changeset 9715:36a6516ca7b8

Merge
author kbarrett
date Tue, 10 Nov 2015 00:18:11 +0000
parents ed57978c72cc 92ff60614bbf
children 88d10461b89b
files src/share/vm/gc/g1/satbQueue.cpp src/share/vm/gc/g1/satbQueue.hpp
diffstat 10 files changed, 496 insertions(+), 496 deletions(-) [+]
line wrap: on
line diff
--- a/src/jdk.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotVMConfig.java	Mon Nov 09 15:19:59 2015 +0300
+++ b/src/jdk.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotVMConfig.java	Tue Nov 10 00:18:11 2015 +0000
@@ -1063,7 +1063,7 @@
     @HotSpotVMField(name = "JavaThread::_osthread", type = "OSThread*", get = HotSpotVMField.Type.OFFSET) @Stable public int osThreadOffset;
     @HotSpotVMField(name = "JavaThread::_dirty_card_queue", type = "DirtyCardQueue", get = HotSpotVMField.Type.OFFSET) @Stable public int javaThreadDirtyCardQueueOffset;
     @HotSpotVMField(name = "JavaThread::_is_method_handle_return", type = "int", get = HotSpotVMField.Type.OFFSET) @Stable public int threadIsMethodHandleReturnOffset;
-    @HotSpotVMField(name = "JavaThread::_satb_mark_queue", type = "ObjPtrQueue", get = HotSpotVMField.Type.OFFSET) @Stable public int javaThreadSatbMarkQueueOffset;
+    @HotSpotVMField(name = "JavaThread::_satb_mark_queue", type = "SATBMarkQueue", get = HotSpotVMField.Type.OFFSET) @Stable public int javaThreadSatbMarkQueueOffset;
     @HotSpotVMField(name = "JavaThread::_vm_result", type = "oop", get = HotSpotVMField.Type.OFFSET) @Stable public int threadObjectResultOffset;
     @HotSpotVMField(name = "JavaThread::_jvmci_counters", type = "jlong*", get = HotSpotVMField.Type.OFFSET) @Stable public int jvmciCountersThreadOffset;
 
--- a/src/share/vm/gc/g1/g1SATBCardTableModRefBS.cpp	Mon Nov 09 15:19:59 2015 +0300
+++ b/src/share/vm/gc/g1/g1SATBCardTableModRefBS.cpp	Tue Nov 10 00:18:11 2015 +0000
@@ -26,7 +26,7 @@
 #include "gc/g1/g1CollectedHeap.inline.hpp"
 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
 #include "gc/g1/heapRegion.hpp"
-#include "gc/g1/satbQueue.hpp"
+#include "gc/g1/satbMarkQueue.hpp"
 #include "gc/shared/memset_with_concurrent_readers.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/atomic.inline.hpp"
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc/g1/satbMarkQueue.cpp	Tue Nov 10 00:18:11 2015 +0000
@@ -0,0 +1,370 @@
+/*
+ * Copyright (c) 2001, 2015, 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 "gc/g1/g1CollectedHeap.inline.hpp"
+#include "gc/g1/satbMarkQueue.hpp"
+#include "gc/shared/collectedHeap.hpp"
+#include "memory/allocation.inline.hpp"
+#include "oops/oop.inline.hpp"
+#include "runtime/mutexLocker.hpp"
+#include "runtime/safepoint.hpp"
+#include "runtime/thread.hpp"
+#include "runtime/vmThread.hpp"
+
+SATBMarkQueue::SATBMarkQueue(SATBMarkQueueSet* qset, bool permanent) :
+  // SATB queues are only active during marking cycles. We create
+  // them with their active field set to false. If a thread is
+  // created during a cycle and its SATB queue needs to be activated
+  // before the thread starts running, we'll need to set its active
+  // field to true. This is done in JavaThread::initialize_queues().
+  PtrQueue(qset, permanent, false /* active */)
+{ }
+
+void SATBMarkQueue::flush() {
+  // Filter now to possibly save work later.  If filtering empties the
+  // buffer then flush_impl can deallocate the buffer.
+  filter();
+  flush_impl();
+}
+
+// Return true if a SATB buffer entry refers to an object that
+// requires marking.
+//
+// The entry must point into the G1 heap.  In particular, it must not
+// be a NULL pointer.  NULL pointers are pre-filtered and never
+// inserted into a SATB buffer.
+//
+// An entry that is below the NTAMS pointer for the containing heap
+// region requires marking. Such an entry must point to a valid object.
+//
+// An entry that is at least the NTAMS pointer for the containing heap
+// region might be any of the following, none of which should be marked.
+//
+// * A reference to an object allocated since marking started.
+//   According to SATB, such objects are implicitly kept live and do
+//   not need to be dealt with via SATB buffer processing.
+//
+// * A reference to a young generation object. Young objects are
+//   handled separately and are not marked by concurrent marking.
+//
+// * A stale reference to a young generation object. If a young
+//   generation object reference is recorded and not filtered out
+//   before being moved by a young collection, the reference becomes
+//   stale.
+//
+// * A stale reference to an eagerly reclaimed humongous object.  If a
+//   humongous object is recorded and then reclaimed, the reference
+//   becomes stale.
