--- a/src/hotspot/share/gc/g1/ptrQueue.cpp Fri Aug 17 21:36:02 2018 -0700
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,314 +0,0 @@
-/*
- * Copyright (c) 2001, 2017, 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/g1/ptrQueue.hpp"
-#include "memory/allocation.hpp"
-#include "memory/allocation.inline.hpp"
-#include "runtime/mutex.hpp"
-#include "runtime/mutexLocker.hpp"
-#include "runtime/thread.inline.hpp"
-
-#include <new>
-
-PtrQueue::PtrQueue(PtrQueueSet* qset, bool permanent, bool active) :
- _qset(qset),
- _active(active),
- _permanent(permanent),
- _index(0),
- _capacity_in_bytes(0),
- _buf(NULL),
- _lock(NULL)
-{}
-
-PtrQueue::~PtrQueue() {
- assert(_permanent || (_buf == NULL), "queue must be flushed before delete");
-}
-
-void PtrQueue::flush_impl() {
- if (_buf != NULL) {
- BufferNode* node = BufferNode::make_node_from_buffer(_buf, index());
- if (is_empty()) {
- // No work to do.
- qset()->deallocate_buffer(node);
- } else {
- qset()->enqueue_complete_buffer(node);
- }
- _buf = NULL;
- set_index(0);
- }
-}
-
-
-void PtrQueue::enqueue_known_active(void* ptr) {
- while (_index == 0) {
- handle_zero_index();
- }
-
- assert(_buf != NULL, "postcondition");
- assert(index() > 0, "postcondition");
- assert(index() <= capacity(), "invariant");
- _index -= _element_size;
- _buf[index()] = ptr;
-}
-
-void PtrQueue::locking_enqueue_completed_buffer(BufferNode* node) {
- assert(_lock->owned_by_self(), "Required.");
- qset()->enqueue_complete_buffer(node);
-}
-
-
-BufferNode* BufferNode::allocate(size_t size) {
- size_t byte_size = size * sizeof(void*);
- void* data = NEW_C_HEAP_ARRAY(char, buffer_offset() + byte_size, mtGC);
- return new (data) BufferNode;
-}
-
-void BufferNode::deallocate(BufferNode* node) {
- node->~BufferNode();
- FREE_C_HEAP_ARRAY(char, node);
-}
-
-PtrQueueSet::PtrQueueSet(bool notify_when_complete) :
- _buffer_size(0),
- _cbl_mon(NULL),
- _completed_buffers_head(NULL),
- _completed_buffers_tail(NULL),
- _n_completed_buffers(0),
- _process_completed_threshold(0),
- _process_completed(false),
- _fl_lock(NULL),
- _buf_free_list(NULL),
- _buf_free_list_sz(0),
- _fl_owner(NULL),
- _all_active(false),
- _notify_when_complete(notify_when_complete),
- _max_completed_queue(0),
- _completed_queue_padding(0)
-{
- _fl_owner = this;
-}
-
-PtrQueueSet::~PtrQueueSet() {
- // There are presently only a couple (derived) instances ever
- // created, and they are permanent, so no harm currently done by
- // doing nothing here.
-}
-
-void PtrQueueSet::initialize(Monitor* cbl_mon,
- Mutex* fl_lock,
- int process_completed_threshold,
- int max_completed_queue,
- PtrQueueSet *fl_owner) {
- _max_completed_queue = max_completed_queue;
- _process_completed_threshold = process_completed_threshold;
- _completed_queue_padding = 0;
- assert(cbl_mon != NULL && fl_lock != NULL, "Init order issue?");
- _cbl_mon = cbl_mon;
- _fl_lock = fl_lock;
- _fl_owner = (fl_owner != NULL) ? fl_owner : this;
-}
-
-void** PtrQueueSet::allocate_buffer() {
- BufferNode* node = NULL;
- {
- MutexLockerEx x(_fl_owner->_fl_lock, Mutex::_no_safepoint_check_flag);
- node = _fl_owner->_buf_free_list;
- if (node != NULL) {
- _fl_owner->_buf_free_list = node->next();
- _fl_owner->_buf_free_list_sz--;
- }
- }
- if (node == NULL) {
- node = BufferNode::allocate(buffer_size());
- } else {
- // Reinitialize buffer obtained from free list.
- node->set_index(0);
- node->set_next(NULL);
- }
- return BufferNode::make_buffer_from_node(node);
-}
-
-void PtrQueueSet::deallocate_buffer(BufferNode* node) {
- MutexLockerEx x(_fl_owner->_fl_lock, Mutex::_no_safepoint_check_flag);
- node->set_next(_fl_owner->_buf_free_list);
- _fl_owner->_buf_free_list = node;
- _fl_owner->_buf_free_list_sz++;
-}
-
-void PtrQueueSet::reduce_free_list() {
- assert(_fl_owner == this, "Free list reduction is allowed only for the owner");
- // For now we'll adopt the strategy of deleting half.
- MutexLockerEx x(_fl_lock, Mutex::_no_safepoint_check_flag);
- size_t n = _buf_free_list_sz / 2;
- for (size_t i = 0; i < n; ++i) {
- assert(_buf_free_list != NULL,
- "_buf_free_list_sz is wrong: " SIZE_FORMAT, _buf_free_list_sz);
- BufferNode* node = _buf_free_list;
- _buf_free_list = node->next();
- _buf_free_list_sz--;
- BufferNode::deallocate(node);
- }
-}
-
-void PtrQueue::handle_zero_index() {
- assert(index() == 0, "precondition");
-
- // This thread records the full buffer and allocates a new one (while
- // holding the lock if there is one).
