6711316: Open source the Garbage-First garbage collector
Summary: First mercurial integration of the code for the Garbage-First garbage collector.
Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr
/*
* Copyright 2001-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
inline size_t G1RemSet::n_workers() {
if (_g1->workers() != NULL) {
return _g1->workers()->total_workers();
} else {
return 1;
}
}
inline void HRInto_G1RemSet::write_ref_nv(HeapRegion* from, oop* p) {
oop obj = *p;
assert(from != NULL && from->is_in_reserved(p),
"p is not in a from");
HeapRegion* to = _g1->heap_region_containing(obj);
if (from != to && to != NULL) {
if (!to->popular() && !from->is_survivor()) {
#if G1_REM_SET_LOGGING
gclog_or_tty->print_cr("Adding " PTR_FORMAT " (" PTR_FORMAT ") to RS"
" for region [" PTR_FORMAT ", " PTR_FORMAT ")",
p, obj,
to->bottom(), to->end());
#endif
assert(to->rem_set() != NULL, "Need per-region 'into' remsets.");
if (to->rem_set()->add_reference(p)) {
_g1->schedule_popular_region_evac(to);
}
}
}
}
inline void HRInto_G1RemSet::write_ref(HeapRegion* from, oop* p) {
write_ref_nv(from, p);
}
inline bool HRInto_G1RemSet::self_forwarded(oop obj) {
bool result = (obj->is_forwarded() && (obj->forwardee()== obj));
return result;
}
inline void HRInto_G1RemSet::par_write_ref(HeapRegion* from, oop* p, int tid) {
oop obj = *p;
#ifdef ASSERT
// can't do because of races
// assert(obj == NULL || obj->is_oop(), "expected an oop");
// Do the safe subset of is_oop
if (obj != NULL) {
#ifdef CHECK_UNHANDLED_OOPS
oopDesc* o = obj.obj();
#else
oopDesc* o = obj;
#endif // CHECK_UNHANDLED_OOPS
assert((intptr_t)o % MinObjAlignmentInBytes == 0, "not oop aligned");
assert(Universe::heap()->is_in_reserved(obj), "must be in heap");
}
#endif // ASSERT
assert(from == NULL || from->is_in_reserved(p),
"p is not in from");
HeapRegion* to = _g1->heap_region_containing(obj);
// The test below could be optimized by applying a bit op to to and from.
if (to != NULL && from != NULL && from != to) {
if (!to->popular() && !from->is_survivor()) {
#if G1_REM_SET_LOGGING
gclog_or_tty->print_cr("Adding " PTR_FORMAT " (" PTR_FORMAT ") to RS"
" for region [" PTR_FORMAT ", " PTR_FORMAT ")",
p, obj,
to->bottom(), to->end());
#endif
assert(to->rem_set() != NULL, "Need per-region 'into' remsets.");
if (to->rem_set()->add_reference(p, tid)) {
_g1->schedule_popular_region_evac(to);
}
}
// There is a tricky infinite loop if we keep pushing
// self forwarding pointers onto our _new_refs list.
if (_par_traversal_in_progress &&
to->in_collection_set() && !self_forwarded(obj)) {
_new_refs[tid]->push(p);
}
}
}