596 p2i(_EntryList));
597
598 if (obj != NULL) {
599 if (log_is_enabled(Trace, monitorinflation)) {
600 ResourceMark rm;
601 log_trace(monitorinflation)("deflate_monitor: object=" INTPTR_FORMAT
602 ", mark=" INTPTR_FORMAT ", type='%s'",
603 p2i(obj), obj->mark().value(),
604 obj->klass()->external_name());
605 }
606
607 // Install the old mark word if nobody else has already done it.
608 install_displaced_markword_in_object(obj);
609 }
610
611 // We leave owner == DEFLATER_MARKER and contentions < 0
612 // to force any racing threads to retry.
613 return true; // Success, ObjectMonitor has been deflated.
614 }
615
616 // Install the displaced mark word (dmw) of a deflating ObjectMonitor
617 // into the header of the object associated with the monitor. This
618 // idempotent method is called by a thread that is deflating a
619 // monitor and by other threads that have detected a race with the
620 // deflation process.
621 void ObjectMonitor::install_displaced_markword_in_object(const oop obj) {
622 // This function must only be called when (owner == DEFLATER_MARKER
623 // && contentions <= 0), but we can't guarantee that here because
624 // those values could change when the ObjectMonitor gets moved from
625 // the global free list to a per-thread free list.
626
627 guarantee(obj != NULL, "must be non-NULL");
628
629 // Separate loads in is_being_async_deflated(), which is almost always
630 // called before this function, from the load of dmw/header below.
631
632 // _contentions and dmw/header may get written by different threads.
633 // Make sure to observe them in the same order when having several observers.
634 OrderAccess::loadload_for_IRIW();
635
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596 p2i(_EntryList));
597
598 if (obj != NULL) {
599 if (log_is_enabled(Trace, monitorinflation)) {
600 ResourceMark rm;
601 log_trace(monitorinflation)("deflate_monitor: object=" INTPTR_FORMAT
602 ", mark=" INTPTR_FORMAT ", type='%s'",
603 p2i(obj), obj->mark().value(),
604 obj->klass()->external_name());
605 }
606
607 // Install the old mark word if nobody else has already done it.
608 install_displaced_markword_in_object(obj);
609 }
610
611 // We leave owner == DEFLATER_MARKER and contentions < 0
612 // to force any racing threads to retry.
613 return true; // Success, ObjectMonitor has been deflated.
614 }
615
616 // We might access the dead object headers for parsable heap walk, make sure
617 // headers are in correct shape, e.g. monitors deflated.
618 void ObjectMonitor::maybe_deflate_dead(oop* p) {
619 oop obj = *p;
620 assert(obj != NULL, "must not yet been cleared");
621 markWord mark = obj->mark();
622 if (mark.has_monitor()) {
623 ObjectMonitor* monitor = mark.monitor();
624 if (p == monitor->_object.ptr_raw()) {
625 assert(monitor->object_peek() == obj, "lock object must match");
626 markWord dmw = monitor->header();
627 obj->set_mark(dmw);
628 }
629 }
630 }
631
632 // Install the displaced mark word (dmw) of a deflating ObjectMonitor
633 // into the header of the object associated with the monitor. This
634 // idempotent method is called by a thread that is deflating a
635 // monitor and by other threads that have detected a race with the
636 // deflation process.
637 void ObjectMonitor::install_displaced_markword_in_object(const oop obj) {
638 // This function must only be called when (owner == DEFLATER_MARKER
639 // && contentions <= 0), but we can't guarantee that here because
640 // those values could change when the ObjectMonitor gets moved from
641 // the global free list to a per-thread free list.
642
643 guarantee(obj != NULL, "must be non-NULL");
644
645 // Separate loads in is_being_async_deflated(), which is almost always
646 // called before this function, from the load of dmw/header below.
647
648 // _contentions and dmw/header may get written by different threads.
649 // Make sure to observe them in the same order when having several observers.
650 OrderAccess::loadload_for_IRIW();
651
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