src/hotspot/share/gc/g1/g1CodeCacheRemSet.cpp - platform/libcore - Git at Google

 /*
  * Copyright (c) 2014, 2017, 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 "code/codeCache.hpp"
 #include "code/nmethod.hpp"
 #include "gc/g1/g1CodeRootSetTable.hpp"
 #include "gc/g1/g1CodeCacheRemSet.hpp"
 #include "gc/g1/heapRegion.hpp"
 #include "memory/heap.hpp"
 #include "memory/iterator.hpp"
 #include "oops/access.inline.hpp"
 #include "oops/oop.inline.hpp"
 #include "utilities/hashtable.inline.hpp"
 #include "utilities/stack.inline.hpp"

 G1CodeRootSetTable* volatile G1CodeRootSetTable::_purge_list = NULL;

 size_t G1CodeRootSetTable::mem_size() {
   return sizeof(G1CodeRootSetTable) + (entry_size() * number_of_entries()) + (sizeof(HashtableBucket<mtGC>) * table_size());
 }

 G1CodeRootSetTable::Entry* G1CodeRootSetTable::new_entry(nmethod* nm) {
   unsigned int hash = compute_hash(nm);
   Entry* entry = (Entry*) new_entry_free_list();
   if (entry == NULL) {
     entry = (Entry*) NEW_C_HEAP_ARRAY2(char, entry_size(), mtGC, CURRENT_PC);
   }
   entry->set_next(NULL);
   entry->set_hash(hash);
   entry->set_literal(nm);
   return entry;
 }

 void G1CodeRootSetTable::remove_entry(Entry* e, Entry* previous) {
   int index = hash_to_index(e->hash());
   assert((e == bucket(index)) == (previous == NULL), "if e is the first entry then previous should be null");

   if (previous == NULL) {
     set_entry(index, e->next());
   } else {
     previous->set_next(e->next());
   }
   free_entry(e);
 }

 G1CodeRootSetTable::~G1CodeRootSetTable() {
   for (int index = 0; index < table_size(); ++index) {
     for (Entry* e = bucket(index); e != NULL; ) {
       Entry* to_remove = e;
       // read next before freeing.
       e = e->next();
       unlink_entry(to_remove);
       FREE_C_HEAP_ARRAY(char, to_remove);
     }
   }
   assert(number_of_entries() == 0, "should have removed all entries");
   free_buckets();
   for (BasicHashtableEntry<mtGC>* e = new_entry_free_list(); e != NULL; e = new_entry_free_list()) {
     FREE_C_HEAP_ARRAY(char, e);
   }
 }

 bool G1CodeRootSetTable::add(nmethod* nm) {
   if (!contains(nm)) {
     Entry* e = new_entry(nm);
     int index = hash_to_index(e->hash());
     add_entry(index, e);
     return true;
   }
   return false;
 }

 bool G1CodeRootSetTable::contains(nmethod* nm) {
   int index = hash_to_index(compute_hash(nm));
   for (Entry* e = bucket(index); e != NULL; e = e->next()) {
     if (e->literal() == nm) {
       return true;
     }
   }
   return false;
 }

 bool G1CodeRootSetTable::remove(nmethod* nm) {
   int index = hash_to_index(compute_hash(nm));
   Entry* previous = NULL;
   for (Entry* e = bucket(index); e != NULL; previous = e, e = e->next()) {
     if (e->literal() == nm) {
       remove_entry(e, previous);
       return true;
     }
   }
   return false;
 }

 void G1CodeRootSetTable::copy_to(G1CodeRootSetTable* new_table) {
   for (int index = 0; index < table_size(); ++index) {
     for (Entry* e = bucket(index); e != NULL; e = e->next()) {
       new_table->add(e->literal());
     }
   }
   new_table->copy_freelist(this);
 }

 void G1CodeRootSetTable::nmethods_do(CodeBlobClosure* blk) {
   for (int index = 0; index < table_size(); ++index) {
     for (Entry* e = bucket(index); e != NULL; e = e->next()) {
       blk->do_code_blob(e->literal());
     }
   }
 }

 template<typename CB>
 int G1CodeRootSetTable::remove_if(CB& should_remove) {
   int num_removed = 0;
   for (int index = 0; index < table_size(); ++index) {
     Entry* previous = NULL;
     Entry* e = bucket(index);
     while (e != NULL) {
       Entry* next = e->next();
       if (should_remove(e->literal())) {
         remove_entry(e, previous);
         ++num_removed;
       } else {
         previous = e;
       }
       e = next;
     }
   }
   return num_removed;
 }

