| /* |
| * Copyright (c) 1997, 2017, 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. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "classfile/altHashing.hpp" |
| #include "classfile/compactHashtable.inline.hpp" |
| #include "classfile/javaClasses.hpp" |
| #include "classfile/symbolTable.hpp" |
| #include "classfile/systemDictionary.hpp" |
| #include "gc/shared/collectedHeap.inline.hpp" |
| #include "gc/shared/gcLocker.inline.hpp" |
| #include "memory/allocation.inline.hpp" |
| #include "memory/filemap.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/atomic.hpp" |
| #include "runtime/mutexLocker.hpp" |
| #include "utilities/hashtable.inline.hpp" |
| |
| // -------------------------------------------------------------------------- |
| // the number of buckets a thread claims |
| const int ClaimChunkSize = 32; |
| |
| SymbolTable* SymbolTable::_the_table = NULL; |
| // Static arena for symbols that are not deallocated |
| Arena* SymbolTable::_arena = NULL; |
| bool SymbolTable::_needs_rehashing = false; |
| bool SymbolTable::_lookup_shared_first = false; |
| |
| CompactHashtable<Symbol*, char> SymbolTable::_shared_table; |
| |
| Symbol* SymbolTable::allocate_symbol(const u1* name, int len, bool c_heap, TRAPS) { |
| assert (len <= Symbol::max_length(), "should be checked by caller"); |
| |
| Symbol* sym; |
| |
| if (DumpSharedSpaces) { |
| // Allocate all symbols to CLD shared metaspace |
| sym = new (len, ClassLoaderData::the_null_class_loader_data(), THREAD) Symbol(name, len, PERM_REFCOUNT); |
| } else if (c_heap) { |
| // refcount starts as 1 |
| sym = new (len, THREAD) Symbol(name, len, 1); |
| assert(sym != NULL, "new should call vm_exit_out_of_memory if C_HEAP is exhausted"); |
| } else { |
| // Allocate to global arena |
| sym = new (len, arena(), THREAD) Symbol(name, len, PERM_REFCOUNT); |
| } |
| return sym; |
| } |
| |
| void SymbolTable::initialize_symbols(int arena_alloc_size) { |
| // Initialize the arena for global symbols, size passed in depends on CDS. |
| if (arena_alloc_size == 0) { |
| _arena = new (mtSymbol) Arena(mtSymbol); |
| } else { |
| _arena = new (mtSymbol) Arena(mtSymbol, arena_alloc_size); |
| } |
| } |
| |
| // Call function for all symbols in the symbol table. |
| void SymbolTable::symbols_do(SymbolClosure *cl) { |
| // all symbols from shared table |
| _shared_table.symbols_do(cl); |
| |
| // all symbols from the dynamic table |
| const int n = the_table()->table_size(); |
| for (int i = 0; i < n; i++) { |
| for (HashtableEntry<Symbol*, mtSymbol>* p = the_table()->bucket(i); |
| p != NULL; |
| p = p->next()) { |
| cl->do_symbol(p->literal_addr()); |
| } |
| } |
| } |
| |
| int SymbolTable::_symbols_removed = 0; |
| int SymbolTable::_symbols_counted = 0; |
| volatile int SymbolTable::_parallel_claimed_idx = 0; |
| |
| void SymbolTable::buckets_unlink(int start_idx, int end_idx, BucketUnlinkContext* context) { |
| for (int i = start_idx; i < end_idx; ++i) { |
| HashtableEntry<Symbol*, mtSymbol>** p = the_table()->bucket_addr(i); |
| HashtableEntry<Symbol*, mtSymbol>* entry = the_table()->bucket(i); |
| while (entry != NULL) { |
| // Shared entries are normally at the end of the bucket and if we run into |
| // a shared entry, then there is nothing more to remove. However, if we |
| // have rehashed the table, then the shared entries are no longer at the |
| // end of the bucket. |
| if (entry->is_shared() && !use_alternate_hashcode()) { |
| break; |
| } |
| Symbol* s = entry->literal(); |
| context->_num_processed++; |
