--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/serial/tenuredGeneration.cpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,293 @@
+/*
+ * Copyright (c) 2001, 2015, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc/serial/genMarkSweep.hpp"
+#include "gc/serial/tenuredGeneration.inline.hpp"
+#include "gc/shared/blockOffsetTable.inline.hpp"
+#include "gc/shared/cardGeneration.inline.hpp"
+#include "gc/shared/collectorCounters.hpp"
+#include "gc/shared/gcTimer.hpp"
+#include "gc/shared/gcTrace.hpp"
+#include "gc/shared/genOopClosures.inline.hpp"
+#include "gc/shared/generationSpec.hpp"
+#include "gc/shared/space.hpp"
+#include "logging/log.hpp"
+#include "memory/allocation.inline.hpp"
+#include "oops/oop.inline.hpp"
+#include "runtime/java.hpp"
+#include "utilities/macros.hpp"
+#if INCLUDE_ALL_GCS
+#include "gc/cms/parOopClosures.hpp"
+#endif
+
+TenuredGeneration::TenuredGeneration(ReservedSpace rs,
+ size_t initial_byte_size,
+ CardTableRS* remset) :
+ CardGeneration(rs, initial_byte_size, remset)
+{
+ HeapWord* bottom = (HeapWord*) _virtual_space.low();
+ HeapWord* end = (HeapWord*) _virtual_space.high();
+ _the_space = new TenuredSpace(_bts, MemRegion(bottom, end));
+ _the_space->reset_saved_mark();
+ _shrink_factor = 0;
+ _capacity_at_prologue = 0;
+
+ _gc_stats = new GCStats();
+
+ // initialize performance counters
+
+ const char* gen_name = "old";
+ GenCollectorPolicy* gcp = GenCollectedHeap::heap()->gen_policy();
+ // Generation Counters -- generation 1, 1 subspace
+ _gen_counters = new GenerationCounters(gen_name, 1, 1,
+ gcp->min_old_size(), gcp->max_old_size(), &_virtual_space);
+
+ _gc_counters = new CollectorCounters("MSC", 1);
+
+ _space_counters = new CSpaceCounters(gen_name, 0,
+ _virtual_space.reserved_size(),
+ _the_space, _gen_counters);
+}
+
+void TenuredGeneration::gc_prologue(bool full) {
+ _capacity_at_prologue = capacity();
+ _used_at_prologue = used();
+}
+
+bool TenuredGeneration::should_collect(bool full,
+ size_t size,
+ bool is_tlab) {
+ // This should be one big conditional or (||), but I want to be able to tell
+ // why it returns what it returns (without re-evaluating the conditionals
+ // in case they aren't idempotent), so I'm doing it this way.
+ // DeMorgan says it's okay.
+ if (full) {
+ log_trace(gc)("TenuredGeneration::should_collect: because full");
+ return true;
+ }
+ if (should_allocate(size, is_tlab)) {
+ log_trace(gc)("TenuredGeneration::should_collect: because should_allocate(" SIZE_FORMAT ")", size);
+ return true;
+ }
+ // If we don't have very much free space.
+ // XXX: 10000 should be a percentage of the capacity!!!
+ if (free() < 10000) {
+ log_trace(gc)("TenuredGeneration::should_collect: because free(): " SIZE_FORMAT, free());
+ return true;
+ }
+ // If we had to expand to accommodate promotions from the young generation
+ if (_capacity_at_prologue < capacity()) {
+ log_trace(gc)("TenuredGeneration::should_collect: because_capacity_at_prologue: " SIZE_FORMAT " < capacity(): " SIZE_FORMAT,
+ _capacity_at_prologue, capacity());
+ return true;
+ }
+
+ return false;
+}
+
+void TenuredGeneration::compute_new_size() {
+ assert_locked_or_safepoint(Heap_lock);
+
+ // Compute some numbers about the state of the heap.
+ const size_t used_after_gc = used();
+ const size_t capacity_after_gc = capacity();
+
+ CardGeneration::compute_new_size();
+
+ assert(used() == used_after_gc && used_after_gc <= capacity(),
+ "used: " SIZE_FORMAT " used_after_gc: " SIZE_FORMAT
+ " capacity: " SIZE_FORMAT, used(), used_after_gc, capacity());
+}
+
+void TenuredGeneration::update_gc_stats(Generation* current_generation,
+ bool full) {
+ // If the young generation has been collected, gather any statistics
+ // that are of interest at this point.
+ bool current_is_young = GenCollectedHeap::heap()->is_young_gen(current_generation);
+ if (!full && current_is_young) {
+ // Calculate size of data promoted from the young generation
+ // before doing the collection.
+ size_t used_before_gc = used();
+
+ // If the young gen collection was skipped, then the
+ // number of promoted bytes will be 0 and adding it to the
+ // average will incorrectly lessen the average. It is, however,
+ // also possible that no promotion was needed.