+//
+// The stale reference cases are implicitly handled by the NTAMS
+// comparison. Because of the possibility of stale references, buffer
+// processing must be somewhat circumspect and not assume entries
+// in an unfiltered buffer refer to valid objects.
+
+inline bool requires_marking(const void* entry, G1CollectedHeap* heap) {
+  // Includes rejection of NULL pointers.
+  assert(heap->is_in_reserved(entry),
+         "Non-heap pointer in SATB buffer: " PTR_FORMAT, p2i(entry));
+
+  HeapRegion* region = heap->heap_region_containing(entry);
+  assert(region != NULL, "No region for " PTR_FORMAT, p2i(entry));
+  if (entry >= region->next_top_at_mark_start()) {
+    return false;
+  }
+
+  assert(((oop)entry)->is_oop(true /* ignore mark word */),
+         "Invalid oop in SATB buffer: " PTR_FORMAT, p2i(entry));
+
+  return true;
+}
+
+// This method removes entries from a SATB buffer that will not be
+// useful to the concurrent marking threads.  Entries are retained if
+// they require marking and are not already marked. Retained entries
+// are compacted toward the top of the buffer.
+
+void SATBMarkQueue::filter() {
+  G1CollectedHeap* g1h = G1CollectedHeap::heap();
+  void** buf = _buf;
+
+  if (buf == NULL) {
+    // nothing to do
+    return;
+  }
+
+  // Used for sanity checking at the end of the loop.
+  DEBUG_ONLY(size_t entries = 0; size_t retained = 0;)
+
+  assert(_index <= _sz, "invariant");
+  void** limit = &buf[byte_index_to_index(_index)];
+  void** src = &buf[byte_index_to_index(_sz)];
+  void** dst = src;
+
+  while (limit < src) {
+    DEBUG_ONLY(entries += 1;)
+    --src;
+    void* entry = *src;
+    // NULL the entry so that unused parts of the buffer contain NULLs
+    // at the end. If we are going to retain it we will copy it to its
+    // final place. If we have retained all entries we have visited so
+    // far, we'll just end up copying it to the same place.
+    *src = NULL;
+
+    if (requires_marking(entry, g1h) && !g1h->isMarkedNext((oop)entry)) {
+      --dst;
+      assert(*dst == NULL, "filtering destination should be clear");
+      *dst = entry;
+      DEBUG_ONLY(retained += 1;);
+    }
+  }
+  size_t new_index = pointer_delta(dst, buf, 1);
+
+#ifdef ASSERT
+  size_t entries_calc = (_sz - _index) / sizeof(void*);
+  assert(entries == entries_calc, "the number of entries we counted "
+         "should match the number of entries we calculated");
+  size_t retained_calc = (_sz - new_index) / sizeof(void*);
+  assert(retained == retained_calc, "the number of retained entries we counted "
+         "should match the number of retained entries we calculated");
+#endif // ASSERT
+
+  _index = new_index;
+}
+
+// This method will first apply the above filtering to the buffer. If
+// post-filtering a large enough chunk of the buffer has been cleared
+// we can re-use the buffer (instead of enqueueing it) and we can just
+// allow the mutator to carry on executing using the same buffer
+// instead of replacing it.
+
+bool SATBMarkQueue::should_enqueue_buffer() {
+  assert(_lock == NULL || _lock->owned_by_self(),
+         "we should have taken the lock before calling this");
+
+  // If G1SATBBufferEnqueueingThresholdPercent == 0 we could skip filtering.
+
+  // This method should only be called if there is a non-NULL buffer
+  // that is full.
+  assert(_index == 0, "pre-condition");
+  assert(_buf != NULL, "pre-condition");
+
+  filter();
+
+  size_t percent_used = ((_sz - _index) * 100) / _sz;
+  bool should_enqueue = percent_used > G1SATBBufferEnqueueingThresholdPercent;
+  return should_enqueue;
+}
+
+void SATBMarkQueue::apply_closure_and_empty(SATBBufferClosure* cl) {
+  assert(SafepointSynchronize::is_at_safepoint(),
+         "SATB queues must only be processed at safepoints");
+  if (_buf != NULL) {
+    assert(_index % sizeof(void*) == 0, "invariant");
+    assert(_sz % sizeof(void*) == 0, "invariant");
+    assert(_index <= _sz, "invariant");
+    cl->do_buffer(_buf + byte_index_to_index(_index),
+                  byte_index_to_index(_sz - _index));
+    _index = _sz;
+  }
+}
+
+#ifndef PRODUCT
+// Helpful for debugging
+
+void SATBMarkQueue::print(const char* name) {
+  print(name, _buf, _index, _sz);
+}
+
+void SATBMarkQueue::print(const char* name,
+                          void** buf, size_t index, size_t sz) {
+  gclog_or_tty->print_cr("  SATB BUFFER [%s] buf: " PTR_FORMAT " "
+                         "index: " SIZE_FORMAT " sz: " SIZE_FORMAT,
+                         name, p2i(buf), index, sz);
+}
+#endif // PRODUCT
+
+SATBMarkQueueSet::SATBMarkQueueSet() :
+  PtrQueueSet(),
+  _shared_satb_queue(this, true /* permanent */) { }
+
+void SATBMarkQueueSet::initialize(Monitor* cbl_mon, Mutex* fl_lock,
+                                  int process_completed_threshold,
+                                  Mutex* lock) {
+  PtrQueueSet::initialize(cbl_mon, fl_lock, process_completed_threshold, -1);
+  _shared_satb_queue.set_lock(lock);
+}
+
+void SATBMarkQueueSet::handle_zero_index_for_thread(JavaThread* t) {