| assert(s != NULL, "just checking"); |
| // If reference count is zero, remove. |
| if (s->refcount() == 0) { |
| assert(!entry->is_shared(), "shared entries should be kept live"); |
| delete s; |
| *p = entry->next(); |
| context->free_entry(entry); |
| } else { |
| p = entry->next_addr(); |
| } |
| // get next entry |
| entry = (HashtableEntry<Symbol*, mtSymbol>*)HashtableEntry<Symbol*, mtSymbol>::make_ptr(*p); |
| } |
| } |
| } |
| |
| // Remove unreferenced symbols from the symbol table |
| // This is done late during GC. |
| void SymbolTable::unlink(int* processed, int* removed) { |
| BucketUnlinkContext context; |
| buckets_unlink(0, the_table()->table_size(), &context); |
| _the_table->bulk_free_entries(&context); |
| *processed = context._num_processed; |
| *removed = context._num_removed; |
| |
| _symbols_removed = context._num_removed; |
| _symbols_counted = context._num_processed; |
| } |
| |
| void SymbolTable::possibly_parallel_unlink(int* processed, int* removed) { |
| const int limit = the_table()->table_size(); |
| |
| BucketUnlinkContext context; |
| for (;;) { |
| // Grab next set of buckets to scan |
| int start_idx = Atomic::add(ClaimChunkSize, &_parallel_claimed_idx) - ClaimChunkSize; |
| if (start_idx >= limit) { |
| // End of table |
| break; |
| } |
| |
| int end_idx = MIN2(limit, start_idx + ClaimChunkSize); |
| buckets_unlink(start_idx, end_idx, &context); |
| } |
| |
| _the_table->bulk_free_entries(&context); |
| *processed = context._num_processed; |
| *removed = context._num_removed; |
| |
| Atomic::add(context._num_processed, &_symbols_counted); |
| Atomic::add(context._num_removed, &_symbols_removed); |
| } |
| |
| // Create a new table and using alternate hash code, populate the new table |
| // with the existing strings. Set flag to use the alternate hash code afterwards. |
| void SymbolTable::rehash_table() { |
| if (DumpSharedSpaces) { |
| tty->print_cr("Warning: rehash_table should not be called while dumping archive"); |
| return; |
| } |
| |
| assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); |
| // This should never happen with -Xshare:dump but it might in testing mode. |
| if (DumpSharedSpaces) return; |
| // Create a new symbol table |
| SymbolTable* new_table = new SymbolTable(); |
| |
| the_table()->move_to(new_table); |
| |
| // Delete the table and buckets (entries are reused in new table). |
| delete _the_table; |
| // Don't check if we need rehashing until the table gets unbalanced again. |
| // Then rehash with a new global seed. |
| _needs_rehashing = false; |
| _the_table = new_table; |
| } |
| |
| // Lookup a symbol in a bucket. |
| |
| Symbol* SymbolTable::lookup_dynamic(int index, const char* name, |
| int len, unsigned int hash) { |
| int count = 0; |
| for (HashtableEntry<Symbol*, mtSymbol>* e = bucket(index); e != NULL; e = e->next()) { |
| count++; // count all entries in this bucket, not just ones with same hash |
| if (e->hash() == hash) { |
| Symbol* sym = e->literal(); |
| if (sym->equals(name, len)) { |
| // something is referencing this symbol now. |
| sym->increment_refcount(); |
| return sym; |
| } |
| } |
| } |
| // If the bucket size is too deep check if this hash code is insufficient. |
| if (count >= rehash_count && !needs_rehashing()) { |
| _needs_rehashing = check_rehash_table(count); |
| } |
| return NULL; |
| } |
| |
| Symbol* SymbolTable::lookup_shared(const char* name, |
| int len, unsigned int hash) { |
| if (use_alternate_hashcode()) { |
