jdk-sandbox: comparison src/hotspot/share/classfile/symbolTable.hpp

equal deleted inserted replaced

-:c5461fe16efb
+:8b23aa7cef47
 /*
-* Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
+* Copyright (c) 1997, 2018, 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.
 #ifndef SHARE_VM_CLASSFILE_SYMBOLTABLE_HPP
 #define SHARE_VM_CLASSFILE_SYMBOLTABLE_HPP
 #include "memory/allocation.hpp"
+#include "memory/padded.hpp"
 #include "oops/symbol.hpp"
+#include "utilities/concurrentHashTable.hpp"
 #include "utilities/hashtable.hpp"
-// The symbol table holds all Symbol*s and corresponding interned strings.
-// Symbol*s and literal strings should be canonicalized.
-//
-// The interned strings are created lazily.
-//
-// It is implemented as an open hash table with a fixed number of buckets.
-//
-// %note:
-//  - symbolTableEntrys are allocated in blocks to reduce the space overhead.
-class BoolObjectClosure;
-class outputStream;
-class SerializeClosure;
 // TempNewSymbol acts as a handle class in a handle/body idiom and is
 // responsible for proper resource management of the body (which is a Symbol*).
 // The body is resource managed by a reference counting scheme.
 // TempNewSymbol can therefore be used to properly hold a newly created or referenced
 // symbol table and add to the symbol's reference count.
 // probe() and lookup_only() will increment the refcount if symbol is found.
 class TempNewSymbol : public StackObj {
 Symbol* _temp;
 public:
 TempNewSymbol() : _temp(NULL) {}
 // Conversion from a Symbol* to a TempNewSymbol.
 // Does not increment the current reference count.
 TempNewSymbol(Symbol *s) : _temp(s) {}
 bool    operator == (Symbol* o) const          { return _temp == o; }
 operator Symbol*()                             { return _temp; }
 };
 template <class T, class N> class CompactHashtable;
+class CompactSymbolTableWriter;
-class SymbolTable : public RehashableHashtable<Symbol*, mtSymbol> {
+class SerializeClosure;
+class SymbolTableConfig;
+typedef ConcurrentHashTable<Symbol*,
+SymbolTableConfig, mtSymbol> SymbolTableHash;
+class SymbolTableCreateEntry;
+class SymbolTable : public CHeapObj<mtSymbol> {
 friend class VMStructs;
+friend class Symbol;
 friend class ClassFileParser;
+friend class SymbolTableConfig;
+friend class SymbolTableCreateEntry;
 private:
+static void delete_symbol(Symbol* sym);
+void grow(JavaThread* jt);
+void clean_dead_entries(JavaThread* jt);
 // The symbol table
 static SymbolTable* _the_table;
+// Shared symbol table.
+static CompactHashtable<Symbol*, char> _shared_table;
+static volatile bool _lookup_shared_first;
+static volatile bool _alt_hash;
+// For statistics
+volatile size_t _symbols_removed;
+volatile size_t _symbols_counted;
+SymbolTableHash* _local_table;
+size_t _current_size;
+volatile bool _has_work;
 // Set if one bucket is out of balance due to hash algorithm deficiency
-static bool _needs_rehashing;
+volatile bool _needs_rehashing;
-static bool _lookup_shared_first;
+volatile size_t _items_count;
-// For statistics
+volatile size_t _uncleaned_items_count;
-static int _symbols_removed;
-static int _symbols_counted;
+double get_load_factor();
+double get_dead_factor();
-// shared symbol table.
