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

 /*

  * Copyright 2001-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

  * CA 95054 USA or visit www.sun.com if you need additional information or

  * have any questions.

  *

  */

 #include "incls/_precompiled.incl"

 #include "incls/_concurrentG1RefineThread.cpp.incl"

 // ======= Concurrent Mark Thread ========

 // The CM thread is created when the G1 garbage collector is used

 ConcurrentG1RefineThread::

 ConcurrentG1RefineThread(ConcurrentG1Refine* cg1r) :

   ConcurrentGCThread(),

   _cg1r(cg1r),

   _started(false),

   _in_progress(false),

   _do_traversal(false),

   _vtime_accum(0.0),

   _co_tracker(G1CRGroup),

   _interval_ms(5.0)

 {

   create_and_start();

 }

 const long timeout = 200; // ms.

 void ConcurrentG1RefineThread::traversalBasedRefinement() {

   _cg1r->wait_for_ConcurrentG1Refine_enabled();

   MutexLocker x(G1ConcRefine_mon);

   while (_cg1r->enabled()) {

     MutexUnlocker ux(G1ConcRefine_mon);

     ResourceMark rm;

     HandleMark   hm;

     if (G1TraceConcurrentRefinement) {

       gclog_or_tty->print_cr("G1-Refine starting pass");

     }

     _sts.join();

     bool no_sleep = _cg1r->refine();

     _sts.leave();

     if (!no_sleep) {

       MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag);

       // We do this only for the timeout; we don't expect this to be signalled.

       CGC_lock->wait(Mutex::_no_safepoint_check_flag, timeout);

     }

   }

 }

 void ConcurrentG1RefineThread::queueBasedRefinement() {

   DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();

   // Wait for completed log buffers to exist.

   {

     MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag);

     while (!_do_traversal && !dcqs.process_completed_buffers() &&

            !_should_terminate) {

       DirtyCardQ_CBL_mon->wait(Mutex::_no_safepoint_check_flag);

     }

   }

   if (_should_terminate) {

     return;

   }

   // Now we take them off (this doesn't hold locks while it applies

   // closures.)  (If we did a full collection, then we'll do a full

   // traversal.

   _sts.join();

   if (_do_traversal) {

     (void)_cg1r->refine();

     switch (_cg1r->get_last_pya()) {

     case PYA_cancel: case PYA_continue:

       // Continue was caught and handled inside "refine".  If it's still

       // "continue" when we get here, we're done.

       _do_traversal = false;

       break;

     case PYA_restart:

       assert(_do_traversal, "Because of Full GC.");

       break;

     }

   } else {

     int n_logs = 0;

     int lower_limit = 0;

     double start_vtime_sec; // only used when G1SmoothConcRefine is on

     int prev_buffer_num; // only used when G1SmoothConcRefine is on

     if (G1SmoothConcRefine) {

       lower_limit = 0;

       start_vtime_sec = os::elapsedVTime();

       prev_buffer_num = (int) dcqs.completed_buffers_num();

     } else {

       lower_limit = DCQBarrierProcessCompletedThreshold / 4; // For now.

     }

     while (dcqs.apply_closure_to_completed_buffer(0, lower_limit)) {

       double end_vtime_sec;

       double elapsed_vtime_sec;

       int elapsed_vtime_ms;

       int curr_buffer_num;

       if (G1SmoothConcRefine) {

         end_vtime_sec = os::elapsedVTime();

         elapsed_vtime_sec = end_vtime_sec - start_vtime_sec;

         elapsed_vtime_ms = (int) (elapsed_vtime_sec * 1000.0);

         curr_buffer_num = (int) dcqs.completed_buffers_num();

         if (curr_buffer_num > prev_buffer_num ||

             curr_buffer_num > DCQBarrierProcessCompletedThreshold) {

           decreaseInterval(elapsed_vtime_ms);

         } else if (curr_buffer_num < prev_buffer_num) {

           increaseInterval(elapsed_vtime_ms);

         }

       }

       sample_young_list_rs_lengths();

       _co_tracker.update(false);

       if (G1SmoothConcRefine) {

         prev_buffer_num = curr_buffer_num;

         _sts.leave();

         os::sleep(Thread::current(), (jlong) _interval_ms, false);

         _sts.join();

         start_vtime_sec = os::elapsedVTime();

       }

       n_logs++;

     }

     // Make sure we harvest the PYA, if any.

     (void)_cg1r->get_pya();

   }

   _sts.leave();

 }

 void ConcurrentG1RefineThread::sample_young_list_rs_lengths() {

   G1CollectedHeap* g1h = G1CollectedHeap::heap();

   G1CollectorPolicy* g1p = g1h->g1_policy();

   if (g1p->adaptive_young_list_length()) {

     int regions_visited = 0;

     g1h->young_list_rs_length_sampling_init();

     while (g1h->young_list_rs_length_sampling_more()) {

       g1h->young_list_rs_length_sampling_next();

       ++regions_visited;

       // we try to yield every time we visit 10 regions

       if (regions_visited == 10) {

         if (_sts.should_yield()) {

           _sts.yield("G1 refine");

           // we just abandon the iteration

           break;

         }

         regions_visited = 0;

       }

     }

     g1p->check_prediction_validity();

   }

 }

 void ConcurrentG1RefineThread::run() {

   initialize_in_thread();

   _vtime_start = os::elapsedVTime();

   wait_for_universe_init();

   _co_tracker.enable();

   _co_tracker.start();

   while (!_should_terminate) {

     // wait until started is set.

     if (G1RSBarrierUseQueue) {

       queueBasedRefinement();

     } else {

       traversalBasedRefinement();

     }

     _sts.join();

     _co_tracker.update();

     _sts.leave();

     if (os::supports_vtime()) {

       _vtime_accum = (os::elapsedVTime() - _vtime_start);

     } else {

       _vtime_accum = 0.0;

     }

   }

   _sts.join();

   _co_tracker.update(true);

   _sts.leave();

   assert(_should_terminate, "just checking");

   terminate();

 }

 void ConcurrentG1RefineThread::yield() {

   if (G1TraceConcurrentRefinement) gclog_or_tty->print_cr("G1-Refine-yield");

   _sts.yield("G1 refine");

   if (G1TraceConcurrentRefinement) gclog_or_tty->print_cr("G1-Refine-yield-end");

 }

 void ConcurrentG1RefineThread::stop() {

   // it is ok to take late safepoints here, if needed

   {

     MutexLockerEx mu(Terminator_lock);

     _should_terminate = true;

   }

   {

     MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag);

     DirtyCardQ_CBL_mon->notify_all();

   }

   {

     MutexLockerEx mu(Terminator_lock);

     while (!_has_terminated) {

       Terminator_lock->wait();

     }

   }

   if (G1TraceConcurrentRefinement) gclog_or_tty->print_cr("G1-Refine-stop");

 }

 void ConcurrentG1RefineThread::print() {

   gclog_or_tty->print("\"Concurrent G1 Refinement Thread\" ");

   Thread::print();

   gclog_or_tty->cr();

 }

 void ConcurrentG1RefineThread::set_do_traversal(bool b) {

   _do_traversal = b;

 }