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src/hotspot/share/classfile/stringTable.hpp

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  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.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_CLASSFILE_STRINGTABLE_HPP
  26 #define SHARE_VM_CLASSFILE_STRINGTABLE_HPP
  27 
  28 #include "gc/shared/oopStorage.hpp"
  29 #include "gc/shared/oopStorageParState.hpp"
  30 #include "memory/allocation.hpp"
  31 #include "memory/padded.hpp"
  32 #include "oops/oop.hpp"
  33 #include "oops/weakHandle.hpp"
  34 #include "utilities/concurrentHashTable.hpp"
  35 
  36 template <class T, class N> class CompactHashtable;
  37 class CompactStringTableWriter;
  38 class SerializeClosure;
  39 
  40 class StringTable;
  41 class StringTableConfig;
  42 typedef ConcurrentHashTable<WeakHandle<vm_string_table_data>,
  43                             StringTableConfig, mtSymbol> StringTableHash;
  44 
  45 class StringTableCreateEntry;
  46 
  47 class StringTable : public CHeapObj<mtSymbol>{
  48   friend class VMStructs;
  49   friend class Symbol;
  50   friend class StringTableConfig;
  51   friend class StringTableCreateEntry;
  52 
  53 private:
  54   void grow(JavaThread* jt);
  55   void clean_dead_entries(JavaThread* jt);
  56 
  57   // The string table
  58   static StringTable* _the_table;
  59   // Shared string table
  60   static CompactHashtable<oop, char> _shared_table;
  61   static volatile bool _shared_string_mapped;
  62   static volatile bool _alt_hash;
  63 
  64 private:
  65 
  66   StringTableHash* _local_table;
  67   size_t _current_size;
  68   volatile bool _has_work;
  69   // Set if one bucket is out of balance due to hash algorithm deficiency
  70   volatile bool _needs_rehashing;
  71 
  72   OopStorage* _weak_handles;
  73 
  74   volatile size_t _items_count;
  75   DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
  76   volatile size_t _uncleaned_items_count;
  77   DEFINE_PAD_MINUS_SIZE(2, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
  78 
  79   double get_load_factor();
  80   double get_dead_factor();
  81 
  82   void check_concurrent_work();
  83   void trigger_concurrent_work();
  84 
  85   static size_t item_added();
  86   static void item_removed();
  87   size_t add_items_count_to_clean(size_t ndead);
  88 
  89   StringTable();
  90 
  91   static oop intern(Handle string_or_null_h, jchar* name, int len, TRAPS);
  92   oop do_intern(Handle string_or_null, jchar* name, int len, uintx hash, TRAPS);
  93   oop do_lookup(jchar* name, int len, uintx hash);
  94 
  95   void concurrent_work(JavaThread* jt);
  96   void print_table_statistics(outputStream* st, const char* table_name);
  97 
  98   void try_rehash_table();
  99   bool do_rehash();
 100 
 101  public:
 102   // The string table
 103   static StringTable* the_table() { return _the_table; }
 104   size_t table_size();
 105 
 106   static OopStorage* weak_storage() { return the_table()->_weak_handles; }
 107 
 108   static void create_table() {
 109     assert(_the_table == NULL, "One string table allowed.");
 110     _the_table = new StringTable();
 111   }
 112 
 113   static void do_concurrent_work(JavaThread* jt);