-static CompactHashtable<Symbol*, char> _shared_table;
+void check_concurrent_work();
+void trigger_concurrent_work();
-Symbol* allocate_symbol(const u1* name, int len, bool c_heap, TRAPS); // Assumes no characters larger than 0x7F
+static void item_added();
+static void item_removed();
+static void set_item_clean_count(size_t ncl);
+static void mark_item_clean_count();
+SymbolTable();
+Symbol* allocate_symbol(const char* name, int len, bool c_heap, TRAPS); // Assumes no characters larger than 0x7F
+Symbol* do_lookup(const char* name, int len, uintx hash);
+Symbol* do_add_if_needed(const char* name, int len, uintx hash, bool heap, TRAPS);
 // Adding elements
-Symbol* basic_add(int index, u1* name, int len, unsigned int hashValue,
+static void add(ClassLoaderData* loader_data,
-bool c_heap, TRAPS);
+const constantPoolHandle& cp, int names_count,
-bool basic_add(ClassLoaderData* loader_data,
+const char** names, int* lengths, int* cp_indices,
-const constantPoolHandle& cp, int names_count,
+unsigned int* hashValues, TRAPS);
-const char** names, int* lengths, int* cp_indices,
-unsigned int* hashValues, TRAPS);
 static void new_symbols(ClassLoaderData* loader_data,
 const constantPoolHandle& cp, int names_count,
 const char** name, int* lengths,
 int* cp_indices, unsigned int* hashValues,
 TRAPS) {
 add(loader_data, cp, names_count, name, lengths, cp_indices, hashValues, THREAD);
 }
 static Symbol* lookup_shared(const char* name, int len, unsigned int hash);
-Symbol* lookup_dynamic(int index, const char* name, int len, unsigned int hash);
+Symbol* lookup_dynamic(const char* name, int len, unsigned int hash);
-Symbol* lookup(int index, const char* name, int len, unsigned int hash);
+Symbol* lookup_common(const char* name, int len, unsigned int hash);
-SymbolTable()
-: RehashableHashtable<Symbol*, mtSymbol>(SymbolTableSize, sizeof (HashtableEntry<Symbol*, mtSymbol>)) {}
-SymbolTable(HashtableBucket<mtSymbol>* t, int number_of_entries)
-: RehashableHashtable<Symbol*, mtSymbol>(SymbolTableSize, sizeof (HashtableEntry<Symbol*, mtSymbol>), t,
-number_of_entries) {}
 // Arena for permanent symbols (null class loader) that are never unloaded
 static Arena*  _arena;
 static Arena* arena() { return _arena; }  // called for statistics
 static void initialize_symbols(int arena_alloc_size = 0);
-static volatile int _parallel_claimed_idx;
+void concurrent_work(JavaThread* jt);
+void print_table_statistics(outputStream* st, const char* table_name);
-typedef SymbolTable::BucketUnlinkContext BucketUnlinkContext;
-// Release any dead symbols. Unlinked bucket entries are collected in the given
+void try_rehash_table();
-// context to be freed later.
+bool do_rehash();
-// This allows multiple threads to work on the table at once.
-static void buckets_unlink(int start_idx, int end_idx, BucketUnlinkContext* context);
 public:
+// The symbol table
+static SymbolTable* the_table() { return _the_table; }
+size_t table_size();
 enum {
 symbol_alloc_batch_size = 8,
 // Pick initial size based on java -version size measurements
-symbol_alloc_arena_size = 360*K
+symbol_alloc_arena_size = 360*K // TODO (revisit)
 };
-// The symbol table
-static SymbolTable* the_table() { return _the_table; }
-// Size of one bucket in the string table.  Used when checking for rollover.
-static uint bucket_size() { return sizeof(HashtableBucket<mtSymbol>); }
 static void create_table() {
 assert(_the_table == NULL, "One symbol table allowed.");
 _the_table = new SymbolTable();
 initialize_symbols(symbol_alloc_arena_size);
 }
-static unsigned int hash_symbol(const char* s, int len);
+static void unlink() {
-static unsigned int hash_shared_symbol(const char* s, int len);
+do_check_concurrent_work();
+}
+static void do_check_concurrent_work();
+static void do_concurrent_work(JavaThread* jt);
+static bool has_work() { return the_table()->_has_work; }
+// Probing
 static Symbol* lookup(const char* name, int len, TRAPS);
 // lookup only, won't add. Also calculate hash.
 static Symbol* lookup_only(const char* name, int len, unsigned int& hash);
-// Only copy to C string to be added if lookup failed.
