| /* |
| * Copyright (c) 1998, 2012, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #ifndef SHARE_VM_CODE_OOPRECORDER_HPP |
| #define SHARE_VM_CODE_OOPRECORDER_HPP |
| |
| #include "memory/universe.hpp" |
| #include "runtime/handles.hpp" |
| #include "utilities/growableArray.hpp" |
| |
| // Recording and retrieval of either oop relocations or metadata in compiled code. |
| |
| class CodeBlob; |
| |
| template <class T> class ValueRecorder : public StackObj { |
| public: |
| // A two-way mapping from positive indexes to oop handles. |
| // The zero index is reserved for a constant (sharable) null. |
| // Indexes may not be negative. |
| |
| // Use the given arena to manage storage, if not NULL. |
| // By default, uses the current ResourceArea. |
| ValueRecorder(Arena* arena = NULL); |
| |
| // Generate a new index on which nmethod::oop_addr_at will work. |
| // allocate_index and find_index never return the same index, |
| // and allocate_index never returns the same index twice. |
| // In fact, two successive calls to allocate_index return successive ints. |
| int allocate_index(T h) { |
| return add_handle(h, false); |
| } |
| |
| // For a given jobject or Metadata*, this will return the same index |
| // repeatedly. The index can later be given to nmethod::oop_at or |
| // metadata_at to retrieve the oop. |
| // However, the oop must not be changed via nmethod::oop_addr_at. |
| int find_index(T h) { |
| int index = maybe_find_index(h); |
| if (index < 0) { // previously unallocated |
| index = add_handle(h, true); |
| } |
| return index; |
| } |
| |
| // returns the size of the generated oop/metadata table, for sizing the |
| // CodeBlob. Must be called after all oops are allocated! |
| int size(); |
| |
| // Retrieve the value at a given index. |
| T at(int index); |
| |
| int count() { |
| if (_handles == NULL) return 0; |
| // there is always a NULL virtually present as first object |
| return _handles->length() + first_index; |
| } |
| |
| // Helper function; returns false for NULL or Universe::non_oop_word(). |
| bool is_real(T h) { |
| return h != NULL && h != (T)Universe::non_oop_word(); |
| } |
| |
| // copy the generated table to nmethod |
| void copy_values_to(nmethod* nm); |
| |
| bool is_unused() { return _handles == NULL && !_complete; } |
| #ifdef ASSERT |
| bool is_complete() { return _complete; } |
| #endif |
| |
| private: |
| // variant of find_index which does not allocate if not found (yields -1) |
| int maybe_find_index(T h); |
| |
| // leaky hash table of handle => index, to help detect duplicate insertion |
| template <class X> class IndexCache : public ResourceObj { |
| // This class is only used by the ValueRecorder class. |
| friend class ValueRecorder; |
| enum { |
| _log_cache_size = 9, |
| _cache_size = (1<<_log_cache_size), |
| // Index entries are ints. The LSBit is a collision indicator. |
| _collision_bit_shift = 0, |
| _collision_bit = 1, |
| _index_shift = _collision_bit_shift+1 |
| }; |
| int _cache[_cache_size]; |
| static juint cache_index(X handle) { |
| juint ci = (int) (intptr_t) handle; |
| ci ^= ci >> (BitsPerByte*2); |
| ci += ci >> (BitsPerByte*1); |
| return ci & (_cache_size-1); |
| } |
| int* cache_location(X handle) { |
| return &_cache[ cache_index(handle) ]; |
| } |
| static bool cache_location_collision(int* cloc) { |
| return ((*cloc) & _collision_bit) != 0; |
| } |
| static int cache_location_index(int* cloc) { |
| return (*cloc) >> _index_shift; |
| } |
