1 /*
  2  * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
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 23  */
 24 
 25 #ifndef SHARE_OOPS_STACKCHUNKOOP_HPP
 26 #define SHARE_OOPS_STACKCHUNKOOP_HPP
 27 
 28 
 29 #include "oops/instanceOop.hpp"
 30 #include "runtime/handles.hpp"
 31 #include "runtime/stackChunkFrameStream.hpp"
 32 #include "utilities/bitMap.hpp"
 33 #include "utilities/macros.hpp"
 34 
 35 class frame;
 36 class MemRegion;
 37 class RegisterMap;
 38 class VMRegImpl;
 39 typedef VMRegImpl* VMReg;
 40 
 41 // A continuation stack-chunk oop.
 42 // See InstanceStackChunkKlass for a description of continuation stack-chunks.
 43 //
 44 // size and sp are in machine words
 45 // max_size is the maximum space a thawed chunk would take up on the stack, *not* including top-most frame's metadata
 46 class stackChunkOopDesc : public instanceOopDesc {
 47 public:
 48   enum class BarrierType { Load, Store };
 49 
 50 private:
 51   template <BarrierType barrier> friend class DoBarriersStackClosure;
 52 
 53   // Chunk flags.
 54   // FLAG_HAS_INTERPRETED_FRAMES actually means "thaw slow because of some content-based chunk condition"
 55   // It is set whenever we freeze slow, but generally signifies there might be interpreted/deoptimized/stub frames
 56   static const uint8_t FLAG_HAS_INTERPRETED_FRAMES = 1 << 0;
 57   static const uint8_t FLAG_CLAIM_RELATIVIZE = 1 << 1; // Only one thread claims relativization of derived pointers
 58   static const uint8_t FLAG_NOTIFY_RELATIVIZE = 1 << 2; // Someone is waiting for relativization to complete
 59   static const uint8_t FLAG_GC_MODE = 1 << 3; // Once true it and FLAG_HAS_INTERPRETED_FRAMES can't change
 60   static const uint8_t FLAG_HAS_BITMAP = 1 << 4; // Can only be true if FLAG_GC_MODE is true
 61 
 62   bool try_acquire_relativization();
 63   void release_relativization();
 64 
 65 public:
 66   static inline stackChunkOop cast(oop obj);
 67 
 68   inline stackChunkOop parent() const;
 69   inline void set_parent(stackChunkOop value);
 70   template<typename P>
 71   inline void set_parent_raw(oop value);
 72   template<DecoratorSet decorators>
 73   inline void set_parent_access(oop value);
 74 
 75   inline int stack_size() const;
 76 
 77   inline int sp() const;
 78   inline void set_sp(int value);
 79 
 80   inline address pc() const;
 81   inline void set_pc(address value);
 82 
 83   inline int argsize() const;
 84   inline void set_argsize(int value);
 85 
 86   inline uint8_t flags() const;
 87   inline uint8_t flags_acquire() const;
 88   inline void set_flags(uint8_t value);
 89   inline void release_set_flags(uint8_t value);
 90 
 91   inline int max_thawing_size() const;
 92   inline void set_max_thawing_size(int value);
 93 
 94   inline oop cont() const;
 95   template<typename P>
 96   inline oop cont() const;
 97   inline void set_cont(oop value);
 98   template<typename P>
 99   inline void set_cont_raw(oop value);
100   template<DecoratorSet decorators>
101   inline void set_cont_access(oop value);
102 
103   inline int bottom() const;
104 
105   inline HeapWord* start_of_stack() const;
106 
107   inline intptr_t* start_address() const;
108   inline intptr_t* end_address() const;
109   inline intptr_t* bottom_address() const; // = end_address - argsize
110   inline intptr_t* sp_address() const;
111 
112 
113   inline int to_offset(intptr_t* p) const;
114   inline intptr_t* from_offset(int offset) const;
115 
116   inline bool is_empty() const;
117   inline bool is_in_chunk(void* p) const;
118   inline bool is_usable_in_chunk(void* p) const;
119 
120   inline bool is_flag(uint8_t flag) const;
121   inline bool is_flag_acquire(uint8_t flag) const;
122   inline void set_flag(uint8_t flag, bool value);
123   inline bool try_set_flags(uint8_t prev_flags, uint8_t new_flags);
124   inline void clear_flags();
125 
126   inline bool has_mixed_frames() const;
127   inline void set_has_mixed_frames(bool value);
128 
129   inline bool is_gc_mode() const;
130   inline bool is_gc_mode_acquire() const;
131   inline void set_gc_mode(bool value);
132 
133   inline bool has_bitmap() const;
134   inline void set_has_bitmap(bool value);
135 
136   inline bool has_thaw_slowpath_condition() const;
137 
138   inline bool requires_barriers();
139 
140   template <BarrierType>
141   void do_barriers();
142 
143   template <BarrierType, ChunkFrames frames, typename RegisterMapT>
144   inline void do_barriers(const StackChunkFrameStream<frames>& f, const RegisterMapT* map);
145 
146   template <typename RegisterMapT>
147   void fix_thawed_frame(const frame& f, const RegisterMapT* map);
148 
149   template <class StackChunkFrameClosureType>
150   inline void iterate_stack(StackChunkFrameClosureType* closure);
151 
152   // Derived pointers are relativized, with respect to their oop base.
