ysr@777: /*
ysr@777:  * Copyright 2001-2007 Sun Microsystems, Inc.  All Rights Reserved.
ysr@777:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@777:  *
ysr@777:  * This code is free software; you can redistribute it and/or modify it
ysr@777:  * under the terms of the GNU General Public License version 2 only, as
ysr@777:  * published by the Free Software Foundation.
ysr@777:  *
ysr@777:  * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@777:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@777:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ysr@777:  * version 2 for more details (a copy is included in the LICENSE file that
ysr@777:  * accompanied this code).
ysr@777:  *
ysr@777:  * You should have received a copy of the GNU General Public License version
ysr@777:  * 2 along with this work; if not, write to the Free Software Foundation,
ysr@777:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@777:  *
ysr@777:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
ysr@777:  * CA 95054 USA or visit www.sun.com if you need additional information or
ysr@777:  * have any questions.
ysr@777:  *
ysr@777:  */
ysr@777: 
ysr@777: #include "incls/_precompiled.incl"
ysr@777: #include "incls/_concurrentG1RefineThread.cpp.incl"
ysr@777: 
ysr@777: // ======= Concurrent Mark Thread ========
ysr@777: 
ysr@777: // The CM thread is created when the G1 garbage collector is used
ysr@777: 
ysr@777: ConcurrentG1RefineThread::
ysr@777: ConcurrentG1RefineThread(ConcurrentG1Refine* cg1r) :
ysr@777:   ConcurrentGCThread(),
ysr@777:   _cg1r(cg1r),
ysr@777:   _started(false),
ysr@777:   _in_progress(false),
ysr@777:   _do_traversal(false),
ysr@777:   _vtime_accum(0.0),
ysr@777:   _co_tracker(G1CRGroup),
ysr@777:   _interval_ms(5.0)
ysr@777: {
ysr@777:   create_and_start();
ysr@777: }
ysr@777: 
ysr@777: const long timeout = 200; // ms.
ysr@777: 
ysr@777: void ConcurrentG1RefineThread::traversalBasedRefinement() {
ysr@777:   _cg1r->wait_for_ConcurrentG1Refine_enabled();
ysr@777:   MutexLocker x(G1ConcRefine_mon);
ysr@777:   while (_cg1r->enabled()) {
ysr@777:     MutexUnlocker ux(G1ConcRefine_mon);
ysr@777:     ResourceMark rm;
ysr@777:     HandleMark   hm;
ysr@777: 
ysr@777:     if (TraceG1Refine) gclog_or_tty->print_cr("G1-Refine starting pass");
ysr@777:     _sts.join();
ysr@777:     bool no_sleep = _cg1r->refine();
ysr@777:     _sts.leave();
ysr@777:     if (!no_sleep) {
ysr@777:       MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag);
ysr@777:       // We do this only for the timeout; we don't expect this to be signalled.
ysr@777:       CGC_lock->wait(Mutex::_no_safepoint_check_flag, timeout);
ysr@777:     }
ysr@777:   }
ysr@777: }
ysr@777: 
ysr@777: void ConcurrentG1RefineThread::queueBasedRefinement() {
ysr@777:   DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
ysr@777:   // Wait for completed log buffers to exist.
ysr@777:   {
ysr@777:     MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag);
ysr@777:     while (!_do_traversal && !dcqs.process_completed_buffers() &&
ysr@777:            !_should_terminate) {
ysr@777:       DirtyCardQ_CBL_mon->wait(Mutex::_no_safepoint_check_flag);
ysr@777:     }
ysr@777:   }
ysr@777: 
ysr@777:   if (_should_terminate) {
ysr@777:     return;
ysr@777:   }
ysr@777: 
ysr@777:   // Now we take them off (this doesn't hold locks while it applies
ysr@777:   // closures.)  (If we did a full collection, then we'll do a full
ysr@777:   // traversal.
ysr@777:   _sts.join();
ysr@777:   if (_do_traversal) {
ysr@777:     (void)_cg1r->refine();
ysr@777:     switch (_cg1r->get_last_pya()) {
ysr@777:     case PYA_cancel: case PYA_continue:
ysr@777:       // Continue was caught and handled inside "refine".  If it's still
ysr@777:       // "continue" when we get here, we're done.
ysr@777:       _do_traversal = false;
ysr@777:       break;
ysr@777:     case PYA_restart:
ysr@777:       assert(_do_traversal, "Because of Full GC.");
ysr@777:       break;
ysr@777:     }
ysr@777:   } else {
ysr@777:     int n_logs = 0;
ysr@777:     int lower_limit = 0;
ysr@777:     double start_vtime_sec; // only used when G1SmoothConcRefine is on
ysr@777:     int prev_buffer_num; // only used when G1SmoothConcRefine is on
ysr@777: 
ysr@777:     if (G1SmoothConcRefine) {
ysr@777:       lower_limit = 0;
ysr@777:       start_vtime_sec = os::elapsedVTime();
ysr@777:       prev_buffer_num = (int) dcqs.completed_buffers_num();
ysr@777:     } else {
ysr@777:       lower_limit = DCQBarrierProcessCompletedThreshold / 4; // For now.
