--- a/src/hotspot/share/gc/g1/ptrQueue.hpp Fri Aug 17 21:36:02 2018 -0700
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,371 +0,0 @@
-/*
- * Copyright (c) 2001, 2018, 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.
- *
- */
-
-#ifndef SHARE_VM_GC_G1_PTRQUEUE_HPP
-#define SHARE_VM_GC_G1_PTRQUEUE_HPP
-
-#include "utilities/align.hpp"
-#include "utilities/sizes.hpp"
-
-// There are various techniques that require threads to be able to log
-// addresses. For example, a generational write barrier might log
-// the addresses of modified old-generation objects. This type supports
-// this operation.
-
-class BufferNode;
-class PtrQueueSet;
-class PtrQueue {
- friend class VMStructs;
-
- // Noncopyable - not defined.
- PtrQueue(const PtrQueue&);
- PtrQueue& operator=(const PtrQueue&);
-
- // The ptr queue set to which this queue belongs.
- PtrQueueSet* const _qset;
-
- // Whether updates should be logged.
- bool _active;
-
- // If true, the queue is permanent, and doesn't need to deallocate
- // its buffer in the destructor (since that obtains a lock which may not
- // be legally locked by then.
- const bool _permanent;
-
- // The (byte) index at which an object was last enqueued. Starts at
- // capacity_in_bytes (indicating an empty buffer) and goes towards zero.
- // Value is always pointer-size aligned.
- size_t _index;
-
- // Size of the current buffer, in bytes.
- // Value is always pointer-size aligned.
- size_t _capacity_in_bytes;
-
- static const size_t _element_size = sizeof(void*);
-
- // Get the capacity, in bytes. The capacity must have been set.
- size_t capacity_in_bytes() const {
- assert(_capacity_in_bytes > 0, "capacity not set");
- return _capacity_in_bytes;
- }
-
- void set_capacity(size_t entries) {
- size_t byte_capacity = index_to_byte_index(entries);
- assert(_capacity_in_bytes == 0 || _capacity_in_bytes == byte_capacity,
- "changing capacity " SIZE_FORMAT " -> " SIZE_FORMAT,
- _capacity_in_bytes, byte_capacity);
- _capacity_in_bytes = byte_capacity;
- }
-
- static size_t byte_index_to_index(size_t ind) {
- assert(is_aligned(ind, _element_size), "precondition");
- return ind / _element_size;
- }
-
- static size_t index_to_byte_index(size_t ind) {
- return ind * _element_size;
- }
-
-protected:
- // The buffer.
- void** _buf;
-
- size_t index() const {
- return byte_index_to_index(_index);
- }
-
- void set_index(size_t new_index) {
- size_t byte_index = index_to_byte_index(new_index);
- assert(byte_index <= capacity_in_bytes(), "precondition");
- _index = byte_index;
- }
-
- size_t capacity() const {
- return byte_index_to_index(capacity_in_bytes());
- }
-
- // If there is a lock associated with this buffer, this is that lock.
- Mutex* _lock;
-
- PtrQueueSet* qset() { return _qset; }
- bool is_permanent() const { return _permanent; }
-
- // Process queue entries and release resources.
- void flush_impl();
-
- // Initialize this queue to contain a null buffer, and be part of the
- // given PtrQueueSet.
- PtrQueue(PtrQueueSet* qset, bool permanent = false, bool active = false);
-
- // Requires queue flushed or permanent.
- ~PtrQueue();
-
-public:
-
- // Associate a lock with a ptr queue.
- void set_lock(Mutex* lock) { _lock = lock; }
-
- // Forcibly set empty.
- void reset() {
- if (_buf != NULL) {
- _index = capacity_in_bytes();
- }
- }
-
- void enqueue(volatile void* ptr) {
- enqueue((void*)(ptr));
- }
-
- // Enqueues the given "obj".
- void enqueue(void* ptr) {
- if (!_active) return;
- else enqueue_known_active(ptr);
- }
-
- // This method is called when we're doing the zero index handling
- // and gives a chance to the queues to do any pre-enqueueing
- // processing they might want to do on the buffer. It should return
- // true if the buffer should be enqueued, or false if enough
- // entries were cleared from it so that it can be re-used. It should
- // not return false if the buffer is still full (otherwise we can
- // get into an infinite loop).
- virtual bool should_enqueue_buffer() { return true; }
- void handle_zero_index();
- void locking_enqueue_completed_buffer(BufferNode* node);
-
- void enqueue_known_active(void* ptr);
-
- // Return the size of the in-use region.
- size_t size() const {
- size_t result = 0;
- if (_buf != NULL) {
- assert(_index <= capacity_in_bytes(), "Invariant");
- result = byte_index_to_index(capacity_in_bytes() - _index);
- }
- return result;
- }
-
- bool is_empty() const {
- return _buf == NULL || capacity_in_bytes() == _index;
- }
-
- // Set the "active" property of the queue to "b". An enqueue to an
- // inactive thread is a no-op. Setting a queue to inactive resets its
- // log to the empty state.
- void set_active(bool b) {
- _active = b;
- if (!b && _buf != NULL) {
- reset();
- } else if (b && _buf != NULL) {
- assert(index() == capacity(),
- "invariant: queues are empty when activated.");
- }
- }
-
- bool is_active() const { return _active; }
-
- // To support compiler.
-
-protected:
- template<typename Derived>
- static ByteSize byte_offset_of_index() {
- return byte_offset_of(Derived, _index);
- }
-
- static ByteSize byte_width_of_index() { return in_ByteSize(sizeof(size_t)); }
-
- template<typename Derived>
- static ByteSize byte_offset_of_buf() {
- return byte_offset_of(Derived, _buf);
- }
-
- static ByteSize byte_width_of_buf() { return in_ByteSize(_element_size); }
-
- template<typename Derived>
- static ByteSize byte_offset_of_active() {
- return byte_offset_of(Derived, _active);
- }
-
- static ByteSize byte_width_of_active() { return in_ByteSize(sizeof(bool)); }
-
-};
-
-class BufferNode {
- size_t _index;
- BufferNode* _next;
- void* _buffer[1]; // Pseudo flexible array member.
