1 /*
  2  * Copyright (c) 2019, 2024, 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
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 24 
 25 #ifndef SHARE_CDS_ARCHIVEUTILS_HPP
 26 #define SHARE_CDS_ARCHIVEUTILS_HPP
 27 
 28 #include "cds/serializeClosure.hpp"
 29 #include "logging/log.hpp"
 30 #include "memory/virtualspace.hpp"
 31 #include "utilities/bitMap.hpp"
 32 #include "utilities/exceptions.hpp"
 33 #include "utilities/macros.hpp"
 34 
 35 class BootstrapInfo;
 36 class ReservedSpace;
 37 class VirtualSpace;
 38 
 39 // ArchivePtrMarker is used to mark the location of pointers embedded in a CDS archive. E.g., when an
 40 // InstanceKlass k is dumped, we mark the location of the k->_name pointer by effectively calling
 41 // mark_pointer(/*ptr_loc=*/&k->_name). It's required that (_prt_base <= ptr_loc < _ptr_end). _ptr_base is
 42 // fixed, but _ptr_end can be expanded as more objects are dumped.
 43 class ArchivePtrMarker : AllStatic {
 44   static CHeapBitMap*  _ptrmap;
 45   static CHeapBitMap*  _rw_ptrmap;
 46   static CHeapBitMap*  _ro_ptrmap;
 47   static VirtualSpace* _vs;
 48 
 49   // Once _ptrmap is compacted, we don't allow bit marking anymore. This is to
 50   // avoid unintentional copy operations after the bitmap has been finalized and written.
 51   static bool         _compacted;
 52 
 53   static address* ptr_base() { return (address*)_vs->low();  } // committed lower bound (inclusive)
 54   static address* ptr_end()  { return (address*)_vs->high(); } // committed upper bound (exclusive)
 55 
 56 public:
 57   static void initialize(CHeapBitMap* ptrmap, VirtualSpace* vs);
 58   static void initialize_rw_ro_maps(CHeapBitMap* rw_ptrmap, CHeapBitMap* ro_ptrmap);
 59   static void mark_pointer(address* ptr_loc);
 60   static void clear_pointer(address* ptr_loc);
 61   static void compact(address relocatable_base, address relocatable_end);
 62   static void compact(size_t max_non_null_offset);
 63 
 64   template <typename T>
 65   static void mark_pointer(T* ptr_loc) {
 66     mark_pointer((address*)ptr_loc);
 67   }
 68 
 69   template <typename T>
 70   static void set_and_mark_pointer(T* ptr_loc, T ptr_value) {
 71     *ptr_loc = ptr_value;
 72     mark_pointer(ptr_loc);
 73   }
 74 
 75   static CHeapBitMap* ptrmap() {
 76     return _ptrmap;
 77   }
 78 
 79   static CHeapBitMap* rw_ptrmap() {
 80     return _rw_ptrmap;
 81   }
 82 
 83   static CHeapBitMap* ro_ptrmap() {
 84     return _ro_ptrmap;
 85   }
 86 
 87   static void reset_map_and_vs() {
 88     _ptrmap = nullptr;
 89     _rw_ptrmap = nullptr;
 90     _ro_ptrmap = nullptr;
 91     _vs = nullptr;
 92   }
 93 };
 94 
 95 // SharedDataRelocator is used to shift pointers in the CDS archive.
 96 //
 97 // The CDS archive is basically a contiguous block of memory (divided into several regions)
 98 // that contains multiple objects. The objects may contain direct pointers that point to other objects
 99 // within the archive (e.g., InstanceKlass::_name points to a Symbol in the archive). During dumping, we
100 // built a bitmap that marks the locations of all these pointers (using ArchivePtrMarker, see comments above).
101 //
102 // The contents of the archive assumes that it’s mapped at the default SharedBaseAddress (e.g. 0x800000000).
103 // If the archive ends up being mapped at a different address (e.g. 0x810000000), SharedDataRelocator
104 // is used to shift each marked pointer by a delta (0x10000000 in this example), so that it points to
105 // the actually mapped location of the target object.
106 class SharedDataRelocator: public BitMapClosure {
107   // for all (address** p), where (is_marked(p) && _patch_base <= p && p < _patch_end) { *p += delta; }
108 
109   // Patch all pointers within this region that are marked.
110   address* _patch_base;
111   address* _patch_end;
112 
113   // Before patching, all pointers must point to this region.
114   address _valid_old_base;
115   address _valid_old_end;
116 
117   // After patching, all pointers must point to this region.
118   address _valid_new_base;
119   address _valid_new_end;
120 
121   // How much to relocate for each pointer.
