1 /*
  2  * Copyright (c) 2017, 2020, Red Hat, Inc. All rights reserved.
  3  * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
  4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  5  *
  6  * This code is free software; you can redistribute it and/or modify it
  7  * under the terms of the GNU General Public License version 2 only, as
  8  * published by the Free Software Foundation.
  9  *
 10  * This code is distributed in the hope that it will be useful, but WITHOUT
 11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 13  * version 2 for more details (a copy is included in the LICENSE file that
 14  * accompanied this code).
 15  *
 16  * You should have received a copy of the GNU General Public License version
 17  * 2 along with this work; if not, write to the Free Software Foundation,
 18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 19  *
 20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 21  * or visit www.oracle.com if you need additional information or have any
 22  * questions.
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 25 
 26 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHVERIFIER_HPP
 27 #define SHARE_GC_SHENANDOAH_SHENANDOAHVERIFIER_HPP
 28 
 29 #include "gc/shared/markBitMap.hpp"
 30 #include "gc/shenandoah/shenandoahRootVerifier.hpp"
 31 #include "memory/allocation.hpp"
 32 #include "oops/oopsHierarchy.hpp"
 33 #include "utilities/stack.hpp"
 34 
 35 class ShenandoahHeap;
 36 class ShenandoahMarkingContext;
 37 
 38 #ifdef _WINDOWS
 39 #pragma warning( disable : 4522 )
 40 #endif
 41 
 42 class ShenandoahVerifierTask {
 43 public:
 44   ShenandoahVerifierTask(oop o = nullptr, int idx = 0): _obj(o) { }
 45   ShenandoahVerifierTask(oop o, size_t idx): _obj(o) { }
 46   // Trivially copyable.
 47 
 48   inline oop obj()  const { return _obj; }
 49 
 50 private:
 51   oop _obj;
 52 };
 53 
 54 typedef Stack<ShenandoahVerifierTask, mtGC> ShenandoahVerifierStack;
 55 typedef volatile juint ShenandoahLivenessData;
 56 
 57 class ShenandoahVerifier : public CHeapObj<mtGC> {
 58 private:
 59   ShenandoahHeap* _heap;
 60   MarkBitMap* _verification_bit_map;
 61 public:
 62   typedef enum {
 63     // Disable remembered set verification.
 64     _verify_remembered_disable,
 65 
 66     // Old objects should be registered and RS cards within *read-only* RS are dirty for all
 67     // inter-generational pointers.
 68     _verify_remembered_before_marking,
 69 
 70     // Old objects should be registered and RS cards within *read-write* RS are dirty for all
 71     // inter-generational pointers.
 72     _verify_remembered_before_updating_references,
 73 
 74     // Old objects should be registered and RS cards within *read-write* RS are dirty for all
 75     // inter-generational pointers. Differs from previous verification modes by using top instead
 76     // of update watermark and not using the marking context.
 77     _verify_remembered_after_full_gc
 78   } VerifyRememberedSet;
 79 
 80   typedef enum {
 81     // Disable marked objects verification.
 82     _verify_marked_disable,
 83 
 84     // Objects should be marked in "next" bitmap.
 85     _verify_marked_incomplete,
 86 
 87     // Objects should be marked in "complete" bitmap.
 88     _verify_marked_complete,
 89 
 90     // Objects should be marked in "complete" bitmap, except j.l.r.Reference referents, which
 91     // may be dangling after marking but before conc-weakrefs-processing.
 92     _verify_marked_complete_except_references,
 93 
 94     // Objects should be marked in "complete" bitmap, except j.l.r.Reference referents, which
 95     // may be dangling after marking but before conc-weakrefs-processing. All SATB buffers must
 96     // be empty.
 97     _verify_marked_complete_satb_empty,
 98   } VerifyMarked;
 99 
100   typedef enum {
101     // Disable forwarded objects verification.
102     _verify_forwarded_disable,
103 
104     // Objects should not have forwardees.
105     _verify_forwarded_none,
106 
107     // Objects may have forwardees.
108     _verify_forwarded_allow
109   } VerifyForwarded;
110 
111   typedef enum {
112     // Disable collection set verification.
113     _verify_cset_disable,
114 
115     // Should have no references to cset.
116     _verify_cset_none,
117 
118     // May have references to cset, all should be forwarded.
