/*
* Copyright (c) 1998, 2010, 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/oopRecorder.hpp"
#include "memory/allocation.inline.hpp"
#include "oops/oop.inline.hpp"
#ifdef ASSERT
int OopRecorder::_find_index_calls = 0;
int OopRecorder::_hit_indexes = 0;
int OopRecorder::_missed_indexes = 0;
#endif //ASSERT
OopRecorder::OopRecorder(Arena* arena) {
_handles = NULL;
_indexes = NULL;
_arena = arena;
_complete = false;
}
OopRecorder::IndexCache::IndexCache() {
assert(first_index > 0, "initial zero state of cache must be invalid index");
Copy::zero_to_bytes(&_cache[0], sizeof(_cache));
}
int OopRecorder::oop_size() {
_complete = true;
if (_handles == NULL) return 0;
return _handles->length() * sizeof(oop);
}
void OopRecorder::copy_to(nmethod* nm) {
assert(_complete, "must be frozen");
maybe_initialize(); // get non-null handles, even if we have no oops
nm->copy_oops(_handles);
}
void OopRecorder::maybe_initialize() {
if (_handles == NULL) {
if (_arena != NULL) {
_handles = new(_arena) GrowableArray<jobject>(_arena, 10, 0, 0);
_no_finds = new(_arena) GrowableArray<int>( _arena, 10, 0, 0);
} else {
_handles = new GrowableArray<jobject>(10, 0, 0);
_no_finds = new GrowableArray<int>( 10, 0, 0);
}
}
}
jobject OopRecorder::handle_at(int index) {
// there is always a NULL virtually present as first object
if (index == null_index) return NULL;
return _handles->at(index - first_index);
}
// Local definition. Used only in this module.
inline bool OopRecorder::is_real_jobject(jobject h) {
return h != NULL && h != (jobject)Universe::non_oop_word();
}
int OopRecorder::add_handle(jobject h, bool make_findable) {
assert(!_complete, "cannot allocate more elements after size query");
maybe_initialize();
// indexing uses 1 as an origin--0 means null
int index = _handles->length() + first_index;
_handles->append(h);
// Support correct operation of find_index().
assert(!(make_findable && !is_real_jobject(h)), "nulls are not findable");
if (make_findable) {
// This index may be returned from find_index().
if (_indexes != NULL) {
int* cloc = _indexes->cache_location(h);
_indexes->set_cache_location_index(cloc, index);
} else if (index == index_cache_threshold && _arena != NULL) {
_indexes = new(_arena) IndexCache();
for (int i = 0; i < _handles->length(); i++) {
// Load the cache with pre-existing elements.
int index0 = i + first_index;
if (_no_finds->contains(index0)) continue;
int* cloc = _indexes->cache_location(_handles->at(i));
_indexes->set_cache_location_index(cloc, index0);
}
}
} else if (is_real_jobject(h)) {
// Remember that this index is not to be returned from find_index().
// This case is rare, because most or all uses of allocate_index pass
// a jobject argument of NULL or Universe::non_oop_word.
// Thus, the expected length of _no_finds is zero.
_no_finds->append(index);
}
return index;
}
int OopRecorder::maybe_find_index(jobject h) {
debug_only(_find_index_calls++);
assert(!_complete, "cannot allocate more elements after size query");
maybe_initialize();
if (h == NULL) return null_index;
assert(is_real_jobject(h), "must be valid jobject");
int* cloc = (_indexes == NULL)? NULL: _indexes->cache_location(h);
if (cloc != NULL) {
int cindex = _indexes->cache_location_index(cloc);
if (cindex == 0) {
return -1; // We know this handle is completely new.
}
if (cindex >= first_index && _handles->at(cindex - first_index) == h) {
debug_only(_hit_indexes++);
return cindex;
}
if (!_indexes->cache_location_collision(cloc)) {
return -1; // We know the current cache occupant is unique to that cloc.
}
}
// Not found in cache, due to a cache collision. (Or, no cache at all.)
// Do a linear search, most recent to oldest.
for (int i = _handles->length() - 1; i >= 0; i--) {
if (_handles->at(i) == h) {
int findex = i + first_index;
if (_no_finds->contains(findex)) continue; // oops; skip this one
if (cloc != NULL) {
_indexes->set_cache_location_index(cloc, findex);
}
debug_only(_missed_indexes++);
return findex;
}
}
return -1;
}