| /* |
| * Copyright (c) 2014, 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 "code/codeCache.hpp" |
| #include "code/nmethod.hpp" |
| #include "gc_implementation/g1/g1CodeCacheRemSet.hpp" |
| #include "gc_implementation/g1/heapRegion.hpp" |
| #include "memory/heap.hpp" |
| #include "memory/iterator.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "utilities/hashtable.inline.hpp" |
| #include "utilities/stack.inline.hpp" |
| |
| PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC |
| |
| class CodeRootSetTable : public Hashtable<nmethod*, mtGC> { |
| friend class G1CodeRootSetTest; |
| typedef HashtableEntry<nmethod*, mtGC> Entry; |
| |
| static CodeRootSetTable* volatile _purge_list; |
| |
| CodeRootSetTable* _purge_next; |
| |
| unsigned int compute_hash(nmethod* nm) { |
| uintptr_t hash = (uintptr_t)nm; |
| return hash ^ (hash >> 7); // code heap blocks are 128byte aligned |
| } |
| |
| void remove_entry(Entry* e, Entry* previous); |
| Entry* new_entry(nmethod* nm); |
| |
| public: |
| CodeRootSetTable(int size) : Hashtable<nmethod*, mtGC>(size, sizeof(Entry)), _purge_next(NULL) {} |
| ~CodeRootSetTable(); |
| |
| // Needs to be protected locks |
| bool add(nmethod* nm); |
| bool remove(nmethod* nm); |
| |
| // Can be called without locking |
| bool contains(nmethod* nm); |
| |
| int entry_size() const { return BasicHashtable<mtGC>::entry_size(); } |
| |
| void copy_to(CodeRootSetTable* new_table); |
| void nmethods_do(CodeBlobClosure* blk); |
| |
| template<typename CB> |
| int remove_if(CB& should_remove); |
| |
| static void purge_list_append(CodeRootSetTable* tbl); |
| static void purge(); |
| |
| static size_t static_mem_size() { |
| return sizeof(_purge_list); |
| } |
| }; |
| |
| CodeRootSetTable* volatile CodeRootSetTable::_purge_list = NULL; |
| |
| CodeRootSetTable::Entry* CodeRootSetTable::new_entry(nmethod* nm) { |
| unsigned int hash = compute_hash(nm); |
| Entry* entry = (Entry*) new_entry_free_list(); |
| if (entry == NULL) { |
| entry = (Entry*) NEW_C_HEAP_ARRAY2(char, entry_size(), mtGC, CURRENT_PC); |
| } |
| entry->set_next(NULL); |
| entry->set_hash(hash); |
| entry->set_literal(nm); |
| return entry; |
| } |
| |
| void CodeRootSetTable::remove_entry(Entry* e, Entry* previous) { |
| int index = hash_to_index(e->hash()); |
| assert((e == bucket(index)) == (previous == NULL), "if e is the first entry then previous should be null"); |
| |
| if (previous == NULL) { |
| set_entry(index, e->next()); |
| } else { |
| previous->set_next(e->next()); |
| } |
| free_entry(e); |
| } |
| |
| CodeRootSetTable::~CodeRootSetTable() { |
| for (int index = 0; index < table_size(); ++index) { |
| for (Entry* e = bucket(index); e != NULL; ) { |
| Entry* to_remove = e; |
| // read next before freeing. |
| e = e->next(); |
| unlink_entry(to_remove); |
| FREE_C_HEAP_ARRAY(char, to_remove, mtGC); |
| } |
| } |
| assert(number_of_entries() == 0, "should have removed all entries"); |
| free_buckets(); |
| for (BasicHashtableEntry<mtGC>* e = new_entry_free_list(); e != NULL; e = new_entry_free_list()) { |
| FREE_C_HEAP_ARRAY(char, e, mtGC); |
| } |
| } |
| |
| bool CodeRootSetTable::add(nmethod* nm) { |
| if (!contains(nm)) { |
| Entry* e = new_entry(nm); |
| int index = hash_to_index(e->hash()); |
| add_entry(index, e); |
| return true; |
| } |
| return false; |
| } |
| |
| bool CodeRootSetTable::contains(nmethod* nm) { |
| int index = hash_to_index(compute_hash(nm)); |
| for (Entry* e = bucket(index); e != NULL; e = e->next()) { |
