jdk8-mips64-public/hotspot: comparison src/share/vm/memory/genMarkSweep.cpp

--1:000000000000
+:a61af66fc99e
+/*
+* Copyright 2001-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+* CA 95054 USA or visit www.sun.com if you need additional information or
+* have any questions.
+*
+*/
+#include "incls/_precompiled.incl"
+#include "incls/_genMarkSweep.cpp.incl"
+void GenMarkSweep::invoke_at_safepoint(int level, ReferenceProcessor* rp,
+bool clear_all_softrefs) {
+assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
+// hook up weak ref data so it can be used during Mark-Sweep
+assert(ref_processor() == NULL, "no stomping");
+_ref_processor = rp;
+assert(rp != NULL, "should be non-NULL");
+TraceTime t1("Full GC", PrintGC && !PrintGCDetails, true, gclog_or_tty);
+// When collecting the permanent generation methodOops may be moving,
+// so we either have to flush all bcp data or convert it into bci.
+CodeCache::gc_prologue();
+Threads::gc_prologue();
+// Increment the invocation count for the permanent generation, since it is
+// implicitly collected whenever we do a full mark sweep collection.
+GenCollectedHeap* gch = GenCollectedHeap::heap();
+gch->perm_gen()->stat_record()->invocations++;
+// Capture heap size before collection for printing.
+size_t gch_prev_used = gch->used();
+// Some of the card table updates below assume that the perm gen is
+// also being collected.
+assert(level == gch->n_gens() - 1,
+"All generations are being collected, ergo perm gen too.");
+// Capture used regions for each generation that will be
+// subject to collection, so that card table adjustments can
+// be made intelligently (see clear / invalidate further below).
+gch->save_used_regions(level, true /* perm */);
+allocate_stacks();
+mark_sweep_phase1(level, clear_all_softrefs);
+mark_sweep_phase2();
+// Don't add any more derived pointers during phase3
+COMPILER2_PRESENT(assert(DerivedPointerTable::is_active(), "Sanity"));
+COMPILER2_PRESENT(DerivedPointerTable::set_active(false));
+mark_sweep_phase3(level);
+VALIDATE_MARK_SWEEP_ONLY(
+if (ValidateMarkSweep) {
+guarantee(_root_refs_stack->length() == 0,
+"should be empty by now");
+}
+)
+mark_sweep_phase4();
+VALIDATE_MARK_SWEEP_ONLY(
+if (ValidateMarkSweep) {
+guarantee(_live_oops->length() == _live_oops_moved_to->length(),
+"should be the same size");
+}
+)
+restore_marks();
+// Set saved marks for allocation profiler (and other things? -- dld)
+// (Should this be in general part?)
+gch->save_marks();
+deallocate_stacks();
+// If compaction completely evacuated all generations younger than this
+// one, then we can clear the card table.  Otherwise, we must invalidate
+// it (consider all cards dirty).  In the future, we might consider doing
+// compaction within generations only, and doing card-table sliding.
+bool all_empty = true;
+for (int i = 0; all_empty && i < level; i++) {
+Generation* g = gch->get_gen(i);
+all_empty = all_empty && gch->get_gen(i)->used() == 0;
+}
+GenRemSet* rs = gch->rem_set();
+// Clear/invalidate below make use of the "prev_used_regions" saved earlier.
+if (all_empty) {
+// We've evacuated all generations below us.
+Generation* g = gch->get_gen(level);
+rs->clear_into_younger(g, true /* perm */);
+} else {
+// Invalidate the cards corresponding to the currently used
+// region and clear those corresponding to the evacuated region
+// of all generations just collected (i.e. level and younger).
+rs->invalidate_or_clear(gch->get_gen(level),
+true /* younger */,
+true /* perm */);
+}
+Threads::gc_epilogue();
+CodeCache::gc_epilogue();
+if (PrintGC && !PrintGCDetails) {
+gch->print_heap_change(gch_prev_used);
+}
+// refs processing: clean slate
+_ref_processor = NULL;
+// Update heap occupancy information which is used as
+// input to soft ref clearing policy at the next gc.
+Universe::update_heap_info_at_gc();
+// Update time of last gc for all generations we collected
+// (which curently is all the generations in the heap).
+gch->update_time_of_last_gc(os::javaTimeMillis());
+}
+void GenMarkSweep::allocate_stacks() {
+GenCollectedHeap* gch = GenCollectedHeap::heap();
+// Scratch request on behalf of oldest generation; will do no
+// allocation.
+ScratchBlock* scratch = gch->gather_scratch(gch->_gens[gch->_n_gens-1], 0);
+// $$$ To cut a corner, we'll only use the first scratch block, and then
+// revert to malloc.