- if (_buf != NULL) {
- if (!should_enqueue_buffer()) {
- assert(index() > 0, "the buffer can only be re-used if it's not full");
- return;
- }
-
- if (_lock) {
- assert(_lock->owned_by_self(), "Required.");
-
- BufferNode* node = BufferNode::make_node_from_buffer(_buf, index());
- _buf = NULL; // clear shared _buf field
-
- locking_enqueue_completed_buffer(node); // enqueue completed buffer
- assert(_buf == NULL, "multiple enqueuers appear to be racing");
- } else {
- BufferNode* node = BufferNode::make_node_from_buffer(_buf, index());
- if (qset()->process_or_enqueue_complete_buffer(node)) {
- // Recycle the buffer. No allocation.
- assert(_buf == BufferNode::make_buffer_from_node(node), "invariant");
- assert(capacity() == qset()->buffer_size(), "invariant");
- reset();
- return;
- }
- }
- }
- // Set capacity in case this is the first allocation.
- set_capacity(qset()->buffer_size());
- // Allocate a new buffer.
- _buf = qset()->allocate_buffer();
- reset();
-}
-
-bool PtrQueueSet::process_or_enqueue_complete_buffer(BufferNode* node) {
- if (Thread::current()->is_Java_thread()) {
- // We don't lock. It is fine to be epsilon-precise here.
- if (_max_completed_queue == 0 ||
- (_max_completed_queue > 0 &&
- _n_completed_buffers >= _max_completed_queue + _completed_queue_padding)) {
- bool b = mut_process_buffer(node);
- if (b) {
- // True here means that the buffer hasn't been deallocated and the caller may reuse it.
- return true;
- }
- }
- }
- // The buffer will be enqueued. The caller will have to get a new one.
- enqueue_complete_buffer(node);
- return false;
-}
-
-void PtrQueueSet::enqueue_complete_buffer(BufferNode* cbn) {
- MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
- cbn->set_next(NULL);
- if (_completed_buffers_tail == NULL) {
- assert(_completed_buffers_head == NULL, "Well-formedness");
- _completed_buffers_head = cbn;
- _completed_buffers_tail = cbn;
- } else {
- _completed_buffers_tail->set_next(cbn);
- _completed_buffers_tail = cbn;
- }
- _n_completed_buffers++;
-
- if (!_process_completed && _process_completed_threshold >= 0 &&
- _n_completed_buffers >= (size_t)_process_completed_threshold) {
- _process_completed = true;
- if (_notify_when_complete) {
- _cbl_mon->notify();
- }
- }
- DEBUG_ONLY(assert_completed_buffer_list_len_correct_locked());
-}
-
-size_t PtrQueueSet::completed_buffers_list_length() {
- size_t n = 0;
- BufferNode* cbn = _completed_buffers_head;
- while (cbn != NULL) {
- n++;
- cbn = cbn->next();
- }
- return n;
-}
-
-void PtrQueueSet::assert_completed_buffer_list_len_correct() {
- MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
- assert_completed_buffer_list_len_correct_locked();
-}
-
-void PtrQueueSet::assert_completed_buffer_list_len_correct_locked() {
- guarantee(completed_buffers_list_length() == _n_completed_buffers,
- "Completed buffer length is wrong.");
-}
-
-void PtrQueueSet::set_buffer_size(size_t sz) {
- assert(_buffer_size == 0 && sz > 0, "Should be called only once.");
- _buffer_size = sz;
-}
-
-// Merge lists of buffers. Notify the processing threads.
-// The source queue is emptied as a result. The queues
-// must share the monitor.
-void PtrQueueSet::merge_bufferlists(PtrQueueSet *src) {
- assert(_cbl_mon == src->_cbl_mon, "Should share the same lock");
- MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
- if (_completed_buffers_tail == NULL) {
- assert(_completed_buffers_head == NULL, "Well-formedness");
- _completed_buffers_head = src->_completed_buffers_head;
- _completed_buffers_tail = src->_completed_buffers_tail;
- } else {
- assert(_completed_buffers_head != NULL, "Well formedness");
- if (src->_completed_buffers_head != NULL) {
- _completed_buffers_tail->set_next(src->_completed_buffers_head);
- _completed_buffers_tail = src->_completed_buffers_tail;
- }
- }
- _n_completed_buffers += src->_n_completed_buffers;
-
- src->_n_completed_buffers = 0;
- src->_completed_buffers_head = NULL;
- src->_completed_buffers_tail = NULL;
-
- assert(_completed_buffers_head == NULL && _completed_buffers_tail == NULL ||
- _completed_buffers_head != NULL && _completed_buffers_tail != NULL,
- "Sanity");
-}
-
-void PtrQueueSet::notify_if_necessary() {
- MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
- assert(_process_completed_threshold >= 0, "_process_completed is negative");
- if (_n_completed_buffers >= (size_t)_process_completed_threshold || _max_completed_queue == 0) {
- _process_completed = true;
- if (_notify_when_complete)
- _cbl_mon->notify();
- }
-}