+  t->satb_mark_queue().handle_zero_index();
+}
+
+#ifdef ASSERT
+void SATBMarkQueueSet::dump_active_states(bool expected_active) {
+  gclog_or_tty->print_cr("Expected SATB active state: %s",
+                         expected_active ? "ACTIVE" : "INACTIVE");
+  gclog_or_tty->print_cr("Actual SATB active states:");
+  gclog_or_tty->print_cr("  Queue set: %s", is_active() ? "ACTIVE" : "INACTIVE");
+  for (JavaThread* t = Threads::first(); t; t = t->next()) {
+    gclog_or_tty->print_cr("  Thread \"%s\" queue: %s", t->name(),
+                           t->satb_mark_queue().is_active() ? "ACTIVE" : "INACTIVE");
+  }
+  gclog_or_tty->print_cr("  Shared queue: %s",
+                         shared_satb_queue()->is_active() ? "ACTIVE" : "INACTIVE");
+}
+
+void SATBMarkQueueSet::verify_active_states(bool expected_active) {
+  // Verify queue set state
+  if (is_active() != expected_active) {
+    dump_active_states(expected_active);
+    guarantee(false, "SATB queue set has an unexpected active state");
+  }
+
+  // Verify thread queue states
+  for (JavaThread* t = Threads::first(); t; t = t->next()) {
+    if (t->satb_mark_queue().is_active() != expected_active) {
+      dump_active_states(expected_active);
+      guarantee(false, "Thread SATB queue has an unexpected active state");
+    }
+  }
+
+  // Verify shared queue state
+  if (shared_satb_queue()->is_active() != expected_active) {
+    dump_active_states(expected_active);
+    guarantee(false, "Shared SATB queue has an unexpected active state");
+  }
+}
+#endif // ASSERT
+
+void SATBMarkQueueSet::set_active_all_threads(bool active, bool expected_active) {
+  assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
+#ifdef ASSERT
+  verify_active_states(expected_active);
+#endif // ASSERT
+  _all_active = active;
+  for (JavaThread* t = Threads::first(); t; t = t->next()) {
+    t->satb_mark_queue().set_active(active);
+  }
+  shared_satb_queue()->set_active(active);
+}
+
+void SATBMarkQueueSet::filter_thread_buffers() {
+  for(JavaThread* t = Threads::first(); t; t = t->next()) {
+    t->satb_mark_queue().filter();
+  }
+  shared_satb_queue()->filter();
+}
+
+bool SATBMarkQueueSet::apply_closure_to_completed_buffer(SATBBufferClosure* cl) {
+  BufferNode* nd = NULL;
+  {
+    MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
+    if (_completed_buffers_head != NULL) {
+      nd = _completed_buffers_head;
+      _completed_buffers_head = nd->next();
+      if (_completed_buffers_head == NULL) _completed_buffers_tail = NULL;
+      _n_completed_buffers--;
+      if (_n_completed_buffers == 0) _process_completed = false;
+    }
+  }
+  if (nd != NULL) {
+    void **buf = BufferNode::make_buffer_from_node(nd);
+    // Skip over NULL entries at beginning (e.g. push end) of buffer.
+    // Filtering can result in non-full completed buffers; see
+    // should_enqueue_buffer.
+    assert(_sz % sizeof(void*) == 0, "invariant");
+    size_t limit = SATBMarkQueue::byte_index_to_index(_sz);
+    for (size_t i = 0; i < limit; ++i) {
+      if (buf[i] != NULL) {
+        // Found the end of the block of NULLs; process the remainder.
+        cl->do_buffer(buf + i, limit - i);
+        break;
+      }
+    }
+    deallocate_buffer(buf);
+    return true;
+  } else {
+    return false;
+  }
+}
+
+#ifndef PRODUCT
+// Helpful for debugging
+
+#define SATB_PRINTER_BUFFER_SIZE 256
+
+void SATBMarkQueueSet::print_all(const char* msg) {
+  char buffer[SATB_PRINTER_BUFFER_SIZE];
+  assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
+
+  gclog_or_tty->cr();
+  gclog_or_tty->print_cr("SATB BUFFERS [%s]", msg);
+
+  BufferNode* nd = _completed_buffers_head;
+  int i = 0;
+  while (nd != NULL) {
+    void** buf = BufferNode::make_buffer_from_node(nd);
+    jio_snprintf(buffer, SATB_PRINTER_BUFFER_SIZE, "Enqueued: %d", i);
+    SATBMarkQueue::print(buffer, buf, 0, _sz);
+    nd = nd->next();
+    i += 1;
+  }
+
+  for (JavaThread* t = Threads::first(); t; t = t->next()) {
+    jio_snprintf(buffer, SATB_PRINTER_BUFFER_SIZE, "Thread: %s", t->name());
+    t->satb_mark_queue().print(buffer);
+  }
+
+  shared_satb_queue()->print("Shared");
+
+  gclog_or_tty->cr();
+}
+#endif // PRODUCT
+
+void SATBMarkQueueSet::abandon_partial_marking() {
+  BufferNode* buffers_to_delete = NULL;
+  {
+    MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
+    while (_completed_buffers_head != NULL) {
+      BufferNode* nd = _completed_buffers_head;
+      _completed_buffers_head = nd->next();
+      nd->set_next(buffers_to_delete);
+      buffers_to_delete = nd;
+    }
+    _completed_buffers_tail = NULL;
+    _n_completed_buffers = 0;
+    DEBUG_ONLY(assert_completed_buffer_list_len_correct_locked());
+  }
+  while (buffers_to_delete != NULL) {
+    BufferNode* nd = buffers_to_delete;
+    buffers_to_delete = nd->next();
+    deallocate_buffer(BufferNode::make_buffer_from_node(nd));
+  }
+  assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
+  // So we can safely manipulate these queues.
