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13 * version 2 for more details (a copy is included in the LICENSE file that |
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14 * accompanied this code). |
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15 * |
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16 * You should have received a copy of the GNU General Public License version |
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17 * 2 along with this work; if not, write to the Free Software Foundation, |
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18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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19 * |
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20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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21 * or visit www.oracle.com if you need additional information or have any |
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22 * questions. |
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23 * |
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24 */ |
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25 |
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26 |
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27 #include <memory/metaspace/settings.hpp> |
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28 #include "precompiled.hpp" |
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29 |
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30 #include "memory/metaspace/commitMask.hpp" |
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31 #include "memory/metaspace/metaspaceCommon.hpp" |
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32 #include "runtime/stubRoutines.hpp" |
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33 |
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34 #include "utilities/align.hpp" |
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35 #include "utilities/debug.hpp" |
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36 |
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37 namespace metaspace { |
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38 |
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39 CommitMask::CommitMask(const MetaWord* start, size_t word_size) |
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40 : CHeapBitMap(mask_size(word_size, Settings::commit_granule_words())) |
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41 , _base(start) |
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42 , _word_size(word_size) |
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43 , _words_per_bit(Settings::commit_granule_words()) |
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44 { |
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45 assert(_word_size > 0 && _words_per_bit > 0 && |
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46 is_aligned(_word_size, _words_per_bit), "Sanity"); |
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47 } |
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48 |
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49 #ifdef ASSERT |
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50 |
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51 static const bool TEST_UNCOMMITTED_REGION = false; |
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52 |
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53 volatile u1 x; |
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54 |
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55 void CommitMask::verify(bool slow, bool do_touch_test) const { |
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56 |
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57 // Walk the whole commit mask. |
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58 // For each 1 bit, check if the associated granule is accessible. |
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59 // For each 0 bit, check if the associated granule is not accessible. Slow mode only. |
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60 |
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61 assert_is_aligned(_base, _words_per_bit * BytesPerWord); |
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62 assert_is_aligned(_word_size, _words_per_bit); |
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63 |
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64 if (slow) { |
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65 assert(CanUseSafeFetch32, "We need SafeFetch for this test."); |
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66 } |
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67 |
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68 if (do_touch_test) { |
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69 for (idx_t i = 0; i < size(); i ++) { |
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70 const MetaWord* const p = _base + (i * _words_per_bit); |
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71 if (at(i)) { |
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72 // Should be accessible. Just touch it. |
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73 x ^= *(u1*)p; |
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74 } else { |
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75 // Should not be accessible. |
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76 if (slow) { |
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77 // Note: results may differ between platforms. On Linux, this should be true since |
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78 // we uncommit memory by setting protection to PROT_NONE. We may have to look if |
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79 // this works as expected on other platforms. |
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80 if (CanUseSafeFetch32() && TEST_UNCOMMITTED_REGION) { |
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81 assert(os::is_readable_pointer(p) == false, |
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82 "index %u, pointer " PTR_FORMAT ", should not be accessible.", |
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83 (unsigned)i, p2i(p)); |
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84 } |
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85 } |
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86 } |
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87 } |
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88 } |
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89 |
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90 } |
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91 |
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92 #endif // ASSERT |
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93 |
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94 void CommitMask::print_on(outputStream* st) const { |
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95 |
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96 st->print("commit mask, base " PTR_FORMAT ":", p2i(base())); |
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97 |
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98 for (idx_t i = 0; i < size(); i ++) { |
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99 st->print("%c", at(i) ? 'X' : '-'); |
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100 } |
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101 |
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102 st->cr(); |
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103 |
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104 } |
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105 |
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106 } // namespace metaspace |
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107 |