+if (scratch != NULL) {
+_preserved_count_max =
+scratch->num_words * HeapWordSize / sizeof(PreservedMark);
+} else {
+_preserved_count_max = 0;
+}
+_preserved_marks = (PreservedMark*)scratch;
+_preserved_count = 0;
+_preserved_mark_stack = NULL;
+_preserved_oop_stack = NULL;
+_marking_stack       = new (ResourceObj::C_HEAP) GrowableArray<oop>(4000, true);
+int size = SystemDictionary::number_of_classes() * 2;
+_revisit_klass_stack = new (ResourceObj::C_HEAP) GrowableArray<Klass*>(size, true);
+#ifdef VALIDATE_MARK_SWEEP
+if (ValidateMarkSweep) {
+_root_refs_stack    = new (ResourceObj::C_HEAP) GrowableArray<oop*>(100, true);
+_other_refs_stack   = new (ResourceObj::C_HEAP) GrowableArray<oop*>(100, true);
+_adjusted_pointers  = new (ResourceObj::C_HEAP) GrowableArray<oop*>(100, true);
+_live_oops          = new (ResourceObj::C_HEAP) GrowableArray<oop>(100, true);
+_live_oops_moved_to = new (ResourceObj::C_HEAP) GrowableArray<oop>(100, true);
+_live_oops_size     = new (ResourceObj::C_HEAP) GrowableArray<size_t>(100, true);
+}
+if (RecordMarkSweepCompaction) {
+if (_cur_gc_live_oops == NULL) {
+_cur_gc_live_oops           = new(ResourceObj::C_HEAP) GrowableArray<HeapWord*>(100, true);
+_cur_gc_live_oops_moved_to  = new(ResourceObj::C_HEAP) GrowableArray<HeapWord*>(100, true);
+_cur_gc_live_oops_size      = new(ResourceObj::C_HEAP) GrowableArray<size_t>(100, true);
+_last_gc_live_oops          = new(ResourceObj::C_HEAP) GrowableArray<HeapWord*>(100, true);
+_last_gc_live_oops_moved_to = new(ResourceObj::C_HEAP) GrowableArray<HeapWord*>(100, true);
+_last_gc_live_oops_size     = new(ResourceObj::C_HEAP) GrowableArray<size_t>(100, true);
+} else {
+_cur_gc_live_oops->clear();
+_cur_gc_live_oops_moved_to->clear();
+_cur_gc_live_oops_size->clear();
+}
+}
+#endif
+}
+void GenMarkSweep::deallocate_stacks() {
+if (_preserved_oop_stack) {
+delete _preserved_mark_stack;
+_preserved_mark_stack = NULL;
+delete _preserved_oop_stack;
+_preserved_oop_stack = NULL;
+}
+delete _marking_stack;
+delete _revisit_klass_stack;
+#ifdef VALIDATE_MARK_SWEEP
+if (ValidateMarkSweep) {
+delete _root_refs_stack;
+delete _other_refs_stack;
+delete _adjusted_pointers;
+delete _live_oops;
+delete _live_oops_size;
+delete _live_oops_moved_to;
+_live_oops_index = 0;
+_live_oops_index_at_perm = 0;
+}
+#endif
+}
+void GenMarkSweep::mark_sweep_phase1(int level,
+bool clear_all_softrefs) {
+// Recursively traverse all live objects and mark them
+EventMark m("1 mark object");
+TraceTime tm("phase 1", PrintGC && Verbose, true, gclog_or_tty);
+trace(" 1");
+VALIDATE_MARK_SWEEP_ONLY(reset_live_oop_tracking(false));
+GenCollectedHeap* gch = GenCollectedHeap::heap();
+// Because follow_root_closure is created statically, cannot
+// use OopsInGenClosure constructor which takes a generation,
+// as the Universe has not been created when the static constructors
+// are run.
+follow_root_closure.set_orig_generation(gch->get_gen(level));
+gch->gen_process_strong_roots(level,
+false, // Younger gens are not roots.
+true,  // Collecting permanent generation.
+SharedHeap::SO_SystemClasses,
+&follow_root_closure, &follow_root_closure);
+// Process reference objects found during marking
+{
+ReferencePolicy *soft_ref_policy;
+if (clear_all_softrefs) {
+soft_ref_policy = new AlwaysClearPolicy();
+} else {
+#ifdef COMPILER2
+soft_ref_policy = new LRUMaxHeapPolicy();
+#else
+soft_ref_policy = new LRUCurrentHeapPolicy();
+#endif // COMPILER2
+}
+assert(soft_ref_policy != NULL,"No soft reference policy");
+ref_processor()->process_discovered_references(
+soft_ref_policy, &is_alive, &keep_alive,
+&follow_stack_closure, NULL);
+}
+// Follow system dictionary roots and unload classes
+bool purged_class = SystemDictionary::do_unloading(&is_alive);
+// Follow code cache roots
+CodeCache::do_unloading(&is_alive, &keep_alive, purged_class);
+follow_stack(); // Flush marking stack
+// Update subklass/sibling/implementor links of live klasses
+follow_weak_klass_links();
+assert(_marking_stack->is_empty(), "just drained");
+// Visit symbol and interned string tables and delete unmarked oops
+SymbolTable::unlink(&is_alive);
+StringTable::unlink(&is_alive);
+assert(_marking_stack->is_empty(), "stack should be empty by now");
+}
+void GenMarkSweep::mark_sweep_phase2() {
+// Now all live objects are marked, compute the new object addresses.