+  for (JavaThread* t = Threads::first(); t; t = t->next()) {
+    t->satb_mark_queue().reset();
+  }
+ shared_satb_queue()->reset();
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc/g1/satbMarkQueue.hpp	Tue Nov 10 00:18:11 2015 +0000
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2001, 2015, 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.
+ *
+ */
+
+#ifndef SHARE_VM_GC_G1_SATBMARKQUEUE_HPP
+#define SHARE_VM_GC_G1_SATBMARKQUEUE_HPP
+
+#include "gc/g1/ptrQueue.hpp"
+#include "memory/allocation.hpp"
+
+class JavaThread;
+class SATBMarkQueueSet;
+
+// Base class for processing the contents of a SATB buffer.
+class SATBBufferClosure : public StackObj {
+protected:
+  ~SATBBufferClosure() { }
+
+public:
+  // Process the SATB entries in the designated buffer range.
+  virtual void do_buffer(void** buffer, size_t size) = 0;
+};
+
+// A PtrQueue whose elements are (possibly stale) pointers to object heads.
+class SATBMarkQueue: public PtrQueue {
+  friend class SATBMarkQueueSet;
+
+private:
+  // Filter out unwanted entries from the buffer.
+  void filter();
+
+public:
+  SATBMarkQueue(SATBMarkQueueSet* qset, bool permanent = false);
+
+  // Process queue entries and free resources.
+  void flush();
+
+  // Apply cl to the active part of the buffer.
+  // Prerequisite: Must be at a safepoint.
+  void apply_closure_and_empty(SATBBufferClosure* cl);
+
+  // Overrides PtrQueue::should_enqueue_buffer(). See the method's
+  // definition for more information.
+  virtual bool should_enqueue_buffer();
+
+#ifndef PRODUCT
+  // Helpful for debugging
+  void print(const char* name);
+  static void print(const char* name, void** buf, size_t index, size_t sz);
+#endif // PRODUCT
+};
+
+class SATBMarkQueueSet: public PtrQueueSet {
+  SATBMarkQueue _shared_satb_queue;
+
+#ifdef ASSERT
+  void dump_active_states(bool expected_active);
+  void verify_active_states(bool expected_active);
+#endif // ASSERT
+
+public:
+  SATBMarkQueueSet();
+
+  void initialize(Monitor* cbl_mon, Mutex* fl_lock,
+                  int process_completed_threshold,
+                  Mutex* lock);
+
+  static void handle_zero_index_for_thread(JavaThread* t);
+
+  // Apply "set_active(active)" to all SATB queues in the set. It should be
+  // called only with the world stopped. The method will assert that the
+  // SATB queues of all threads it visits, as well as the SATB queue
+  // set itself, has an active value same as expected_active.
+  void set_active_all_threads(bool active, bool expected_active);
+
+  // Filter all the currently-active SATB buffers.
+  void filter_thread_buffers();
+
+  // If there exists some completed buffer, pop and process it, and
+  // return true.  Otherwise return false.  Processing a buffer
+  // consists of applying the closure to the buffer range starting
+  // with the first non-NULL entry to the end of the buffer; the
+  // leading entries may be NULL due to filtering.
+  bool apply_closure_to_completed_buffer(SATBBufferClosure* cl);
+
+#ifndef PRODUCT
+  // Helpful for debugging
+  void print_all(const char* msg);
+#endif // PRODUCT
+
+  SATBMarkQueue* shared_satb_queue() { return &_shared_satb_queue; }
+
+  // If a marking is being abandoned, reset any unprocessed log buffers.
+  void abandon_partial_marking();
+};
+
+#endif // SHARE_VM_GC_G1_SATBMARKQUEUE_HPP
--- a/src/share/vm/gc/g1/satbQueue.cpp	Mon Nov 09 15:19:59 2015 +0300
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,370 +0,0 @@
-/*
- * Copyright (c) 2001, 2015, 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 "gc/g1/g1CollectedHeap.inline.hpp"
-#include "gc/g1/satbQueue.hpp"
-#include "gc/shared/collectedHeap.hpp"
-#include "memory/allocation.inline.hpp"
-#include "oops/oop.inline.hpp"
-#include "runtime/mutexLocker.hpp"
-#include "runtime/safepoint.hpp"
-#include "runtime/thread.hpp"
-#include "runtime/vmThread.hpp"
-
-ObjPtrQueue::ObjPtrQueue(SATBMarkQueueSet* qset, bool permanent) :
-  // SATB queues are only active during marking cycles. We create
-  // them with their active field set to false. If a thread is
-  // created during a cycle and its SATB queue needs to be activated
-  // before the thread starts running, we'll need to set its active
-  // field to true. This is done in JavaThread::initialize_queues().
-  PtrQueue(qset, permanent, false /* active */)
-{ }
-
-void ObjPtrQueue::flush() {
-  // Filter now to possibly save work later.  If filtering empties the
-  // buffer then flush_impl can deallocate the buffer.
-  filter();
-  flush_impl();
-}
-
-// Return true if a SATB buffer entry refers to an object that
-// requires marking.
-//
-// The entry must point into the G1 heap.  In particular, it must not
-// be a NULL pointer.  NULL pointers are pre-filtered and never
-// inserted into a SATB buffer.
-//
-// An entry that is below the NTAMS pointer for the containing heap
-// region requires marking. Such an entry must point to a valid object.
-//
-// An entry that is at least the NTAMS pointer for the containing heap
-// region might be any of the following, none of which should be marked.
-//
-// * A reference to an object allocated since marking started.
-//   According to SATB, such objects are implicitly kept live and do
-//   not need to be dealt with via SATB buffer processing.
-//
-// * A reference to a young generation object. Young objects are
-//   handled separately and are not marked by concurrent marking.
-//
-// * A stale reference to a young generation object. If a young
-//   generation object reference is recorded and not filtered out
-//   before being moved by a young collection, the reference becomes
-//   stale.
-//
-// * A stale reference to an eagerly reclaimed humongous object.  If a
-//   humongous object is recorded and then reclaimed, the reference
-//   becomes stale.
-//
-// The stale reference cases are implicitly handled by the NTAMS
-// comparison. Because of the possibility of stale references, buffer
-// processing must be somewhat circumspect and not assume entries
-// in an unfiltered buffer refer to valid objects.
-
-inline bool requires_marking(const void* entry, G1CollectedHeap* heap) {
-  // Includes rejection of NULL pointers.
-  assert(heap->is_in_reserved(entry),
-         "Non-heap pointer in SATB buffer: " PTR_FORMAT, p2i(entry));
-
-  HeapRegion* region = heap->heap_region_containing(entry);
-  assert(region != NULL, "No region for " PTR_FORMAT, p2i(entry));
-  if (entry >= region->next_top_at_mark_start()) {
-    return false;
-  }
-
-  assert(((oop)entry)->is_oop(true /* ignore mark word */),
-         "Invalid oop in SATB buffer: " PTR_FORMAT, p2i(entry));
-
-  return true;
-}
-
-// This method removes entries from a SATB buffer that will not be
-// useful to the concurrent marking threads.  Entries are retained if
-// they require marking and are not already marked. Retained entries
-// are compacted toward the top of the buffer.
-
-void ObjPtrQueue::filter() {
-  G1CollectedHeap* g1h = G1CollectedHeap::heap();
-  void** buf = _buf;
-
-  if (buf == NULL) {
-    // nothing to do
-    return;
-  }
-
-  // Used for sanity checking at the end of the loop.
-  DEBUG_ONLY(size_t entries = 0; size_t retained = 0;)
-
-  assert(_index <= _sz, "invariant");
-  void** limit = &buf[byte_index_to_index(_index)];
-  void** src = &buf[byte_index_to_index(_sz)];
-  void** dst = src;
-
-  while (limit < src) {
-    DEBUG_ONLY(entries += 1;)
-    --src;
-    void* entry = *src;
-    // NULL the entry so that unused parts of the buffer contain NULLs
-    // at the end. If we are going to retain it we will copy it to its
-    // final place. If we have retained all entries we have visited so
-    // far, we'll just end up copying it to the same place.
-    *src = NULL;
-
-    if (requires_marking(entry, g1h) && !g1h->isMarkedNext((oop)entry)) {
-      --dst;
-      assert(*dst == NULL, "filtering destination should be clear");
-      *dst = entry;
-      DEBUG_ONLY(retained += 1;);
-    }
-  }
-  size_t new_index = pointer_delta(dst, buf, 1);
-
-#ifdef ASSERT
-  size_t entries_calc = (_sz - _index) / sizeof(void*);
-  assert(entries == entries_calc, "the number of entries we counted "
-         "should match the number of entries we calculated");
-  size_t retained_calc = (_sz - new_index) / sizeof(void*);
-  assert(retained == retained_calc, "the number of retained entries we counted "
-         "should match the number of retained entries we calculated");
-#endif // ASSERT
-
-  _index = new_index;
-}
-
-// This method will first apply the above filtering to the buffer. If
-// post-filtering a large enough chunk of the buffer has been cleared
-// we can re-use the buffer (instead of enqueueing it) and we can just
-// allow the mutator to carry on executing using the same buffer
-// instead of replacing it.
-
-bool ObjPtrQueue::should_enqueue_buffer() {
-  assert(_lock == NULL || _lock->owned_by_self(),
-         "we should have taken the lock before calling this");
-
-  // If G1SATBBufferEnqueueingThresholdPercent == 0 we could skip filtering.
-
-  // This method should only be called if there is a non-NULL buffer
-  // that is full.