| // hash_code parameter may use alternate hashing algorithm but the shared table |
| // always uses the same original hash code. |
| hash = hash_shared_symbol(name, len); |
| } |
| return _shared_table.lookup(name, hash, len); |
| } |
| |
| Symbol* SymbolTable::lookup(int index, const char* name, |
| int len, unsigned int hash) { |
| Symbol* sym; |
| if (_lookup_shared_first) { |
| sym = lookup_shared(name, len, hash); |
| if (sym != NULL) { |
| return sym; |
| } |
| _lookup_shared_first = false; |
| return lookup_dynamic(index, name, len, hash); |
| } else { |
| sym = lookup_dynamic(index, name, len, hash); |
| if (sym != NULL) { |
| return sym; |
| } |
| sym = lookup_shared(name, len, hash); |
| if (sym != NULL) { |
| _lookup_shared_first = true; |
| } |
| return sym; |
| } |
| } |
| |
| u4 SymbolTable::encode_shared(Symbol* sym) { |
| assert(DumpSharedSpaces, "called only during dump time"); |
| uintx base_address = uintx(MetaspaceShared::shared_rs()->base()); |
| uintx offset = uintx(sym) - base_address; |
| assert(offset < 0x7fffffff, "sanity"); |
| return u4(offset); |
| } |
| |
| Symbol* SymbolTable::decode_shared(u4 offset) { |
| assert(!DumpSharedSpaces, "called only during runtime"); |
| uintx base_address = _shared_table.base_address(); |
| Symbol* sym = (Symbol*)(base_address + offset); |
| |
| #ifndef PRODUCT |
| const char* s = (const char*)sym->bytes(); |
| int len = sym->utf8_length(); |
| unsigned int hash = hash_symbol(s, len); |
| assert(sym == lookup_shared(s, len, hash), "must be shared symbol"); |
| #endif |
| |
| return sym; |
| } |
| |
| // Pick hashing algorithm. |
| unsigned int SymbolTable::hash_symbol(const char* s, int len) { |
| return use_alternate_hashcode() ? |
| AltHashing::murmur3_32(seed(), (const jbyte*)s, len) : |
| java_lang_String::hash_code((const jbyte*)s, len); |
| } |
| |
| unsigned int SymbolTable::hash_shared_symbol(const char* s, int len) { |
| return java_lang_String::hash_code((const jbyte*)s, len); |
| } |
| |
| |
| // We take care not to be blocking while holding the |
| // SymbolTable_lock. Otherwise, the system might deadlock, since the |
| // symboltable is used during compilation (VM_thread) The lock free |
| // synchronization is simplified by the fact that we do not delete |
| // entries in the symbol table during normal execution (only during |
| // safepoints). |
| |
| Symbol* SymbolTable::lookup(const char* name, int len, TRAPS) { |
| unsigned int hashValue = hash_symbol(name, len); |
| int index = the_table()->hash_to_index(hashValue); |
| |
| Symbol* s = the_table()->lookup(index, name, len, hashValue); |
| |
| // Found |
| if (s != NULL) return s; |
| |
| // Grab SymbolTable_lock first. |
| MutexLocker ml(SymbolTable_lock, THREAD); |
| |
| // Otherwise, add to symbol to table |
| return the_table()->basic_add(index, (u1*)name, len, hashValue, true, THREAD); |
| } |
| |
| Symbol* SymbolTable::lookup(const Symbol* sym, int begin, int end, TRAPS) { |
| char* buffer; |
| int index, len; |
| unsigned int hashValue; |
| char* name; |
| { |
| debug_only(NoSafepointVerifier nsv;) |
| |
| name = (char*)sym->base() + begin; |
| len = end - begin; |
| hashValue = hash_symbol(name, len); |
| index = the_table()->hash_to_index(hashValue); |
| Symbol* s = the_table()->lookup(index, name, len, hashValue); |
| |
| // Found |
| if (s != NULL) return s; |
| } |
| |
| // Otherwise, add to symbol to table. Copy to a C string first. |
| char stack_buf[128]; |
| ResourceMark rm(THREAD); |
| if (len <= 128) { |
| buffer = stack_buf; |
| } else { |