+// It is imperative that we traverse perm_gen LAST. If dead space is
+// allowed a range of dead object may get overwritten by a dead int
+// array. If perm_gen is not traversed last a klassOop may get
+// overwritten. This is fine since it is dead, but if the class has dead
+// instances we have to skip them, and in order to find their size we
+// need the klassOop!
+//
+// It is not required that we traverse spaces in the same order in
+// phase2, phase3 and phase4, but the ValidateMarkSweep live oops
+// tracking expects us to do so. See comment under phase4.
+GenCollectedHeap* gch = GenCollectedHeap::heap();
+Generation* pg = gch->perm_gen();
+EventMark m("2 compute new addresses");
+TraceTime tm("phase 2", PrintGC && Verbose, true, gclog_or_tty);
+trace("2");
+VALIDATE_MARK_SWEEP_ONLY(reset_live_oop_tracking(false));
+gch->prepare_for_compaction();
+VALIDATE_MARK_SWEEP_ONLY(_live_oops_index_at_perm = _live_oops_index);
+CompactPoint perm_cp(pg, NULL, NULL);
+pg->prepare_for_compaction(&perm_cp);
+}
+class GenAdjustPointersClosure: public GenCollectedHeap::GenClosure {
+public:
+void do_generation(Generation* gen) {
+gen->adjust_pointers();
+}
+};
+void GenMarkSweep::mark_sweep_phase3(int level) {
+GenCollectedHeap* gch = GenCollectedHeap::heap();
+Generation* pg = gch->perm_gen();
+// Adjust the pointers to reflect the new locations
+EventMark m("3 adjust pointers");
+TraceTime tm("phase 3", PrintGC && Verbose, true, gclog_or_tty);
+trace("3");
+VALIDATE_MARK_SWEEP_ONLY(reset_live_oop_tracking(false));
+// Needs to be done before the system dictionary is adjusted.
+pg->pre_adjust_pointers();
+// Because the two closures below are created statically, cannot
+// use OopsInGenClosure constructor which takes a generation,
+// as the Universe has not been created when the static constructors
+// are run.
+adjust_root_pointer_closure.set_orig_generation(gch->get_gen(level));
+adjust_pointer_closure.set_orig_generation(gch->get_gen(level));
+gch->gen_process_strong_roots(level,
+false, // Younger gens are not roots.
+true,  // Collecting permanent generation.
+SharedHeap::SO_AllClasses,
+&adjust_root_pointer_closure,
+&adjust_root_pointer_closure);
+// Now adjust pointers in remaining weak roots.  (All of which should
+// have been cleared if they pointed to non-surviving objects.)
+gch->gen_process_weak_roots(&adjust_root_pointer_closure,
+&adjust_pointer_closure);
+adjust_marks();
+GenAdjustPointersClosure blk;
+gch->generation_iterate(&blk, true);
+pg->adjust_pointers();
+}
+class GenCompactClosure: public GenCollectedHeap::GenClosure {
+public:
+void do_generation(Generation* gen) {
+gen->compact();
+}
+};
+void GenMarkSweep::mark_sweep_phase4() {
+// All pointers are now adjusted, move objects accordingly
+// It is imperative that we traverse perm_gen first in phase4. All
+// classes must be allocated earlier than their instances, and traversing
+// perm_gen first makes sure that all klassOops have moved to their new
+// location before any instance does a dispatch through it's klass!
+// The ValidateMarkSweep live oops tracking expects us to traverse spaces
+// in the same order in phase2, phase3 and phase4. We don't quite do that
+// here (perm_gen first rather than last), so we tell the validate code
+// to use a higher index (saved from phase2) when verifying perm_gen.
+GenCollectedHeap* gch = GenCollectedHeap::heap();
+Generation* pg = gch->perm_gen();
+EventMark m("4 compact heap");
+TraceTime tm("phase 4", PrintGC && Verbose, true, gclog_or_tty);
+trace("4");
+VALIDATE_MARK_SWEEP_ONLY(reset_live_oop_tracking(true));
+pg->compact();
+VALIDATE_MARK_SWEEP_ONLY(reset_live_oop_tracking(false));
+GenCompactClosure blk;
+gch->generation_iterate(&blk, true);
+VALIDATE_MARK_SWEEP_ONLY(compaction_complete());
+pg->post_compact(); // Shared spaces verification.
+}

Mercurial > jdk8-mips64-public > hotspot / file comparison

comparison: src/share/vm/memory/genMarkSweep.cpp

src/share/vm/memory/genMarkSweep.cpp