--- old/src/share/vm/classfile/dictionary.cpp 2013-09-25 14:45:11.144642571 +0200 +++ new/src/share/vm/classfile/dictionary.cpp 2013-09-25 14:45:11.080642572 +0200 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2003, 2013, 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 @@ -38,17 +38,21 @@ : TwoOopHashtable(table_size, sizeof(DictionaryEntry)) { _current_class_index = 0; _current_class_entry = NULL; + _pd_cache_table = new ProtectionDomainCacheTable(ProtectionDomainCacheSize); }; - Dictionary::Dictionary(int table_size, HashtableBucket* t, int number_of_entries) : TwoOopHashtable(table_size, sizeof(DictionaryEntry), t, number_of_entries) { _current_class_index = 0; _current_class_entry = NULL; + _pd_cache_table = new ProtectionDomainCacheTable(ProtectionDomainCacheSize); }; +ProtectionDomainCacheEntry* Dictionary::cache_get(oop protection_domain) { + return _pd_cache_table->get(protection_domain); +} DictionaryEntry* Dictionary::new_entry(unsigned int hash, Klass* klass, ClassLoaderData* loader_data) { @@ -65,6 +69,10 @@ while (entry->pd_set() != NULL) { ProtectionDomainEntry* to_delete = entry->pd_set(); entry->set_pd_set(to_delete->next()); + ProtectionDomainCacheEntry* cache = to_delete->release_pd_cache(); + if (cache != NULL) { + _pd_cache_table->free(cache); + } delete to_delete; } Hashtable::free_entry(entry); @@ -105,11 +113,12 @@ } -void DictionaryEntry::add_protection_domain(oop protection_domain) { +void DictionaryEntry::add_protection_domain(Dictionary* dict, oop protection_domain) { assert_locked_or_safepoint(SystemDictionary_lock); if (!contains_protection_domain(protection_domain)) { + ProtectionDomainCacheEntry* entry = dict->cache_get(protection_domain); ProtectionDomainEntry* new_head = - new ProtectionDomainEntry(protection_domain, _pd_set); + new ProtectionDomainEntry(entry, _pd_set); // Warning: Preserve store ordering. The SystemDictionary is read // without locks. The new ProtectionDomainEntry must be // complete before other threads can be allowed to see it @@ -193,7 +202,10 @@ void Dictionary::always_strong_oops_do(OopClosure* blk) { - // Follow all system classes and temporary placeholders in dictionary + // Follow all system classes and temporary placeholders in dictionary; only + // protection domain oops contain references into the heap. In a first + // pass over the system dictionary determine which need to be treated as + // strongly reachable and mark them as such. for (int index = 0; index < table_size(); index++) { for (DictionaryEntry *probe = bucket(index); probe != NULL; @@ -201,10 +213,13 @@ Klass* e = probe->klass(); ClassLoaderData* loader_data = probe->loader_data(); if (is_strongly_reachable(loader_data, e)) { - probe->protection_domain_set_oops_do(blk); + probe->set_strongly_reachable(); } } } + // then iterate over the protection domain cache to apply the closure on the + // previously marked ones. + _pd_cache_table->always_strong_oops_do(blk); } @@ -266,18 +281,12 @@ } } - void Dictionary::oops_do(OopClosure* f) { - for (int index = 0; index < table_size(); index++) { - for (DictionaryEntry* probe = bucket(index); - probe != NULL; - probe = probe->next()) { - probe->protection_domain_set_oops_do(f); - } - } + // only the protection domain oops contain references into the heap. Iterate + // over all of them. + _pd_cache_table->oops_do(f); } - void Dictionary::methods_do(void f(Method*)) { for (int index = 0; index < table_size(); index++) { for (DictionaryEntry* probe = bucket(index); @@ -292,7 +301,6 @@ } } - Klass* Dictionary::try_get_next_class() { while (true) { if (_current_class_entry != NULL) { @@ -306,7 +314,6 @@ // never reached } - // Add a loaded class to the system dictionary. // Readers of the SystemDictionary aren't always locked, so _buckets // is volatile. The store of the next field in the constructor is @@ -396,7 +403,7 @@ assert(protection_domain() != NULL, "real protection domain should be present"); - entry->add_protection_domain(protection_domain()); + entry->add_protection_domain(this, protection_domain()); assert(entry->contains_protection_domain(protection_domain()), "now protection domain should be present"); @@ -446,6 +453,130 @@ } } +ProtectionDomainCacheTable::ProtectionDomainCacheTable(int