 134   //   Delete pointers to otherwise-unreachable objects.
 135   static void unlink(BoolObjectClosure* cl) {
 136     unlink_or_oops_do(cl);
 137   }
 138   static void unlink_or_oops_do(BoolObjectClosure* is_alive, OopClosure* f = NULL,
 139                                 size_t* processed = NULL, size_t* removed = NULL);
 140 
 141   // Serially invoke "f->do_oop" on the locations of all oops in the table.
 142   static void oops_do(OopClosure* f);
 143 
 144   // Possibly parallel versions of the above
 145   static void possibly_parallel_unlink(
 146      OopStorage::ParState<false /* concurrent */, false /* const*/>* par_state_string,
 147      BoolObjectClosure* cl, size_t* processed, size_t* removed);
 148   static void possibly_parallel_oops_do(
 149      OopStorage::ParState<false /* concurrent */, false /* const*/>* par_state_string,
 150      OopClosure* f);
 151 
 152   // Probing
 153   static oop lookup(Symbol* symbol);
 154   static oop lookup(jchar* chars, int length);
 155 
 156   // Interning
 157   static oop intern(Symbol* symbol, TRAPS);
 158   static oop intern(oop string, TRAPS);
 159   static oop intern(const char *utf8_string, TRAPS);
 160 
 161   // Rehash the string table if it gets out of balance
 162   static void rehash_table();
 163   static bool needs_rehashing()
 164     { return StringTable::the_table()->_needs_rehashing; }
 165 
 166   // Sharing
 167  private:
 168   oop lookup_shared(jchar* name, int len, unsigned int hash) NOT_CDS_JAVA_HEAP_RETURN_(NULL);
 169   static void copy_shared_string_table(CompactStringTableWriter* ch_table) NOT_CDS_JAVA_HEAP_RETURN;
 170  public:
 171   static oop create_archived_string(oop s, Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN_(NULL);
 172   static void set_shared_string_mapped() { _shared_string_mapped = true; }
 173   static bool shared_string_mapped()     { return _shared_string_mapped; }
 174   static void shared_oops_do(OopClosure* f) NOT_CDS_JAVA_HEAP_RETURN;
 175   static void write_to_archive() NOT_CDS_JAVA_HEAP_RETURN;
 176   static void serialize(SerializeClosure* soc) NOT_CDS_JAVA_HEAP_RETURN;
 177 
 178   // Jcmd
 179   static void dump(outputStream* st, bool verbose=false);
 180   // Debugging
 181   static size_t verify_and_compare_entries();
 182   static void verify();
 183 };
 184 
 185 #endif // SHARE_VM_CLASSFILE_STRINGTABLE_HPP


  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.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_CLASSFILE_STRINGTABLE_HPP
  26 #define SHARE_VM_CLASSFILE_STRINGTABLE_HPP
  27 
  28 #include "gc/shared/oopStorage.hpp"
  29 #include "gc/shared/oopStorageParState.hpp"
  30 #include "memory/allocation.hpp"
  31 #include "memory/padded.hpp"
  32 #include "oops/oop.hpp"
  33 #include "oops/weakHandle.hpp"
  34 #include "utilities/concurrentHashTable.hpp"
  35 

  36 class CompactStringTableWriter;
  37 class SerializeClosure;
  38 
  39 class StringTable;
  40 class StringTableConfig;
  41 typedef ConcurrentHashTable<WeakHandle<vm_string_table_data>,
  42                             StringTableConfig, mtSymbol> StringTableHash;
  43 
  44 class StringTableCreateEntry;
  45 
  46 class StringTable : public CHeapObj<mtSymbol>{
  47   friend class VMStructs;
  48   friend class Symbol;
  49   friend class StringTableConfig;
  50   friend class StringTableCreateEntry;
  51 
  52 private:
  53   void grow(JavaThread* jt);
  54   void clean_dead_entries(JavaThread* jt);
  55 
  56   // The string table
  57   static StringTable* _the_table;


