--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp Mon Mar 17 10:12:21 2014 +0100
@@ -0,0 +1,317 @@
+/*
+ * 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/nmethod.hpp"
+#include "gc_implementation/g1/g1CodeCacheRemSet.hpp"
+#include "memory/iterator.hpp"
+
+G1CodeRootChunk::G1CodeRootChunk() : _top(NULL), _next(NULL), _prev(NULL) {
+ _top = bottom();
+}
+
+void G1CodeRootChunk::reset() {
+ _next = _prev = NULL;
+ _top = bottom();
+}
+
+void G1CodeRootChunk::nmethods_do(CodeBlobClosure* cl) {
+ nmethod** cur = bottom();
+ while (cur != _top) {
+ cl->do_code_blob(*cur);
+ cur++;
+ }
+}
+
+FreeList<G1CodeRootChunk> G1CodeRootSet::_free_list;
+size_t G1CodeRootSet::_num_chunks_handed_out = 0;
+
+G1CodeRootChunk* G1CodeRootSet::new_chunk() {
+ G1CodeRootChunk* result = _free_list.get_chunk_at_head();
+ if (result == NULL) {
+ result = new G1CodeRootChunk();
+ }
+ G1CodeRootSet::_num_chunks_handed_out++;
+ result->reset();
+ return result;
+}
+
+void G1CodeRootSet::free_chunk(G1CodeRootChunk* chunk) {
+ _free_list.return_chunk_at_head(chunk);
+ G1CodeRootSet::_num_chunks_handed_out--;
+}
+
+void G1CodeRootSet::free_all_chunks(FreeList<G1CodeRootChunk>* list) {
+ G1CodeRootSet::_num_chunks_handed_out -= list->count();
+ _free_list.prepend(list);
+}
+
+void G1CodeRootSet::purge_chunks(size_t keep_ratio) {
+ size_t keep = G1CodeRootSet::_num_chunks_handed_out * keep_ratio / 100;
+
+ if (keep >= (size_t)_free_list.count()) {
+ return;
+ }
+
+ FreeList<G1CodeRootChunk> temp;
+ temp.initialize();
+ temp.set_size(G1CodeRootChunk::word_size());
+
+ _free_list.getFirstNChunksFromList((size_t)_free_list.count() - keep, &temp);
+
+ G1CodeRootChunk* cur = temp.get_chunk_at_head();
+ while (cur != NULL) {
+ delete cur;
+ cur = temp.get_chunk_at_head();
+ }
+}
+
+size_t G1CodeRootSet::static_mem_size() {
+ return sizeof(_free_list) + sizeof(_num_chunks_handed_out);
+}
+
+size_t G1CodeRootSet::fl_mem_size() {
+ return _free_list.count() * _free_list.size();
+}
+
+void G1CodeRootSet::initialize() {
+ _free_list.initialize();
+ _free_list.set_size(G1CodeRootChunk::word_size());
+}
+
+G1CodeRootSet::G1CodeRootSet() : _list(), _length(0) {
+ _list.initialize();
+ _list.set_size(G1CodeRootChunk::word_size());
+}
+
+G1CodeRootSet::~G1CodeRootSet() {
+ clear();
+}
+
+void G1CodeRootSet::add(nmethod* method) {
+ if (!contains(method)) {
+ // Try to add the nmethod. If there is not enough space, get a new chunk.
+ if (_list.head() == NULL || _list.head()->is_full()) {
+ G1CodeRootChunk* cur = new_chunk();
+ _list.return_chunk_at_head(cur);
+ }
+ bool result = _list.head()->add(method);
+ guarantee(result, err_msg("Not able to add nmethod "PTR_FORMAT" to newly allocated chunk.", method));
+ _length++;
+ }
+}
+
+void G1CodeRootSet::remove(nmethod* method) {
+ G1CodeRootChunk* found = find(method);
+ if (found != NULL) {
+ bool result = found->remove(method);
+ guarantee(result, err_msg("could not find nmethod "PTR_FORMAT" during removal although we previously found it", method));
+ // eventually free completely emptied chunk
+ if (found->is_empty()) {
+ _list.remove_chunk(found);
+ free(found);
+ }
+ _length--;
+ }
+ assert(!contains(method), err_msg(PTR_FORMAT" still contains nmethod "PTR_FORMAT, this, method));
+}
+
+nmethod* G1CodeRootSet::pop() {
+ do {
+ G1CodeRootChunk* cur = _list.head();
+ if (cur == NULL) {
+ assert(_length == 0, "when there are no chunks, there should be no elements");
+ return NULL;
+ }
+ nmethod* result = cur->pop();
+ if (result != NULL) {
+ _length--;
+ return result;
+ } else {
+ free(_list.get_chunk_at_head());
+ }
+ } while (true);
+}
+
+G1CodeRootChunk* G1CodeRootSet::find(nmethod* method) {
+ G1CodeRootChunk* cur = _list.head();
+ while (cur != NULL) {
+ if (cur->contains(method)) {
+ return cur;
+ }
+ cur = (G1CodeRootChunk*)cur->next();
+ }
+ return NULL;
+}
+
+void G1CodeRootSet::free(G1CodeRootChunk* chunk) {
+ free_chunk(chunk);
+}
+
+bool G1CodeRootSet::contains(nmethod* method) {
+ return find(method) != NULL;
+}
+
+void G1CodeRootSet::clear() {
+ free_all_chunks(&_list);
+ _length = 0;
+}
+
+void G1CodeRootSet::nmethods_do(CodeBlobClosure* blk) const {
+ G1CodeRootChunk* cur = _list.head();
+ while (cur != NULL) {
+ cur->nmethods_do(blk);
+ cur = (G1CodeRootChunk*)cur->next();
+ }
+}
+
+size_t G1CodeRootSet::mem_size() {
+ return sizeof(this) + _list.count() * _list.size();
+}
+
+#ifndef PRODUCT
+
+void G1CodeRootSet::test() {
+ initialize();
+
+ assert(_free_list.count() == 0, "Free List must be empty");
+ assert(_num_chunks_handed_out == 0, "No elements must have been handed out yet");
+
+ // The number of chunks that we allocate for purge testing.
+ size_t const num_chunks = 10;
+ {
+ G1CodeRootSet set1;
+ assert(set1.is_empty(), "Code root set must be initially empty but is not.");
+
+ set1.add((nmethod*)1);
+ assert(_num_chunks_handed_out == 1,
+ err_msg("Must have allocated and handed out one chunk, but handed out "
+ SIZE_FORMAT" chunks", _num_chunks_handed_out));
+ assert(set1.length() == 1, err_msg("Added exactly one element, but set contains "
+ SIZE_FORMAT" elements", set1.length()));
+
+ // G1CodeRootChunk::word_size() is larger than G1CodeRootChunk::num_entries which
+ // we cannot access.
+ for (uint i = 0; i < G1CodeRootChunk::word_size() + 1; i++) {
+ set1.add((nmethod*)1);
+ }
+ assert(_num_chunks_handed_out == 1,
+ err_msg("Duplicate detection must have prevented allocation of further "
+ "chunks but contains "SIZE_FORMAT, _num_chunks_handed_out));
+ assert(set1.length() == 1,
+ err_msg("Duplicate detection should not have increased the set size but "
+ "is "SIZE_FORMAT, set1.length()));
+
+ size_t num_total_after_add = G1CodeRootChunk::word_size() + 1;
+ for (size_t i = 0; i < num_total_after_add - 1; i++) {
+ set1.add((nmethod*)(2 + i));
+ }
+ assert(_num_chunks_handed_out > 1,
+ "After adding more code roots, more than one chunks should have been handed out");
+ assert(set1.length() == num_total_after_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_total_after_add, set1.length()));
+
+ size_t num_popped = 0;
+ while (set1.pop() != NULL) {
+ num_popped++;
+ }
+ assert(num_popped == num_total_after_add,
+ err_msg("Managed to pop "SIZE_FORMAT" code roots, but only "SIZE_FORMAT" "
+ "were added", num_popped, num_total_after_add));
+ assert(_num_chunks_handed_out == 0,
+ err_msg("After popping all elements, all chunks must have been returned "
+ "but are still "SIZE_FORMAT, _num_chunks_handed_out));
+
+ purge_chunks(0);
+ assert(_free_list.count() == 0,
+ err_msg("After purging everything, the free list must be empty but still "
+ "contains "SIZE_FORMAT" chunks", _free_list.count()));
+
+ // Add some more handed out chunks.
+ size_t i = 0;
+ while (_num_chunks_handed_out < num_chunks) {
+ set1.add((nmethod*)i);
+ i++;
+ }
+
+ {
+ // Generate chunks on the free list.
+ G1CodeRootSet set2;
+ size_t i = 0;
+ while (_num_chunks_handed_out < num_chunks * 2) {
+ set2.add((nmethod*)i);
+ i++;
+ }
+ // Exit of the scope of the set2 object will call the destructor that generates
+ // num_chunks elements on the free list.
+ }
+
+ assert(_num_chunks_handed_out == num_chunks,
+ err_msg("Deletion of the second set must have resulted in giving back "
+ "those, but there is still "SIZE_FORMAT" handed out, expecting "
+ SIZE_FORMAT, _num_chunks_handed_out, num_chunks));
+ assert((size_t)_free_list.count() == num_chunks,
+ err_msg("After freeing "SIZE_FORMAT" chunks, they must be on the free list "
+ "but there are only "SIZE_FORMAT, num_chunks, _free_list.count()));
+
+ size_t const test_percentage = 50;
+ purge_chunks(test_percentage);
+ assert(_num_chunks_handed_out == num_chunks,
+ err_msg("Purging must not hand out chunks but there are "SIZE_FORMAT,
+ _num_chunks_handed_out));
+ assert((size_t)_free_list.count() == (ssize_t)(num_chunks * test_percentage / 100),
+ err_msg("Must have purged "SIZE_FORMAT" percent of "SIZE_FORMAT" chunks"
+ "but there are "SSIZE_FORMAT, test_percentage, num_chunks,
+ _free_list.count()));
+ // Purge the remainder of the chunks on the free list.
+ purge_chunks(0);
+ assert(_free_list.count() == 0, "Free List must be empty");
+ assert(_num_chunks_handed_out == num_chunks,
+ err_msg("Expected to be "SIZE_FORMAT" chunks handed out from the first set "
+ "but there are "SIZE_FORMAT, num_chunks, _num_chunks_handed_out));
+
+ // Exit of the scope of the set1 object will call the destructor that generates
+ // num_chunks additional elements on the free list.
+ }
+
+ assert(_num_chunks_handed_out == 0,
+ err_msg("Deletion of the only set must have resulted in no chunks handed "
+ "out, but there is still "SIZE_FORMAT" handed out", _num_chunks_handed_out));
+ assert((size_t)_free_list.count() == num_chunks,
+ err_msg("After freeing "SIZE_FORMAT" chunks, they must be on the free list "
+ "but there are only "SSIZE_FORMAT, num_chunks, _free_list.count()));
+
+ // Restore initial state.
+ purge_chunks(0);
+ assert(_free_list.count() == 0, "Free List must be empty");
+ assert(_num_chunks_handed_out == 0, "No elements must have been handed out yet");
+}
+
+void TestCodeCacheRemSet_test() {
+ G1CodeRootSet::test();
+}
+#endif