-
- BufferNode() : _index(0), _next(NULL) { }
- ~BufferNode() { }
-
- static size_t buffer_offset() {
- return offset_of(BufferNode, _buffer);
- }
-
-public:
- BufferNode* next() const { return _next; }
- void set_next(BufferNode* n) { _next = n; }
- size_t index() const { return _index; }
- void set_index(size_t i) { _index = i; }
-
- // Allocate a new BufferNode with the "buffer" having size elements.
- static BufferNode* allocate(size_t size);
-
- // Free a BufferNode.
- static void deallocate(BufferNode* node);
-
- // Return the BufferNode containing the buffer, after setting its index.
- static BufferNode* make_node_from_buffer(void** buffer, size_t index) {
- BufferNode* node =
- reinterpret_cast<BufferNode*>(
- reinterpret_cast<char*>(buffer) - buffer_offset());
- node->set_index(index);
- return node;
- }
-
- // Return the buffer for node.
- static void** make_buffer_from_node(BufferNode *node) {
- // &_buffer[0] might lead to index out of bounds warnings.
- return reinterpret_cast<void**>(
- reinterpret_cast<char*>(node) + buffer_offset());
- }
-};
-
-// A PtrQueueSet represents resources common to a set of pointer queues.
-// In particular, the individual queues allocate buffers from this shared
-// set, and return completed buffers to the set.
-// All these variables are are protected by the TLOQ_CBL_mon. XXX ???
-class PtrQueueSet {
- // The size of all buffers in the set.
- size_t _buffer_size;
-
-protected:
- Monitor* _cbl_mon; // Protects the fields below.
- BufferNode* _completed_buffers_head;
- BufferNode* _completed_buffers_tail;
- size_t _n_completed_buffers;
- int _process_completed_threshold;
- volatile bool _process_completed;
-
- // This (and the interpretation of the first element as a "next"
- // pointer) are protected by the TLOQ_FL_lock.
- Mutex* _fl_lock;
- BufferNode* _buf_free_list;
- size_t _buf_free_list_sz;
- // Queue set can share a freelist. The _fl_owner variable
- // specifies the owner. It is set to "this" by default.
- PtrQueueSet* _fl_owner;
-
- bool _all_active;
-
- // If true, notify_all on _cbl_mon when the threshold is reached.
- bool _notify_when_complete;
-
- // Maximum number of elements allowed on completed queue: after that,
- // enqueuer does the work itself. Zero indicates no maximum.
- int _max_completed_queue;
- size_t _completed_queue_padding;
-
- size_t completed_buffers_list_length();
- void assert_completed_buffer_list_len_correct_locked();
- void assert_completed_buffer_list_len_correct();
-
-protected:
- // A mutator thread does the the work of processing a buffer.
- // Returns "true" iff the work is complete (and the buffer may be
- // deallocated).
- virtual bool mut_process_buffer(BufferNode* node) {
- ShouldNotReachHere();
- return false;
- }
-
- // Create an empty ptr queue set.
- PtrQueueSet(bool notify_when_complete = false);
- ~PtrQueueSet();
-
- // Because of init-order concerns, we can't pass these as constructor
- // arguments.
- void initialize(Monitor* cbl_mon,
- Mutex* fl_lock,
- int process_completed_threshold,
- int max_completed_queue,
- PtrQueueSet *fl_owner = NULL);
-
-public:
-
- // Return the buffer for a BufferNode of size buffer_size().
- void** allocate_buffer();
-
- // Return an empty buffer to the free list. The node is required
- // to have been allocated with a size of buffer_size().
- void deallocate_buffer(BufferNode* node);
-
- // Declares that "buf" is a complete buffer.
- void enqueue_complete_buffer(BufferNode* node);
-
- // To be invoked by the mutator.
- bool process_or_enqueue_complete_buffer(BufferNode* node);
-
- bool completed_buffers_exist_dirty() {
- return _n_completed_buffers > 0;
- }
-
- bool process_completed_buffers() { return _process_completed; }
- void set_process_completed(bool x) { _process_completed = x; }
-
- bool is_active() { return _all_active; }
-
- // Set the buffer size. Should be called before any "enqueue" operation
- // can be called. And should only be called once.
- void set_buffer_size(size_t sz);
-
- // Get the buffer size. Must have been set.
- size_t buffer_size() const {
- assert(_buffer_size > 0, "buffer size not set");
- return _buffer_size;
- }
-
- // Get/Set the number of completed buffers that triggers log processing.
- void set_process_completed_threshold(int sz) { _process_completed_threshold = sz; }
- int process_completed_threshold() const { return _process_completed_threshold; }
-
- // Must only be called at a safe point. Indicates that the buffer free
- // list size may be reduced, if that is deemed desirable.
- void reduce_free_list();
-
- size_t completed_buffers_num() { return _n_completed_buffers; }
-
- void merge_bufferlists(PtrQueueSet* src);
-
- void set_max_completed_queue(int m) { _max_completed_queue = m; }
- int max_completed_queue() { return _max_completed_queue; }
-
- void set_completed_queue_padding(size_t padding) { _completed_queue_padding = padding; }
- size_t completed_queue_padding() { return _completed_queue_padding; }
-
- // Notify the consumer if the number of buffers crossed the threshold
- void notify_if_necessary();
-};
-
-#endif // SHARE_VM_GC_G1_PTRQUEUE_HPP