| buffer = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len); |
| } |
| for (int i=0; i<len; i++) { |
| buffer[i] = name[i]; |
| } |
| // Make sure there is no safepoint in the code above since name can't move. |
| // We can't include the code in NoSafepointVerifier because of the |
| // ResourceMark. |
| |
| // Grab SymbolTable_lock first. |
| MutexLocker ml(SymbolTable_lock, THREAD); |
| |
| return the_table()->basic_add(index, (u1*)buffer, len, hashValue, true, THREAD); |
| } |
| |
| Symbol* SymbolTable::lookup_only(const char* name, int len, |
| unsigned int& hash) { |
| hash = hash_symbol(name, len); |
| int index = the_table()->hash_to_index(hash); |
| |
| Symbol* s = the_table()->lookup(index, name, len, hash); |
| return s; |
| } |
| |
| // Look up the address of the literal in the SymbolTable for this Symbol* |
| // Do not create any new symbols |
| // Do not increment the reference count to keep this alive |
| Symbol** SymbolTable::lookup_symbol_addr(Symbol* sym){ |
| unsigned int hash = hash_symbol((char*)sym->bytes(), sym->utf8_length()); |
| int index = the_table()->hash_to_index(hash); |
| |
| for (HashtableEntry<Symbol*, mtSymbol>* e = the_table()->bucket(index); e != NULL; e = e->next()) { |
| if (e->hash() == hash) { |
| Symbol* literal_sym = e->literal(); |
| if (sym == literal_sym) { |
| return e->literal_addr(); |
| } |
| } |
| } |
| return NULL; |
| } |
| |
| // Suggestion: Push unicode-based lookup all the way into the hashing |
| // and probing logic, so there is no need for convert_to_utf8 until |
| // an actual new Symbol* is created. |
| Symbol* SymbolTable::lookup_unicode(const jchar* name, int utf16_length, TRAPS) { |
| int utf8_length = UNICODE::utf8_length((jchar*) name, utf16_length); |
| char stack_buf[128]; |
| if (utf8_length < (int) sizeof(stack_buf)) { |
| char* chars = stack_buf; |
| UNICODE::convert_to_utf8(name, utf16_length, chars); |
| return lookup(chars, utf8_length, THREAD); |
| } else { |
| ResourceMark rm(THREAD); |
| char* chars = NEW_RESOURCE_ARRAY(char, utf8_length + 1);; |
| UNICODE::convert_to_utf8(name, utf16_length, chars); |
| return lookup(chars, utf8_length, THREAD); |
| } |
| } |
| |
| Symbol* SymbolTable::lookup_only_unicode(const jchar* name, int utf16_length, |
| unsigned int& hash) { |
| int utf8_length = UNICODE::utf8_length((jchar*) name, utf16_length); |
| char stack_buf[128]; |
| if (utf8_length < (int) sizeof(stack_buf)) { |
| char* chars = stack_buf; |
| UNICODE::convert_to_utf8(name, utf16_length, chars); |
| return lookup_only(chars, utf8_length, hash); |
| } else { |
| ResourceMark rm; |
| char* chars = NEW_RESOURCE_ARRAY(char, utf8_length + 1);; |
| UNICODE::convert_to_utf8(name, utf16_length, chars); |
| return lookup_only(chars, utf8_length, hash); |
| } |
| } |
| |
| void SymbolTable::add(ClassLoaderData* loader_data, const constantPoolHandle& cp, |
| int names_count, |
| const char** names, int* lengths, int* cp_indices, |
| unsigned int* hashValues, TRAPS) { |
| // Grab SymbolTable_lock first. |
| MutexLocker ml(SymbolTable_lock, THREAD); |
| |
| SymbolTable* table = the_table(); |
| bool added = table->basic_add(loader_data, cp, names_count, names, lengths, |
| cp_indices, hashValues, CHECK); |
| if (!added) { |
| // do it the hard way |
| for (int i=0; i<names_count; i++) { |
| int index = table->hash_to_index(hashValues[i]); |
| bool c_heap = !loader_data->is_the_null_class_loader_data(); |
| Symbol* sym = table->basic_add(index, (u1*)names[i], lengths[i], hashValues[i], c_heap, CHECK); |