| static void set_cache_location_index(int* cloc, int index) { |
| int cval0 = (*cloc); |
| int cval1 = (index << _index_shift); |
| if (cval0 != 0 && cval1 != cval0) cval1 += _collision_bit; |
| (*cloc) = cval1; |
| } |
| IndexCache(); |
| }; |
| |
| void maybe_initialize(); |
| int add_handle(T h, bool make_findable); |
| |
| enum { null_index = 0, first_index = 1, index_cache_threshold = 20 }; |
| |
| GrowableArray<T>* _handles; // ordered list (first is always NULL) |
| GrowableArray<int>* _no_finds; // all unfindable indexes; usually empty |
| IndexCache<T>* _indexes; // map: handle -> its probable index |
| Arena* _arena; |
| bool _complete; |
| |
| #ifdef ASSERT |
| static int _find_index_calls, _hit_indexes, _missed_indexes; |
| #endif |
| }; |
| |
| class OopRecorder; |
| |
| class ObjectLookup : public ResourceObj { |
| private: |
| class ObjectEntry { |
| private: |
| jobject _value; |
| int _index; |
| |
| public: |
| ObjectEntry(jobject value, int index) : _value(value), _index(index) {} |
| ObjectEntry() : _value(NULL), _index(0) {} |
| oop oop_value() const; |
| int index() { return _index; } |
| }; |
| |
| GrowableArray<ObjectEntry> _values; |
| unsigned int _gc_count; |
| |
| // Utility sort functions |
| static int sort_by_address(oop a, oop b); |
| static int sort_by_address(ObjectEntry* a, ObjectEntry* b); |
| static int sort_oop_by_address(oop const& a, ObjectEntry const& b); |
| |
| public: |
| ObjectLookup(); |
| |
| // Resort list if a GC has occurred since the last sort |
| void maybe_resort(); |
| int find_index(jobject object, OopRecorder* oop_recorder); |
| }; |
| |
| class OopRecorder : public ResourceObj { |
| private: |
| ValueRecorder<jobject> _oops; |
| ValueRecorder<Metadata*> _metadata; |
| ObjectLookup* _object_lookup; |
| public: |
| OopRecorder(Arena* arena = NULL, bool deduplicate = false): _oops(arena), _metadata(arena) { |
| if (deduplicate) { |
| _object_lookup = new ObjectLookup(); |
| } else { |
| _object_lookup = NULL; |
| } |
| } |
| |
| int allocate_oop_index(jobject h) { |
| return _oops.allocate_index(h); |
| } |
| virtual int find_index(jobject h) { |
| return _object_lookup != NULL ? _object_lookup->find_index(h, this) : _oops.find_index(h); |
| } |
| jobject oop_at(int index) { |
| return _oops.at(index); |
| } |
| int oop_size() { |
| return _oops.size(); |
| } |
| int oop_count() { |
| return _oops.count(); |
| } |
| bool is_real(jobject h) { |
| return _oops.is_real(h); |
| } |
| |
| int allocate_metadata_index(Metadata* oop) { |
| return _metadata.allocate_index(oop); |
| } |
| virtual int find_index(Metadata* h) { |
| return _metadata.find_index(h); |
| } |
| Metadata* metadata_at(int index) { |
| return _metadata.at(index); |
| } |
| int metadata_size() { |
| return _metadata.size(); |
| } |
| int metadata_count() { |
| return _metadata.count(); |
| } |
| bool is_real(Metadata* h) { |
| return _metadata.is_real(h); |
| } |
| |
| bool is_unused() { |
| return _oops.is_unused() && _metadata.is_unused(); |
| } |
| |
| void freeze() { |
| _oops.size(); |
| _metadata.size(); |
| } |
| |
| void copy_values_to(nmethod* nm) { |
| if (!_oops.is_unused()) { |
| _oops.copy_values_to(nm); |
| } |
| if (!_metadata.is_unused()) { |
| _metadata.copy_values_to(nm); |
| } |
| } |
| |
| #ifdef ASSERT |
| bool is_complete() { |
| assert(_oops.is_complete() == _metadata.is_complete(), "must agree"); |
| return _oops.is_complete(); |
| } |
| #endif |
| }; |
| |
| |
| #endif // SHARE_VM_CODE_OOPRECORDER_HPP |