| /* |
| * Copyright (c) 2011, 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_implementation/g1/g1CollectedHeap.inline.hpp" |
| #include "gc_implementation/g1/heapRegionRemSet.hpp" |
| #include "gc_implementation/g1/heapRegionSet.inline.hpp" |
| |
| PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC |
| |
| uint FreeRegionList::_unrealistically_long_length = 0; |
| |
| void HeapRegionSetBase::fill_in_ext_msg(hrs_ext_msg* msg, const char* message) { |
| msg->append("[%s] %s ln: %u cy: "SIZE_FORMAT, |
| name(), message, length(), total_capacity_bytes()); |
| fill_in_ext_msg_extra(msg); |
| } |
| |
| #ifndef PRODUCT |
| void HeapRegionSetBase::verify_region(HeapRegion* hr) { |
| assert(hr->containing_set() == this, err_msg("Inconsistent containing set for %u", hr->hrm_index())); |
| assert(!hr->is_young(), err_msg("Adding young region %u", hr->hrm_index())); // currently we don't use these sets for young regions |
| assert(hr->is_humongous() == regions_humongous(), err_msg("Wrong humongous state for region %u and set %s", hr->hrm_index(), name())); |
| assert(hr->is_free() == regions_free(), err_msg("Wrong free state for region %u and set %s", hr->hrm_index(), name())); |
| assert(!hr->is_free() || hr->is_empty(), err_msg("Free region %u is not empty for set %s", hr->hrm_index(), name())); |
| assert(!hr->is_empty() || hr->is_free(), err_msg("Empty region %u is not free for set %s", hr->hrm_index(), name())); |
| assert(hr->rem_set()->verify_ready_for_par_iteration(), err_msg("Wrong iteration state %u", hr->hrm_index())); |
| } |
| #endif |
| |
| void HeapRegionSetBase::verify() { |
| // It's important that we also observe the MT safety protocol even |
| // for the verification calls. If we do verification without the |
| // appropriate locks and the set changes underneath our feet |
| // verification might fail and send us on a wild goose chase. |
| check_mt_safety(); |
| |
| guarantee(( is_empty() && length() == 0 && total_capacity_bytes() == 0) || |
| (!is_empty() && length() > 0 && total_capacity_bytes() > 0) , |
| hrs_ext_msg(this, "invariant")); |
| } |
| |
| void HeapRegionSetBase::verify_start() { |
| // See comment in verify() about MT safety and verification. |
| check_mt_safety(); |
| assert(!_verify_in_progress, |
| hrs_ext_msg(this, "verification should not be in progress")); |
| |
| // Do the basic verification first before we do the checks over the regions. |
| HeapRegionSetBase::verify(); |
| |
| _verify_in_progress = true; |
| } |
| |
| void HeapRegionSetBase::verify_end() { |
| // See comment in verify() about MT safety and verification. |
| check_mt_safety(); |
| assert(_verify_in_progress, |
| hrs_ext_msg(this, "verification should be in progress")); |
| |
| _verify_in_progress = false; |
| } |
| |
| void HeapRegionSetBase::print_on(outputStream* out, bool print_contents) { |
| out->cr(); |
| out->print_cr("Set: %s ("PTR_FORMAT")", name(), this); |
| out->print_cr(" Region Assumptions"); |
| out->print_cr(" humongous : %s", BOOL_TO_STR(regions_humongous())); |
| out->print_cr(" free : %s", BOOL_TO_STR(regions_free())); |
| out->print_cr(" Attributes"); |
| out->print_cr(" length : %14u", length()); |
| out->print_cr(" total capacity : "SIZE_FORMAT_W(14)" bytes", |
| total_capacity_bytes()); |
| } |
| |
| HeapRegionSetBase::HeapRegionSetBase(const char* name, bool humongous, bool free, HRSMtSafeChecker* mt_safety_checker) |
| : _name(name), _verify_in_progress(false), |
| _is_humongous(humongous), _is_free(free), _mt_safety_checker(mt_safety_checker), |
| _count() |
| { } |
| |
| void FreeRegionList::set_unrealistically_long_length(uint len) { |
| guarantee(_unrealistically_long_length == 0, "should only be set once"); |
| _unrealistically_long_length = len; |
| } |
| |
| void FreeRegionList::fill_in_ext_msg_extra(hrs_ext_msg* msg) { |
| msg->append(" hd: "PTR_FORMAT" tl: "PTR_FORMAT, _head, _tail); |