| cp->symbol_at_put(cp_indices[i], sym); |
| } |
| } |
| } |
| |
| Symbol* SymbolTable::new_permanent_symbol(const char* name, TRAPS) { |
| unsigned int hash; |
| Symbol* result = SymbolTable::lookup_only((char*)name, (int)strlen(name), hash); |
| if (result != NULL) { |
| return result; |
| } |
| // Grab SymbolTable_lock first. |
| MutexLocker ml(SymbolTable_lock, THREAD); |
| |
| SymbolTable* table = the_table(); |
| int index = table->hash_to_index(hash); |
| return table->basic_add(index, (u1*)name, (int)strlen(name), hash, false, THREAD); |
| } |
| |
| Symbol* SymbolTable::basic_add(int index_arg, u1 *name, int len, |
| unsigned int hashValue_arg, bool c_heap, TRAPS) { |
| assert(!Universe::heap()->is_in_reserved(name), |
| "proposed name of symbol must be stable"); |
| |
| // Don't allow symbols to be created which cannot fit in a Symbol*. |
| if (len > Symbol::max_length()) { |
| THROW_MSG_0(vmSymbols::java_lang_InternalError(), |
| "name is too long to represent"); |
| } |
| |
| // Cannot hit a safepoint in this function because the "this" pointer can move. |
| NoSafepointVerifier nsv; |
| |
| // Check if the symbol table has been rehashed, if so, need to recalculate |
| // the hash value and index. |
| unsigned int hashValue; |
| int index; |
| if (use_alternate_hashcode()) { |
| hashValue = hash_symbol((const char*)name, len); |
| index = hash_to_index(hashValue); |
| } else { |
| hashValue = hashValue_arg; |
| index = index_arg; |
| } |
| |
| // Since look-up was done lock-free, we need to check if another |
| // thread beat us in the race to insert the symbol. |
| Symbol* test = lookup(index, (char*)name, len, hashValue); |
| if (test != NULL) { |
| // A race occurred and another thread introduced the symbol. |
| assert(test->refcount() != 0, "lookup should have incremented the count"); |
| return test; |
| } |
| |
| // Create a new symbol. |
| Symbol* sym = allocate_symbol(name, len, c_heap, CHECK_NULL); |
| assert(sym->equals((char*)name, len), "symbol must be properly initialized"); |
| |
| HashtableEntry<Symbol*, mtSymbol>* entry = new_entry(hashValue, sym); |
| add_entry(index, entry); |
| return sym; |
| } |
| |
| // This version of basic_add adds symbols in batch from the constant pool |
| // parsing. |
| bool SymbolTable::basic_add(ClassLoaderData* loader_data, const constantPoolHandle& cp, |
| int names_count, |
| const char** names, int* lengths, |
| int* cp_indices, unsigned int* hashValues, |
| TRAPS) { |
| |
| // Check symbol names are not too long. If any are too long, don't add any. |
| for (int i = 0; i< names_count; i++) { |
| if (lengths[i] > Symbol::max_length()) { |
| THROW_MSG_0(vmSymbols::java_lang_InternalError(), |
| "name is too long to represent"); |
| } |
| } |
| |
| // Cannot hit a safepoint in this function because the "this" pointer can move. |
| NoSafepointVerifier nsv; |
| |
| for (int i=0; i<names_count; i++) { |
| // Check if the symbol table has been rehashed, if so, need to recalculate |
| // the hash value. |
| unsigned int hashValue; |
| if (use_alternate_hashcode()) { |
| hashValue = hash_symbol(names[i], lengths[i]); |
| } else { |
| hashValue = hashValues[i]; |
| } |
| // Since look-up was done lock-free, we need to check if another |
| // thread beat us in the race to insert the symbol. |
| int index = hash_to_index(hashValue); |
| Symbol* test = lookup(index, names[i], lengths[i], hashValue); |
| if (test != NULL) { |
| // A race occurred and another thread introduced the symbol, this one |
