jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp@2c6ef90f030a (annotated)

src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp@2c6ef90f030a (annotated)

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

Mon, 07 Jul 2014 10:12:40 +0200

author: stefank
date: Mon, 07 Jul 2014 10:12:40 +0200
changeset 6992: 2c6ef90f030a
parent 6932: 828056cf311f
child 6993: 870c03421152
permissions: -rw-r--r--

8049421: G1 Class Unloading after completing a concurrent mark cycle
Reviewed-by: tschatzl, ehelin, brutisso, coleenp, roland, iveresov
Contributed-by: stefan.karlsson@oracle.com, mikael.gerdin@oracle.com

 /*
  * 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), _free(NULL) {
   _top = bottom();
 }
 void G1CodeRootChunk::reset() {
   _next = _prev = NULL;
   _free = NULL;
   _top = bottom();
 }
 void G1CodeRootChunk::nmethods_do(CodeBlobClosure* cl) {
   NmethodOrLink* cur = bottom();
   while (cur != _top) {
     if (is_nmethod(cur)) {
       cl->do_code_blob(cur->_nmethod);
     }
     cur++;
   }
 }
 bool G1CodeRootChunk::remove_lock_free(nmethod* method) {
   NmethodOrLink* cur = bottom();
   for (NmethodOrLink* cur = bottom(); cur != _top; cur++) {
     if (cur->_nmethod == method) {
       bool result = Atomic::cmpxchg_ptr(NULL, &cur->_nmethod, method) == method;
       if (!result) {
         // Someone else cleared out this entry.
         return false;
       }
       // The method was cleared. Time to link it into the free list.
       NmethodOrLink* prev_free;
       do {
         prev_free = (NmethodOrLink*)_free;
         cur->_link = prev_free;
       } while (Atomic::cmpxchg_ptr(cur, &_free, prev_free) != prev_free);
       return true;
     }
   }
   return false;
 }
 G1CodeRootChunkManager::G1CodeRootChunkManager() : _free_list(), _num_chunks_handed_out(0) {
   _free_list.initialize();
   _free_list.set_size(G1CodeRootChunk::word_size());
 }
 size_t G1CodeRootChunkManager::fl_mem_size() {
   return _free_list.count() * _free_list.size();
 }
 void G1CodeRootChunkManager::free_all_chunks(FreeList<G1CodeRootChunk>* list) {
   _num_chunks_handed_out -= list->count();
   _free_list.prepend(list);
 }
 void G1CodeRootChunkManager::free_chunk(G1CodeRootChunk* chunk) {
   _free_list.return_chunk_at_head(chunk);
   _num_chunks_handed_out--;
 }
 void G1CodeRootChunkManager::purge_chunks(size_t keep_ratio) {
   size_t keep = _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 G1CodeRootChunkManager::static_mem_size() {
   return sizeof(G1CodeRootChunkManager);
 }
 G1CodeRootChunk* G1CodeRootChunkManager::new_chunk() {
   G1CodeRootChunk* result = _free_list.get_chunk_at_head();
   if (result == NULL) {
     result = new G1CodeRootChunk();
   }
   _num_chunks_handed_out++;
   result->reset();
   return result;
 }
 #ifndef PRODUCT
 size_t G1CodeRootChunkManager::num_chunks_handed_out() const {
   return _num_chunks_handed_out;
 }
 size_t G1CodeRootChunkManager::num_free_chunks() const {
   return (size_t)_free_list.count();
 }
 #endif
 G1CodeRootChunkManager G1CodeRootSet::_default_chunk_manager;
 void G1CodeRootSet::purge_chunks(size_t keep_ratio) {
   _default_chunk_manager.purge_chunks(keep_ratio);
 }
 size_t G1CodeRootSet::free_chunks_static_mem_size() {
   return _default_chunk_manager.static_mem_size();
 }
 size_t G1CodeRootSet::free_chunks_mem_size() {
   return _default_chunk_manager.fl_mem_size();
 }
 G1CodeRootSet::G1CodeRootSet(G1CodeRootChunkManager* manager) : _manager(manager), _list(), _length(0) {
   if (_manager == NULL) {
     _manager = &_default_chunk_manager;
   }
   _list.initialize();
   _list.set_size(G1CodeRootChunk::word_size());
 }
 G1CodeRootSet::~G1CodeRootSet() {
   clear();
 }
 void G1CodeRootSet::add(nmethod* method) {
   if (!contains(method)) {
     // Find the first chunk thatisn't full.
     G1CodeRootChunk* cur = _list.head();
     while (cur != NULL) {
       if (!cur->is_full()) {
         break;
       }
       cur = cur->next();
     }
     // All chunks are full, get a new chunk.
     if (cur == NULL) {
       cur = new_chunk();
       _list.return_chunk_at_head(cur);
     }
     // Add the nmethod.
     bool result = cur->add(method);
     guarantee(result, err_msg("Not able to add nmethod "PTR_FORMAT" to newly allocated chunk.", method));
     _length++;
   }
 }
 void G1CodeRootSet::remove_lock_free(nmethod* method) {
   G1CodeRootChunk* found = find(method);
   if (found != NULL) {
     bool result = found->remove_lock_free(method);
     if (result) {
       Atomic::dec_ptr((volatile intptr_t*)&_length);
     }
   }