 G1CodeRootSet::~G1CodeRootSet() {
   delete _table;
 }

 G1CodeRootSetTable* G1CodeRootSet::load_acquire_table() {
   return OrderAccess::load_acquire(&_table);
 }

 void G1CodeRootSet::allocate_small_table() {
   G1CodeRootSetTable* temp = new G1CodeRootSetTable(SmallSize);

   OrderAccess::release_store(&_table, temp);
 }

 void G1CodeRootSetTable::purge_list_append(G1CodeRootSetTable* table) {
   for (;;) {
     table->_purge_next = _purge_list;
     G1CodeRootSetTable* old = Atomic::cmpxchg(table, &_purge_list, table->_purge_next);
     if (old == table->_purge_next) {
       break;
     }
   }
 }

 void G1CodeRootSetTable::purge() {
   G1CodeRootSetTable* table = _purge_list;
   _purge_list = NULL;
   while (table != NULL) {
     G1CodeRootSetTable* to_purge = table;
     table = table->_purge_next;
     delete to_purge;
   }
 }

 void G1CodeRootSet::move_to_large() {
   G1CodeRootSetTable* temp = new G1CodeRootSetTable(LargeSize);

   _table->copy_to(temp);

   G1CodeRootSetTable::purge_list_append(_table);

   OrderAccess::release_store(&_table, temp);
 }

 void G1CodeRootSet::purge() {
   G1CodeRootSetTable::purge();
 }

 size_t G1CodeRootSet::static_mem_size() {
   return G1CodeRootSetTable::static_mem_size();
 }

 void G1CodeRootSet::add(nmethod* method) {
   bool added = false;
   if (is_empty()) {
     allocate_small_table();
   }
   added = _table->add(method);
   if (added) {
     if (_length == Threshold) {
       move_to_large();
     }
     ++_length;
   }
   assert(_length == (size_t)_table->number_of_entries(), "sizes should match");
 }

 bool G1CodeRootSet::remove(nmethod* method) {
   bool removed = false;
   if (_table != NULL) {
     removed = _table->remove(method);
   }
   if (removed) {
     _length--;
     if (_length == 0) {
       clear();
     }
   }
   assert((_length == 0 && _table == NULL) ||
          (_length == (size_t)_table->number_of_entries()), "sizes should match");
   return removed;
 }

 bool G1CodeRootSet::contains(nmethod* method) {
   G1CodeRootSetTable* table = load_acquire_table(); // contains() may be called outside of lock, so ensure mem sync.
   if (table != NULL) {
     return table->contains(method);
   }
   return false;
 }

 void G1CodeRootSet::clear() {
   delete _table;
   _table = NULL;
   _length = 0;
 }

 size_t G1CodeRootSet::mem_size() {
   return sizeof(*this) + (_table != NULL ? _table->mem_size() : 0);
 }

 void G1CodeRootSet::nmethods_do(CodeBlobClosure* blk) const {
   if (_table != NULL) {
     _table->nmethods_do(blk);
   }
 }

 class CleanCallback : public StackObj {
   class PointsIntoHRDetectionClosure : public OopClosure {
     HeapRegion* _hr;
    public:
     bool _points_into;
     PointsIntoHRDetectionClosure(HeapRegion* hr) : _hr(hr), _points_into(false) {}

     void do_oop(narrowOop* o) {
       do_oop_work(o);
     }

     void do_oop(oop* o) {
       do_oop_work(o);
     }

     template <typename T>
     void do_oop_work(T* p) {
       if (_hr->is_in(RawAccess<>::oop_load(p))) {
         _points_into = true;
       }
     }
   };

   PointsIntoHRDetectionClosure _detector;
   CodeBlobToOopClosure _blobs;

  public:
   CleanCallback(HeapRegion* hr) : _detector(hr), _blobs(&_detector, !CodeBlobToOopClosure::FixRelocations) {}

   bool operator() (nmethod* nm) {
     _detector._points_into = false;
     _blobs.do_code_blob(nm);
     return !_detector._points_into;
   }
 };

 void G1CodeRootSet::clean(HeapRegion* owner) {
   CleanCallback should_clean(owner);
   if (_table != NULL) {
     int removed = _table->remove_if(should_clean);
     assert((size_t)removed <= _length, "impossible");
     _length -= removed;
   }
   if (_length == 0) {
     clear();
   }
 }
	/*
	* Copyright (c) 2014, 2017, 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 "code/codeCache.hpp"
	#include "code/nmethod.hpp"
	#include "gc/g1/g1CodeRootSetTable.hpp"
	#include "gc/g1/g1CodeCacheRemSet.hpp"
	#include "gc/g1/heapRegion.hpp"
	#include "memory/heap.hpp"
	#include "memory/iterator.hpp"
	#include "oops/access.inline.hpp"
	#include "oops/oop.inline.hpp"
	#include "utilities/hashtable.inline.hpp"
	#include "utilities/stack.inline.hpp"

