1 /*
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  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  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.
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  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 template<class E> class Array;
 40 template<class E> class GrowableArray;
 41 
 42 // ArchivePtrMarker is used to mark the location of pointers embedded in a CDS archive. E.g., when an
 43 // InstanceKlass k is dumped, we mark the location of the k->_name pointer by effectively calling
 44 // mark_pointer(/*ptr_loc=*/&k->_name). It's required that (_prt_base <= ptr_loc < _ptr_end). _ptr_base is
 45 // fixed, but _ptr_end can be expanded as more objects are dumped.
 46 class ArchivePtrMarker : AllStatic {
 47   static CHeapBitMap*  _ptrmap;
 48   static CHeapBitMap*  _rw_ptrmap;
 49   static CHeapBitMap*  _ro_ptrmap;
 50   static CHeapBitMap*  _cc_ptrmap;
 51   static VirtualSpace* _vs;
 52 
 53   // Once _ptrmap is compacted, we don't allow bit marking anymore. This is to
 54   // avoid unintentional copy operations after the bitmap has been finalized and written.
 55   static bool         _compacted;
 56 
 57   static address* ptr_base() { return (address*)_vs->low();  } // committed lower bound (inclusive)
 58   static address* ptr_end()  { return (address*)_vs->high(); } // committed upper bound (exclusive)
 59 
 60 public:
 61   static void initialize(CHeapBitMap* ptrmap, VirtualSpace* vs);
 62   static void initialize_rw_ro_cc_maps(CHeapBitMap* rw_ptrmap, CHeapBitMap* ro_ptrmap, CHeapBitMap* cc_ptrmap);
 63   static void mark_pointer(address* ptr_loc);
 64   static void clear_pointer(address* ptr_loc);
 65   static void compact(address relocatable_base, address relocatable_end);
 66   static void compact(size_t max_non_null_offset);
 67 
 68   template <typename T>
 69   static void mark_pointer(T* ptr_loc) {
 70     mark_pointer((address*)ptr_loc);
 71   }
 72 
 73   template <typename T>
 74   static void set_and_mark_pointer(T* ptr_loc, T ptr_value) {
 75     *ptr_loc = ptr_value;
 76     mark_pointer(ptr_loc);
 77   }
 78 
 79   static CHeapBitMap* ptrmap() {
 80     return _ptrmap;
 81   }
 82 
 83   static CHeapBitMap* rw_ptrmap() {
 84     return _rw_ptrmap;
 85   }
 86 
 87   static CHeapBitMap* ro_ptrmap() {
 88     return _ro_ptrmap;
 89   }
 90 
 91   static CHeapBitMap* cc_ptrmap() {
 92     return _cc_ptrmap;
 93   }
 94 
 95   static void reset_map_and_vs() {
 96     _ptrmap = nullptr;
 97     _rw_ptrmap = nullptr;
 98     _ro_ptrmap = nullptr;
 99     _cc_ptrmap = nullptr;
100     _vs = nullptr;
101   }
102 };
103 
104 // SharedDataRelocator is used to shift pointers in the CDS archive.
105 //
106 // The CDS archive is basically a contiguous block of memory (divided into several regions)
107 // that contains multiple objects. The objects may contain direct pointers that point to other objects
108 // within the archive (e.g., InstanceKlass::_name points to a Symbol in the archive). During dumping, we
109 // built a bitmap that marks the locations of all these pointers (using ArchivePtrMarker, see comments above).
110 //
111 // The contents of the archive assumes that it’s mapped at the default SharedBaseAddress (e.g. 0x800000000).
112 // If the archive ends up being mapped at a different address (e.g. 0x810000000), SharedDataRelocator
113 // is used to shift each marked pointer by a delta (0x10000000 in this example), so that it points to
114 // the actually mapped location of the target object.
115 class SharedDataRelocator: public BitMapClosure {
116   // for all (address** p), where (is_marked(p) && _patch_base <= p && p < _patch_end) { *p += delta; }
117 
118   // Patch all pointers within this region that are marked.
119   address* _patch_base;
120   address* _patch_end;
121 
122   // Before patching, all pointers must point to this region.
123   address _valid_old_base;
124   address _valid_old_end;
125 
126   // After patching, all pointers must point to this region.
127   address _valid_new_base;
128   address _valid_new_end;
129 
130   // How much to relocate for each pointer.
131   intx _delta;
132 
133  public:
134   SharedDataRelocator(address* patch_base, address* patch_end,
135                       address valid_old_base, address valid_old_end,
136                       address valid_new_base, address valid_new_end, intx delta) :
137     _patch_base(patch_base), _patch_end(patch_end),
138     _valid_old_base(valid_old_base), _valid_old_end(valid_old_end),
139     _valid_new_base(valid_new_base), _valid_new_end(valid_new_end),
140     _delta(delta) {
141     log_debug(cds, reloc)("SharedDataRelocator::_patch_base     = " PTR_FORMAT, p2i(_patch_base));
142     log_debug(cds, reloc)("SharedDataRelocator::_patch_end      = " PTR_FORMAT, p2i(_patch_end));
143     log_debug(cds, reloc)("SharedDataRelocator::_valid_old_base = " PTR_FORMAT, p2i(_valid_old_base));
144     log_debug(cds, reloc)("SharedDataRelocator::_valid_old_end  = " PTR_FORMAT, p2i(_valid_old_end));
145     log_debug(cds, reloc)("SharedDataRelocator::_valid_new_base = " PTR_FORMAT, p2i(_valid_new_base));
146     log_debug(cds, reloc)("SharedDataRelocator::_valid_new_end  = " PTR_FORMAT, p2i(_valid_new_end));
147   }
148 
149   bool do_bit(size_t offset);
150 };
151 
152 class DumpRegion {
153 private:
154   const char* _name;
155   char* _base;
156   char* _top;
157   char* _end;
158   uintx _max_delta;
159   bool _is_packed;
160   ReservedSpace* _rs;
161   VirtualSpace* _vs;
162 
163   void commit_to(char* newtop);
164 
165 public:
166   DumpRegion(const char* name, uintx max_delta = 0)
167     : _name(name), _base(nullptr), _top(nullptr), _end(nullptr),
168       _max_delta(max_delta), _is_packed(false) {}
169 
170   char* expand_top_to(char* newtop);
171   char* allocate(size_t num_bytes);
172 
173   void append_intptr_t(intptr_t n, bool need_to_mark = false) NOT_CDS_RETURN;
174 
175   char* base()      const { return _base;        }
176   char* top()       const { return _top;         }
177   char* end()       const { return _end;         }
178   size_t reserved() const { return _end - _base; }
179   size_t used()     const { return _top - _base; }
180   bool is_packed()  const { return _is_packed;   }
181   bool is_allocatable() const {
182     return !is_packed() && _base != nullptr;
183   }
184 
185   void print(size_t total_bytes) const;
186   void print_out_of_space_msg(const char* failing_region, size_t needed_bytes);
187 
188   void init(ReservedSpace* rs, VirtualSpace* vs);
189 
190   void pack(DumpRegion* next = nullptr);
191 
192   bool contains(char* p) {
193     return base() <= p && p < top();
194   }
195 };
196 
197 // Closure for serializing initialization data out to a data area to be
198 // written to the shared file.
199 
200 class WriteClosure : public SerializeClosure {
201 private:
202   DumpRegion* _dump_region;
203 
204 public:
205   WriteClosure(DumpRegion* r) {
206     _dump_region = r;
207   }
208 
209   void do_ptr(void** p);
210 
211   void do_u4(u4* p) {
212     _dump_region->append_intptr_t((intptr_t)(*p));
213   }
214 
215   void do_int(int* p) {
216     _dump_region->append_intptr_t((intptr_t)(*p));
217   }
218 
219   void do_bool(bool *p) {
220     _dump_region->append_intptr_t((intptr_t)(*p));
221   }
222 
223   void do_tag(int tag) {
224     _dump_region->append_intptr_t((intptr_t)tag);
225   }
226 
227   char* region_top() {
228     return _dump_region->top();
229   }
230 
231   bool reading() const { return false; }
232 };
233 
234 // Closure for serializing initialization data in from a data area
235 // (ptr_array) read from the shared file.
236 
237 class ReadClosure : public SerializeClosure {
238 private:
239   intptr_t** _ptr_array;
240 
241   inline intptr_t nextPtr() {
242     return *(*_ptr_array)++;
243   }
244 
245 public:
246   ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
247 
248   void do_ptr(void** p);
249   void do_u4(u4* p);
250   void do_int(int* p);
251   void do_bool(bool *p);
252   void do_tag(int tag);
253   bool reading() const { return true; }
254   char* region_top() { return nullptr; }
255 };
256 
257 class ArchiveUtils {
258 public:
259   static void log_to_classlist(BootstrapInfo* bootstrap_specifier, TRAPS) NOT_CDS_RETURN;
260 
261   template <typename T> static Array<T>* archive_array(GrowableArray<T>* tmp_array);
262 
263   // Used in logging: "boot", "boot2", "plat", "app" and "unreg";
264   static const char* class_category(Klass* k);
265 
266   static const char* builtin_loader_name_or_null(oop loader); // "boot", "platform", "app", or nullptr
267   static const char* builtin_loader_name(oop loader); // "boot", "platform", or "app". Asserts if not a built-in-loader.
268 
269   static bool builtin_loader_from_type(const char* loader_type, oop* value_ret);
270   static oop builtin_loader_from_type(int loader_type);
271 };
272 
273 class HeapRootSegments {
274 private:
275   size_t _base_offset;
276   size_t _count;
277   int _roots_count;
278   int _max_size_in_bytes;
279   int _max_size_in_elems;
280 
281 public:
282   size_t base_offset() { return _base_offset; }
283   size_t count() { return _count; }
284   int roots_count() { return _roots_count; }
285   int max_size_in_bytes() { return _max_size_in_bytes; }
286   int max_size_in_elems() { return _max_size_in_elems; }
287 
288   size_t size_in_bytes(size_t seg_idx);
289   int size_in_elems(size_t seg_idx);
290   size_t segment_offset(size_t seg_idx);
291 
292   // Trivial copy assignments are allowed to copy the entire object representation.
293   // We also inline this class into archive header. Therefore, it is important to make
294   // sure any gaps in object representation are initialized to zeroes. This is why
295   // constructors memset before doing field assignments.
296   HeapRootSegments() {
297     memset(this, 0, sizeof(*this));
298   }
299   HeapRootSegments(size_t base_offset, int roots_count, int max_size_in_bytes, int max_size_in_elems) {
300     memset(this, 0, sizeof(*this));
301     _base_offset = base_offset;
302     _count = (roots_count + max_size_in_elems - 1) / max_size_in_elems;
303     _roots_count = roots_count;
304     _max_size_in_bytes = max_size_in_bytes;
305     _max_size_in_elems = max_size_in_elems;
306   }
307 
308   // This class is trivially copyable and assignable.
309   HeapRootSegments(const HeapRootSegments&) = default;
310   HeapRootSegments& operator=(const HeapRootSegments&) = default;
311 };
312 
313 #endif // SHARE_CDS_ARCHIVEUTILS_HPP