| // will be dropped and collected. Use test instead. |
| cp->symbol_at_put(cp_indices[i], test); |
| assert(test->refcount() != 0, "lookup should have incremented the count"); |
| } else { |
| // Create a new symbol. The null class loader is never unloaded so these |
| // are allocated specially in a permanent arena. |
| bool c_heap = !loader_data->is_the_null_class_loader_data(); |
| Symbol* sym = allocate_symbol((const u1*)names[i], lengths[i], c_heap, CHECK_(false)); |
| assert(sym->equals(names[i], lengths[i]), "symbol must be properly initialized"); // why wouldn't it be??? |
| HashtableEntry<Symbol*, mtSymbol>* entry = new_entry(hashValue, sym); |
| add_entry(index, entry); |
| cp->symbol_at_put(cp_indices[i], sym); |
| } |
| } |
| return true; |
| } |
| |
| |
| void SymbolTable::verify() { |
| for (int i = 0; i < the_table()->table_size(); ++i) { |
| HashtableEntry<Symbol*, mtSymbol>* p = the_table()->bucket(i); |
| for ( ; p != NULL; p = p->next()) { |
| Symbol* s = (Symbol*)(p->literal()); |
| guarantee(s != NULL, "symbol is NULL"); |
| unsigned int h = hash_symbol((char*)s->bytes(), s->utf8_length()); |
| guarantee(p->hash() == h, "broken hash in symbol table entry"); |
| guarantee(the_table()->hash_to_index(h) == i, |
| "wrong index in symbol table"); |
| } |
| } |
| } |
| |
| void SymbolTable::dump(outputStream* st, bool verbose) { |
| if (!verbose) { |
| the_table()->dump_table(st, "SymbolTable"); |
| } else { |
| st->print_cr("VERSION: 1.0"); |
| for (int i = 0; i < the_table()->table_size(); ++i) { |
| HashtableEntry<Symbol*, mtSymbol>* p = the_table()->bucket(i); |
| for ( ; p != NULL; p = p->next()) { |
| Symbol* s = (Symbol*)(p->literal()); |
| const char* utf8_string = (const char*)s->bytes(); |
| int utf8_length = s->utf8_length(); |
| st->print("%d %d: ", utf8_length, s->refcount()); |
| HashtableTextDump::put_utf8(st, utf8_string, utf8_length); |
| st->cr(); |
| } |
| } |
| } |
| } |
| |
| void SymbolTable::serialize(SerializeClosure* soc) { |
| #if INCLUDE_CDS |
| _shared_table.reset(); |
| if (soc->writing()) { |
| int num_buckets = the_table()->number_of_entries() / |
| SharedSymbolTableBucketSize; |
| CompactSymbolTableWriter writer(num_buckets, |
| &MetaspaceShared::stats()->symbol); |
| for (int i = 0; i < the_table()->table_size(); ++i) { |
| HashtableEntry<Symbol*, mtSymbol>* p = the_table()->bucket(i); |
| for ( ; p != NULL; p = p->next()) { |
| Symbol* s = (Symbol*)(p->literal()); |
| unsigned int fixed_hash = hash_shared_symbol((char*)s->bytes(), s->utf8_length()); |
| assert(fixed_hash == p->hash(), "must not rehash during dumping"); |
| writer.add(fixed_hash, s); |
| } |
| } |
| |
| writer.dump(&_shared_table); |
| } |
| |
| _shared_table.set_type(CompactHashtable<Symbol*, char>::_symbol_table); |
| _shared_table.serialize(soc); |
| |
| if (soc->writing()) { |
| // Verify table is correct |
| Symbol* sym = vmSymbols::java_lang_Object(); |
| const char* name = (const char*)sym->bytes(); |
| int len = sym->utf8_length(); |
| unsigned int hash = hash_symbol(name, len); |
| assert(sym == _shared_table.lookup(name, hash, len), "sanity"); |
| |
| // Sanity. Make sure we don't use the shared table at dump time |
| _shared_table.reset(); |
| } |
| #endif |
| } |
| |
| //--------------------------------------------------------------------------- |
| // Non-product code |
| |
| #ifndef PRODUCT |
| |
| void SymbolTable::print_histogram() { |
| MutexLocker ml(SymbolTable_lock); |
| const int results_length = 100; |
| int counts[results_length]; |