| } |
| |
| void FreeRegionList::remove_all() { |
| check_mt_safety(); |
| verify_optional(); |
| |
| HeapRegion* curr = _head; |
| while (curr != NULL) { |
| verify_region(curr); |
| |
| HeapRegion* next = curr->next(); |
| curr->set_next(NULL); |
| curr->set_prev(NULL); |
| curr->set_containing_set(NULL); |
| curr = next; |
| } |
| clear(); |
| |
| verify_optional(); |
| } |
| |
| void FreeRegionList::add_ordered(FreeRegionList* from_list) { |
| check_mt_safety(); |
| from_list->check_mt_safety(); |
| |
| verify_optional(); |
| from_list->verify_optional(); |
| |
| if (from_list->is_empty()) { |
| return; |
| } |
| |
| #ifdef ASSERT |
| FreeRegionListIterator iter(from_list); |
| while (iter.more_available()) { |
| HeapRegion* hr = iter.get_next(); |
| // In set_containing_set() we check that we either set the value |
| // from NULL to non-NULL or vice versa to catch bugs. So, we have |
| // to NULL it first before setting it to the value. |
| hr->set_containing_set(NULL); |
| hr->set_containing_set(this); |
| } |
| #endif // ASSERT |
| |
| if (is_empty()) { |
| assert(length() == 0 && _tail == NULL, hrs_ext_msg(this, "invariant")); |
| _head = from_list->_head; |
| _tail = from_list->_tail; |
| } else { |
| HeapRegion* curr_to = _head; |
| HeapRegion* curr_from = from_list->_head; |
| |
| while (curr_from != NULL) { |
| while (curr_to != NULL && curr_to->hrm_index() < curr_from->hrm_index()) { |
| curr_to = curr_to->next(); |
| } |
| |
| if (curr_to == NULL) { |
| // The rest of the from list should be added as tail |
| _tail->set_next(curr_from); |
| curr_from->set_prev(_tail); |
| curr_from = NULL; |
| } else { |
| HeapRegion* next_from = curr_from->next(); |
| |
| curr_from->set_next(curr_to); |
| curr_from->set_prev(curr_to->prev()); |
| if (curr_to->prev() == NULL) { |
| _head = curr_from; |
| } else { |
| curr_to->prev()->set_next(curr_from); |
| } |
| curr_to->set_prev(curr_from); |
| |
| curr_from = next_from; |
| } |
| } |
| |
| if (_tail->hrm_index() < from_list->_tail->hrm_index()) { |
| _tail = from_list->_tail; |
| } |
| } |
| |
| _count.increment(from_list->length(), from_list->total_capacity_bytes()); |
| from_list->clear(); |
| |
| verify_optional(); |
| from_list->verify_optional(); |
| } |
| |
| void FreeRegionList::remove_starting_at(HeapRegion* first, uint num_regions) { |
| check_mt_safety(); |
| assert(num_regions >= 1, hrs_ext_msg(this, "pre-condition")); |
| assert(!is_empty(), hrs_ext_msg(this, "pre-condition")); |
| |
| verify_optional(); |
| DEBUG_ONLY(uint old_length = length();) |
| |
| HeapRegion* curr = first; |
| uint count = 0; |
| while (count < num_regions) { |
| verify_region(curr); |
| HeapRegion* next = curr->next(); |
| HeapRegion* prev = curr->prev(); |
| |
| assert(count < num_regions, |
| hrs_err_msg("[%s] should not come across more regions " |
| "pending for removal than num_regions: %u", |
| name(), num_regions)); |
| |
| if (prev == NULL) { |
| assert(_head == curr, hrs_ext_msg(this, "invariant")); |
| _head = next; |
| } else { |
| assert(_head != curr, hrs_ext_msg(this, "invariant")); |
| prev->set_next(next); |
| } |
| if (next == NULL) { |
| assert(_tail == curr, hrs_ext_msg(this, "invariant")); |
| _tail = prev; |
| } else { |
| assert(_tail != curr, hrs_ext_msg(this, "invariant")); |
| next->set_prev(prev); |
| } |
| if (_last = curr) { |
| _last = NULL; |
| } |
| |
| curr->set_next(NULL); |
| curr->set_prev(NULL); |
| remove(curr); |
| |
| count++; |
| curr = next; |
| } |
| |
| assert(count == num_regions, |
| hrs_err_msg("[%s] count: %u should be == num_regions: %u", |
| name(), count, num_regions)); |
| assert(length() + num_regions == old_length, |
| hrs_err_msg("[%s] new length should be consistent " |
| "new length: %u old length: %u num_regions: %u", |
| name(), length(), old_length, num_regions)); |
| |
| verify_optional(); |
| } |
| |