table_size) + : Hashtable(table_size, sizeof(ProtectionDomainCacheEntry)) +{ +} + +void ProtectionDomainCacheTable::oops_do(OopClosure* f) { + for (int index = 0; index < table_size(); index++) { + for (ProtectionDomainCacheEntry* probe = bucket(index); + probe != NULL; + probe = probe->next()) { + probe->oops_do(f); + } + } +} + +uint ProtectionDomainCacheTable::bucket_size() { + return sizeof(ProtectionDomainCacheEntry); +} + +#ifndef PRODUCT +void ProtectionDomainCacheTable::print() { + tty->print_cr("Protection domain cache table (table_size=%d, classes=%d)", + table_size(), number_of_entries()); + for (int index = 0; index < table_size(); index++) { + for (ProtectionDomainCacheEntry* probe = bucket(index); + probe != NULL; + probe = probe->next()) { + probe->print(); + } + } +} + +void ProtectionDomainCacheEntry::print() { + tty->print_cr("entry "PTR_FORMAT" value "PTR_FORMAT" refcount %d strongly_reachable %d next "PTR_FORMAT, + this, literal(), refcount(), _strongly_reachable, next()); +} +#endif + +void ProtectionDomainCacheTable::verify() { + int element_count = 0; + for (int index = 0; index < table_size(); index++) { + for (ProtectionDomainCacheEntry* probe = bucket(index); + probe != NULL; + probe = probe->next()) { + probe->verify(); + element_count++; + } + } + guarantee(number_of_entries() == element_count, + "Verify of protection domain cache table failed"); + debug_only(verify_lookup_length((double)number_of_entries() / table_size())); +} + +void ProtectionDomainCacheEntry::verify() { + guarantee(literal()->is_oop(), "must be an oop"); + guarantee(_refcount >= 0, "must be"); +} + +void ProtectionDomainCacheTable::always_strong_oops_do(OopClosure* f) { + // the caller marked the protection domain cache entries that we need to apply + // the closure on. Only process them. + for (int index = 0; index < table_size(); index++) { + for (ProtectionDomainCacheEntry* probe = bucket(index); + probe != NULL; + probe = probe->next()) { + if (probe->is_strongly_reachable()) { + probe->reset_strongly_reachable(); + probe->oops_do(f); + } + } + } +} + +ProtectionDomainCacheEntry* ProtectionDomainCacheTable::get(oop protection_domain) { + unsigned int hash = compute_hash(protection_domain); + int index = hash_to_index(hash); + + ProtectionDomainCacheEntry* entry = find_entry(index, protection_domain); + if (entry == NULL) { + entry = add_entry(index, hash, protection_domain); + } + return entry; +} + +ProtectionDomainCacheEntry* ProtectionDomainCacheTable::find_entry(int index, oop protection_domain) { + for (ProtectionDomainCacheEntry* e = bucket(index); e != NULL; e = e->next()) { + if (e->protection_domain() == protection_domain) { + return e; + } + } + + return NULL; +} + +ProtectionDomainCacheEntry* ProtectionDomainCacheTable::add_entry(int index, unsigned int hash, oop protection_domain) { + assert_locked_or_safepoint(SystemDictionary_lock); + assert(index == index_for(protection_domain), "incorrect index?"); + assert(find_entry(index, protection_domain) == NULL, "no double entry"); + + ProtectionDomainCacheEntry* p = new_entry(hash, protection_domain); + Hashtable::add_entry(index, p); + return p; +} + +void ProtectionDomainCacheTable::free(ProtectionDomainCacheEntry* to_delete) { + unsigned int hash = compute_hash(to_delete->protection_domain()); + int index = hash_to_index(hash); + + ProtectionDomainCacheEntry** p = bucket_addr(index); + ProtectionDomainCacheEntry* entry = bucket(index); + while (true) { + assert(entry != NULL, "sanity"); + + if (entry == to_delete) { + *p = entry->next(); + Hashtable::free_entry(entry); + break; + } else { + p = entry->next_addr(); + entry = *p; + } + } +} + SymbolPropertyTable::SymbolPropertyTable(int table_size) : Hashtable(table_size, sizeof(SymbolPropertyEntry)) { @@ -532,11 +663,12 @@ tty->cr(); } } + tty->cr(); + _pd_cache_table->print(); } #endif - void Dictionary::verify() { guarantee(number_of_entries() >= 0, "Verify of system dictionary failed"); @@ -563,5 +695,7 @@ guarantee(number_of_entries() == element_count, "Verify of system dictionary failed"); debug_only(verify_lookup_length((double)number_of_entries() / table_size())); + + _pd_cache_table->verify(); }