	G1CodeRootSetTable* volatile G1CodeRootSetTable::_purge_list = NULL;

	size_t G1CodeRootSetTable::mem_size() {
	return sizeof(G1CodeRootSetTable) + (entry_size() * number_of_entries()) + (sizeof(HashtableBucket<mtGC>) * table_size());
	}

	G1CodeRootSetTable::Entry* G1CodeRootSetTable::new_entry(nmethod* nm) {
	unsigned int hash = compute_hash(nm);
	Entry* entry = (Entry*) new_entry_free_list();
	if (entry == NULL) {
	entry = (Entry*) NEW_C_HEAP_ARRAY2(char, entry_size(), mtGC, CURRENT_PC);
	}
	entry->set_next(NULL);
	entry->set_hash(hash);
	entry->set_literal(nm);
	return entry;
	}

	void G1CodeRootSetTable::remove_entry(Entry* e, Entry* previous) {
	int index = hash_to_index(e->hash());
	assert((e == bucket(index)) == (previous == NULL), "if e is the first entry then previous should be null");

	if (previous == NULL) {
	set_entry(index, e->next());
	} else {
	previous->set_next(e->next());
	}
	free_entry(e);
	}

	G1CodeRootSetTable::~G1CodeRootSetTable() {
	for (int index = 0; index < table_size(); ++index) {
	for (Entry* e = bucket(index); e != NULL; ) {
	Entry* to_remove = e;
	// read next before freeing.
	e = e->next();
	unlink_entry(to_remove);
	FREE_C_HEAP_ARRAY(char, to_remove);
	}
	}
	assert(number_of_entries() == 0, "should have removed all entries");
	free_buckets();
	for (BasicHashtableEntry<mtGC>* e = new_entry_free_list(); e != NULL; e = new_entry_free_list()) {
	FREE_C_HEAP_ARRAY(char, e);
	}
	}

	bool G1CodeRootSetTable::add(nmethod* nm) {
	if (!contains(nm)) {
	Entry* e = new_entry(nm);
	int index = hash_to_index(e->hash());
	add_entry(index, e);
	return true;
	}
	return false;
	}

	bool G1CodeRootSetTable::contains(nmethod* nm) {
	int index = hash_to_index(compute_hash(nm));
	for (Entry* e = bucket(index); e != NULL; e = e->next()) {
	if (e->literal() == nm) {
	return true;
	}
	}
	return false;
	}

	bool G1CodeRootSetTable::remove(nmethod* nm) {
	int index = hash_to_index(compute_hash(nm));
	Entry* previous = NULL;
	for (Entry* e = bucket(index); e != NULL; previous = e, e = e->next()) {
	if (e->literal() == nm) {
	remove_entry(e, previous);
	return true;
	}
	}
	return false;
	}

	void G1CodeRootSetTable::copy_to(G1CodeRootSetTable* new_table) {
	for (int index = 0; index < table_size(); ++index) {
	for (Entry* e = bucket(index); e != NULL; e = e->next()) {
	new_table->add(e->literal());
	}
	}
	new_table->copy_freelist(this);
	}

	void G1CodeRootSetTable::nmethods_do(CodeBlobClosure* blk) {
	for (int index = 0; index < table_size(); ++index) {
	for (Entry* e = bucket(index); e != NULL; e = e->next()) {
	blk->do_code_blob(e->literal());
	}
	}
	}

	template<typename CB>
	int G1CodeRootSetTable::remove_if(CB& should_remove) {
	int num_removed = 0;
	for (int index = 0; index < table_size(); ++index) {
	Entry* previous = NULL;
	Entry* e = bucket(index);
	while (e != NULL) {
	Entry* next = e->next();
	if (should_remove(e->literal())) {
	remove_entry(e, previous);
	++num_removed;
	} else {
	previous = e;
	}
	e = next;
	}
	}
	return num_removed;
	}

