8004241: NPG: Metaspace occupies more memory than specified by -XX:MaxMetaspaceSize option
Summary: Enforce MaxMetaspaceSize for both metaspace parts, check MaxMetaspaceSize against "reserved", not "capacity"
Reviewed-by: jmasa, johnc
/*
* Copyright (c) 2011, 2013, 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.
*
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*/
#include "precompiled.hpp"
#include "gc_interface/collectedHeap.hpp"
#include "memory/binaryTreeDictionary.hpp"
#include "memory/freeList.hpp"
#include "memory/collectorPolicy.hpp"
#include "memory/filemap.hpp"
#include "memory/freeList.hpp"
#include "memory/metablock.hpp"
#include "memory/metachunk.hpp"
#include "memory/metaspace.hpp"
#include "memory/metaspaceShared.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.hpp"
#include "runtime/globals.hpp"
#include "runtime/mutex.hpp"
#include "runtime/orderAccess.hpp"
#include "services/memTracker.hpp"
#include "utilities/copy.hpp"
#include "utilities/debug.hpp"
typedef BinaryTreeDictionary<Metablock, FreeList> BlockTreeDictionary;
typedef BinaryTreeDictionary<Metachunk, FreeList> ChunkTreeDictionary;
// Define this macro to enable slow integrity checking of
// the free chunk lists
const bool metaspace_slow_verify = false;
// Parameters for stress mode testing
const uint metadata_deallocate_a_lot_block = 10;
const uint metadata_deallocate_a_lock_chunk = 3;
size_t const allocation_from_dictionary_limit = 64 * K;
MetaWord* last_allocated = 0;
// Used in declarations in SpaceManager and ChunkManager
enum ChunkIndex {
ZeroIndex = 0,
SpecializedIndex = ZeroIndex,
SmallIndex = SpecializedIndex + 1,
MediumIndex = SmallIndex + 1,
HumongousIndex = MediumIndex + 1,
NumberOfFreeLists = 3,
NumberOfInUseLists = 4
};
enum ChunkSizes { // in words.
ClassSpecializedChunk = 128,
SpecializedChunk = 128,
ClassSmallChunk = 256,
SmallChunk = 512,
ClassMediumChunk = 1 * K,
MediumChunk = 8 * K,
HumongousChunkGranularity = 8
};
static ChunkIndex next_chunk_index(ChunkIndex i) {
assert(i < NumberOfInUseLists, "Out of bound");
return (ChunkIndex) (i+1);
}
// Originally _capacity_until_GC was set to MetaspaceSize here but
// the default MetaspaceSize before argument processing was being
// used which was not the desired value. See the code
// in should_expand() to see how the initialization is handled
// now.
size_t MetaspaceGC::_capacity_until_GC = 0;
bool MetaspaceGC::_expand_after_GC = false;
uint MetaspaceGC::_shrink_factor = 0;
bool MetaspaceGC::_should_concurrent_collect = false;
// Blocks of space for metadata are allocated out of Metachunks.
//
// Metachunk are allocated out of MetadataVirtualspaces and once
// allocated there is no explicit link between a Metachunk and
// the MetadataVirtualspaces from which it was allocated.
//
// Each SpaceManager maintains a
// list of the chunks it is using and the current chunk. The current
// chunk is the chunk from which allocations are done. Space freed in
// a chunk is placed on the free list of blocks (BlockFreelist) and
// reused from there.
// Pointer to list of Metachunks.
class ChunkList VALUE_OBJ_CLASS_SPEC {
// List of free chunks
Metachunk* _head;
public:
// Constructor
ChunkList() : _head(NULL) {}
// Accessors
Metachunk* head() { return _head; }
void set_head(Metachunk* v) { _head = v; }
// Link at head of the list
void add_at_head(Metachunk* head, Metachunk* tail);
void add_at_head(Metachunk* head);
size_t sum_list_size();
size_t sum_list_count();
size_t sum_list_capacity();
};
// Manages the global free lists of chunks.
// Has three lists of free chunks, and a total size and
// count that includes all three
class ChunkManager VALUE_OBJ_CLASS_SPEC {
// Free list of chunks of different sizes.
// SmallChunk
// MediumChunk
// HumongousChunk
ChunkList _free_chunks[NumberOfFreeLists];
// HumongousChunk
ChunkTreeDictionary _humongous_dictionary;
// ChunkManager in all lists of this type
size_t _free_chunks_total;
size_t _free_chunks_count;
void dec_free_chunks_total(size_t v) {
assert(_free_chunks_count > 0 &&
_free_chunks_total > 0,
"About to go negative");
Atomic::add_ptr(-1, &_free_chunks_count);
jlong minus_v = (jlong) - (jlong) v;
Atomic::add_ptr(minus_v, &_free_chunks_total);
}
// Debug support
size_t sum_free_chunks();
size_t sum_free_chunks_count();
void locked_verify_free_chunks_total();
void slow_locked_verify_free_chunks_total() {
if (metaspace_slow_verify) {
locked_verify_free_chunks_total();
}
}
void locked_verify_free_chunks_count();
void slow_locked_verify_free_chunks_count() {
if (metaspace_slow_verify) {
locked_verify_free_chunks_count();
}
}
void verify_free_chunks_count();
public:
ChunkManager() : _free_chunks_total(0), _free_chunks_count(0) {}
// add or delete (return) a chunk to the global freelist.
Metachunk* chunk_freelist_allocate(size_t word_size);
void chunk_freelist_deallocate(Metachunk* chunk);
// Map a size to a list index assuming that there are lists
// for special, small, medium, and humongous chunks.
static ChunkIndex list_index(size_t size);
// Total of the space in the free chunks list
size_t free_chunks_total();
size_t free_chunks_total_in_bytes();
// Number of chunks in the free chunks list
size_t free_chunks_count();
void inc_free_chunks_total(size_t v, size_t count = 1) {
Atomic::add_ptr(count, &_free_chunks_count);
Atomic::add_ptr(v, &_free_chunks_total);
}
ChunkTreeDictionary* humongous_dictionary() {
return &_humongous_dictionary;
}
ChunkList* free_chunks(ChunkIndex index);
// Returns the list for the given chunk word size.
ChunkList* find_free_chunks_list(size_t word_size);
// Add and remove from a list by size. Selects
// list based on size of chunk.
void free_chunks_put(Metachunk* chuck);
Metachunk* free_chunks_get(size_t chunk_word_size);
// Debug support
void verify();
void slow_verify() {
if (metaspace_slow_verify) {
verify();
}
}
void locked_verify();
void slow_locked_verify() {
if (metaspace_slow_verify) {
locked_verify();
}
}
void verify_free_chunks_total();
void locked_print_free_chunks(outputStream* st);
void locked_print_sum_free_chunks(outputStream* st);
void print_on(outputStream* st);
};
// Used to manage the free list of Metablocks (a block corresponds
// to the allocation of a quantum of metadata).
