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src/share/vm/gc/g1/g1CollectionSet.cpp
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rev 11545 : [mq]: 8159978-collection-set-as-array
rev 11546 : [mq]: 8159978-erikh-review
@@ -28,10 +28,11 @@
#include "gc/g1/g1CollectorState.hpp"
#include "gc/g1/g1Policy.hpp"
#include "gc/g1/heapRegion.inline.hpp"
#include "gc/g1/heapRegionRemSet.hpp"
#include "gc/g1/heapRegionSet.hpp"
+#include "logging/logStream.hpp"
#include "utilities/debug.hpp"
G1CollectorState* G1CollectionSet::collector_state() {
return _g1->collector_state();
}
@@ -53,66 +54,79 @@
_policy(policy),
_cset_chooser(new CollectionSetChooser()),
_eden_region_length(0),
_survivor_region_length(0),
_old_region_length(0),
-
- _head(NULL),
_bytes_used_before(0),
_recorded_rs_lengths(0),
+ _collection_set_regions(NULL),
+ _collection_set_cur_length(0),
+ _collection_set_max_length(0),
// Incremental CSet attributes
_inc_build_state(Inactive),
- _inc_head(NULL),
- _inc_tail(NULL),
_inc_bytes_used_before(0),
_inc_recorded_rs_lengths(0),
_inc_recorded_rs_lengths_diffs(0),
_inc_predicted_elapsed_time_ms(0.0),
- _inc_predicted_elapsed_time_ms_diffs(0.0),
- _inc_region_length(0) {}
+ _inc_predicted_elapsed_time_ms_diffs(0.0) {
+}
G1CollectionSet::~G1CollectionSet() {
+ if (_collection_set_regions != NULL) {
+ FREE_C_HEAP_ARRAY(uint, _collection_set_regions);
+ }
delete _cset_chooser;
}
void G1CollectionSet::init_region_lengths(uint eden_cset_region_length,
uint survivor_cset_region_length) {
+ assert_at_safepoint(true);
+
_eden_region_length = eden_cset_region_length;
_survivor_region_length = survivor_cset_region_length;
- assert(young_region_length() == _inc_region_length, "should match %u == %u", young_region_length(), _inc_region_length);
+ assert((size_t) young_region_length() == _collection_set_cur_length,
+ "Young region length %u should match collection set length " SIZE_FORMAT, young_region_length(), _collection_set_cur_length);
_old_region_length = 0;
}
+void G1CollectionSet::set_max_length(uint max_region_length) {
+ guarantee(_collection_set_regions == NULL, "Must only initialize once.");
+ _collection_set_max_length = max_region_length;
+ _collection_set_regions = NEW_C_HEAP_ARRAY(uint, max_region_length, mtGC);
+}
+
void G1CollectionSet::set_recorded_rs_lengths(size_t rs_lengths) {
_recorded_rs_lengths = rs_lengths;
}
// Add the heap region at the head of the non-incremental collection set
void G1CollectionSet::add_old_region(HeapRegion* hr) {
+ assert_at_safepoint(true);
+
assert(_inc_build_state == Active, "Precondition");
assert(hr->is_old(), "the region should be old");
assert(!hr->in_collection_set(), "should not already be in the CSet");
_g1->register_old_region_with_cset(hr);
- hr->set_next_in_collection_set(_head);
- _head = hr;
+
+ _collection_set_regions[_collection_set_cur_length++] = hr->hrm_index();
+ assert(_collection_set_cur_length <= _collection_set_max_length, "Collection set now larger than maximum size.");
+
_bytes_used_before += hr->used();
size_t rs_length = hr->rem_set()->occupied();
_recorded_rs_lengths += rs_length;
_old_region_length += 1;
}
// Initialize the per-collection-set information
void G1CollectionSet::start_incremental_building() {
+ assert(_collection_set_cur_length == 0, "Collection set must be empty before starting a new collection set.");
assert(_inc_build_state == Inactive, "Precondition");
- _inc_head = NULL;
- _inc_tail = NULL;
_inc_bytes_used_before = 0;
- _inc_region_length = 0;
_inc_recorded_rs_lengths = 0;
_inc_recorded_rs_lengths_diffs = 0;
_inc_predicted_elapsed_time_ms = 0.0;
_inc_predicted_elapsed_time_ms_diffs = 0.0;
@@ -149,10 +163,43 @@
_inc_recorded_rs_lengths_diffs = 0;
_inc_predicted_elapsed_time_ms_diffs = 0.0;
}
+void G1CollectionSet::clear() {
+ assert_at_safepoint(true);
+ _collection_set_cur_length = 0;
+}
+
+void G1CollectionSet::iterate(HeapRegionClosure* cl, bool may_be_aborted) {
+ iterate_from(cl, 0, 1, may_be_aborted);
+}
+