| if (e->literal() == nm) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| bool CodeRootSetTable::remove(nmethod* nm) { |
| int index = hash_to_index(compute_hash(nm)); |
| Entry* previous = NULL; |
| for (Entry* e = bucket(index); e != NULL; previous = e, e = e->next()) { |
| if (e->literal() == nm) { |
| remove_entry(e, previous); |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| void CodeRootSetTable::copy_to(CodeRootSetTable* new_table) { |
| for (int index = 0; index < table_size(); ++index) { |
| for (Entry* e = bucket(index); e != NULL; e = e->next()) { |
| new_table->add(e->literal()); |
| } |
| } |
| new_table->copy_freelist(this); |
| } |
| |
| void CodeRootSetTable::nmethods_do(CodeBlobClosure* blk) { |
| for (int index = 0; index < table_size(); ++index) { |
| for (Entry* e = bucket(index); e != NULL; e = e->next()) { |
| blk->do_code_blob(e->literal()); |
| } |
| } |
| } |
| |
| template<typename CB> |
| int CodeRootSetTable::remove_if(CB& should_remove) { |
| int num_removed = 0; |
| for (int index = 0; index < table_size(); ++index) { |
| Entry* previous = NULL; |
| Entry* e = bucket(index); |
| while (e != NULL) { |
| Entry* next = e->next(); |
| if (should_remove(e->literal())) { |
| remove_entry(e, previous); |
| ++num_removed; |
| } else { |
| previous = e; |
| } |
| e = next; |
| } |
| } |
| return num_removed; |
| } |
| |
| G1CodeRootSet::~G1CodeRootSet() { |
| delete _table; |
| } |
| |
| CodeRootSetTable* G1CodeRootSet::load_acquire_table() { |
| return (CodeRootSetTable*) OrderAccess::load_ptr_acquire(&_table); |
| } |
| |
| void G1CodeRootSet::allocate_small_table() { |
| _table = new CodeRootSetTable(SmallSize); |
| } |
| |
| void CodeRootSetTable::purge_list_append(CodeRootSetTable* table) { |
| for (;;) { |
| table->_purge_next = _purge_list; |
| CodeRootSetTable* old = (CodeRootSetTable*) Atomic::cmpxchg_ptr(table, &_purge_list, table->_purge_next); |
| if (old == table->_purge_next) { |
| break; |
| } |
| } |
| } |
| |
| void CodeRootSetTable::purge() { |
| CodeRootSetTable* table = _purge_list; |
| _purge_list = NULL; |
| while (table != NULL) { |
| CodeRootSetTable* to_purge = table; |
| table = table->_purge_next; |
| delete to_purge; |
| } |
| } |
| |
| void G1CodeRootSet::move_to_large() { |
| CodeRootSetTable* temp = new CodeRootSetTable(LargeSize); |
| |
| _table->copy_to(temp); |
| |
| CodeRootSetTable::purge_list_append(_table); |
| |
| OrderAccess::release_store_ptr(&_table, temp); |
| } |
| |
| |
| void G1CodeRootSet::purge() { |
| CodeRootSetTable::purge(); |
| } |
| |
| size_t G1CodeRootSet::static_mem_size() { |
| return CodeRootSetTable::static_mem_size(); |
| } |
| |
| void G1CodeRootSet::add(nmethod* method) { |
| bool added = false; |
| if (is_empty()) { |
| allocate_small_table(); |
| } |
| added = _table->add(method); |
| if (_length == Threshold) { |
| move_to_large(); |
| } |
| if (added) { |
| ++_length; |
| } |
| } |
| |
| bool G1CodeRootSet::remove(nmethod* method) { |
| bool removed = false; |
| if (_table != NULL) { |
| removed = _table->remove(method); |
| } |
| if (removed) { |
| _length--; |
| if (_length == 0) { |
| clear(); |
| } |
| } |
| return removed; |
| } |
| |
| bool G1CodeRootSet::contains(nmethod* method) { |
| CodeRootSetTable* table = load_acquire_table(); |
| if (table != NULL) { |
| return table->contains(method); |
| } |
| return false; |
| } |
| |
| void G1CodeRootSet::clear() { |
| delete _table; |
| _table = NULL; |
