--- a/hotspot/src/share/vm/memory/referenceProcessor.cpp Thu Sep 22 07:18:51 2011 -0400
+++ b/hotspot/src/share/vm/memory/referenceProcessor.cpp Thu Sep 22 10:57:37 2011 -0700
@@ -35,42 +35,8 @@
ReferencePolicy* ReferenceProcessor::_always_clear_soft_ref_policy = NULL;
ReferencePolicy* ReferenceProcessor::_default_soft_ref_policy = NULL;
-const int subclasses_of_ref = REF_PHANTOM - REF_OTHER;
bool ReferenceProcessor::_pending_list_uses_discovered_field = false;
-// List of discovered references.
-class DiscoveredList {
-public:
- DiscoveredList() : _len(0), _compressed_head(0), _oop_head(NULL) { }
- oop head() const {
- return UseCompressedOops ? oopDesc::decode_heap_oop(_compressed_head) :
- _oop_head;
- }
- HeapWord* adr_head() {
- return UseCompressedOops ? (HeapWord*)&_compressed_head :
- (HeapWord*)&_oop_head;
- }
- void set_head(oop o) {
- if (UseCompressedOops) {
- // Must compress the head ptr.
- _compressed_head = oopDesc::encode_heap_oop(o);
- } else {
- _oop_head = o;
- }
- }
- bool empty() const { return head() == NULL; }
- size_t length() { return _len; }
- void set_length(size_t len) { _len = len; }
- void inc_length(size_t inc) { _len += inc; assert(_len > 0, "Error"); }
- void dec_length(size_t dec) { _len -= dec; }
-private:
- // Set value depending on UseCompressedOops. This could be a template class
- // but then we have to fix all the instantiations and declarations that use this class.
- oop _oop_head;
- narrowOop _compressed_head;
- size_t _len;
-};
-
void referenceProcessor_init() {
ReferenceProcessor::init_statics();
}
@@ -112,7 +78,8 @@
_discovery_is_mt = mt_discovery;
_num_q = MAX2(1, mt_processing_degree);
_max_num_q = MAX2(_num_q, mt_discovery_degree);
- _discoveredSoftRefs = NEW_C_HEAP_ARRAY(DiscoveredList, _max_num_q * subclasses_of_ref);
+ _discoveredSoftRefs = NEW_C_HEAP_ARRAY(DiscoveredList,
+ _max_num_q * number_of_subclasses_of_ref());
if (_discoveredSoftRefs == NULL) {
vm_exit_during_initialization("Could not allocated RefProc Array");
}
@@ -120,7 +87,7 @@
_discoveredFinalRefs = &_discoveredWeakRefs[_max_num_q];
_discoveredPhantomRefs = &_discoveredFinalRefs[_max_num_q];
// Initialized all entries to NULL
- for (int i = 0; i < _max_num_q * subclasses_of_ref; i++) {
+ for (int i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
_discoveredSoftRefs[i].set_head(NULL);
_discoveredSoftRefs[i].set_length(0);
}
@@ -134,19 +101,15 @@
#ifndef PRODUCT
void ReferenceProcessor::verify_no_references_recorded() {
guarantee(!_discovering_refs, "Discovering refs?");
- for (int i = 0; i < _max_num_q * subclasses_of_ref; i++) {
- guarantee(_discoveredSoftRefs[i].empty(),
+ for (int i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
+ guarantee(_discoveredSoftRefs[i].is_empty(),
"Found non-empty discovered list");
}
}
#endif
void ReferenceProcessor::weak_oops_do(OopClosure* f) {
- // Should this instead be
- // for (int i = 0; i < subclasses_of_ref; i++_ {
- // for (int j = 0; j < _num_q; j++) {
- // int index = i * _max_num_q + j;
- for (int i = 0; i < _max_num_q * subclasses_of_ref; i++) {
+ for (int i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
if (UseCompressedOops) {
f->do_oop((narrowOop*)_discoveredSoftRefs[i].adr_head());
} else {
@@ -404,7 +367,7 @@
// allocated and are indexed into.
assert(_n_queues == (int) _ref_processor.max_num_q(), "Different number not expected");
for (int j = 0;
- j < subclasses_of_ref;
+ j < ReferenceProcessor::number_of_subclasses_of_ref();
j++, index += _n_queues) {
_ref_processor.enqueue_discovered_reflist(
_refs_lists[index], _pending_list_addr);
@@ -424,7 +387,7 @@
task_executor->execute(tsk);
} else {
// Serial code: call the parent class's implementation
- for (int i = 0; i < _max_num_q * subclasses_of_ref; i++) {
+ for (int i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
enqueue_discovered_reflist(_discoveredSoftRefs[i], pending_list_addr);
_discoveredSoftRefs[i].set_head(NULL);
_discoveredSoftRefs[i].set_length(0);
@@ -432,119 +395,7 @@
}
}
-// Iterator for the list of discovered references.