| void FreeRegionList::verify() { |
| // See comment in HeapRegionSetBase::verify() about MT safety and |
| // verification. |
| check_mt_safety(); |
| |
| // This will also do the basic verification too. |
| verify_start(); |
| |
| verify_list(); |
| |
| verify_end(); |
| } |
| |
| void FreeRegionList::clear() { |
| _count = HeapRegionSetCount(); |
| _head = NULL; |
| _tail = NULL; |
| _last = NULL; |
| } |
| |
| void FreeRegionList::print_on(outputStream* out, bool print_contents) { |
| HeapRegionSetBase::print_on(out, print_contents); |
| out->print_cr(" Linking"); |
| out->print_cr(" head : "PTR_FORMAT, _head); |
| out->print_cr(" tail : "PTR_FORMAT, _tail); |
| |
| if (print_contents) { |
| out->print_cr(" Contents"); |
| FreeRegionListIterator iter(this); |
| while (iter.more_available()) { |
| HeapRegion* hr = iter.get_next(); |
| hr->print_on(out); |
| } |
| } |
| |
| out->cr(); |
| } |
| |
| void FreeRegionList::verify_list() { |
| HeapRegion* curr = _head; |
| HeapRegion* prev1 = NULL; |
| HeapRegion* prev0 = NULL; |
| uint count = 0; |
| size_t capacity = 0; |
| uint last_index = 0; |
| |
| guarantee(_head == NULL || _head->prev() == NULL, "_head should not have a prev"); |
| while (curr != NULL) { |
| verify_region(curr); |
| |
| count++; |
| guarantee(count < _unrealistically_long_length, |
| hrs_err_msg("[%s] the calculated length: %u seems very long, is there maybe a cycle? curr: "PTR_FORMAT" prev0: "PTR_FORMAT" " "prev1: "PTR_FORMAT" length: %u", name(), count, curr, prev0, prev1, length())); |
| |
| if (curr->next() != NULL) { |
| guarantee(curr->next()->prev() == curr, "Next or prev pointers messed up"); |
| } |
| guarantee(curr->hrm_index() == 0 || curr->hrm_index() > last_index, "List should be sorted"); |
| last_index = curr->hrm_index(); |
| |
| capacity += curr->capacity(); |
| |
| prev1 = prev0; |
| prev0 = curr; |
| curr = curr->next(); |
| } |
| |
| guarantee(_tail == prev0, err_msg("Expected %s to end with %u but it ended with %u.", name(), _tail->hrm_index(), prev0->hrm_index())); |
| guarantee(_tail == NULL || _tail->next() == NULL, "_tail should not have a next"); |
| guarantee(length() == count, err_msg("%s count mismatch. Expected %u, actual %u.", name(), length(), count)); |
| guarantee(total_capacity_bytes() == capacity, err_msg("%s capacity mismatch. Expected " SIZE_FORMAT ", actual " SIZE_FORMAT, |
| name(), total_capacity_bytes(), capacity)); |
| } |
| |
| // Note on the check_mt_safety() methods below: |
| // |
| // Verification of the "master" heap region sets / lists that are |
| // maintained by G1CollectedHeap is always done during a STW pause and |
| // by the VM thread at the start / end of the pause. The standard |
| // verification methods all assert check_mt_safety(). This is |
| // important as it ensures that verification is done without |
| // concurrent updates taking place at the same time. It follows, that, |
| // for the "master" heap region sets / lists, the check_mt_safety() |
| // method should include the VM thread / STW case. |
| |
| void MasterFreeRegionListMtSafeChecker::check() { |
| // Master Free List MT safety protocol: |
| // (a) If we're at a safepoint, operations on the master free list |
| // should be invoked by either the VM thread (which will serialize |
| // them) or by the GC workers while holding the |
| // FreeList_lock. |
| // (b) If we're not at a safepoint, operations on the master free |
| // list should be invoked while holding the Heap_lock. |
| |
| if (SafepointSynchronize::is_at_safepoint()) { |
| guarantee(Thread::current()->is_VM_thread() || |
| FreeList_lock->owned_by_self(), "master free list MT safety protocol at a safepoint"); |
| } else { |
| guarantee(Heap_lock->owned_by_self(), "master free list MT safety protocol outside a safepoint"); |
| } |
| } |
| |
| void SecondaryFreeRegionListMtSafeChecker::check() { |