ysr@777:     }
ysr@777:     while (dcqs.apply_closure_to_completed_buffer(0, lower_limit)) {
ysr@777:       double end_vtime_sec;
ysr@777:       double elapsed_vtime_sec;
ysr@777:       int elapsed_vtime_ms;
ysr@777:       int curr_buffer_num;
ysr@777: 
ysr@777:       if (G1SmoothConcRefine) {
ysr@777:         end_vtime_sec = os::elapsedVTime();
ysr@777:         elapsed_vtime_sec = end_vtime_sec - start_vtime_sec;
ysr@777:         elapsed_vtime_ms = (int) (elapsed_vtime_sec * 1000.0);
ysr@777:         curr_buffer_num = (int) dcqs.completed_buffers_num();
ysr@777: 
ysr@777:         if (curr_buffer_num > prev_buffer_num ||
ysr@777:             curr_buffer_num > DCQBarrierProcessCompletedThreshold) {
ysr@777:           decreaseInterval(elapsed_vtime_ms);
ysr@777:         } else if (curr_buffer_num < prev_buffer_num) {
ysr@777:           increaseInterval(elapsed_vtime_ms);
ysr@777:         }
ysr@777:       }
ysr@777: 
ysr@777:       sample_young_list_rs_lengths();
ysr@777:       _co_tracker.update(false);
ysr@777: 
ysr@777:       if (G1SmoothConcRefine) {
ysr@777:         prev_buffer_num = curr_buffer_num;
ysr@777:         _sts.leave();
ysr@777:         os::sleep(Thread::current(), (jlong) _interval_ms, false);
ysr@777:         _sts.join();
iveresov@1051:         start_vtime_sec = os::elapsedVTime();
ysr@777:       }
ysr@777:       n_logs++;
ysr@777:     }
ysr@777:     // Make sure we harvest the PYA, if any.
ysr@777:     (void)_cg1r->get_pya();
ysr@777:   }
ysr@777:   _sts.leave();
ysr@777: }
ysr@777: 
ysr@777: void ConcurrentG1RefineThread::sample_young_list_rs_lengths() {
ysr@777:   G1CollectedHeap* g1h = G1CollectedHeap::heap();
ysr@777:   G1CollectorPolicy* g1p = g1h->g1_policy();
ysr@777:   if (g1p->adaptive_young_list_length()) {
ysr@777:     int regions_visited = 0;
ysr@777: 
ysr@777:     g1h->young_list_rs_length_sampling_init();
ysr@777:     while (g1h->young_list_rs_length_sampling_more()) {
ysr@777:       g1h->young_list_rs_length_sampling_next();
ysr@777:       ++regions_visited;
ysr@777: 
ysr@777:       // we try to yield every time we visit 10 regions
ysr@777:       if (regions_visited == 10) {
ysr@777:         if (_sts.should_yield()) {
ysr@777:           _sts.yield("G1 refine");
ysr@777:           // we just abandon the iteration
ysr@777:           break;
ysr@777:         }
ysr@777:         regions_visited = 0;
ysr@777:       }
ysr@777:     }
ysr@777: 
ysr@777:     g1p->check_prediction_validity();
ysr@777:   }
ysr@777: }
ysr@777: 
ysr@777: void ConcurrentG1RefineThread::run() {
ysr@777:   initialize_in_thread();
ysr@777:   _vtime_start = os::elapsedVTime();
ysr@777:   wait_for_universe_init();
ysr@777: 
ysr@777:   _co_tracker.enable();
ysr@777:   _co_tracker.start();
ysr@777: 
ysr@777:   while (!_should_terminate) {
ysr@777:     // wait until started is set.
ysr@777:     if (G1RSBarrierUseQueue) {
ysr@777:       queueBasedRefinement();
ysr@777:     } else {
ysr@777:       traversalBasedRefinement();
ysr@777:     }
ysr@777:     _sts.join();
ysr@777:     _co_tracker.update();
ysr@777:     _sts.leave();
ysr@777:     if (os::supports_vtime()) {
ysr@777:       _vtime_accum = (os::elapsedVTime() - _vtime_start);
ysr@777:     } else {
ysr@777:       _vtime_accum = 0.0;
ysr@777:     }
ysr@777:   }
ysr@777:   _sts.join();
ysr@777:   _co_tracker.update(true);
ysr@777:   _sts.leave();
ysr@777:   assert(_should_terminate, "just checking");
ysr@777: 
ysr@777:   terminate();
ysr@777: }
ysr@777: 
ysr@777: 
ysr@777: void ConcurrentG1RefineThread::yield() {
ysr@777:   if (TraceG1Refine) gclog_or_tty->print_cr("G1-Refine-yield");
ysr@777:   _sts.yield("G1 refine");
ysr@777:   if (TraceG1Refine) gclog_or_tty->print_cr("G1-Refine-yield-end");
ysr@777: }
ysr@777: 
ysr@777: void ConcurrentG1RefineThread::stop() {
ysr@777:   // it is ok to take late safepoints here, if needed
ysr@777:   {
ysr@777:     MutexLockerEx mu(Terminator_lock);
ysr@777:     _should_terminate = true;
ysr@777:   }
ysr@777: 
ysr@777:   {
ysr@777:     MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag);
ysr@777:     DirtyCardQ_CBL_mon->notify_all();
ysr@777:   }
ysr@777: 
ysr@777:   {
ysr@777:     MutexLockerEx mu(Terminator_lock);
ysr@777:     while (!_has_terminated) {
ysr@777:       Terminator_lock->wait();
ysr@777:     }
ysr@777:   }
ysr@777:   if (TraceG1Refine) gclog_or_tty->print_cr("G1-Refine-stop");
ysr@777: }
ysr@777: 
ysr@777: void ConcurrentG1RefineThread::print() {
ysr@777:   gclog_or_tty->print("\"Concurrent G1 Refinement Thread\" ");
ysr@777:   Thread::print();
ysr@777:   gclog_or_tty->cr();
ysr@777: }
ysr@777: 
ysr@777: void ConcurrentG1RefineThread::set_do_traversal(bool b) {
ysr@777:   _do_traversal = b;
ysr@777: }