153   void relativize_derived_pointers_concurrently();
154   void transform();
155 
156   inline void* gc_data() const;
157   inline BitMapView bitmap() const;
158   inline BitMap::idx_t bit_index_for(intptr_t* p) const;
159   inline intptr_t* address_for_bit(BitMap::idx_t index) const;
160   template <typename OopT> inline BitMap::idx_t bit_index_for(OopT* p) const;
161   template <typename OopT> inline OopT* address_for_bit(BitMap::idx_t index) const;
162 
163   MemRegion range();
164 
165   // Returns a relative frame (with offset_sp, offset_unextended_sp, and offset_fp) that can be held
166   // during safepoints.  This is orthogonal to the relativizing of the actual content of interpreted frames.
167   // To be used, frame objects need to be derelativized with `derelativize`.
168   inline frame relativize(frame fr) const;
169   inline frame derelativize(frame fr) const;
170 
171   frame top_frame(RegisterMap* map);
172   frame sender(const frame& fr, RegisterMap* map);
173 
174   inline int relativize_usp_offset(const frame& fr, const int usp_offset_in_bytes) const;
175   inline address usp_offset_to_location(const frame& fr, const int usp_offset_in_bytes) const;
176   inline address reg_to_location(const frame& fr, const RegisterMap* map, VMReg reg) const;
177 
178   // Access to relativized interpreter frames (both the frame object and frame content are relativized)
179   inline Method* interpreter_frame_method(const frame& fr);
180   inline address interpreter_frame_bcp(const frame& fr);
181   inline intptr_t* interpreter_frame_expression_stack_at(const frame& fr, int index) const;
182   inline intptr_t* interpreter_frame_local_at(const frame& fr, int index) const;
183 
184   int num_java_frames() const;
185 
186   inline void copy_from_stack_to_chunk(intptr_t* from, intptr_t* to, int size);
187   inline void copy_from_chunk_to_stack(intptr_t* from, intptr_t* to, int size);
188 
189   template <typename OopT>
190   inline oop load_oop(OopT* addr);
191 
192   using oopDesc::print_on;
193   void print_on(bool verbose, outputStream* st) const;
194 
195   // Verifies the consistency of the chunk's data
196   bool verify(size_t* out_size = nullptr, int* out_oops = nullptr,
197               int* out_frames = nullptr, int* out_interpreted_frames = nullptr) NOT_DEBUG({ return true; });
198 
199 private:
200   template <BarrierType barrier, ChunkFrames frames = ChunkFrames::Mixed, typename RegisterMapT>
201   void do_barriers0(const StackChunkFrameStream<frames>& f, const RegisterMapT* map);
202 
203   template <ChunkFrames frames, class StackChunkFrameClosureType>
204   inline void iterate_stack(StackChunkFrameClosureType* closure);
205 
206   inline intptr_t* relative_base() const;
207 
208   inline intptr_t* derelativize_address(int offset) const;
209   int relativize_address(intptr_t* p) const;
210 
211   inline void relativize_frame(frame& fr) const;
212   inline void derelativize_frame(frame& fr) const;
213 
214   inline void relativize_frame_pd(frame& fr) const;
215   inline void derelativize_frame_pd(frame& fr) const;
216 };
217 
218 #endif // SHARE_OOPS_STACKCHUNKOOP_HPP