| // Secondary Free List MT safety protocol: |
| // Operations on the secondary free list should always be invoked |
| // while holding the SecondaryFreeList_lock. |
| |
| guarantee(SecondaryFreeList_lock->owned_by_self(), "secondary free list MT safety protocol"); |
| } |
| |
| void OldRegionSetMtSafeChecker::check() { |
| // Master Old Set MT safety protocol: |
| // (a) If we're at a safepoint, operations on the master old set |
| // should be invoked: |
| // - by the VM thread (which will serialize them), or |
| // - by the GC workers while holding the FreeList_lock, if we're |
| // at a safepoint for an evacuation pause (this lock is taken |
| // anyway when an GC alloc region is retired so that a new one |
| // is allocated from the free list), or |
| // - by the GC workers while holding the OldSets_lock, if we're at a |
| // safepoint for a cleanup pause. |
| // (b) If we're not at a safepoint, operations on the master old set |
| // should be invoked while holding the Heap_lock. |
| |
| if (SafepointSynchronize::is_at_safepoint()) { |
| guarantee(Thread::current()->is_VM_thread() |
| || FreeList_lock->owned_by_self() || OldSets_lock->owned_by_self(), |
| "master old set MT safety protocol at a safepoint"); |
| } else { |
| guarantee(Heap_lock->owned_by_self(), "master old set MT safety protocol outside a safepoint"); |
| } |
| } |
| |
| void HumongousRegionSetMtSafeChecker::check() { |
| // Humongous Set MT safety protocol: |
| // (a) If we're at a safepoint, operations on the master humongous |
| // set should be invoked by either the VM thread (which will |
| // serialize them) or by the GC workers while holding the |
| // OldSets_lock. |
| // (b) If we're not at a safepoint, operations on the master |
| // humongous set should be invoked while holding the Heap_lock. |
| |
| if (SafepointSynchronize::is_at_safepoint()) { |
| guarantee(Thread::current()->is_VM_thread() || |
| OldSets_lock->owned_by_self(), |
| "master humongous set MT safety protocol at a safepoint"); |
| } else { |
| guarantee(Heap_lock->owned_by_self(), |
| "master humongous set MT safety protocol outside a safepoint"); |
| } |
| } |
| |
| void FreeRegionList_test() { |
| FreeRegionList l("test"); |
| |
| const uint num_regions_in_test = 5; |
| // Create a fake heap. It does not need to be valid, as the HeapRegion constructor |
| // does not access it. |
| MemRegion heap(NULL, num_regions_in_test * HeapRegion::GrainWords); |
| // Allocate a fake BOT because the HeapRegion constructor initializes |
| // the BOT. |
| size_t bot_size = G1BlockOffsetSharedArray::compute_size(heap.word_size()); |
| HeapWord* bot_data = NEW_C_HEAP_ARRAY(HeapWord, bot_size, mtGC); |
| ReservedSpace bot_rs(G1BlockOffsetSharedArray::compute_size(heap.word_size())); |
| G1RegionToSpaceMapper* bot_storage = |
| G1RegionToSpaceMapper::create_mapper(bot_rs, |
| os::vm_page_size(), |
| HeapRegion::GrainBytes, |
| G1BlockOffsetSharedArray::N_bytes, |
| mtGC); |
| G1BlockOffsetSharedArray oa(heap, bot_storage); |
| bot_storage->commit_regions(0, num_regions_in_test); |
| |
| // Set up memory regions for the heap regions. |
| MemRegion mr0(heap.start(), HeapRegion::GrainWords); |
| MemRegion mr1(mr0.end(), HeapRegion::GrainWords); |
| MemRegion mr2(mr1.end(), HeapRegion::GrainWords); |
| MemRegion mr3(mr2.end(), HeapRegion::GrainWords); |
| MemRegion mr4(mr3.end(), HeapRegion::GrainWords); |
| |
| HeapRegion hr0(0, &oa, mr0); |
| HeapRegion hr1(1, &oa, mr1); |
| HeapRegion hr2(2, &oa, mr2); |
| HeapRegion hr3(3, &oa, mr3); |
| HeapRegion hr4(4, &oa, mr4); |
| l.add_ordered(&hr1); |
| l.add_ordered(&hr0); |
| l.add_ordered(&hr3); |
| l.add_ordered(&hr4); |
| l.add_ordered(&hr2); |
| assert(l.length() == num_regions_in_test, "wrong length"); |
| l.verify_list(); |
| |
| bot_storage->uncommit_regions(0, num_regions_in_test); |
| delete bot_storage; |
| FREE_C_HEAP_ARRAY(HeapWord, bot_data); |
| } |