-  assert(_index == 0, "pre-condition");
-  assert(_buf != NULL, "pre-condition");
-
-  filter();
-
-  size_t percent_used = ((_sz - _index) * 100) / _sz;
-  bool should_enqueue = percent_used > G1SATBBufferEnqueueingThresholdPercent;
-  return should_enqueue;
-}
-
-void ObjPtrQueue::apply_closure_and_empty(SATBBufferClosure* cl) {
-  assert(SafepointSynchronize::is_at_safepoint(),
-         "SATB queues must only be processed at safepoints");
-  if (_buf != NULL) {
-    assert(_index % sizeof(void*) == 0, "invariant");
-    assert(_sz % sizeof(void*) == 0, "invariant");
-    assert(_index <= _sz, "invariant");
-    cl->do_buffer(_buf + byte_index_to_index(_index),
-                  byte_index_to_index(_sz - _index));
-    _index = _sz;
-  }
-}
-
-#ifndef PRODUCT
-// Helpful for debugging
-
-void ObjPtrQueue::print(const char* name) {
-  print(name, _buf, _index, _sz);
-}
-
-void ObjPtrQueue::print(const char* name,
-                        void** buf, size_t index, size_t sz) {
-  gclog_or_tty->print_cr("  SATB BUFFER [%s] buf: " PTR_FORMAT " "
-                         "index: " SIZE_FORMAT " sz: " SIZE_FORMAT,
-                         name, p2i(buf), index, sz);
-}
-#endif // PRODUCT
-
-SATBMarkQueueSet::SATBMarkQueueSet() :
-  PtrQueueSet(),
-  _shared_satb_queue(this, true /* permanent */) { }
-
-void SATBMarkQueueSet::initialize(Monitor* cbl_mon, Mutex* fl_lock,
-                                  int process_completed_threshold,
-                                  Mutex* lock) {
-  PtrQueueSet::initialize(cbl_mon, fl_lock, process_completed_threshold, -1);
-  _shared_satb_queue.set_lock(lock);
-}
-
-void SATBMarkQueueSet::handle_zero_index_for_thread(JavaThread* t) {
-  t->satb_mark_queue().handle_zero_index();
-}
-
-#ifdef ASSERT
-void SATBMarkQueueSet::dump_active_states(bool expected_active) {
-  gclog_or_tty->print_cr("Expected SATB active state: %s",
-                         expected_active ? "ACTIVE" : "INACTIVE");
-  gclog_or_tty->print_cr("Actual SATB active states:");
-  gclog_or_tty->print_cr("  Queue set: %s", is_active() ? "ACTIVE" : "INACTIVE");
-  for (JavaThread* t = Threads::first(); t; t = t->next()) {
-    gclog_or_tty->print_cr("  Thread \"%s\" queue: %s", t->name(),
-                           t->satb_mark_queue().is_active() ? "ACTIVE" : "INACTIVE");
-  }
-  gclog_or_tty->print_cr("  Shared queue: %s",
-                         shared_satb_queue()->is_active() ? "ACTIVE" : "INACTIVE");
-}
-
-void SATBMarkQueueSet::verify_active_states(bool expected_active) {
-  // Verify queue set state
-  if (is_active() != expected_active) {
-    dump_active_states(expected_active);
-    guarantee(false, "SATB queue set has an unexpected active state");
-  }
-
-  // Verify thread queue states
-  for (JavaThread* t = Threads::first(); t; t = t->next()) {
-    if (t->satb_mark_queue().is_active() != expected_active) {
-      dump_active_states(expected_active);
-      guarantee(false, "Thread SATB queue has an unexpected active state");
-    }
-  }
-
-  // Verify shared queue state
-  if (shared_satb_queue()->is_active() != expected_active) {
-    dump_active_states(expected_active);
-    guarantee(false, "Shared SATB queue has an unexpected active state");
-  }
-}
-#endif // ASSERT
-
-void SATBMarkQueueSet::set_active_all_threads(bool active, bool expected_active) {
-  assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
-#ifdef ASSERT
-  verify_active_states(expected_active);
-#endif // ASSERT
-  _all_active = active;
-  for (JavaThread* t = Threads::first(); t; t = t->next()) {
-    t->satb_mark_queue().set_active(active);
-  }
-  shared_satb_queue()->set_active(active);
-}
-
-void SATBMarkQueueSet::filter_thread_buffers() {
-  for(JavaThread* t = Threads::first(); t; t = t->next()) {
-    t->satb_mark_queue().filter();
-  }
-  shared_satb_queue()->filter();
-}
-
-bool SATBMarkQueueSet::apply_closure_to_completed_buffer(SATBBufferClosure* cl) {
-  BufferNode* nd = NULL;
-  {
-    MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
-    if (_completed_buffers_head != NULL) {
-      nd = _completed_buffers_head;
-      _completed_buffers_head = nd->next();
-      if (_completed_buffers_head == NULL) _completed_buffers_tail = NULL;
-      _n_completed_buffers--;
-      if (_n_completed_buffers == 0) _process_completed = false;
-    }
-  }
-  if (nd != NULL) {
-    void **buf = BufferNode::make_buffer_from_node(nd);
-    // Skip over NULL entries at beginning (e.g. push end) of buffer.
-    // Filtering can result in non-full completed buffers; see
-    // should_enqueue_buffer.
-    assert(_sz % sizeof(void*) == 0, "invariant");
-    size_t limit = ObjPtrQueue::byte_index_to_index(_sz);
-    for (size_t i = 0; i < limit; ++i) {
-      if (buf[i] != NULL) {
-        // Found the end of the block of NULLs; process the remainder.
-        cl->do_buffer(buf + i, limit - i);
-        break;
-      }
-    }
-    deallocate_buffer(buf);
-    return true;
-  } else {
-    return false;
-  }
-}
-
-#ifndef PRODUCT
-// Helpful for debugging
-
-#define SATB_PRINTER_BUFFER_SIZE 256
-
-void SATBMarkQueueSet::print_all(const char* msg) {
-  char buffer[SATB_PRINTER_BUFFER_SIZE];
-  assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
-
-  gclog_or_tty->cr();
-  gclog_or_tty->print_cr("SATB BUFFERS [%s]", msg);
-
-  BufferNode* nd = _completed_buffers_head;
-  int i = 0;
-  while (nd != NULL) {
-    void** buf = BufferNode::make_buffer_from_node(nd);
-    jio_snprintf(buffer, SATB_PRINTER_BUFFER_SIZE, "Enqueued: %d", i);
-    ObjPtrQueue::print(buffer, buf, 0, _sz);
-    nd = nd->next();
-    i += 1;
-  }
-
-  for (JavaThread* t = Threads::first(); t; t = t->next()) {
-    jio_snprintf(buffer, SATB_PRINTER_BUFFER_SIZE, "Thread: %s", t->name());
-    t->satb_mark_queue().print(buffer);
-  }
-
-  shared_satb_queue()->print("Shared");
-
-  gclog_or_tty->cr();
-}
-#endif // PRODUCT
-
-void SATBMarkQueueSet::abandon_partial_marking() {
-  BufferNode* buffers_to_delete = NULL;
-  {
-    MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
-    while (_completed_buffers_head != NULL) {
-      BufferNode* nd = _completed_buffers_head;
-      _completed_buffers_head = nd->next();
-      nd->set_next(buffers_to_delete);
-      buffers_to_delete = nd;
-    }
-    _completed_buffers_tail = NULL;
-    _n_completed_buffers = 0;
-    DEBUG_ONLY(assert_completed_buffer_list_len_correct_locked());
-  }
-  while (buffers_to_delete != NULL) {
-    BufferNode* nd = buffers_to_delete;
-    buffers_to_delete = nd->next();
-    deallocate_buffer(BufferNode::make_buffer_from_node(nd));
-  }
-  assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
-  // So we can safely manipulate these queues.
-  for (JavaThread* t = Threads::first(); t; t = t->next()) {
-    t->satb_mark_queue().reset();
-  }
- shared_satb_queue()->reset();
-}
--- a/src/share/vm/gc/g1/satbQueue.hpp	Mon Nov 09 15:19:59 2015 +0300
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,117 +0,0 @@
-/*
- * Copyright (c) 2001, 2015, 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.
- *
- */
-
-#ifndef SHARE_VM_GC_G1_SATBQUEUE_HPP
-#define SHARE_VM_GC_G1_SATBQUEUE_HPP
-
-#include "gc/g1/ptrQueue.hpp"
-#include "memory/allocation.hpp"
-
-class JavaThread;
-class SATBMarkQueueSet;
-
-// Base class for processing the contents of a SATB buffer.
-class SATBBufferClosure : public StackObj {
-protected:
-  ~SATBBufferClosure() { }
-
-public:
-  // Process the SATB entries in the designated buffer range.
-  virtual void do_buffer(void** buffer, size_t size) = 0;
-};
-
-// A ptrQueue whose elements are "oops", pointers to object heads.
-class ObjPtrQueue: public PtrQueue {
-  friend class SATBMarkQueueSet;
-
-private:
-  // Filter out unwanted entries from the buffer.
-  void filter();
-
-public:
-  ObjPtrQueue(SATBMarkQueueSet* qset, bool permanent = false);
-
-  // Process queue entries and free resources.
-  void flush();
-
-  // Apply cl to the active part of the buffer.
-  // Prerequisite: Must be at a safepoint.
-  void apply_closure_and_empty(SATBBufferClosure* cl);
-
-  // Overrides PtrQueue::should_enqueue_buffer(). See the method's
-  // definition for more information.
-  virtual bool should_enqueue_buffer();
-
-#ifndef PRODUCT
-  // Helpful for debugging
-  void print(const char* name);
-  static void print(const char* name, void** buf, size_t index, size_t sz);
-#endif // PRODUCT
-};
-
-class SATBMarkQueueSet: public PtrQueueSet {
-  ObjPtrQueue _shared_satb_queue;
-
-#ifdef ASSERT
-  void dump_active_states(bool expected_active);
-  void verify_active_states(bool expected_active);
-#endif // ASSERT
-
-public:
-  SATBMarkQueueSet();
-
-  void initialize(Monitor* cbl_mon, Mutex* fl_lock,
-                  int process_completed_threshold,
-                  Mutex* lock);
-
-  static void handle_zero_index_for_thread(JavaThread* t);
-
-  // Apply "set_active(active)" to all SATB queues in the set. It should be
-  // called only with the world stopped. The method will assert that the
-  // SATB queues of all threads it visits, as well as the SATB queue
-  // set itself, has an active value same as expected_active.
-  void set_active_all_threads(bool active, bool expected_active);
-
-  // Filter all the currently-active SATB buffers.