class BlockFreelist VALUE_OBJ_CLASS_SPEC {
BlockTreeDictionary* _dictionary;
static Metablock* initialize_free_chunk(MetaWord* p, size_t word_size);
// Accessors
BlockTreeDictionary* dictionary() const { return _dictionary; }
public:
BlockFreelist();
~BlockFreelist();
// Get and return a block to the free list
MetaWord* get_block(size_t word_size);
void return_block(MetaWord* p, size_t word_size);
size_t total_size() {
if (dictionary() == NULL) {
return 0;
} else {
return dictionary()->total_size();
}
}
void print_on(outputStream* st) const;
};
class VirtualSpaceNode : public CHeapObj<mtClass> {
friend class VirtualSpaceList;
// Link to next VirtualSpaceNode
VirtualSpaceNode* _next;
// total in the VirtualSpace
MemRegion _reserved;
ReservedSpace _rs;
VirtualSpace _virtual_space;
MetaWord* _top;
// Convenience functions for logical bottom and end
MetaWord* bottom() const { return (MetaWord*) _virtual_space.low(); }
MetaWord* end() const { return (MetaWord*) _virtual_space.high(); }
// Convenience functions to access the _virtual_space
char* low() const { return virtual_space()->low(); }
char* high() const { return virtual_space()->high(); }
public:
VirtualSpaceNode(size_t byte_size);
VirtualSpaceNode(ReservedSpace rs) : _top(NULL), _next(NULL), _rs(rs) {}
~VirtualSpaceNode();
// address of next available space in _virtual_space;
// Accessors
VirtualSpaceNode* next() { return _next; }
void set_next(VirtualSpaceNode* v) { _next = v; }
void set_reserved(MemRegion const v) { _reserved = v; }
void set_top(MetaWord* v) { _top = v; }
// Accessors
MemRegion* reserved() { return &_reserved; }
VirtualSpace* virtual_space() const { return (VirtualSpace*) &_virtual_space; }
// Returns true if "word_size" is available in the virtual space
bool is_available(size_t word_size) { return _top + word_size <= end(); }
MetaWord* top() const { return _top; }
void inc_top(size_t word_size) { _top += word_size; }
// used and capacity in this single entry in the list
size_t used_words_in_vs() const;
size_t capacity_words_in_vs() const;
bool initialize();
// get space from the virtual space
Metachunk* take_from_committed(size_t chunk_word_size);
// Allocate a chunk from the virtual space and return it.
Metachunk* get_chunk_vs(size_t chunk_word_size);
Metachunk* get_chunk_vs_with_expand(size_t chunk_word_size);
// Expands/shrinks the committed space in a virtual space. Delegates
// to Virtualspace
bool expand_by(size_t words, bool pre_touch = false);
bool shrink_by(size_t words);
#ifdef ASSERT
// Debug support
static void verify_virtual_space_total();
static void verify_virtual_space_count();
void mangle();
#endif
void print_on(outputStream* st) const;
};
// byte_size is the size of the associated virtualspace.
VirtualSpaceNode::VirtualSpaceNode(size_t byte_size) : _top(NULL), _next(NULL), _rs(0) {
// This allocates memory with mmap. For DumpSharedspaces, allocate the
// space at low memory so that other shared images don't conflict.
// This is the same address as memory needed for UseCompressedOops but
// compressed oops don't work with CDS (offsets in metadata are wrong), so
// borrow the same address.
if (DumpSharedSpaces) {
char* shared_base = (char*)HeapBaseMinAddress;
_rs = ReservedSpace(byte_size, 0, false, shared_base, 0);
if (_rs.is_reserved()) {
assert(_rs.base() == shared_base, "should match");
} else {
// If we are dumping the heap, then allocate a wasted block of address
// space in order to push the heap to a lower address. This extra
// address range allows for other (or larger) libraries to be loaded
// without them occupying the space required for the shared spaces.
uintx reserved = 0;
uintx block_size = 64*1024*1024;
while (reserved < SharedDummyBlockSize) {
char* dummy = os::reserve_memory(block_size);
reserved += block_size;
}
_rs = ReservedSpace(byte_size);
}
MetaspaceShared::set_shared_rs(&_rs);
} else {
_rs = ReservedSpace(byte_size);
}
MemTracker::record_virtual_memory_type((address)_rs.base(), mtClass);
}
// List of VirtualSpaces for metadata allocation.
// It has a _next link for singly linked list and a MemRegion
// for total space in the VirtualSpace.
class VirtualSpaceList : public CHeapObj<mtClass> {
friend class VirtualSpaceNode;
enum VirtualSpaceSizes {
VirtualSpaceSize = 256 * K
};
// Global list of virtual spaces
// Head of the list
VirtualSpaceNode* _virtual_space_list;
// virtual space currently being used for allocations
VirtualSpaceNode* _current_virtual_space;
// Free chunk list for all other metadata
ChunkManager _chunk_manager;
// Can this virtual list allocate >1 spaces? Also, used to determine
// whether to allocate unlimited small chunks in this virtual space
bool _is_class;
bool can_grow() const { return !is_class() || !UseCompressedKlassPointers; }
// Sum of space in all virtual spaces and number of virtual spaces
size_t _virtual_space_total;
size_t _virtual_space_count;
~VirtualSpaceList();
VirtualSpaceNode* virtual_space_list() const { return _virtual_space_list; }
void set_virtual_space_list(VirtualSpaceNode* v) {
_virtual_space_list = v;
}
void set_current_virtual_space(VirtualSpaceNode* v) {
_current_virtual_space = v;
}
void link_vs(VirtualSpaceNode* new_entry, size_t vs_word_size);
// Get another virtual space and add it to the list. This
// is typically prompted by a failed attempt to allocate a chunk
// and is typically followed by the allocation of a chunk.
bool grow_vs(size_t vs_word_size);
public:
VirtualSpaceList(size_t word_size);
VirtualSpaceList(ReservedSpace rs);
Metachunk* get_new_chunk(size_t word_size,
size_t grow_chunks_by_words,
size_t medium_chunk_bunch);
// Get the first chunk for a Metaspace. Used for
// special cases such as the boot class loader, reflection
// class loader and anonymous class loader.
Metachunk* get_initialization_chunk(size_t word_size, size_t chunk_bunch);
VirtualSpaceNode* current_virtual_space() {
return _current_virtual_space;
}
ChunkManager* chunk_manager() { return &_chunk_manager; }
bool is_class() const { return _is_class; }
// Allocate the first virtualspace.
void initialize(size_t word_size);
size_t virtual_space_total() { return _virtual_space_total; }
void inc_virtual_space_total(size_t v) {
Atomic::add_ptr(v, &_virtual_space_total);
}
size_t virtual_space_count() { return _virtual_space_count; }
void inc_virtual_space_count() {
Atomic::inc_ptr(&_virtual_space_count);
}
// Used and capacity in the entire list of virtual spaces.
// These are global values shared by all Metaspaces
size_t capacity_words_sum();
size_t capacity_bytes_sum() { return capacity_words_sum() * BytesPerWord; }
size_t used_words_sum();
size_t used_bytes_sum() { return used_words_sum() * BytesPerWord; }
bool contains(const void *ptr);
void print_on(outputStream* st) const;
class VirtualSpaceListIterator : public StackObj {
VirtualSpaceNode* _virtual_spaces;
public:
VirtualSpaceListIterator(VirtualSpaceNode* virtual_spaces) :
_virtual_spaces(virtual_spaces) {}
bool repeat() {
return _virtual_spaces != NULL;
}
VirtualSpaceNode* get_next() {
VirtualSpaceNode* result = _virtual_spaces;
if (_virtual_spaces != NULL) {
_virtual_spaces = _virtual_spaces->next();
}
return result;
}
};
};
class Metadebug : AllStatic {
// Debugging support for Metaspaces
static int _deallocate_block_a_lot_count;
static int _deallocate_chunk_a_lot_count;
static int _allocation_fail_alot_count;
public:
static int deallocate_block_a_lot_count() {
return _deallocate_block_a_lot_count;
}
static void set_deallocate_block_a_lot_count(int v) {
_deallocate_block_a_lot_count = v;
}
static void inc_deallocate_block_a_lot_count() {
_deallocate_block_a_lot_count++;
}
static int deallocate_chunk_a_lot_count() {
return _deallocate_chunk_a_lot_count;
}
static void reset_deallocate_chunk_a_lot_count() {
_deallocate_chunk_a_lot_count = 1;
}
static void inc_deallocate_chunk_a_lot_count() {
_deallocate_chunk_a_lot_count++;
}
static void init_allocation_fail_alot_count();
#ifdef ASSERT
static bool test_metadata_failure();
#endif
static void deallocate_chunk_a_lot(SpaceManager* sm,
size_t chunk_word_size);
static void deallocate_block_a_lot(SpaceManager* sm,
size_t chunk_word_size);
};
int Metadebug::_deallocate_block_a_lot_count = 0;
int Metadebug::_deallocate_chunk_a_lot_count = 0;
int Metadebug::_allocation_fail_alot_count = 0;
// SpaceManager - used by Metaspace to handle allocations
class SpaceManager : public CHeapObj<mtClass> {
friend class Metaspace;
friend class Metadebug;
private:
// protects allocations and contains.