   assert(!contains(method), err_msg(PTR_FORMAT" still contains nmethod "PTR_FORMAT, this, method));
 }
 nmethod* G1CodeRootSet::pop() {
   while (true) {
     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());
     }
   }
 }
 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::static_mem_size() {
   return sizeof(G1CodeRootSet);
 }
 size_t G1CodeRootSet::mem_size() {
   return G1CodeRootSet::static_mem_size() + _list.count() * _list.size();
 }
 #ifndef PRODUCT
 void G1CodeRootSet::test() {
   G1CodeRootChunkManager mgr;
   assert(mgr.num_chunks_handed_out() == 0, "Must not have handed out chunks yet");
   assert(G1CodeRootChunkManager::static_mem_size() > sizeof(void*),
          err_msg("The chunk manager's static memory usage seems too small, is only "SIZE_FORMAT" bytes.", G1CodeRootChunkManager::static_mem_size()));
   // The number of chunks that we allocate for purge testing.
   size_t const num_chunks = 10;
   {
     G1CodeRootSet set1(&mgr);
     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 seems too small, is only "SIZE_FORMAT" bytes", G1CodeRootSet::static_mem_size()));
     set1.add((nmethod*)1);
     assert(mgr.num_chunks_handed_out() == 1,
            err_msg("Must have allocated and handed out one chunk, but handed out "
                    SIZE_FORMAT" chunks", mgr.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(mgr.num_chunks_handed_out() == 1,
            err_msg("Duplicate detection must have prevented allocation of further "
                    "chunks but allocated "SIZE_FORMAT, mgr.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*)(uintptr_t)(2 + i));
     }
     assert(mgr.num_chunks_handed_out() > 1,
            "After adding more code roots, more than one additional chunk 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(mgr.num_chunks_handed_out() == 0,
            err_msg("After popping all elements, all chunks must have been returned "
                    "but there are still "SIZE_FORMAT" additional", mgr.num_chunks_handed_out()));
     mgr.purge_chunks(0);
     assert(mgr.num_free_chunks() == 0,
            err_msg("After purging everything, the free list must be empty but still "
                    "contains "SIZE_FORMAT" chunks", mgr.num_free_chunks()));
     // Add some more handed out chunks.
     size_t i = 0;
     while (mgr.num_chunks_handed_out() < num_chunks) {
       set1.add((nmethod*)i);
       i++;
     }
     {
       // Generate chunks on the free list.
       G1CodeRootSet set2(&mgr);
       size_t i = 0;
       while (mgr.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(mgr.num_chunks_handed_out() == num_chunks,
            err_msg("Deletion of the second set must have resulted in giving back "
                    "those, but there are still "SIZE_FORMAT" additional handed out, expecting "
                    SIZE_FORMAT, mgr.num_chunks_handed_out(), num_chunks));
     assert(mgr.num_free_chunks() == num_chunks,
            err_msg("After freeing "SIZE_FORMAT" chunks, they must be on the free list "
                    "but there are only "SIZE_FORMAT, num_chunks, mgr.num_free_chunks()));
     size_t const test_percentage = 50;
     mgr.purge_chunks(test_percentage);
     assert(mgr.num_chunks_handed_out() == num_chunks,
            err_msg("Purging must not hand out chunks but there are "SIZE_FORMAT,
                    mgr.num_chunks_handed_out()));
     assert(mgr.num_free_chunks() == (size_t)(mgr.num_chunks_handed_out() * test_percentage / 100),
            err_msg("Must have purged "SIZE_FORMAT" percent of "SIZE_FORMAT" chunks"
                    "but there are "SIZE_FORMAT, test_percentage, num_chunks,
                    mgr.num_free_chunks()));
     // Purge the remainder of the chunks on the free list.
     mgr.purge_chunks(0);
     assert(mgr.num_free_chunks() == 0, "Free List must be empty");
     assert(mgr.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, mgr.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(mgr.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", mgr.num_chunks_handed_out()));
   assert(mgr.num_free_chunks() == num_chunks,
          err_msg("After freeing "SIZE_FORMAT" chunks, they must be on the free list "
                  "but there are only "SIZE_FORMAT, num_chunks, mgr.num_free_chunks()));
   // Restore initial state.
   mgr.purge_chunks(0);
   assert(mgr.num_free_chunks() == 0, "Free List must be empty");
   assert(mgr.num_chunks_handed_out() == 0, "No additional 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@2c6ef90f030a (annotated)

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