jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp@e2ed74d2e054 (annotated)

src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp@e2ed74d2e054 (annotated)

src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp

Tue, 19 Aug 2014 02:05:49 -0700

author: poonam
date: Tue, 19 Aug 2014 02:05:49 -0700
changeset 7452: e2ed74d2e054
parent 6680: 78bbf4d43a14
child 6876: 710a3c8b516e
child 6925: 82693fb204a5
permissions: -rw-r--r--

8044406: JVM crash with JDK8 (build 1.8.0-b132) with G1 GC
Summary: Fill the last card that has been allocated into with a dummy object
Reviewed-by: tschatzl, mgerdin

 /*
  * 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"
 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
 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

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp@e2ed74d2e054 (annotated)

src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp