--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp	Thu Jun 05 15:57:56 2008 -0700
@@ -0,0 +1,246 @@
+/*
+ * 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 (TraceG1Refine) 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) {
+        start_vtime_sec = os::elapsedVTime();
+        prev_buffer_num = curr_buffer_num;
+
+        _sts.leave();
+        os::sleep(Thread::current(), (jlong) _interval_ms, false);
+        _sts.join();
+      }
+
+      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 (TraceG1Refine) gclog_or_tty->print_cr("G1-Refine-yield");
+  _sts.yield("G1 refine");
+  if (TraceG1Refine) 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 (TraceG1Refine) 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;
+}