Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/g1/ptrQueue.hpp @ 8002:8391fdd36e1f
Merge
author | dlong |
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date | Sun, 27 Jan 2013 01:07:09 -0800 |
parents | 2ace1c4ee8da |
children | 69f26e8e09f9 |
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/* * Copyright (c) 2001, 2012, 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_IMPLEMENTATION_G1_PTRQUEUE_HPP #define SHARE_VM_GC_IMPLEMENTATION_G1_PTRQUEUE_HPP #include "memory/allocation.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. // The definition of placement operator new(size_t, void*) in the <new>. #include <new> class PtrQueueSet; class PtrQueue VALUE_OBJ_CLASS_SPEC { protected: // The ptr queue set to which this queue belongs. PtrQueueSet* _qset; // Whether updates should be logged. bool _active; // The buffer. void** _buf; // The index at which an object was last enqueued. Starts at "_sz" // (indicating an empty buffer) and goes towards zero. size_t _index; // The size of the buffer. size_t _sz; // 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. bool _perm; // If there is a lock associated with this buffer, this is that lock. Mutex* _lock; PtrQueueSet* qset() { return _qset; } public: // Initialize this queue to contain a null buffer, and be part of the // given PtrQueueSet. PtrQueue(PtrQueueSet* qset, bool perm = false, bool active = false); // Release any contained resources. virtual void flush(); // Calls flush() when destroyed. ~PtrQueue() { flush(); } // Associate a lock with a ptr queue. void set_lock(Mutex* lock) { _lock = lock; } void reset() { if (_buf != NULL) _index = _sz; } // 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(void** buf); void enqueue_known_active(void* ptr); size_t size() { assert(_sz >= _index, "Invariant."); return _buf == NULL ? 0 : _sz - _index; } bool is_empty() { return _buf == NULL || _sz == _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) { _index = _sz; } else if (b && _buf != NULL) { assert(_index == _sz, "invariant: queues are empty when activated."); } } bool is_active() { return _active; } static int byte_index_to_index(int ind) { assert((ind % oopSize) == 0, "Invariant."); return ind / oopSize; } static int index_to_byte_index(int byte_ind) { return byte_ind * oopSize; } // To support compiler. static ByteSize byte_offset_of_index() { return byte_offset_of(PtrQueue, _index); } static ByteSize byte_width_of_index() { return in_ByteSize(sizeof(size_t)); } static ByteSize byte_offset_of_buf() { return byte_offset_of(PtrQueue, _buf); } static ByteSize byte_width_of_buf() { return in_ByteSize(sizeof(void*)); } static ByteSize byte_offset_of_active() { return byte_offset_of(PtrQueue, _active); } static ByteSize byte_width_of_active() { return in_ByteSize(sizeof(bool)); } }; class BufferNode { size_t _index; BufferNode* _next; public: BufferNode() : _index(0), _next(NULL) { } 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; } // Align the size of the structure to the size of the pointer static size_t aligned_size() { static const size_t alignment = round_to(sizeof(BufferNode), sizeof(void*)); return alignment; } // BufferNode is allocated before the buffer. // The chunk of memory that holds both of them is a block. // Produce a new BufferNode given a buffer. static BufferNode* new_from_buffer(void** buf) { return new (make_block_from_buffer(buf)) BufferNode; } // The following are the required conversion routines: static BufferNode* make_node_from_buffer(void** buf) { return (BufferNode*)make_block_from_buffer(buf); } static void** make_buffer_from_node(BufferNode *node) { return make_buffer_from_block(node); } static void* make_block_from_node(BufferNode *node) { return (void*)node; } static void** make_buffer_from_block(void* p) { return (void**)((char*)p + aligned_size()); } static void* make_block_from_buffer(void** p) { return (void*)((char*)p - aligned_size()); } }; // 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 VALUE_OBJ_CLASS_SPEC { protected: Monitor* _cbl_mon; // Protects the fields below. BufferNode* _completed_buffers_head; BufferNode* _completed_buffers_tail; int _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; // The size of all buffers in the set. size_t _sz; 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; int _completed_queue_padding; int 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(void** buf) { ShouldNotReachHere(); return false; } public: // Create an empty ptr queue set. PtrQueueSet(bool notify_when_complete = false); // 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) { _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; } // Return an empty oop array of size _sz (required to be non-zero). void** allocate_buffer(); // Return an empty buffer to the free list. The "buf" argument is // required to be a pointer to the head of an array of length "_sz". void deallocate_buffer(void** buf); // Declares that "buf" is a complete buffer. void enqueue_complete_buffer(void** buf, size_t index = 0); // To be invoked by the mutator. bool process_or_enqueue_complete_buffer(void** buf); 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. size_t buffer_size() { return _sz; } // 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(); int 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(int padding) { _completed_queue_padding = padding; } int 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_IMPLEMENTATION_G1_PTRQUEUE_HPP