119     // Note: Allowing non-forwarded references to cset is equivalent
120     // to _verify_cset_disable.
121     _verify_cset_forwarded
122   } VerifyCollectionSet;
123 
124   typedef enum {
125     // Disable liveness verification
126     _verify_liveness_disable,
127 
128     // All objects should belong to live regions
129     _verify_liveness_conservative,
130 
131     // All objects should belong to live regions,
132     // and liveness data should be accurate
133     _verify_liveness_complete
134   } VerifyLiveness;
135 
136   typedef enum {
137     // Disable region verification
138     _verify_regions_disable,
139 
140     // No trash regions allowed
141     _verify_regions_notrash,
142 
143     // No collection set regions allowed
144     _verify_regions_nocset,
145 
146     // No trash and no cset regions allowed
147     _verify_regions_notrash_nocset
148   } VerifyRegions;
149 
150   typedef enum {
151     // Disable size verification
152     _verify_size_disable,
153 
154     // Enforce exact consistency
155     _verify_size_exact,
156 
157     // Expect promote-in-place adjustments: padding inserted to temporarily prevent further allocation in regular regions
158     _verify_size_adjusted_for_padding
159   } VerifySize;
160 
161   typedef enum {
162     // Disable gc-state verification
163     _verify_gcstate_disable,
164 
165     // Nothing is in progress, no forwarded objects
166     _verify_gcstate_stable,
167 
168     // Nothing is in progress, no forwarded objects, weak roots handling
169     _verify_gcstate_stable_weakroots,
170 
171     // Nothing is in progress, some objects are forwarded
172     _verify_gcstate_forwarded
173   } VerifyGCState;
174 
175   struct VerifyOptions {
176     VerifyForwarded     _verify_forwarded;
177     VerifyMarked        _verify_marked;
178     VerifyCollectionSet _verify_cset;
179     VerifyLiveness      _verify_liveness;
180     VerifyRegions       _verify_regions;
181     VerifyGCState       _verify_gcstate;
182 
183     VerifyOptions(VerifyForwarded verify_forwarded,
184                   VerifyMarked verify_marked,
185                   VerifyCollectionSet verify_collection_set,
186                   VerifyLiveness verify_liveness,
187                   VerifyRegions verify_regions,
188                   VerifyGCState verify_gcstate) :
189             _verify_forwarded(verify_forwarded), _verify_marked(verify_marked),
190             _verify_cset(verify_collection_set),
191             _verify_liveness(verify_liveness), _verify_regions(verify_regions),
192             _verify_gcstate(verify_gcstate) {}
193   };
194 
195 private:
196   void verify_at_safepoint(const char* label,
197                            VerifyRememberedSet remembered,
198                            VerifyForwarded forwarded,
199                            VerifyMarked marked,
200                            VerifyCollectionSet cset,
201                            VerifyLiveness liveness,
202                            VerifyRegions regions,
203                            VerifySize sizeness,
204                            VerifyGCState gcstate);
205 
206 public:
207   ShenandoahVerifier(ShenandoahHeap* heap, MarkBitMap* verification_bitmap) :
208           _heap(heap), _verification_bit_map(verification_bitmap) {};
209 
210   void verify_before_concmark();
211   void verify_after_concmark();
212   void verify_after_concmark_with_promotions();
213   void verify_before_evacuation();
214   void verify_before_updaterefs();
215   void verify_after_updaterefs();
216   void verify_before_fullgc();
217   void verify_after_fullgc();
218   void verify_after_degenerated();
219   void verify_generic(VerifyOption option);
220 
221   // Roots should only contain to-space oops
222   void verify_roots_in_to_space();
223   void verify_roots_no_forwarded();
224 
225   // Check that generation usages are accurate before rebuilding free set
226   void verify_before_rebuilding_free_set();
227 private:
228   template<typename Scanner>
229   void help_verify_region_rem_set(Scanner* scanner, ShenandoahHeapRegion* r, ShenandoahMarkingContext* ctx,
230                                   HeapWord* update_watermark, const char* message);
231 
232   void verify_rem_set_before_mark();
233   void verify_rem_set_before_update_ref();
234   void verify_rem_set_after_full_gc();
235 
236   ShenandoahMarkingContext* get_marking_context_for_old();
237 };
238 
239 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHVERIFIER_HPP