| int sizes[results_length]; |
| int i,j; |
| |
| // initialize results to zero |
| for (j = 0; j < results_length; j++) { |
| counts[j] = 0; |
| sizes[j] = 0; |
| } |
| |
| int total_size = 0; |
| int total_count = 0; |
| int total_length = 0; |
| int max_length = 0; |
| int out_of_range_count = 0; |
| int out_of_range_size = 0; |
| for (i = 0; i < the_table()->table_size(); i++) { |
| HashtableEntry<Symbol*, mtSymbol>* p = the_table()->bucket(i); |
| for ( ; p != NULL; p = p->next()) { |
| int size = p->literal()->size(); |
| int len = p->literal()->utf8_length(); |
| if (len < results_length) { |
| counts[len]++; |
| sizes[len] += size; |
| } else { |
| out_of_range_count++; |
| out_of_range_size += size; |
| } |
| total_count++; |
| total_size += size; |
| total_length += len; |
| max_length = MAX2(max_length, len); |
| } |
| } |
| tty->print_cr("Symbol Table Histogram:"); |
| tty->print_cr(" Total number of symbols %7d", total_count); |
| tty->print_cr(" Total size in memory %7dK", |
| (total_size*wordSize)/1024); |
| tty->print_cr(" Total counted %7d", _symbols_counted); |
| tty->print_cr(" Total removed %7d", _symbols_removed); |
| if (_symbols_counted > 0) { |
| tty->print_cr(" Percent removed %3.2f", |
| ((float)_symbols_removed/(float)_symbols_counted)* 100); |
| } |
| tty->print_cr(" Reference counts %7d", Symbol::_total_count); |
| tty->print_cr(" Symbol arena used " SIZE_FORMAT_W(7) "K", arena()->used()/1024); |
| tty->print_cr(" Symbol arena size " SIZE_FORMAT_W(7) "K", arena()->size_in_bytes()/1024); |
| tty->print_cr(" Total symbol length %7d", total_length); |
| tty->print_cr(" Maximum symbol length %7d", max_length); |
| tty->print_cr(" Average symbol length %7.2f", ((float) total_length / (float) total_count)); |
| tty->print_cr(" Symbol length histogram:"); |
| tty->print_cr(" %6s %10s %10s", "Length", "#Symbols", "Size"); |
| for (i = 0; i < results_length; i++) { |
| if (counts[i] > 0) { |
| tty->print_cr(" %6d %10d %10dK", i, counts[i], (sizes[i]*wordSize)/1024); |
| } |
| } |
| tty->print_cr(" >=%6d %10d %10dK\n", results_length, |
| out_of_range_count, (out_of_range_size*wordSize)/1024); |
| } |
| |
| void SymbolTable::print() { |
| for (int i = 0; i < the_table()->table_size(); ++i) { |
| HashtableEntry<Symbol*, mtSymbol>** p = the_table()->bucket_addr(i); |
| HashtableEntry<Symbol*, mtSymbol>* entry = the_table()->bucket(i); |
| if (entry != NULL) { |
| while (entry != NULL) { |
| tty->print(PTR_FORMAT " ", p2i(entry->literal())); |
| entry->literal()->print(); |
| tty->print(" %d", entry->literal()->refcount()); |
| p = entry->next_addr(); |
| entry = (HashtableEntry<Symbol*, mtSymbol>*)HashtableEntry<Symbol*, mtSymbol>::make_ptr(*p); |
| } |
| tty->cr(); |
| } |
| } |
| } |
| #endif // PRODUCT |
| |
| |
| // Utility for dumping symbols |
| SymboltableDCmd::SymboltableDCmd(outputStream* output, bool heap) : |
| DCmdWithParser(output, heap), |
| _verbose("-verbose", "Dump the content of each symbol in the table", |
| "BOOLEAN", false, "false") { |
| _dcmdparser.add_dcmd_option(&_verbose); |
| } |
| |
| void SymboltableDCmd::execute(DCmdSource source, TRAPS) { |
| VM_DumpHashtable dumper(output(), VM_DumpHashtable::DumpSymbols, |
| _verbose.value()); |
| VMThread::execute(&dumper); |
| } |
| |
| int SymboltableDCmd::num_arguments() { |
| ResourceMark rm; |
| SymboltableDCmd* dcmd = new SymboltableDCmd(NULL, false); |
| if (dcmd != NULL) { |
| DCmdMark mark(dcmd); |
| return dcmd->_dcmdparser.num_arguments(); |
| } else { |
| return 0; |
| } |
| } |