	G1CodeRootSet::~G1CodeRootSet() {
	delete _table;
	}

	G1CodeRootSetTable* G1CodeRootSet::load_acquire_table() {
	return OrderAccess::load_acquire(&_table);
	}

	void G1CodeRootSet::allocate_small_table() {
	G1CodeRootSetTable* temp = new G1CodeRootSetTable(SmallSize);

	OrderAccess::release_store(&_table, temp);
	}

	void G1CodeRootSetTable::purge_list_append(G1CodeRootSetTable* table) {
	for (;;) {
	table->_purge_next = _purge_list;
	G1CodeRootSetTable* old = Atomic::cmpxchg(table, &_purge_list, table->_purge_next);
	if (old == table->_purge_next) {
	break;
	}
	}
	}

	void G1CodeRootSetTable::purge() {
	G1CodeRootSetTable* table = _purge_list;
	_purge_list = NULL;
	while (table != NULL) {
	G1CodeRootSetTable* to_purge = table;
	table = table->_purge_next;
	delete to_purge;
	}
	}

	void G1CodeRootSet::move_to_large() {
	G1CodeRootSetTable* temp = new G1CodeRootSetTable(LargeSize);

	_table->copy_to(temp);

	G1CodeRootSetTable::purge_list_append(_table);

	OrderAccess::release_store(&_table, temp);
	}

	void G1CodeRootSet::purge() {
	G1CodeRootSetTable::purge();
	}

	size_t G1CodeRootSet::static_mem_size() {
	return G1CodeRootSetTable::static_mem_size();
	}

	void G1CodeRootSet::add(nmethod* method) {
	bool added = false;
	if (is_empty()) {
	allocate_small_table();
	}
	added = _table->add(method);
	if (added) {
	if (_length == Threshold) {
	move_to_large();
	}
	++_length;
	}
	assert(_length == (size_t)_table->number_of_entries(), "sizes should match");
	}

	bool G1CodeRootSet::remove(nmethod* method) {
	bool removed = false;
	if (_table != NULL) {
	removed = _table->remove(method);
	}
	if (removed) {
	_length--;
	if (_length == 0) {
	clear();
	}
	}
	assert((_length == 0 && _table == NULL) \|\|
	(_length == (size_t)_table->number_of_entries()), "sizes should match");
	return removed;
	}

	bool G1CodeRootSet::contains(nmethod* method) {
	G1CodeRootSetTable* table = load_acquire_table(); // contains() may be called outside of lock, so ensure mem sync.
	if (table != NULL) {
	return table->contains(method);
	}
	return false;
	}

	void G1CodeRootSet::clear() {
	delete _table;
	_table = NULL;
	_length = 0;
	}

	size_t G1CodeRootSet::mem_size() {
	return sizeof(*this) + (_table != NULL ? _table->mem_size() : 0);
	}

	void G1CodeRootSet::nmethods_do(CodeBlobClosure* blk) const {
	if (_table != NULL) {
	_table->nmethods_do(blk);
	}
	}

	class CleanCallback : public StackObj {
	class PointsIntoHRDetectionClosure : public OopClosure {
	HeapRegion* _hr;
	public:
	bool _points_into;
	PointsIntoHRDetectionClosure(HeapRegion* hr) : _hr(hr), _points_into(false) {}

	void do_oop(narrowOop* o) {
	do_oop_work(o);
	}

	void do_oop(oop* o) {
	do_oop_work(o);
	}

	template <typename T>
	void do_oop_work(T* p) {
	if (_hr->is_in(RawAccess<>::oop_load(p))) {
	_points_into = true;
	}
	}
	};

	PointsIntoHRDetectionClosure _detector;
	CodeBlobToOopClosure _blobs;

	public:
	CleanCallback(HeapRegion* hr) : _detector(hr), _blobs(&_detector, !CodeBlobToOopClosure::FixRelocations) {}

	bool operator() (nmethod* nm) {
	_detector._points_into = false;
	_blobs.do_code_blob(nm);
	return !_detector._points_into;
	}
	};

	void G1CodeRootSet::clean(HeapRegion* owner) {
	CleanCallback should_clean(owner);
	if (_table != NULL) {
	int removed = _table->remove_if(should_clean);
	assert((size_t)removed <= _length, "impossible");
	_length -= removed;
	}
	if (_length == 0) {
	clear();
	}
	}