Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/g1/g1StringDedupQueue.cpp @ 18350:23a2faa68470
converted HotSpotForeignCallLinkage to an interface
author | Doug Simon <doug.simon@oracle.com> |
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date | Wed, 12 Nov 2014 14:43:58 +0100 |
parents | 1772223a25a2 |
children |
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/* * Copyright (c) 2014, 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 "classfile/javaClasses.hpp" #include "gc_implementation/g1/g1StringDedupQueue.hpp" #include "memory/gcLocker.hpp" #include "runtime/mutexLocker.hpp" #include "utilities/stack.inline.hpp" G1StringDedupQueue* G1StringDedupQueue::_queue = NULL; const size_t G1StringDedupQueue::_max_size = 1000000; // Max number of elements per queue const size_t G1StringDedupQueue::_max_cache_size = 0; // Max cache size per queue G1StringDedupQueue::G1StringDedupQueue() : _cursor(0), _cancel(false), _empty(true), _dropped(0) { _nqueues = MAX2(ParallelGCThreads, (size_t)1); _queues = NEW_C_HEAP_ARRAY(G1StringDedupWorkerQueue, _nqueues, mtGC); for (size_t i = 0; i < _nqueues; i++) { new (_queues + i) G1StringDedupWorkerQueue(G1StringDedupWorkerQueue::default_segment_size(), _max_cache_size, _max_size); } } G1StringDedupQueue::~G1StringDedupQueue() { ShouldNotReachHere(); } void G1StringDedupQueue::create() { assert(_queue == NULL, "One string deduplication queue allowed"); _queue = new G1StringDedupQueue(); } void G1StringDedupQueue::wait() { MonitorLockerEx ml(StringDedupQueue_lock, Mutex::_no_safepoint_check_flag); while (_queue->_empty && !_queue->_cancel) { ml.wait(Mutex::_no_safepoint_check_flag); } } void G1StringDedupQueue::cancel_wait() { MonitorLockerEx ml(StringDedupQueue_lock, Mutex::_no_safepoint_check_flag); _queue->_cancel = true; ml.notify(); } void G1StringDedupQueue::push(uint worker_id, oop java_string) { assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint"); assert(worker_id < _queue->_nqueues, "Invalid queue"); // Push and notify waiter G1StringDedupWorkerQueue& worker_queue = _queue->_queues[worker_id]; if (!worker_queue.is_full()) { worker_queue.push(java_string); if (_queue->_empty) { MonitorLockerEx ml(StringDedupQueue_lock, Mutex::_no_safepoint_check_flag); if (_queue->_empty) { // Mark non-empty and notify waiter _queue->_empty = false; ml.notify(); } } } else { // Queue is full, drop the string and update the statistics Atomic::inc_ptr(&_queue->_dropped); } } oop G1StringDedupQueue::pop() { assert(!SafepointSynchronize::is_at_safepoint(), "Must not be at safepoint"); No_Safepoint_Verifier nsv; // Try all queues before giving up for (size_t tries = 0; tries < _queue->_nqueues; tries++) { // The cursor indicates where we left of last time G1StringDedupWorkerQueue* queue = &_queue->_queues[_queue->_cursor]; while (!queue->is_empty()) { oop obj = queue->pop(); // The oop we pop can be NULL if it was marked // dead. Just ignore those and pop the next oop. if (obj != NULL) { return obj; } } // Try next queue _queue->_cursor = (_queue->_cursor + 1) % _queue->_nqueues; } // Mark empty _queue->_empty = true; return NULL; } void G1StringDedupQueue::unlink_or_oops_do(G1StringDedupUnlinkOrOopsDoClosure* cl) { // A worker thread first claims a queue, which ensures exclusive // access to that queue, then continues to process it. for (;;) { // Grab next queue to scan size_t queue = cl->claim_queue(); if (queue >= _queue->_nqueues) { // End of queues break; } // Scan the queue unlink_or_oops_do(cl, queue); } } void G1StringDedupQueue::unlink_or_oops_do(G1StringDedupUnlinkOrOopsDoClosure* cl, size_t queue) { assert(queue < _queue->_nqueues, "Invalid queue"); StackIterator<oop, mtGC> iter(_queue->_queues[queue]); while (!iter.is_empty()) { oop* p = iter.next_addr(); if (*p != NULL) { if (cl->is_alive(*p)) { cl->keep_alive(p); } else { // Clear dead reference *p = NULL; } } } } void G1StringDedupQueue::print_statistics(outputStream* st) { st->print_cr( " [Queue]\n" " [Dropped: "UINTX_FORMAT"]", _queue->_dropped); } void G1StringDedupQueue::verify() { for (size_t i = 0; i < _queue->_nqueues; i++) { StackIterator<oop, mtGC> iter(_queue->_queues[i]); while (!iter.is_empty()) { oop obj = iter.next(); if (obj != NULL) { guarantee(Universe::heap()->is_in_reserved(obj), "Object must be on the heap"); guarantee(!obj->is_forwarded(), "Object must not be forwarded"); guarantee(java_lang_String::is_instance(obj), "Object must be a String"); } } } }