| _length = 0; |
| } |
| |
| size_t G1CodeRootSet::mem_size() { |
| return sizeof(*this) + |
| (_table != NULL ? sizeof(CodeRootSetTable) + _table->entry_size() * _length : 0); |
| } |
| |
| void G1CodeRootSet::nmethods_do(CodeBlobClosure* blk) const { |
| if (_table != NULL) { |
| _table->nmethods_do(blk); |
| } |
| } |
| |
| class CleanCallback : public StackObj { |
| class PointsIntoHRDetectionClosure : public OopClosure { |
| HeapRegion* _hr; |
| public: |
| bool _points_into; |
| PointsIntoHRDetectionClosure(HeapRegion* hr) : _hr(hr), _points_into(false) {} |
| |
| void do_oop(narrowOop* o) { |
| do_oop_work(o); |
| } |
| |
| void do_oop(oop* o) { |
| do_oop_work(o); |
| } |
| |
| template <typename T> |
| void do_oop_work(T* p) { |
| if (_hr->is_in(oopDesc::load_decode_heap_oop(p))) { |
| _points_into = true; |
| } |
| } |
| }; |
| |
| PointsIntoHRDetectionClosure _detector; |
| CodeBlobToOopClosure _blobs; |
| |
| public: |
| CleanCallback(HeapRegion* hr) : _detector(hr), _blobs(&_detector, !CodeBlobToOopClosure::FixRelocations) {} |
| |
| bool operator() (nmethod* nm) { |
| _detector._points_into = false; |
| _blobs.do_code_blob(nm); |
| return !_detector._points_into; |
| } |
| }; |
| |
| void G1CodeRootSet::clean(HeapRegion* owner) { |
| CleanCallback should_clean(owner); |
| if (_table != NULL) { |
| int removed = _table->remove_if(should_clean); |
| assert((size_t)removed <= _length, "impossible"); |
| _length -= removed; |
| } |
| if (_length == 0) { |
| clear(); |
| } |
| } |
| |
| #ifndef PRODUCT |
| |
| class G1CodeRootSetTest { |
| public: |
| static void test() { |
| { |
| G1CodeRootSet set1; |
| assert(set1.is_empty(), "Code root set must be initially empty but is not."); |
| |
| assert(G1CodeRootSet::static_mem_size() == sizeof(void*), |
| err_msg("The code root set's static memory usage is incorrect, "SIZE_FORMAT" bytes", G1CodeRootSet::static_mem_size())); |
| |
| set1.add((nmethod*)1); |
| assert(set1.length() == 1, err_msg("Added exactly one element, but set contains " |
| SIZE_FORMAT" elements", set1.length())); |
| |
| const size_t num_to_add = (size_t)G1CodeRootSet::Threshold + 1; |
| |
| for (size_t i = 1; i <= num_to_add; i++) { |
| set1.add((nmethod*)1); |
| } |
| assert(set1.length() == 1, |
| err_msg("Duplicate detection should not have increased the set size but " |
| "is "SIZE_FORMAT, set1.length())); |
| |
| for (size_t i = 2; i <= num_to_add; i++) { |
| set1.add((nmethod*)(uintptr_t)(i)); |
| } |
| assert(set1.length() == num_to_add, |
| err_msg("After adding in total "SIZE_FORMAT" distinct code roots, they " |
| "need to be in the set, but there are only "SIZE_FORMAT, |
| num_to_add, set1.length())); |
| |
| assert(CodeRootSetTable::_purge_list != NULL, "should have grown to large hashtable"); |
| |
| size_t num_popped = 0; |
| for (size_t i = 1; i <= num_to_add; i++) { |
| bool removed = set1.remove((nmethod*)i); |
| if (removed) { |
| num_popped += 1; |
| } else { |
| break; |
| } |
| } |
| assert(num_popped == num_to_add, |
| err_msg("Managed to pop "SIZE_FORMAT" code roots, but only "SIZE_FORMAT" " |
| "were added", num_popped, num_to_add)); |
| assert(CodeRootSetTable::_purge_list != NULL, "should have grown to large hashtable"); |
| |
| G1CodeRootSet::purge(); |
| |
| assert(CodeRootSetTable::_purge_list == NULL, "should have purged old small tables"); |
| |
| } |
| |
| } |
| }; |
| |
| void TestCodeCacheRemSet_test() { |
| G1CodeRootSetTest::test(); |
| } |
| |
| #endif |