+ if (used_before_gc >= _used_at_prologue) {
+ size_t promoted_in_bytes = used_before_gc - _used_at_prologue;
+ gc_stats()->avg_promoted()->sample(promoted_in_bytes);
+ }
+ }
+}
+
+void TenuredGeneration::update_counters() {
+ if (UsePerfData) {
+ _space_counters->update_all();
+ _gen_counters->update_all();
+ }
+}
+
+bool TenuredGeneration::promotion_attempt_is_safe(size_t max_promotion_in_bytes) const {
+ size_t available = max_contiguous_available();
+ size_t av_promo = (size_t)gc_stats()->avg_promoted()->padded_average();
+ bool res = (available >= av_promo) || (available >= max_promotion_in_bytes);
+
+ log_trace(gc)("Tenured: promo attempt is%s safe: available(" SIZE_FORMAT ") %s av_promo(" SIZE_FORMAT "), max_promo(" SIZE_FORMAT ")",
+ res? "":" not", available, res? ">=":"<", av_promo, max_promotion_in_bytes);
+
+ return res;
+}
+
+void TenuredGeneration::collect(bool full,
+ bool clear_all_soft_refs,
+ size_t size,
+ bool is_tlab) {
+ GenCollectedHeap* gch = GenCollectedHeap::heap();
+
+ // Temporarily expand the span of our ref processor, so
+ // refs discovery is over the entire heap, not just this generation
+ ReferenceProcessorSpanMutator
+ x(ref_processor(), gch->reserved_region());
+
+ STWGCTimer* gc_timer = GenMarkSweep::gc_timer();
+ gc_timer->register_gc_start();
+
+ SerialOldTracer* gc_tracer = GenMarkSweep::gc_tracer();
+ gc_tracer->report_gc_start(gch->gc_cause(), gc_timer->gc_start());
+
+ gch->pre_full_gc_dump(gc_timer);
+
+ GenMarkSweep::invoke_at_safepoint(ref_processor(), clear_all_soft_refs);
+
+ gch->post_full_gc_dump(gc_timer);
+
+ gc_timer->register_gc_end();
+
+ gc_tracer->report_gc_end(gc_timer->gc_end(), gc_timer->time_partitions());
+}
+
+HeapWord*
+TenuredGeneration::expand_and_allocate(size_t word_size,
+ bool is_tlab,
+ bool parallel) {
+ assert(!is_tlab, "TenuredGeneration does not support TLAB allocation");
+ if (parallel) {
+ MutexLocker x(ParGCRareEvent_lock);
+ HeapWord* result = NULL;
+ size_t byte_size = word_size * HeapWordSize;
+ while (true) {
+ expand(byte_size, _min_heap_delta_bytes);
+ if (GCExpandToAllocateDelayMillis > 0) {
+ os::sleep(Thread::current(), GCExpandToAllocateDelayMillis, false);
+ }
+ result = _the_space->par_allocate(word_size);
+ if ( result != NULL) {
+ return result;
+ } else {
+ // If there's not enough expansion space available, give up.
+ if (_virtual_space.uncommitted_size() < byte_size) {
+ return NULL;
+ }
+ // else try again
+ }
+ }
+ } else {
+ expand(word_size*HeapWordSize, _min_heap_delta_bytes);
+ return _the_space->allocate(word_size);
+ }
+}
+
+bool TenuredGeneration::expand(size_t bytes, size_t expand_bytes) {
+ GCMutexLocker x(ExpandHeap_lock);
+ return CardGeneration::expand(bytes, expand_bytes);
+}
+
+size_t TenuredGeneration::unsafe_max_alloc_nogc() const {
+ return _the_space->free();
+}
+
+size_t TenuredGeneration::contiguous_available() const {
+ return _the_space->free() + _virtual_space.uncommitted_size();
+}
+
+void TenuredGeneration::assert_correct_size_change_locking() {
+ assert_locked_or_safepoint(ExpandHeap_lock);
+}
+
+// Currently nothing to do.
+void TenuredGeneration::prepare_for_verify() {}
+
+void TenuredGeneration::object_iterate(ObjectClosure* blk) {
+ _the_space->object_iterate(blk);
+}
+
+void TenuredGeneration::save_marks() {
+ _the_space->set_saved_mark();
+}
+
+void TenuredGeneration::reset_saved_marks() {
+ _the_space->reset_saved_mark();
+}
+
+bool TenuredGeneration::no_allocs_since_save_marks() {
+ return _the_space->saved_mark_at_top();
+}
+
+#define TenuredGen_SINCE_SAVE_MARKS_ITERATE_DEFN(OopClosureType, nv_suffix) \
+ \
+void TenuredGeneration:: \
+oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk) { \
+ blk->set_generation(this); \
+ _the_space->oop_since_save_marks_iterate##nv_suffix(blk); \
+ blk->reset_generation(); \
+ save_marks(); \
+}
+
+ALL_SINCE_SAVE_MARKS_CLOSURES(TenuredGen_SINCE_SAVE_MARKS_ITERATE_DEFN)
+
+#undef TenuredGen_SINCE_SAVE_MARKS_ITERATE_DEFN
+
+void TenuredGeneration::gc_epilogue(bool full) {
+ // update the generation and space performance counters
+ update_counters();
+ if (ZapUnusedHeapArea) {
+ _the_space->check_mangled_unused_area_complete();
+ }
+}
+
+void TenuredGeneration::record_spaces_top() {
+ assert(ZapUnusedHeapArea, "Not mangling unused space");
+ _the_space->set_top_for_allocations();
+}
+
+void TenuredGeneration::verify() {
+ _the_space->verify();
+}
+
+void TenuredGeneration::print_on(outputStream* st) const {
+ Generation::print_on(st);
+ st->print(" the");
+ _the_space->print_on(st);
+}