-class DiscoveredListIterator {
-public:
- inline DiscoveredListIterator(DiscoveredList& refs_list,
- OopClosure* keep_alive,
- BoolObjectClosure* is_alive);
-
- // End Of List.
- inline bool has_next() const { return _ref != NULL; }
-
- // Get oop to the Reference object.
- inline oop obj() const { return _ref; }
-
- // Get oop to the referent object.
- inline oop referent() const { return _referent; }
-
- // Returns true if referent is alive.
- inline bool is_referent_alive() const;
-
- // Loads data for the current reference.
- // The "allow_null_referent" argument tells us to allow for the possibility
- // of a NULL referent in the discovered Reference object. This typically
- // happens in the case of concurrent collectors that may have done the
- // discovery concurrently, or interleaved, with mutator execution.
- inline void load_ptrs(DEBUG_ONLY(bool allow_null_referent));
-
- // Move to the next discovered reference.
- inline void next();
-
- // Remove the current reference from the list
- inline void remove();
-
- // Make the Reference object active again.
- inline void make_active() { java_lang_ref_Reference::set_next(_ref, NULL); }
-
- // Make the referent alive.
- inline void make_referent_alive() {
- if (UseCompressedOops) {
- _keep_alive->do_oop((narrowOop*)_referent_addr);
- } else {
- _keep_alive->do_oop((oop*)_referent_addr);
- }
- }
-
- // Update the discovered field.
- inline void update_discovered() {
- // First _prev_next ref actually points into DiscoveredList (gross).
- if (UseCompressedOops) {
- if (!oopDesc::is_null(*(narrowOop*)_prev_next)) {
- _keep_alive->do_oop((narrowOop*)_prev_next);
- }
- } else {
- if (!oopDesc::is_null(*(oop*)_prev_next)) {
- _keep_alive->do_oop((oop*)_prev_next);
- }
- }
- }
-
- // NULL out referent pointer.
- inline void clear_referent() { oop_store_raw(_referent_addr, NULL); }
-
- // Statistics
- NOT_PRODUCT(
- inline size_t processed() const { return _processed; }
- inline size_t removed() const { return _removed; }
- )
-
- inline void move_to_next();
-
-private:
- DiscoveredList& _refs_list;
- HeapWord* _prev_next;
- oop _prev;
- oop _ref;
- HeapWord* _discovered_addr;
- oop _next;
- HeapWord* _referent_addr;
- oop _referent;
- OopClosure* _keep_alive;
- BoolObjectClosure* _is_alive;
- DEBUG_ONLY(
- oop _first_seen; // cyclic linked list check
- )
- NOT_PRODUCT(
- size_t _processed;
- size_t _removed;
- )
-};
-
-inline DiscoveredListIterator::DiscoveredListIterator(DiscoveredList& refs_list,
- OopClosure* keep_alive,
- BoolObjectClosure* is_alive)
- : _refs_list(refs_list),
- _prev_next(refs_list.adr_head()),
- _prev(NULL),
- _ref(refs_list.head()),
-#ifdef ASSERT
- _first_seen(refs_list.head()),
-#endif
-#ifndef PRODUCT
- _processed(0),
- _removed(0),
-#endif
- _next(NULL),
- _keep_alive(keep_alive),
- _is_alive(is_alive)
-{ }
-
-inline bool DiscoveredListIterator::is_referent_alive() const {
- return _is_alive->do_object_b(_referent);
-}
-
-inline void DiscoveredListIterator::load_ptrs(DEBUG_ONLY(bool allow_null_referent)) {
+void DiscoveredListIterator::load_ptrs(DEBUG_ONLY(bool allow_null_referent)) {
_discovered_addr = java_lang_ref_Reference::discovered_addr(_ref);
oop discovered = java_lang_ref_Reference::discovered(_ref);
assert(_discovered_addr && discovered->is_oop_or_null(),
@@ -560,13 +411,7 @@
"bad referent");
}
-inline void DiscoveredListIterator::next() {
- _prev_next = _discovered_addr;
- _prev = _ref;
- move_to_next();
-}
-
-inline void DiscoveredListIterator::remove() {
+void DiscoveredListIterator::remove() {
assert(_ref->is_oop(), "Dropping a bad reference");
oop_store_raw(_discovered_addr, NULL);
@@ -592,15 +437,29 @@
_refs_list.dec_length(1);
}
-inline void DiscoveredListIterator::move_to_next() {
- if (_ref == _next) {
- // End of the list.