+void G1CollectionSet::iterate_from(HeapRegionClosure* cl, uint worker_id, uint total_workers, bool may_be_aborted) {
+ size_t len = _collection_set_cur_length;
+ OrderAccess::loadload();
+ if (len == 0) {
+ return;
+ }
+ size_t start_pos = (worker_id * len) / total_workers;
+ size_t cur_pos = start_pos;
+
+ do {
+ HeapRegion* r = G1CollectedHeap::heap()->region_at(_collection_set_regions[cur_pos]);
+ bool result = cl->doHeapRegion(r);
+ guarantee(may_be_aborted || !result, "This iteration should not abort.");
+ if (result) {
+ cl->incomplete();
+ return;
+ }
+ cur_pos++;
+ if (cur_pos == len) {
+ cur_pos = 0;
+ }
+ } while (cur_pos != start_pos);
+}
+
void G1CollectionSet::update_young_region_prediction(HeapRegion* hr,
size_t new_rs_length) {
// Update the CSet information that is dependent on the new RS length
assert(hr->is_young(), "Precondition");
assert(!SafepointSynchronize::is_at_safepoint(), "should not be at a safepoint");
@@ -181,12 +228,20 @@
void G1CollectionSet::add_young_region_common(HeapRegion* hr) {
assert(hr->is_young(), "invariant");
assert(_inc_build_state == Active, "Precondition");
- hr->set_young_index_in_cset(_inc_region_length);
- _inc_region_length++;
+ size_t collection_set_length = _collection_set_cur_length;
+ assert(collection_set_length <= INT_MAX, "Collection set is too large with %d entries", (int)collection_set_length);
+ hr->set_young_index_in_cset((int)collection_set_length);
+
+ _collection_set_regions[_collection_set_cur_length] = hr->hrm_index();
+ // Concurrent readers must observe the store of the value in the array before an
+ // update to the length field.
+ OrderAccess::storestore();
+ _collection_set_cur_length++;
+ assert(_collection_set_cur_length <= _collection_set_max_length, "Collection set larger than maximum allowed.");
// This routine is used when:
// * adding survivor regions to the incremental cset at the end of an
// evacuation pause or
// * adding the current allocation region to the incremental cset
@@ -216,74 +271,86 @@
_inc_predicted_elapsed_time_ms += region_elapsed_time_ms;
_inc_bytes_used_before += used_bytes;
assert(!hr->in_collection_set(), "invariant");
_g1->register_young_region_with_cset(hr);
- assert(hr->next_in_collection_set() == NULL, "invariant");
}
-// Add the region at the RHS of the incremental cset
void G1CollectionSet::add_survivor_regions(HeapRegion* hr) {
- // We should only ever be appending survivors at the end of a pause
- assert(hr->is_survivor(), "Logic");
-
- // Do the 'common' stuff
+ assert(hr->is_survivor(), "Must only add survivor regions, but is %s", hr->get_type_str());
add_young_region_common(hr);
-
- // Now add the region at the right hand side
- if (_inc_tail == NULL) {
- assert(_inc_head == NULL, "invariant");
- _inc_head = hr;
- } else {
- _inc_tail->set_next_in_collection_set(hr);
- }
- _inc_tail = hr;
}
-// Add the region to the LHS of the incremental cset
void G1CollectionSet::add_eden_region(HeapRegion* hr) {
- // Survivors should be added to the RHS at the end of a pause
- assert(hr->is_eden(), "Logic");
-
- // Do the 'common' stuff
+ assert(hr->is_eden(), "Must only add eden regions, but is %s", hr->get_type_str());
add_young_region_common(hr);
+}
+
+#ifndef PRODUCT
+bool G1CollectionSet::verify_young_ages() {
+ assert_at_safepoint(true);
+
+ bool ret = true;
+
+ size_t length = _collection_set_cur_length;
+ for (size_t i = 0; i < length; i++) {
+ HeapRegion* curr = G1CollectedHeap::heap()->region_at(_collection_set_regions[i]);
+
+ guarantee(curr->is_young(), "Region must be young but is %s", curr->get_type_str());
+
+ SurvRateGroup* group = curr->surv_rate_group();
+
+ if (group == NULL) {
+ log_error(gc, verify)("## encountered NULL surv_rate_group in young region");
+ ret = false;
+ }
- // Add the region at the left hand side
- hr->set_next_in_collection_set(_inc_head);
- if (_inc_head == NULL) {
- assert(_inc_tail == NULL, "Invariant");
- _inc_tail = hr;
+ if (curr->age_in_surv_rate_group() < 0) {
+ log_error(gc, verify)("## encountered negative age in young region");
