6935821: G1: threads created during marking do not active their SATB queues
Summary: Newly-created threads always had the active field of their SATB queue initialized to false, even if they were created during marking. As a result, updates from threads created during a marking cycle were never enqueued and never processed. The fix includes remaining a method from active() to is_active() for readability and naming consistency.
Reviewed-by: ysr, johnc
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* under the terms of the GNU General Public License version 2 only, as
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* 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).
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#include "incls/_precompiled.incl"
#include "incls/_g1SATBCardTableModRefBS.cpp.incl"
G1SATBCardTableModRefBS::G1SATBCardTableModRefBS(MemRegion whole_heap,
int max_covered_regions) :
CardTableModRefBSForCTRS(whole_heap, max_covered_regions)
{
_kind = G1SATBCT;
}
void G1SATBCardTableModRefBS::enqueue(oop pre_val) {
assert(pre_val->is_oop_or_null(true), "Error");
if (!JavaThread::satb_mark_queue_set().is_active()) return;
Thread* thr = Thread::current();
if (thr->is_Java_thread()) {
JavaThread* jt = (JavaThread*)thr;
jt->satb_mark_queue().enqueue(pre_val);
} else {
MutexLocker x(Shared_SATB_Q_lock);
JavaThread::satb_mark_queue_set().shared_satb_queue()->enqueue(pre_val);
}
}
// When we know the current java thread:
template <class T> void
G1SATBCardTableModRefBS::write_ref_field_pre_static(T* field,
oop new_val,
JavaThread* jt) {
if (!JavaThread::satb_mark_queue_set().is_active()) return;
T heap_oop = oopDesc::load_heap_oop(field);
if (!oopDesc::is_null(heap_oop)) {
oop pre_val = oopDesc::decode_heap_oop_not_null(heap_oop);
assert(pre_val->is_oop(true /* ignore mark word */), "Error");
jt->satb_mark_queue().enqueue(pre_val);
}
}
template <class T> void
G1SATBCardTableModRefBS::write_ref_array_pre_work(T* dst, int count) {
if (!JavaThread::satb_mark_queue_set().is_active()) return;
T* elem_ptr = dst;
for (int i = 0; i < count; i++, elem_ptr++) {
T heap_oop = oopDesc::load_heap_oop(elem_ptr);
if (!oopDesc::is_null(heap_oop)) {
enqueue(oopDesc::decode_heap_oop_not_null(heap_oop));
}
}
}
G1SATBCardTableLoggingModRefBS::
G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
int max_covered_regions) :
G1SATBCardTableModRefBS(whole_heap, max_covered_regions),
_dcqs(JavaThread::dirty_card_queue_set())
{
_kind = G1SATBCTLogging;
}
void
G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field,
oop new_val) {
jbyte* byte = byte_for(field);
if (*byte != dirty_card) {
*byte = dirty_card;
Thread* thr = Thread::current();
if (thr->is_Java_thread()) {
JavaThread* jt = (JavaThread*)thr;
jt->dirty_card_queue().enqueue(byte);
} else {
MutexLockerEx x(Shared_DirtyCardQ_lock,
Mutex::_no_safepoint_check_flag);
_dcqs.shared_dirty_card_queue()->enqueue(byte);
}
}
}
void
G1SATBCardTableLoggingModRefBS::write_ref_field_static(void* field,
oop new_val) {
uintptr_t field_uint = (uintptr_t)field;
uintptr_t new_val_uint = (uintptr_t)new_val;
uintptr_t comb = field_uint ^ new_val_uint;
comb = comb >> HeapRegion::LogOfHRGrainBytes;
if (comb == 0) return;
if (new_val == NULL) return;
// Otherwise, log it.
G1SATBCardTableLoggingModRefBS* g1_bs =
(G1SATBCardTableLoggingModRefBS*)Universe::heap()->barrier_set();
g1_bs->write_ref_field_work(field, new_val);
}
void
G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) {
jbyte* byte = byte_for(mr.start());
jbyte* last_byte = byte_for(mr.last());
Thread* thr = Thread::current();
if (whole_heap) {
while (byte <= last_byte) {
*byte = dirty_card;
byte++;
}
} else {
// Enqueue if necessary.
if (thr->is_Java_thread()) {
JavaThread* jt = (JavaThread*)thr;
while (byte <= last_byte) {
if (*byte != dirty_card) {
*byte = dirty_card;
jt->dirty_card_queue().enqueue(byte);
}
byte++;
}
} else {
MutexLockerEx x(Shared_DirtyCardQ_lock,
Mutex::_no_safepoint_check_flag);
while (byte <= last_byte) {
if (*byte != dirty_card) {
*byte = dirty_card;
_dcqs.shared_dirty_card_queue()->enqueue(byte);
}
byte++;
}
}
}
}