Mutex* const _lock;
// Chunk related size
size_t _medium_chunk_bunch;
// List of chunks in use by this SpaceManager. Allocations
// are done from the current chunk. The list is used for deallocating
// chunks when the SpaceManager is freed.
Metachunk* _chunks_in_use[NumberOfInUseLists];
Metachunk* _current_chunk;
// Virtual space where allocation comes from.
VirtualSpaceList* _vs_list;
// Number of small chunks to allocate to a manager
// If class space manager, small chunks are unlimited
static uint const _small_chunk_limit;
bool has_small_chunk_limit() { return !vs_list()->is_class(); }
// Sum of all space in allocated chunks
size_t _allocation_total;
// Free lists of blocks are per SpaceManager since they
// are assumed to be in chunks in use by the SpaceManager
// and all chunks in use by a SpaceManager are freed when
// the class loader using the SpaceManager is collected.
BlockFreelist _block_freelists;
// protects virtualspace and chunk expansions
static const char* _expand_lock_name;
static const int _expand_lock_rank;
static Mutex* const _expand_lock;
private:
// Accessors
Metachunk* chunks_in_use(ChunkIndex index) const { return _chunks_in_use[index]; }
void set_chunks_in_use(ChunkIndex index, Metachunk* v) { _chunks_in_use[index] = v; }
BlockFreelist* block_freelists() const {
return (BlockFreelist*) &_block_freelists;
}
VirtualSpaceList* vs_list() const { return _vs_list; }
Metachunk* current_chunk() const { return _current_chunk; }
void set_current_chunk(Metachunk* v) {
_current_chunk = v;
}
Metachunk* find_current_chunk(size_t word_size);
// Add chunk to the list of chunks in use
void add_chunk(Metachunk* v, bool make_current);
Mutex* lock() const { return _lock; }
const char* chunk_size_name(ChunkIndex index) const;
protected:
void initialize();
public:
SpaceManager(Mutex* lock,
VirtualSpaceList* vs_list);
~SpaceManager();
enum ChunkMultiples {
MediumChunkMultiple = 4
};
// Accessors
size_t specialized_chunk_size() { return SpecializedChunk; }
size_t small_chunk_size() { return (size_t) vs_list()->is_class() ? ClassSmallChunk : SmallChunk; }
size_t medium_chunk_size() { return (size_t) vs_list()->is_class() ? ClassMediumChunk : MediumChunk; }
size_t medium_chunk_bunch() { return medium_chunk_size() * MediumChunkMultiple; }
size_t allocation_total() const { return _allocation_total; }
void inc_allocation_total(size_t v) { Atomic::add_ptr(v, &_allocation_total); }
bool is_humongous(size_t word_size) { return word_size > medium_chunk_size(); }
static Mutex* expand_lock() { return _expand_lock; }
// Set the sizes for the initial chunks.
void get_initial_chunk_sizes(Metaspace::MetaspaceType type,
size_t* chunk_word_size,
size_t* class_chunk_word_size);
size_t sum_capacity_in_chunks_in_use() const;
size_t sum_used_in_chunks_in_use() const;
size_t sum_free_in_chunks_in_use() const;
size_t sum_waste_in_chunks_in_use() const;
size_t sum_waste_in_chunks_in_use(ChunkIndex index ) const;
size_t sum_count_in_chunks_in_use();
size_t sum_count_in_chunks_in_use(ChunkIndex i);
Metachunk* get_new_chunk(size_t word_size, size_t grow_chunks_by_words);
// Block allocation and deallocation.
// Allocates a block from the current chunk
MetaWord* allocate(size_t word_size);
// Helper for allocations
MetaWord* allocate_work(size_t word_size);
// Returns a block to the per manager freelist
void deallocate(MetaWord* p, size_t word_size);
// Based on the allocation size and a minimum chunk size,
// returned chunk size (for expanding space for chunk allocation).
size_t calc_chunk_size(size_t allocation_word_size);
// Called when an allocation from the current chunk fails.
// Gets a new chunk (may require getting a new virtual space),
// and allocates from that chunk.
MetaWord* grow_and_allocate(size_t word_size);
// debugging support.
void dump(outputStream* const out) const;
void print_on(outputStream* st) const;
void locked_print_chunks_in_use_on(outputStream* st) const;
void verify();
void verify_chunk_size(Metachunk* chunk);
NOT_PRODUCT(void mangle_freed_chunks();)
#ifdef ASSERT
void verify_allocation_total();
#endif
};
uint const SpaceManager::_small_chunk_limit = 4;
const char* SpaceManager::_expand_lock_name =
"SpaceManager chunk allocation lock";
const int SpaceManager::_expand_lock_rank = Monitor::leaf - 1;
Mutex* const SpaceManager::_expand_lock =
new Mutex(SpaceManager::_expand_lock_rank,
SpaceManager::_expand_lock_name,
Mutex::_allow_vm_block_flag);
// BlockFreelist methods
BlockFreelist::BlockFreelist() : _dictionary(NULL) {}
BlockFreelist::~BlockFreelist() {
if (_dictionary != NULL) {
if (Verbose && TraceMetadataChunkAllocation) {
_dictionary->print_free_lists(gclog_or_tty);
}
delete _dictionary;
}
}
Metablock* BlockFreelist::initialize_free_chunk(MetaWord* p, size_t word_size) {
Metablock* block = (Metablock*) p;
block->set_word_size(word_size);
block->set_prev(NULL);
block->set_next(NULL);
return block;
}
void BlockFreelist::return_block(MetaWord* p, size_t word_size) {
Metablock* free_chunk = initialize_free_chunk(p, word_size);
if (dictionary() == NULL) {
_dictionary = new BlockTreeDictionary();
}
dictionary()->return_chunk(free_chunk);
}
MetaWord* BlockFreelist::get_block(size_t word_size) {
if (dictionary() == NULL) {
return NULL;
}
if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
// Dark matter. Too small for dictionary.
return NULL;
}
Metablock* free_block =
dictionary()->get_chunk(word_size, FreeBlockDictionary<Metablock>::exactly);
if (free_block == NULL) {
return NULL;
}
return (MetaWord*) free_block;
}
void BlockFreelist::print_on(outputStream* st) const {
if (dictionary() == NULL) {
return;
}
dictionary()->print_free_lists(st);
}
// VirtualSpaceNode methods
VirtualSpaceNode::~VirtualSpaceNode() {
_rs.release();
}
size_t VirtualSpaceNode::used_words_in_vs() const {
return pointer_delta(top(), bottom(), sizeof(MetaWord));
}
// Space committed in the VirtualSpace
size_t VirtualSpaceNode::capacity_words_in_vs() const {
return pointer_delta(end(), bottom(), sizeof(MetaWord));
}
// Allocates the chunk from the virtual space only.
// This interface is also used internally for debugging. Not all
// chunks removed here are necessarily used for allocation.
Metachunk* VirtualSpaceNode::take_from_committed(size_t chunk_word_size) {
// Bottom of the new chunk
MetaWord* chunk_limit = top();
assert(chunk_limit != NULL, "Not safe to call this method");
if (!is_available(chunk_word_size)) {
if (TraceMetadataChunkAllocation) {
tty->print("VirtualSpaceNode::take_from_committed() not available %d words ", chunk_word_size);
// Dump some information about the virtual space that is nearly full
print_on(tty);
}
return NULL;
}
// Take the space (bump top on the current virtual space).
inc_top(chunk_word_size);
// Point the chunk at the space
Metachunk* result = Metachunk::initialize(chunk_limit, chunk_word_size);
return result;
}
// Expand the virtual space (commit more of the reserved space)
bool VirtualSpaceNode::expand_by(size_t words, bool pre_touch) {
size_t bytes = words * BytesPerWord;
bool result = virtual_space()->expand_by(bytes, pre_touch);
if (TraceMetavirtualspaceAllocation && !result) {
gclog_or_tty->print_cr("VirtualSpaceNode::expand_by() failed "
"for byte size " SIZE_FORMAT, bytes);
virtual_space()->print();
}
return result;
}
// Shrink the virtual space (commit more of the reserved space)
bool VirtualSpaceNode::shrink_by(size_t words) {
size_t bytes = words * BytesPerWord;
virtual_space()->shrink_by(bytes);
return true;
}
// Add another chunk to the chunk list.
Metachunk* VirtualSpaceNode::get_chunk_vs(size_t chunk_word_size) {
assert_lock_strong(SpaceManager::expand_lock());
Metachunk* result = NULL;
return take_from_committed(chunk_word_size);
}
Metachunk* VirtualSpaceNode::get_chunk_vs_with_expand(size_t chunk_word_size) {
assert_lock_strong(SpaceManager::expand_lock());
Metachunk* new_chunk = get_chunk_vs(chunk_word_size);
if (new_chunk == NULL) {
// Only a small part of the virtualspace is committed when first
// allocated so committing more here can be expected.
size_t page_size_words = os::vm_page_size() / BytesPerWord;
size_t aligned_expand_vs_by_words = align_size_up(chunk_word_size,
page_size_words);
expand_by(aligned_expand_vs_by_words, false);
new_chunk = get_chunk_vs(chunk_word_size);
}
return new_chunk;
}
bool VirtualSpaceNode::initialize() {
if (!_rs.is_reserved()) {
return false;
}
// An allocation out of this Virtualspace that is larger
// than an initial commit size can waste that initial committed
// space.
size_t committed_byte_size = 0;
bool result = virtual_space()->initialize(_rs, committed_byte_size);
if (result) {
set_top((MetaWord*)virtual_space()->low());
set_reserved(MemRegion((HeapWord*)_rs.base(),
(HeapWord*)(_rs.base() + _rs.size())));
assert(reserved()->start() == (HeapWord*) _rs.base(),
err_msg("Reserved start was not set properly " PTR_FORMAT
" != " PTR_FORMAT, reserved()->start(), _rs.base()));
assert(reserved()->word_size() == _rs.size() / BytesPerWord,
err_msg("Reserved size was not set properly " SIZE_FORMAT
" != " SIZE_FORMAT, reserved()->word_size(),
_rs.size() / BytesPerWord));
}
return result;
}
void VirtualSpaceNode::print_on(outputStream* st) const {
size_t used = used_words_in_vs();
size_t capacity = capacity_words_in_vs();
VirtualSpace* vs = virtual_space();
st->print_cr(" space @ " PTR_FORMAT " " SIZE_FORMAT "K, %3d%% used "
"[" PTR_FORMAT ", " PTR_FORMAT ", "
PTR_FORMAT ", " PTR_FORMAT ")",
vs, capacity / K,
capacity == 0 ? 0 : used * 100 / capacity,
bottom(), top(), end(),
vs->high_boundary());
}
#ifdef ASSERT
void VirtualSpaceNode::mangle() {
size_t word_size = capacity_words_in_vs();
Copy::fill_to_words((HeapWord*) low(), word_size, 0xf1f1f1f1);
}
#endif // ASSERT
// VirtualSpaceList methods
// Space allocated from the VirtualSpace
VirtualSpaceList::~VirtualSpaceList() {
VirtualSpaceListIterator iter(virtual_space_list());
while (iter.repeat()) {
VirtualSpaceNode* vsl = iter.get_next();
delete vsl;
}
}
size_t VirtualSpaceList::used_words_sum() {
size_t allocated_by_vs = 0;
VirtualSpaceListIterator iter(virtual_space_list());
while (iter.repeat()) {
VirtualSpaceNode* vsl = iter.get_next();
// Sum used region [bottom, top) in each virtualspace
allocated_by_vs += vsl->used_words_in_vs();
}
assert(allocated_by_vs >= chunk_manager()->free_chunks_total(),
err_msg("Total in free chunks " SIZE_FORMAT
" greater than total from virtual_spaces " SIZE_FORMAT,
allocated_by_vs, chunk_manager()->free_chunks_total()));
size_t used =
allocated_by_vs - chunk_manager()->free_chunks_total();
return used;
}
// Space available in all MetadataVirtualspaces allocated
// for metadata. This is the upper limit on the capacity
// of chunks allocated out of all the MetadataVirtualspaces.
size_t VirtualSpaceList::capacity_words_sum() {
size_t capacity = 0;
VirtualSpaceListIterator iter(virtual_space_list());
while (iter.repeat()) {
VirtualSpaceNode* vsl = iter.get_next();
capacity += vsl->capacity_words_in_vs();
}
return capacity;
}
VirtualSpaceList::VirtualSpaceList(size_t word_size ) :
_is_class(false),
_virtual_space_list(NULL),
_current_virtual_space(NULL),
_virtual_space_total(0),
_virtual_space_count(0) {
MutexLockerEx cl(SpaceManager::expand_lock(),
Mutex::_no_safepoint_check_flag);
bool initialization_succeeded = grow_vs(word_size);
assert(initialization_succeeded,
" VirtualSpaceList initialization should not fail");
}
VirtualSpaceList::VirtualSpaceList(ReservedSpace rs) :
_is_class(true),
_virtual_space_list(NULL),
_current_virtual_space(NULL),
_virtual_space_total(0),
_virtual_space_count(0) {
MutexLockerEx cl(SpaceManager::expand_lock(),
Mutex::_no_safepoint_check_flag);
VirtualSpaceNode* class_entry = new VirtualSpaceNode(rs);
bool succeeded = class_entry->initialize();
assert(succeeded, " VirtualSpaceList initialization should not fail");
link_vs(class_entry, rs.size()/BytesPerWord);
}
// Allocate another meta virtual space and add it to the list.
bool VirtualSpaceList::grow_vs(size_t vs_word_size) {
assert_lock_strong(SpaceManager::expand_lock());
if (vs_word_size == 0) {
return false;
}
// Reserve the space
size_t vs_byte_size = vs_word_size * BytesPerWord;
assert(vs_byte_size % os::vm_page_size() == 0, "Not aligned");
// Allocate the meta virtual space and initialize it.
VirtualSpaceNode* new_entry = new VirtualSpaceNode(vs_byte_size);
if (!new_entry->initialize()) {
delete new_entry;
return false;
} else {
// ensure lock-free iteration sees fully initialized node
OrderAccess::storestore();
link_vs(new_entry, vs_word_size);
return true;
}
}
void VirtualSpaceList::link_vs(VirtualSpaceNode* new_entry, size_t vs_word_size) {
if (virtual_space_list() == NULL) {
set_virtual_space_list(new_entry);
} else {
current_virtual_space()->set_next(new_entry);
}
set_current_virtual_space(new_entry);
inc_virtual_space_total(vs_word_size);
inc_virtual_space_count();
#ifdef ASSERT
new_entry->mangle();
#endif
if (TraceMetavirtualspaceAllocation && Verbose) {
VirtualSpaceNode* vsl = current_virtual_space();
vsl->print_on(tty);
}
}
Metachunk* VirtualSpaceList::get_new_chunk(size_t word_size,
size_t grow_chunks_by_words,
size_t medium_chunk_bunch) {
// Get a chunk from the chunk freelist
Metachunk* next = chunk_manager()->chunk_freelist_allocate(grow_chunks_by_words);
// Allocate a chunk out of the current virtual space.
if (next == NULL) {
next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
}
if (next == NULL) {
// Not enough room in current virtual space. Try to commit
// more space.
size_t expand_vs_by_words = MAX2(medium_chunk_bunch,
grow_chunks_by_words);
size_t page_size_words = os::vm_page_size() / BytesPerWord;
size_t aligned_expand_vs_by_words = align_size_up(expand_vs_by_words,
page_size_words);
bool vs_expanded =
current_virtual_space()->expand_by(aligned_expand_vs_by_words, false);
if (!vs_expanded) {
// Should the capacity of the metaspaces be expanded for
// this allocation? If it's the virtual space for classes and is
// being used for CompressedHeaders, don't allocate a new virtualspace.
if (can_grow() && MetaspaceGC::should_expand(this, word_size)) {
// Get another virtual space.
size_t grow_vs_words =
MAX2((size_t)VirtualSpaceSize, aligned_expand_vs_by_words);
if (grow_vs(grow_vs_words)) {
// Got it. It's on the list now. Get a chunk from it.
next = current_virtual_space()->get_chunk_vs_with_expand(grow_chunks_by_words);
}
} else {
// Allocation will fail and induce a GC
if (TraceMetadataChunkAllocation && Verbose) {
gclog_or_tty->print_cr("VirtualSpaceList::get_new_chunk():"
" Fail instead of expand the metaspace");
}
}
} else {
// The virtual space expanded, get a new chunk
next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
assert(next != NULL, "Just expanded, should succeed");
}
}
assert(next == NULL || (next->next() == NULL && next->prev() == NULL),
"New chunk is still on some list");
return next;
}
Metachunk* VirtualSpaceList::get_initialization_chunk(size_t chunk_word_size,
size_t chunk_bunch) {
// Get a chunk from the chunk freelist
Metachunk* new_chunk = get_new_chunk(chunk_word_size,
chunk_word_size,
chunk_bunch);
return new_chunk;
}
void VirtualSpaceList::print_on(outputStream* st) const {
if (TraceMetadataChunkAllocation && Verbose) {
VirtualSpaceListIterator iter(virtual_space_list());
while (iter.repeat()) {
VirtualSpaceNode* node = iter.get_next();
node->print_on(st);
}
}
}
bool VirtualSpaceList::contains(const void *ptr) {
VirtualSpaceNode* list = virtual_space_list();
VirtualSpaceListIterator iter(list);
while (iter.repeat()) {
VirtualSpaceNode* node = iter.get_next();
if (node->reserved()->contains(ptr)) {
return true;
}
}
return false;
}
// MetaspaceGC methods
// VM_CollectForMetadataAllocation is the vm operation used to GC.
// Within the VM operation after the GC the attempt to allocate the metadata
// should succeed. If the GC did not free enough space for the metaspace
// allocation, the HWM is increased so that another virtualspace will be
// allocated for the metadata. With perm gen the increase in the perm
// gen had bounds, MinMetaspaceExpansion and MaxMetaspaceExpansion. The
// metaspace policy uses those as the small and large steps for the HWM.
//
// After the GC the compute_new_size() for MetaspaceGC is called to
// resize the capacity of the metaspaces. The current implementation
// is based on the flags MinMetaspaceFreeRatio and MaxHeapFreeRatio used
// to resize the Java heap by some GC's. New flags can be implemented
// if really needed. MinHeapFreeRatio is used to calculate how much
// free space is desirable in the metaspace capacity to decide how much
// to increase the HWM. MaxMetaspaceFreeRatio is used to decide how much
// free space is desirable in the metaspace capacity before decreasing
// the HWM.
// Calculate the amount to increase the high water mark (HWM).
// Increase by a minimum amount (MinMetaspaceExpansion) so that
// another expansion is not requested too soon. If that is not
// enough to satisfy the allocation (i.e. big enough for a word_size
// allocation), increase by MaxMetaspaceExpansion. If that is still
// not enough, expand by the size of the allocation (word_size) plus
// some.
size_t MetaspaceGC::delta_capacity_until_GC(size_t word_size) {
size_t before_inc = MetaspaceGC::capacity_until_GC();
size_t min_delta_words = MinMetaspaceExpansion / BytesPerWord;
size_t max_delta_words = MaxMetaspaceExpansion / BytesPerWord;
size_t page_size_words = os::vm_page_size() / BytesPerWord;
size_t size_delta_words = align_size_up(word_size, page_size_words);
size_t delta_words = MAX2(size_delta_words, min_delta_words);
if (delta_words > min_delta_words) {
// Don't want to hit the high water mark on the next
// allocation so make the delta greater than just enough
// for this allocation.
delta_words = MAX2(delta_words, max_delta_words);
if (delta_words > max_delta_words) {
// This allocation is large but the next ones are probably not
// so increase by the minimum.
delta_words = delta_words + min_delta_words;
}
}
return delta_words;
}
bool MetaspaceGC::should_expand(VirtualSpaceList* vsl, size_t word_size) {
// If the user wants a limit, impose one.
if (!FLAG_IS_DEFAULT(MaxMetaspaceSize) &&
MetaspaceAux::reserved_in_bytes() >= MaxMetaspaceSize) {
return false;
}
// Class virtual space should always be expanded. Call GC for the other
// metadata virtual space.
if (vsl == Metaspace::class_space_list()) return true;
// If this is part of an allocation after a GC, expand
// unconditionally.
if(MetaspaceGC::expand_after_GC()) {
return true;
}
size_t metaspace_size_words = MetaspaceSize / BytesPerWord;
// If the capacity is below the minimum capacity, allow the
// expansion. Also set the high-water-mark (capacity_until_GC)
// to that minimum capacity so that a GC will not be induced
// until that minimum capacity is exceeded.
if (vsl->capacity_words_sum() < metaspace_size_words ||
capacity_until_GC() == 0) {
set_capacity_until_GC(metaspace_size_words);
return true;
} else {
if (vsl->capacity_words_sum() < capacity_until_GC()) {
return true;
} else {
if (TraceMetadataChunkAllocation && Verbose) {
gclog_or_tty->print_cr(" allocation request size " SIZE_FORMAT
" capacity_until_GC " SIZE_FORMAT
" capacity_words_sum " SIZE_FORMAT
" used_words_sum " SIZE_FORMAT
" free chunks " SIZE_FORMAT
" free chunks count %d",
word_size,
capacity_until_GC(),
vsl->capacity_words_sum(),
vsl->used_words_sum(),
vsl->chunk_manager()->free_chunks_total(),
vsl->chunk_manager()->free_chunks_count());
}
return false;
}
}
}
// Variables are in bytes
void MetaspaceGC::compute_new_size() {
assert(_shrink_factor <= 100, "invalid shrink factor");
uint current_shrink_factor = _shrink_factor;
_shrink_factor = 0;
VirtualSpaceList *vsl = Metaspace::space_list();
size_t capacity_after_gc = vsl->capacity_bytes_sum();
// Check to see if these two can be calculated without walking the CLDG
size_t used_after_gc = vsl->used_bytes_sum();
size_t capacity_until_GC = vsl->capacity_bytes_sum();
size_t free_after_gc = capacity_until_GC - used_after_gc;
const double minimum_free_percentage = MinMetaspaceFreeRatio / 100.0;
const double maximum_used_percentage = 1.0 - minimum_free_percentage;
const double min_tmp = used_after_gc / maximum_used_percentage;
size_t minimum_desired_capacity =
(size_t)MIN2(min_tmp, double(max_uintx));
// Don't shrink less than the initial generation size
minimum_desired_capacity = MAX2(minimum_desired_capacity,
MetaspaceSize);
if (PrintGCDetails && Verbose) {
const double free_percentage = ((double)free_after_gc) / capacity_until_GC;
gclog_or_tty->print_cr("\nMetaspaceGC::compute_new_size: ");
gclog_or_tty->print_cr(" "
" minimum_free_percentage: %6.2f"
" maximum_used_percentage: %6.2f",
minimum_free_percentage,
maximum_used_percentage);
double d_free_after_gc = free_after_gc / (double) K;
gclog_or_tty->print_cr(" "
" free_after_gc : %6.1fK"
" used_after_gc : %6.1fK"
" capacity_after_gc : %6.1fK"
" metaspace HWM : %6.1fK",
free_after_gc / (double) K,
used_after_gc / (double) K,
capacity_after_gc / (double) K,
capacity_until_GC / (double) K);
gclog_or_tty->print_cr(" "
" free_percentage: %6.2f",
free_percentage);
}
if (capacity_until_GC < minimum_desired_capacity) {
// If we have less capacity below the metaspace HWM, then
// increment the HWM.
size_t expand_bytes = minimum_desired_capacity - capacity_until_GC;
// Don't expand unless it's significant
if (expand_bytes >= MinMetaspaceExpansion) {
size_t expand_words = expand_bytes / BytesPerWord;
MetaspaceGC::inc_capacity_until_GC(expand_words);
}
if (PrintGCDetails && Verbose) {
size_t new_capacity_until_GC = MetaspaceGC::capacity_until_GC_in_bytes();
gclog_or_tty->print_cr(" expanding:"
" minimum_desired_capacity: %6.1fK"
" expand_words: %6.1fK"
" MinMetaspaceExpansion: %6.1fK"
" new metaspace HWM: %6.1fK",
minimum_desired_capacity / (double) K,
expand_bytes / (double) K,
MinMetaspaceExpansion / (double) K,
new_capacity_until_GC / (double) K);
}
return;
}
// No expansion, now see if we want to shrink
size_t shrink_words = 0;
// We would never want to shrink more than this
size_t max_shrink_words = capacity_until_GC - minimum_desired_capacity;
assert(max_shrink_words >= 0, err_msg("max_shrink_words " SIZE_FORMAT,
max_shrink_words));
// Should shrinking be considered?
if (MaxMetaspaceFreeRatio < 100) {
const double maximum_free_percentage = MaxMetaspaceFreeRatio / 100.0;
const double minimum_used_percentage = 1.0 - maximum_free_percentage;
const double max_tmp = used_after_gc / minimum_used_percentage;
size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx));
maximum_desired_capacity = MAX2(maximum_desired_capacity,
MetaspaceSize);
if (PrintGC && Verbose) {
gclog_or_tty->print_cr(" "
" maximum_free_percentage: %6.2f"
" minimum_used_percentage: %6.2f",
maximum_free_percentage,
minimum_used_percentage);
gclog_or_tty->print_cr(" "
" capacity_until_GC: %6.1fK"
" minimum_desired_capacity: %6.1fK"
" maximum_desired_capacity: %6.1fK",
capacity_until_GC / (double) K,
minimum_desired_capacity / (double) K,
maximum_desired_capacity / (double) K);
}
assert(minimum_desired_capacity <= maximum_desired_capacity,
"sanity check");
if (capacity_until_GC > maximum_desired_capacity) {
// Capacity too large, compute shrinking size
shrink_words = capacity_until_GC - maximum_desired_capacity;
// We don't want shrink all the way back to initSize if people call
// System.gc(), because some programs do that between "phases" and then
// we'd just have to grow the heap up again for the next phase. So we
// damp the shrinking: 0% on the first call, 10% on the second call, 40%
// on the third call, and 100% by the fourth call. But if we recompute
// size without shrinking, it goes back to 0%.
shrink_words = shrink_words / 100 * current_shrink_factor;
assert(shrink_words <= max_shrink_words,
err_msg("invalid shrink size " SIZE_FORMAT " not <= " SIZE_FORMAT,
shrink_words, max_shrink_words));
if (current_shrink_factor == 0) {
_shrink_factor = 10;
} else {
_shrink_factor = MIN2(current_shrink_factor * 4, (uint) 100);
}
if (PrintGCDetails && Verbose) {
gclog_or_tty->print_cr(" "
" shrinking:"
" initSize: %.1fK"
" maximum_desired_capacity: %.1fK",
MetaspaceSize / (double) K,
maximum_desired_capacity / (double) K);
gclog_or_tty->print_cr(" "
" shrink_words: %.1fK"
" current_shrink_factor: %d"
" new shrink factor: %d"
" MinMetaspaceExpansion: %.1fK",
shrink_words / (double) K,
current_shrink_factor,
_shrink_factor,
MinMetaspaceExpansion / (double) K);
}
}
}
// Don't shrink unless it's significant
if (shrink_words >= MinMetaspaceExpansion) {
VirtualSpaceNode* csp = vsl->current_virtual_space();
size_t available_to_shrink = csp->capacity_words_in_vs() -
csp->used_words_in_vs();
shrink_words = MIN2(shrink_words, available_to_shrink);
csp->shrink_by(shrink_words);
MetaspaceGC::dec_capacity_until_GC(shrink_words);
if (PrintGCDetails && Verbose) {
size_t new_capacity_until_GC = MetaspaceGC::capacity_until_GC_in_bytes();
gclog_or_tty->print_cr(" metaspace HWM: %.1fK", new_capacity_until_GC / (double) K);
}
}
assert(used_after_gc <= vsl->capacity_bytes_sum(),
"sanity check");
}
// Metadebug methods
void Metadebug::deallocate_chunk_a_lot(SpaceManager* sm,
size_t chunk_word_size){
#ifdef ASSERT
VirtualSpaceList* vsl = sm->vs_list();
if (MetaDataDeallocateALot &&
Metadebug::deallocate_chunk_a_lot_count() % MetaDataDeallocateALotInterval == 0 ) {
Metadebug::reset_deallocate_chunk_a_lot_count();
for (uint i = 0; i < metadata_deallocate_a_lock_chunk; i++) {
Metachunk* dummy_chunk = vsl->current_virtual_space()->take_from_committed(chunk_word_size);
if (dummy_chunk == NULL) {
break;
}
vsl->chunk_manager()->chunk_freelist_deallocate(dummy_chunk);
if (TraceMetadataChunkAllocation && Verbose) {
gclog_or_tty->print("Metadebug::deallocate_chunk_a_lot: %d) ",
sm->sum_count_in_chunks_in_use());
dummy_chunk->print_on(gclog_or_tty);
gclog_or_tty->print_cr(" Free chunks total %d count %d",
vsl->chunk_manager()->free_chunks_total(),
vsl->chunk_manager()->free_chunks_count());
}
}
} else {
Metadebug::inc_deallocate_chunk_a_lot_count();
}
#endif
}
void Metadebug::deallocate_block_a_lot(SpaceManager* sm,
size_t raw_word_size){
#ifdef ASSERT
if (MetaDataDeallocateALot &&
Metadebug::deallocate_block_a_lot_count() % MetaDataDeallocateALotInterval == 0 ) {
Metadebug::set_deallocate_block_a_lot_count(0);
for (uint i = 0; i < metadata_deallocate_a_lot_block; i++) {
MetaWord* dummy_block = sm->allocate_work(raw_word_size);
if (dummy_block == 0) {
break;
}
sm->deallocate(dummy_block, raw_word_size);
}
} else {
Metadebug::inc_deallocate_block_a_lot_count();
}
#endif
}
void Metadebug::init_allocation_fail_alot_count() {
if (MetadataAllocationFailALot) {
_allocation_fail_alot_count =
1+(long)((double)MetadataAllocationFailALotInterval*os::random()/(max_jint+1.0));
}
}
#ifdef ASSERT
bool Metadebug::test_metadata_failure() {
if (MetadataAllocationFailALot &&
Threads::is_vm_complete()) {
if (_allocation_fail_alot_count > 0) {
_allocation_fail_alot_count--;
} else {
if (TraceMetadataChunkAllocation && Verbose) {
gclog_or_tty->print_cr("Metadata allocation failing for "
"MetadataAllocationFailALot");
}
init_allocation_fail_alot_count();
return true;
}
}
return false;
}
#endif
// ChunkList methods
size_t ChunkList::sum_list_size() {
size_t result = 0;
Metachunk* cur = head();
while (cur != NULL) {
result += cur->word_size();
cur = cur->next();
}
return result;
}
size_t ChunkList::sum_list_count() {
size_t result = 0;
Metachunk* cur = head();
while (cur != NULL) {
result++;
cur = cur->next();
}
return result;
}
size_t ChunkList::sum_list_capacity() {
size_t result = 0;
Metachunk* cur = head();
while (cur != NULL) {
result += cur->capacity_word_size();
cur = cur->next();
}
return result;
}
void ChunkList::add_at_head(Metachunk* head, Metachunk* tail) {
assert_lock_strong(SpaceManager::expand_lock());
assert(head == tail || tail->next() == NULL,
"Not the tail or the head has already been added to a list");
if (TraceMetadataChunkAllocation && Verbose) {
gclog_or_tty->print("ChunkList::add_at_head(head, tail): ");
Metachunk* cur = head;
while (cur != NULL) {
gclog_or_tty->print(PTR_FORMAT " (" SIZE_FORMAT ") ", cur, cur->word_size());
cur = cur->next();
}
gclog_or_tty->print_cr("");
}
if (tail != NULL) {
tail->set_next(_head);
}
set_head(head);
}
void ChunkList::add_at_head(Metachunk* list) {
if (list == NULL) {
// Nothing to add
return;
}
assert_lock_strong(SpaceManager::expand_lock());
Metachunk* head = list;
Metachunk* tail = list;
Metachunk* cur = head->next();
// Search for the tail since it is not passed.