+ ret = false;
}
- _inc_head = hr;
+ }
+
+ if (!ret) {
+ LogStreamHandle(Error, gc, verify) log;
+ print(&log);
+ }
+
+ return ret;
}
-#ifndef PRODUCT
-void G1CollectionSet::print(HeapRegion* list_head, outputStream* st) {
- assert(list_head == inc_head() || list_head == head(), "must be");
+class G1PrintCollectionSetClosure : public HeapRegionClosure {
+ outputStream* _st;
+public:
+ G1PrintCollectionSetClosure(outputStream* st) : HeapRegionClosure(), _st(st) { }
- st->print_cr("\nCollection_set:");
- HeapRegion* csr = list_head;
- while (csr != NULL) {
- HeapRegion* next = csr->next_in_collection_set();
- assert(csr->in_collection_set(), "bad CS");
- st->print_cr(" " HR_FORMAT ", P: " PTR_FORMAT "N: " PTR_FORMAT ", age: %4d",
- HR_FORMAT_PARAMS(csr),
- p2i(csr->prev_top_at_mark_start()), p2i(csr->next_top_at_mark_start()),
- csr->age_in_surv_rate_group_cond());
- csr = next;
+ virtual bool doHeapRegion(HeapRegion* r) {
+ assert(r->in_collection_set(), "Region %u should be in collection set", r->hrm_index());
+ _st->print_cr(" " HR_FORMAT ", P: " PTR_FORMAT "N: " PTR_FORMAT ", age: %4d",
+ HR_FORMAT_PARAMS(r),
+ p2i(r->prev_top_at_mark_start()),
+ p2i(r->next_top_at_mark_start()),
+ r->age_in_surv_rate_group_cond());
+ return false;
}
+};
+
+void G1CollectionSet::print(outputStream* st) {
+ st->print_cr("\nCollection_set:");
+
+ G1PrintCollectionSetClosure cl(st);
+ iterate(&cl);
}
#endif // !PRODUCT
double G1CollectionSet::finalize_young_part(double target_pause_time_ms, G1SurvivorRegions* survivors) {
double young_start_time_sec = os::elapsedTime();
finalize_incremental_building();
guarantee(target_pause_time_ms > 0.0,
"target_pause_time_ms = %1.6lf should be positive", target_pause_time_ms);
- guarantee(_head == NULL, "Precondition");
size_t pending_cards = _policy->pending_cards();
double base_time_ms = _policy->predict_base_elapsed_time_ms(pending_cards);
double time_remaining_ms = MAX2(target_pause_time_ms - base_time_ms, 0.0);
@@ -303,11 +370,10 @@
verify_young_cset_indices();
// Clear the fields that point to the survivor list - they are all young now.
survivors->convert_to_eden();
- _head = _inc_head;
_bytes_used_before = _inc_bytes_used_before;
time_remaining_ms = MAX2(time_remaining_ms - _inc_predicted_elapsed_time_ms, 0.0);
log_trace(gc, ergo, cset)("Add young regions to CSet. eden: %u regions, survivors: %u regions, predicted young region time: %1.2fms, target pause time: %1.2fms",
eden_region_length, survivor_region_length, _inc_predicted_elapsed_time_ms, target_pause_time_ms);
@@ -421,23 +487,28 @@
phase_times()->record_non_young_cset_choice_time_ms((non_young_end_time_sec - non_young_start_time_sec) * 1000.0);
}
#ifdef ASSERT
void G1CollectionSet::verify_young_cset_indices() const {
+ assert_at_safepoint(true);
+
ResourceMark rm;
uint* heap_region_indices = NEW_RESOURCE_ARRAY(uint, young_region_length());
for (uint i = 0; i < young_region_length(); ++i) {
heap_region_indices[i] = (uint)-1;
}
- for (HeapRegion* hr = _inc_head; hr != NULL; hr = hr->next_in_collection_set()) {
+ size_t length = _collection_set_cur_length;
+ for (size_t i = 0; i < length; i++) {
+ HeapRegion* hr = G1CollectedHeap::heap()->region_at(_collection_set_regions[i]);
+
const int idx = hr->young_index_in_cset();
- assert(idx > -1, "must be set for all inc cset regions");
- assert((uint)idx < young_region_length(), "young cset index too large");
+ assert(idx > -1, "Young index must be set for all regions in the incremental collection set but is not for region %u.", hr->hrm_index());
+ assert((uint)idx < young_region_length(), "Young cset index too large for region %u", hr->hrm_index());
assert(heap_region_indices[idx] == (uint)-1,
- "index %d used by multiple regions, first use by %u, second by %u",
+ "Index %d used by multiple regions, first use by region %u, second by region %u",
idx, heap_region_indices[idx], hr->hrm_index());
heap_region_indices[idx] = hr->hrm_index();
}
}
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