-  void filter_thread_buffers();
-
-  // If there exists some completed buffer, pop and process it, and
-  // return true.  Otherwise return false.  Processing a buffer
-  // consists of applying the closure to the buffer range starting
-  // with the first non-NULL entry to the end of the buffer; the
-  // leading entries may be NULL due to filtering.
-  bool apply_closure_to_completed_buffer(SATBBufferClosure* cl);
-
-#ifndef PRODUCT
-  // Helpful for debugging
-  void print_all(const char* msg);
-#endif // PRODUCT
-
-  ObjPtrQueue* shared_satb_queue() { return &_shared_satb_queue; }
-
-  // If a marking is being abandoned, reset any unprocessed log buffers.
-  void abandon_partial_marking();
-};
-
-#endif // SHARE_VM_GC_G1_SATBQUEUE_HPP
--- a/src/share/vm/precompiled/precompiled.hpp	Mon Nov 09 15:19:59 2015 +0300
+++ b/src/share/vm/precompiled/precompiled.hpp	Tue Nov 10 00:18:11 2015 +0000
@@ -304,7 +304,7 @@
 # include "gc/g1/g1OopClosures.hpp"
 # include "gc/g1/g1_globals.hpp"
 # include "gc/g1/ptrQueue.hpp"
-# include "gc/g1/satbQueue.hpp"
+# include "gc/g1/satbMarkQueue.hpp"
 # include "gc/parallel/gcAdaptivePolicyCounters.hpp"
 # include "gc/parallel/objectStartArray.hpp"
 # include "gc/parallel/parMarkBitMap.hpp"
--- a/src/share/vm/runtime/thread.cpp	Mon Nov 09 15:19:59 2015 +0300
+++ b/src/share/vm/runtime/thread.cpp	Tue Nov 10 00:18:11 2015 +0000
@@ -1938,7 +1938,7 @@
   assert(!SafepointSynchronize::is_at_safepoint(),
          "we should not be at a safepoint");
 
-  ObjPtrQueue& satb_queue = satb_mark_queue();
+  SATBMarkQueue& satb_queue = satb_mark_queue();
   SATBMarkQueueSet& satb_queue_set = satb_mark_queue_set();
   // The SATB queue should have been constructed with its active
   // field set to false.
--- a/src/share/vm/runtime/thread.hpp	Mon Nov 09 15:19:59 2015 +0300
+++ b/src/share/vm/runtime/thread.hpp	Tue Nov 10 00:18:11 2015 +0000
@@ -49,7 +49,7 @@
 #include "utilities/top.hpp"
 #if INCLUDE_ALL_GCS
 #include "gc/g1/dirtyCardQueue.hpp"
-#include "gc/g1/satbQueue.hpp"
+#include "gc/g1/satbMarkQueue.hpp"
 #endif // INCLUDE_ALL_GCS
 #ifdef TARGET_ARCH_zero
 # include "stack_zero.hpp"
@@ -992,7 +992,7 @@
 #if INCLUDE_ALL_GCS
   // Support for G1 barriers
 
-  ObjPtrQueue _satb_mark_queue;          // Thread-local log for SATB barrier.
+  SATBMarkQueue _satb_mark_queue;        // Thread-local log for SATB barrier.
   // Set of all such queues.
   static SATBMarkQueueSet _satb_mark_queue_set;
 
@@ -1727,7 +1727,7 @@
 
 #if INCLUDE_ALL_GCS
   // SATB marking queue support
-  ObjPtrQueue& satb_mark_queue() { return _satb_mark_queue; }
+  SATBMarkQueue& satb_mark_queue() { return _satb_mark_queue; }
   static SATBMarkQueueSet& satb_mark_queue_set() {
     return _satb_mark_queue_set;
   }
--- a/src/share/vm/runtime/vmStructs.cpp	Mon Nov 09 15:19:59 2015 +0300
+++ b/src/share/vm/runtime/vmStructs.cpp	Tue Nov 10 00:18:11 2015 +0000
@@ -1030,7 +1030,7 @@
   nonstatic_field(JavaThread,                  _stack_size,                                   size_t)                                \
   nonstatic_field(JavaThread,                  _vframe_array_head,                            vframeArray*)                          \
   nonstatic_field(JavaThread,                  _vframe_array_last,                            vframeArray*)                          \
-  nonstatic_field(JavaThread,                  _satb_mark_queue,                              ObjPtrQueue)                           \
+  nonstatic_field(JavaThread,                  _satb_mark_queue,                              SATBMarkQueue)                         \
   nonstatic_field(JavaThread,                  _dirty_card_queue,                             DirtyCardQueue)                        \
   nonstatic_field(Thread,                      _resource_area,                                ResourceArea*)                         \
   nonstatic_field(CompilerThread,              _env,                                          ciEnv*)                                \
@@ -1622,7 +1622,7 @@
   declare_toplevel_type(MemRegion)                                        \
   declare_toplevel_type(ThreadLocalAllocBuffer)                           \
   declare_toplevel_type(VirtualSpace)                                     \
-  declare_toplevel_type(ObjPtrQueue)                                      \
+  declare_toplevel_type(SATBMarkQueue)                                    \
   declare_toplevel_type(DirtyCardQueue)                                   \
                                                                           \
   /* Pointers to Garbage Collection types */                              \