  58   static volatile bool _shared_string_mapped;
  59   static volatile bool _alt_hash;
  60 
  61 private:
  62 
  63   StringTableHash* _local_table;
  64   size_t _current_size;
  65   volatile bool _has_work;
  66   // Set if one bucket is out of balance due to hash algorithm deficiency
  67   volatile bool _needs_rehashing;
  68 
  69   OopStorage* _weak_handles;
  70 
  71   volatile size_t _items_count;
  72   DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
  73   volatile size_t _uncleaned_items_count;
  74   DEFINE_PAD_MINUS_SIZE(2, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
  75 
  76   double get_load_factor();
  77   double get_dead_factor();
  78 
  79   void check_concurrent_work();
  80   void trigger_concurrent_work();
  81 
  82   static size_t item_added();
  83   static void item_removed();
  84   size_t add_items_count_to_clean(size_t ndead);
  85 
  86   StringTable();
  87 
  88   static oop intern(Handle string_or_null_h, const jchar* name, int len, TRAPS);
  89   oop do_intern(Handle string_or_null, const jchar* name, int len, uintx hash, TRAPS);
  90   oop do_lookup(const jchar* name, int len, uintx hash);
  91 
  92   void concurrent_work(JavaThread* jt);
  93   void print_table_statistics(outputStream* st, const char* table_name);
  94 
  95   void try_rehash_table();
  96   bool do_rehash();
  97 
  98  public:
  99   // The string table
 100   static StringTable* the_table() { return _the_table; }
 101   size_t table_size();
 102 
 103   static OopStorage* weak_storage() { return the_table()->_weak_handles; }
 104 
 105   static void create_table() {
 106     assert(_the_table == NULL, "One string table allowed.");
 107     _the_table = new StringTable();
 108   }
 109 
 110   static void do_concurrent_work(JavaThread* jt);


 131   //   Delete pointers to otherwise-unreachable objects.
 132   static void unlink(BoolObjectClosure* cl) {
 133     unlink_or_oops_do(cl);
 134   }
 135   static void unlink_or_oops_do(BoolObjectClosure* is_alive, OopClosure* f = NULL,
 136                                 size_t* processed = NULL, size_t* removed = NULL);
 137 
 138   // Serially invoke "f->do_oop" on the locations of all oops in the table.
 139   static void oops_do(OopClosure* f);
 140 
 141   // Possibly parallel versions of the above
 142   static void possibly_parallel_unlink(
 143      OopStorage::ParState<false /* concurrent */, false /* const*/>* par_state_string,
 144      BoolObjectClosure* cl, size_t* processed, size_t* removed);
 145   static void possibly_parallel_oops_do(
 146      OopStorage::ParState<false /* concurrent */, false /* const*/>* par_state_string,
 147      OopClosure* f);
 148 
 149   // Probing
 150   static oop lookup(Symbol* symbol);
 151   static oop lookup(const jchar* chars, int length);
 152 
 153   // Interning
 154   static oop intern(Symbol* symbol, TRAPS);
 155   static oop intern(oop string, TRAPS);
 156   static oop intern(const char *utf8_string, TRAPS);
 157 
 158   // Rehash the string table if it gets out of balance
 159   static void rehash_table();
 160   static bool needs_rehashing()
 161     { return StringTable::the_table()->_needs_rehashing; }
 162 
 163   // Sharing
 164  private:
 165   oop lookup_shared(const jchar* name, int len, unsigned int hash) NOT_CDS_JAVA_HEAP_RETURN_(NULL);
 166   static void copy_shared_string_table(CompactStringTableWriter* ch_table) NOT_CDS_JAVA_HEAP_RETURN;
 167  public:
 168   static oop create_archived_string(oop s, Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN_(NULL);
 169   static void set_shared_string_mapped() { _shared_string_mapped = true; }
 170   static bool shared_string_mapped()     { return _shared_string_mapped; }
 171   static void shared_oops_do(OopClosure* f) NOT_CDS_JAVA_HEAP_RETURN;
 172   static void write_to_archive() NOT_CDS_JAVA_HEAP_RETURN;
 173   static void serialize(SerializeClosure* soc) NOT_CDS_JAVA_HEAP_RETURN;
 174 
 175   // Jcmd
 176   static void dump(outputStream* st, bool verbose=false);
 177   // Debugging
 178   static size_t verify_and_compare_entries();
 179   static void verify();
 180 };
 181 
 182 #endif // SHARE_VM_CLASSFILE_STRINGTABLE_HPP
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