122   intx _delta;
123 
124  public:
125   SharedDataRelocator(address* patch_base, address* patch_end,
126                       address valid_old_base, address valid_old_end,
127                       address valid_new_base, address valid_new_end, intx delta) :
128     _patch_base(patch_base), _patch_end(patch_end),
129     _valid_old_base(valid_old_base), _valid_old_end(valid_old_end),
130     _valid_new_base(valid_new_base), _valid_new_end(valid_new_end),
131     _delta(delta) {
132     log_debug(cds, reloc)("SharedDataRelocator::_patch_base     = " PTR_FORMAT, p2i(_patch_base));
133     log_debug(cds, reloc)("SharedDataRelocator::_patch_end      = " PTR_FORMAT, p2i(_patch_end));
134     log_debug(cds, reloc)("SharedDataRelocator::_valid_old_base = " PTR_FORMAT, p2i(_valid_old_base));
135     log_debug(cds, reloc)("SharedDataRelocator::_valid_old_end  = " PTR_FORMAT, p2i(_valid_old_end));
136     log_debug(cds, reloc)("SharedDataRelocator::_valid_new_base = " PTR_FORMAT, p2i(_valid_new_base));
137     log_debug(cds, reloc)("SharedDataRelocator::_valid_new_end  = " PTR_FORMAT, p2i(_valid_new_end));
138   }
139 
140   bool do_bit(size_t offset);
141 };
142 
143 class DumpRegion {
144 private:
145   const char* _name;
146   char* _base;
147   char* _top;
148   char* _end;
149   uintx _max_delta;
150   bool _is_packed;
151   ReservedSpace* _rs;
152   VirtualSpace* _vs;
153 
154   void commit_to(char* newtop);
155 
156 public:
157   DumpRegion(const char* name, uintx max_delta = 0)
158     : _name(name), _base(nullptr), _top(nullptr), _end(nullptr),
159       _max_delta(max_delta), _is_packed(false) {}
160 
161   char* expand_top_to(char* newtop);
162   char* allocate(size_t num_bytes);
163 
164   void append_intptr_t(intptr_t n, bool need_to_mark = false) NOT_CDS_RETURN;
165 
166   char* base()      const { return _base;        }
167   char* top()       const { return _top;         }
168   char* end()       const { return _end;         }
169   size_t reserved() const { return _end - _base; }
170   size_t used()     const { return _top - _base; }
171   bool is_packed()  const { return _is_packed;   }
172   bool is_allocatable() const {
173     return !is_packed() && _base != nullptr;
174   }
175 
176   void print(size_t total_bytes) const;
177   void print_out_of_space_msg(const char* failing_region, size_t needed_bytes);
178 
179   void init(ReservedSpace* rs, VirtualSpace* vs);
180 
181   void pack(DumpRegion* next = nullptr);
182 
183   bool contains(char* p) {
184     return base() <= p && p < top();
185   }
186 };
187 
188 // Closure for serializing initialization data out to a data area to be
189 // written to the shared file.
190 
191 class WriteClosure : public SerializeClosure {
192 private:
193   DumpRegion* _dump_region;
194 
195 public:
196   WriteClosure(DumpRegion* r) {
197     _dump_region = r;
198   }
199 
200   void do_ptr(void** p);
201 
202   void do_u4(u4* p) {
203     _dump_region->append_intptr_t((intptr_t)(*p));
204   }
205 
206   void do_int(int* p) {
207     _dump_region->append_intptr_t((intptr_t)(*p));
208   }
209 
210   void do_bool(bool *p) {
211     _dump_region->append_intptr_t((intptr_t)(*p));
212   }
213 
214   void do_tag(int tag) {
215     _dump_region->append_intptr_t((intptr_t)tag);
216   }
217 
218   char* region_top() {
219     return _dump_region->top();
220   }
221 
222   bool reading() const { return false; }
223 };
224 
225 // Closure for serializing initialization data in from a data area
226 // (ptr_array) read from the shared file.
227 
228 class ReadClosure : public SerializeClosure {
229 private:
230   intptr_t** _ptr_array;
231 
232   inline intptr_t nextPtr() {
233     return *(*_ptr_array)++;
234   }
235 
236 public:
237   ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
238 
239   void do_ptr(void** p);
240   void do_u4(u4* p);
241   void do_int(int* p);
242   void do_bool(bool *p);
243   void do_tag(int tag);
244   bool reading() const { return true; }
245   char* region_top() { return nullptr; }
246 };
247 
248 class ArchiveUtils {
249 public:
250   static void log_to_classlist(BootstrapInfo* bootstrap_specifier, TRAPS) NOT_CDS_RETURN;
251 };
252 
253 #endif // SHARE_CDS_ARCHIVEUTILS_HPP