+// adds new symbol if not found
 static Symbol* lookup(const Symbol* sym, int begin, int end, TRAPS);
-static void release(Symbol* sym);
-// Look up the address of the literal in the SymbolTable for this Symbol*
-static Symbol** lookup_symbol_addr(Symbol* sym);
 // jchar (UTF16) version of lookups
 static Symbol* lookup_unicode(const jchar* name, int len, TRAPS);
 static Symbol* lookup_only_unicode(const jchar* name, int len, unsigned int& hash);
-static void add(ClassLoaderData* loader_data,
-const constantPoolHandle& cp, int names_count,
-const char** names, int* lengths, int* cp_indices,
-unsigned int* hashValues, TRAPS);
-// Release any dead symbols
-static void unlink() {
-int processed = 0;
-int removed = 0;
-unlink(&processed, &removed);
-}
-static void unlink(int* processed, int* removed);
-// Release any dead symbols, possibly parallel version
-static void possibly_parallel_unlink(int* processed, int* removed);
-// iterate over symbols
-static void symbols_do(SymbolClosure *cl);
-static void metaspace_pointers_do(MetaspaceClosure* it);
-// Symbol creation
-static Symbol* new_symbol(const char* utf8_buffer, int length, TRAPS) {
-assert(utf8_buffer != NULL, "just checking");
-return lookup(utf8_buffer, length, THREAD);
-}
-static Symbol*       new_symbol(const char* name, TRAPS) {
-return new_symbol(name, (int)strlen(name), THREAD);
-}
-static Symbol*       new_symbol(const Symbol* sym, int begin, int end, TRAPS) {
-assert(begin <= end && end <= sym->utf8_length(), "just checking");
-return lookup(sym, begin, end, THREAD);
-}
-// Create a symbol in the arena for symbols that are not deleted
-static Symbol* new_permanent_symbol(const char* name, TRAPS);
-// Symbol lookup
-static Symbol* lookup(int index, const char* name, int len, TRAPS);
 // Needed for preloading classes in signatures when compiling.
 // Returns the symbol is already present in symbol table, otherwise
 // NULL.  NO ALLOCATION IS GUARANTEED!
 static Symbol* probe(const char* name, int len) {
 unsigned int ignore_hash;
 static Symbol* probe_unicode(const jchar* name, int len) {
 unsigned int ignore_hash;
 return lookup_only_unicode(name, len, ignore_hash);
 }
-// Histogram
+// Symbol creation
-static void print_histogram()     PRODUCT_RETURN;
+static Symbol* new_symbol(const char* utf8_buffer, int length, TRAPS) {
-static void print()     PRODUCT_RETURN;
+assert(utf8_buffer != NULL, "just checking");
+return lookup(utf8_buffer, length, THREAD);
+}
+static Symbol* new_symbol(const char* name, TRAPS) {
+return new_symbol(name, (int)strlen(name), THREAD);
+}
+static Symbol* new_symbol(const Symbol* sym, int begin, int end, TRAPS) {
+assert(begin <= end && end <= sym->utf8_length(), "just checking");
+return lookup(sym, begin, end, THREAD);
+}
+// Create a symbol in the arena for symbols that are not deleted
+static Symbol* new_permanent_symbol(const char* name, TRAPS);
+// Rehash the string table if it gets out of balance
+static void rehash_table();
+static bool needs_rehashing()
+{ return SymbolTable::the_table()->_needs_rehashing; }
+// Heap dumper and CDS
+static void symbols_do(SymbolClosure *cl);
+// Sharing
+private:
+static void copy_shared_symbol_table(CompactSymbolTableWriter* ch_table);
+public:
+static void write_to_archive() NOT_CDS_RETURN;
+static void serialize(SerializeClosure* soc) NOT_CDS_RETURN;
+static void metaspace_pointers_do(MetaspaceClosure* it);
+// Jcmd
+static void dump(outputStream* st, bool verbose=false);
 // Debugging
 static void verify();
-static void dump(outputStream* st, bool verbose=false);
 static void read(const char* filename, TRAPS);
-// Sharing
+// Histogram
-static void write_to_archive();
+static void print_histogram() PRODUCT_RETURN;
-static void serialize(SerializeClosure* soc);
-static u4 encode_shared(Symbol* sym);
-static Symbol* decode_shared(u4 offset);
-// Rehash the symbol table if it gets out of balance
-static void rehash_table();
-static bool needs_rehashing()         { return _needs_rehashing; }
-// Parallel chunked scanning
-static void clear_parallel_claimed_index() { _parallel_claimed_idx = 0; }
-static int parallel_claimed_index()        { return _parallel_claimed_idx; }
 };
 #endif // SHARE_VM_CLASSFILE_SYMBOLTABLE_HPP

changeset 51405	8b23aa7cef47
parent 48157	7c4d43c26352
child 51823	2a51125b2794