- _ref = NULL;
+// Make the Reference object active again.
+void DiscoveredListIterator::make_active() {
+ // For G1 we don't want to use set_next - it
+ // will dirty the card for the next field of
+ // the reference object and will fail
+ // CT verification.
+ if (UseG1GC) {
+ BarrierSet* bs = oopDesc::bs();
+ HeapWord* next_addr = java_lang_ref_Reference::next_addr(_ref);
+
+ if (UseCompressedOops) {
+ bs->write_ref_field_pre((narrowOop*)next_addr, NULL);
+ } else {
+ bs->write_ref_field_pre((oop*)next_addr, NULL);
+ }
+ java_lang_ref_Reference::set_next_raw(_ref, NULL);
} else {
- _ref = _next;
+ java_lang_ref_Reference::set_next(_ref, NULL);
}
- assert(_ref != _first_seen, "cyclic ref_list found");
- NOT_PRODUCT(_processed++);
+}
+
+void DiscoveredListIterator::clear_referent() {
+ oop_store_raw(_referent_addr, NULL);
}
// NOTE: process_phase*() are largely similar, and at a high level
@@ -786,10 +645,9 @@
void ReferenceProcessor::abandon_partial_discovery() {
// loop over the lists
- for (int i = 0; i < _max_num_q * subclasses_of_ref; i++) {
+ for (int i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
if (TraceReferenceGC && PrintGCDetails && ((i % _max_num_q) == 0)) {
- gclog_or_tty->print_cr("\nAbandoning %s discovered list",
- list_name(i));
+ gclog_or_tty->print_cr("\nAbandoning %s discovered list", list_name(i));
}
abandon_partial_discovered_list(_discoveredSoftRefs[i]);
}
@@ -858,6 +716,14 @@
bool _clear_referent;
};
+void ReferenceProcessor::set_discovered(oop ref, oop value) {
+ if (_discovered_list_needs_barrier) {
+ java_lang_ref_Reference::set_discovered(ref, value);
+ } else {
+ java_lang_ref_Reference::set_discovered_raw(ref, value);
+ }
+}
+
// Balances reference queues.
// Move entries from all queues[0, 1, ..., _max_num_q-1] to
// queues[0, 1, ..., _num_q-1] because only the first _num_q
@@ -915,9 +781,9 @@
// Add the chain to the to list.
if (ref_lists[to_idx].head() == NULL) {
// to list is empty. Make a loop at the end.
- java_lang_ref_Reference::set_discovered(move_tail, move_tail);
+ set_discovered(move_tail, move_tail);
} else {
- java_lang_ref_Reference::set_discovered(move_tail, ref_lists[to_idx].head());
+ set_discovered(move_tail, ref_lists[to_idx].head());
}
ref_lists[to_idx].set_head(move_head);
ref_lists[to_idx].inc_length(refs_to_move);
@@ -1038,11 +904,7 @@
void ReferenceProcessor::clean_up_discovered_references() {
// loop over the lists
- // Should this instead be
- // for (int i = 0; i < subclasses_of_ref; i++_ {
- // for (int j = 0; j < _num_q; j++) {
- // int index = i * _max_num_q + j;
- for (int i = 0; i < _max_num_q * subclasses_of_ref; i++) {
+ for (int i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
if (TraceReferenceGC && PrintGCDetails && ((i % _max_num_q) == 0)) {
gclog_or_tty->print_cr(
"\nScrubbing %s discovered list of Null referents",
@@ -1260,6 +1122,8 @@
}
}
+ ResourceMark rm; // Needed for tracing.
+
HeapWord* const discovered_addr = java_lang_ref_Reference::discovered_addr(obj);
const oop discovered = java_lang_ref_Reference::discovered(obj);
assert(discovered->is_oop_or_null(), "bad discovered field");
@@ -1472,7 +1336,9 @@
}
const char* ReferenceProcessor::list_name(int i) {
- assert(i >= 0 && i <= _max_num_q * subclasses_of_ref, "Out of bounds index");
+ assert(i >= 0 && i <= _max_num_q * number_of_subclasses_of_ref(),
+ "Out of bounds index");
+
int j = i / _max_num_q;
switch (j) {
case 0: return "SoftRef";
@@ -1493,7 +1359,7 @@
#ifndef PRODUCT
void ReferenceProcessor::clear_discovered_references() {
guarantee(!_discovering_refs, "Discovering refs?");
- for (int i = 0; i < _max_num_q * subclasses_of_ref; i++) {
+ for (int i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
clear_discovered_references(_discoveredSoftRefs[i]);
}
}