while (cur != NULL) {
tail = cur;
cur = cur->next();
}
add_at_head(head, tail);
}
// ChunkManager methods
// Verification of _free_chunks_total and _free_chunks_count does not
// work with the CMS collector because its use of additional locks
// complicate the mutex deadlock detection but it can still be useful
// for detecting errors in the chunk accounting with other collectors.
size_t ChunkManager::free_chunks_total() {
#ifdef ASSERT
if (!UseConcMarkSweepGC && !SpaceManager::expand_lock()->is_locked()) {
MutexLockerEx cl(SpaceManager::expand_lock(),
Mutex::_no_safepoint_check_flag);
slow_locked_verify_free_chunks_total();
}
#endif
return _free_chunks_total;
}
size_t ChunkManager::free_chunks_total_in_bytes() {
return free_chunks_total() * BytesPerWord;
}
size_t ChunkManager::free_chunks_count() {
#ifdef ASSERT
if (!UseConcMarkSweepGC && !SpaceManager::expand_lock()->is_locked()) {
MutexLockerEx cl(SpaceManager::expand_lock(),
Mutex::_no_safepoint_check_flag);
// This lock is only needed in debug because the verification
// of the _free_chunks_totals walks the list of free chunks
slow_locked_verify_free_chunks_count();
}
#endif
return _free_chunks_count;
}
void ChunkManager::locked_verify_free_chunks_total() {
assert_lock_strong(SpaceManager::expand_lock());
assert(sum_free_chunks() == _free_chunks_total,
err_msg("_free_chunks_total " SIZE_FORMAT " is not the"
" same as sum " SIZE_FORMAT, _free_chunks_total,
sum_free_chunks()));
}
void ChunkManager::verify_free_chunks_total() {
MutexLockerEx cl(SpaceManager::expand_lock(),
Mutex::_no_safepoint_check_flag);
locked_verify_free_chunks_total();
}
void ChunkManager::locked_verify_free_chunks_count() {
assert_lock_strong(SpaceManager::expand_lock());
assert(sum_free_chunks_count() == _free_chunks_count,
err_msg("_free_chunks_count " SIZE_FORMAT " is not the"
" same as sum " SIZE_FORMAT, _free_chunks_count,
sum_free_chunks_count()));
}
void ChunkManager::verify_free_chunks_count() {
#ifdef ASSERT
MutexLockerEx cl(SpaceManager::expand_lock(),
Mutex::_no_safepoint_check_flag);
locked_verify_free_chunks_count();
#endif
}
void ChunkManager::verify() {
MutexLockerEx cl(SpaceManager::expand_lock(),
Mutex::_no_safepoint_check_flag);
locked_verify();
}
void ChunkManager::locked_verify() {
locked_verify_free_chunks_count();
locked_verify_free_chunks_total();
}
void ChunkManager::locked_print_free_chunks(outputStream* st) {
assert_lock_strong(SpaceManager::expand_lock());
st->print_cr("Free chunk total " SIZE_FORMAT " count " SIZE_FORMAT,
_free_chunks_total, _free_chunks_count);
}
void ChunkManager::locked_print_sum_free_chunks(outputStream* st) {
assert_lock_strong(SpaceManager::expand_lock());
st->print_cr("Sum free chunk total " SIZE_FORMAT " count " SIZE_FORMAT,
sum_free_chunks(), sum_free_chunks_count());
}
ChunkList* ChunkManager::free_chunks(ChunkIndex index) {
return &_free_chunks[index];
}
// These methods that sum the free chunk lists are used in printing
// methods that are used in product builds.
size_t ChunkManager::sum_free_chunks() {
assert_lock_strong(SpaceManager::expand_lock());
size_t result = 0;
for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
ChunkList* list = free_chunks(i);
if (list == NULL) {
continue;
}
result = result + list->sum_list_capacity();
}
result = result + humongous_dictionary()->total_size();
return result;
}
size_t ChunkManager::sum_free_chunks_count() {
assert_lock_strong(SpaceManager::expand_lock());
size_t count = 0;
for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
ChunkList* list = free_chunks(i);
if (list == NULL) {
continue;
}
count = count + list->sum_list_count();
}
count = count + humongous_dictionary()->total_free_blocks();
return count;
}
ChunkList* ChunkManager::find_free_chunks_list(size_t word_size) {
ChunkIndex index = list_index(word_size);
assert(index < HumongousIndex, "No humongous list");
return free_chunks(index);
}
void ChunkManager::free_chunks_put(Metachunk* chunk) {
assert_lock_strong(SpaceManager::expand_lock());
ChunkList* free_list = find_free_chunks_list(chunk->word_size());
chunk->set_next(free_list->head());
free_list->set_head(chunk);
// chunk is being returned to the chunk free list
inc_free_chunks_total(chunk->capacity_word_size());
slow_locked_verify();
}
void ChunkManager::chunk_freelist_deallocate(Metachunk* chunk) {
// The deallocation of a chunk originates in the freelist
// manangement code for a Metaspace and does not hold the
// lock.
assert(chunk != NULL, "Deallocating NULL");
assert_lock_strong(SpaceManager::expand_lock());
slow_locked_verify();
if (TraceMetadataChunkAllocation) {
tty->print_cr("ChunkManager::chunk_freelist_deallocate: chunk "
PTR_FORMAT " size " SIZE_FORMAT,
chunk, chunk->word_size());
}
free_chunks_put(chunk);
}
Metachunk* ChunkManager::free_chunks_get(size_t word_size) {
assert_lock_strong(SpaceManager::expand_lock());
slow_locked_verify();
Metachunk* chunk = NULL;
if (list_index(word_size) != HumongousIndex) {
ChunkList* free_list = find_free_chunks_list(word_size);
assert(free_list != NULL, "Sanity check");
chunk = free_list->head();
debug_only(Metachunk* debug_head = chunk;)
if (chunk == NULL) {
return NULL;
}
// Remove the chunk as the head of the list.
free_list->set_head(chunk->next());
// Chunk is being removed from the chunks free list.
dec_free_chunks_total(chunk->capacity_word_size());
if (TraceMetadataChunkAllocation && Verbose) {
tty->print_cr("ChunkManager::free_chunks_get: free_list "
PTR_FORMAT " head " PTR_FORMAT " size " SIZE_FORMAT,
free_list, chunk, chunk->word_size());
}
} else {
chunk = humongous_dictionary()->get_chunk(
word_size,
FreeBlockDictionary<Metachunk>::atLeast);
if (chunk != NULL) {
if (TraceMetadataHumongousAllocation) {
size_t waste = chunk->word_size() - word_size;
tty->print_cr("Free list allocate humongous chunk size " SIZE_FORMAT
" for requested size " SIZE_FORMAT
" waste " SIZE_FORMAT,
chunk->word_size(), word_size, waste);
}
// Chunk is being removed from the chunks free list.
