jdk8-mips64-public/hotspot: comparison src/share/vm/gc_implementation/g1/g1StringDedupQueue.cpp

--1:000000000000
+:f90c822e73f8
+/*
+* 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");
+}
+}
+}
+}

Mercurial > jdk8-mips64-public > hotspot / file comparison

comparison: src/share/vm/gc_implementation/g1/g1StringDedupQueue.cpp

src/share/vm/gc_implementation/g1/g1StringDedupQueue.cpp