dec_free_chunks_total(chunk->capacity_word_size());
#ifdef ASSERT
chunk->set_is_free(false);
#endif
} else {
return NULL;
}
}
// Remove it from the links to this freelist
chunk->set_next(NULL);
chunk->set_prev(NULL);
slow_locked_verify();
return chunk;
}
Metachunk* ChunkManager::chunk_freelist_allocate(size_t word_size) {
assert_lock_strong(SpaceManager::expand_lock());
slow_locked_verify();
// Take from the beginning of the list
Metachunk* chunk = free_chunks_get(word_size);
if (chunk == NULL) {
return NULL;
}
assert((word_size <= chunk->word_size()) ||
list_index(chunk->word_size() == HumongousIndex),
"Non-humongous variable sized chunk");
if (TraceMetadataChunkAllocation) {
size_t list_count;
if (list_index(word_size) < HumongousIndex) {
ChunkList* list = find_free_chunks_list(word_size);
list_count = list->sum_list_count();
} else {
list_count = humongous_dictionary()->total_count();
}
tty->print("ChunkManager::chunk_freelist_allocate: " PTR_FORMAT " chunk "
PTR_FORMAT " size " SIZE_FORMAT " count " SIZE_FORMAT " ",
this, chunk, chunk->word_size(), list_count);
locked_print_free_chunks(tty);
}
return chunk;
}
void ChunkManager::print_on(outputStream* out) {
if (PrintFLSStatistics != 0) {
humongous_dictionary()->report_statistics();
}
}
// SpaceManager methods
void SpaceManager::get_initial_chunk_sizes(Metaspace::MetaspaceType type,
size_t* chunk_word_size,
size_t* class_chunk_word_size) {
switch (type) {
case Metaspace::BootMetaspaceType:
*chunk_word_size = Metaspace::first_chunk_word_size();
*class_chunk_word_size = Metaspace::first_class_chunk_word_size();
break;
case Metaspace::ROMetaspaceType:
*chunk_word_size = SharedReadOnlySize / wordSize;
*class_chunk_word_size = ClassSpecializedChunk;
break;
case Metaspace::ReadWriteMetaspaceType:
*chunk_word_size = SharedReadWriteSize / wordSize;
*class_chunk_word_size = ClassSpecializedChunk;
break;
case Metaspace::AnonymousMetaspaceType:
case Metaspace::ReflectionMetaspaceType:
*chunk_word_size = SpecializedChunk;
*class_chunk_word_size = ClassSpecializedChunk;
break;
default:
*chunk_word_size = SmallChunk;
*class_chunk_word_size = ClassSmallChunk;
break;
}
assert(*chunk_word_size != 0 && *class_chunk_word_size != 0,
err_msg("Initial chunks sizes bad: data " SIZE_FORMAT
" class " SIZE_FORMAT,
*chunk_word_size, *class_chunk_word_size));
}
size_t SpaceManager::sum_free_in_chunks_in_use() const {
MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
size_t free = 0;
for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
Metachunk* chunk = chunks_in_use(i);
while (chunk != NULL) {
free += chunk->free_word_size();
chunk = chunk->next();
}
}
return free;
}
size_t SpaceManager::sum_waste_in_chunks_in_use() const {
MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
size_t result = 0;
for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
result += sum_waste_in_chunks_in_use(i);
}
return result;
}
size_t SpaceManager::sum_waste_in_chunks_in_use(ChunkIndex index) const {
size_t result = 0;
Metachunk* chunk = chunks_in_use(index);
// Count the free space in all the chunk but not the
// current chunk from which allocations are still being done.
if (chunk != NULL) {
Metachunk* prev = chunk;
while (chunk != NULL && chunk != current_chunk()) {
result += chunk->free_word_size();
prev = chunk;
chunk = chunk->next();
}
}
return result;
}
size_t SpaceManager::sum_capacity_in_chunks_in_use() const {
MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
size_t sum = 0;
for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
Metachunk* chunk = chunks_in_use(i);
while (chunk != NULL) {
// Just changed this sum += chunk->capacity_word_size();
// sum += chunk->word_size() - Metachunk::overhead();
sum += chunk->capacity_word_size();
chunk = chunk->next();
}
}
return sum;
}
size_t SpaceManager::sum_count_in_chunks_in_use() {
size_t count = 0;
for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
count = count + sum_count_in_chunks_in_use(i);
}
return count;
}
size_t SpaceManager::sum_count_in_chunks_in_use(ChunkIndex i) {
size_t count = 0;
Metachunk* chunk = chunks_in_use(i);
while (chunk != NULL) {
count++;
chunk = chunk->next();
}
return count;
}
size_t SpaceManager::sum_used_in_chunks_in_use() const {
MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
size_t used = 0;
for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
Metachunk* chunk = chunks_in_use(i);
while (chunk != NULL) {
used += chunk->used_word_size();
chunk = chunk->next();
}
}
return used;
}
void SpaceManager::locked_print_chunks_in_use_on(outputStream* st) const {
for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
Metachunk* chunk = chunks_in_use(i);
st->print("SpaceManager: %s " PTR_FORMAT,
chunk_size_name(i), chunk);
if (chunk != NULL) {
st->print_cr(" free " SIZE_FORMAT,
chunk->free_word_size());
} else {
st->print_cr("");
}
}
vs_list()->chunk_manager()->locked_print_free_chunks(st);
vs_list()->chunk_manager()->locked_print_sum_free_chunks(st);
}
size_t SpaceManager::calc_chunk_size(size_t word_size) {
// Decide between a small chunk and a medium chunk. Up to
// _small_chunk_limit small chunks can be allocated but
// once a medium chunk has been allocated, no more small
// chunks will be allocated.
size_t chunk_word_size;
if (chunks_in_use(MediumIndex) == NULL &&
(!has_small_chunk_limit() ||
sum_count_in_chunks_in_use(SmallIndex) < _small_chunk_limit)) {
chunk_word_size = (size_t) small_chunk_size();
if (word_size + Metachunk::overhead() > small_chunk_size()) {
chunk_word_size = medium_chunk_size();
}
} else {
chunk_word_size = medium_chunk_size();
}
// Might still need a humongous chunk. Enforce an
// eight word granularity to facilitate reuse (some
// wastage but better chance of reuse).
size_t if_humongous_sized_chunk =
align_size_up(word_size + Metachunk::overhead(),
HumongousChunkGranularity);
chunk_word_size =
MAX2((size_t) chunk_word_size, if_humongous_sized_chunk);
assert(!SpaceManager::is_humongous(word_size) ||
chunk_word_size == if_humongous_sized_chunk,
err_msg("Size calculation is wrong, word_size " SIZE_FORMAT
" chunk_word_size " SIZE_FORMAT,
word_size, chunk_word_size));
if (TraceMetadataHumongousAllocation &&
SpaceManager::is_humongous(word_size)) {
gclog_or_tty->print_cr("Metadata humongous allocation:");
gclog_or_tty->print_cr(" word_size " PTR_FORMAT, word_size);
gclog_or_tty->print_cr(" chunk_word_size " PTR_FORMAT,
chunk_word_size);
gclog_or_tty->print_cr(" chunk overhead " PTR_FORMAT,
Metachunk::overhead());
}
return chunk_word_size;
}
MetaWord* SpaceManager::grow_and_allocate(size_t word_size) {
assert(vs_list()->current_virtual_space() != NULL,
"Should have been set");
assert(current_chunk() == NULL ||
current_chunk()->allocate(word_size) == NULL,
"Don't need to expand");
MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
if (TraceMetadataChunkAllocation && Verbose) {
size_t words_left = 0;
size_t words_used = 0;
if (current_chunk() != NULL) {
words_left = current_chunk()->free_word_size();
words_used = current_chunk()->used_word_size();
}
gclog_or_tty->print_cr("SpaceManager::grow_and_allocate for " SIZE_FORMAT
" words " SIZE_FORMAT " words used " SIZE_FORMAT
" words left",
word_size, words_used, words_left);
}
// Get another chunk out of the virtual space
size_t grow_chunks_by_words = calc_chunk_size(word_size);
Metachunk* next = get_new_chunk(word_size, grow_chunks_by_words);
// If a chunk was available, add it to the in-use chunk list
// and do an allocation from it.
if (next != NULL) {
Metadebug::deallocate_chunk_a_lot(this, grow_chunks_by_words);
// Add to this manager's list of chunks in use.
add_chunk(next, false);
return next->allocate(word_size);
}
return NULL;
}
void SpaceManager::print_on(outputStream* st) const {
for (ChunkIndex i = ZeroIndex;
i < NumberOfInUseLists ;
i = next_chunk_index(i) ) {
st->print_cr(" chunks_in_use " PTR_FORMAT " chunk size " PTR_FORMAT,
chunks_in_use(i),
chunks_in_use(i) == NULL ? 0 : chunks_in_use(i)->word_size());
}
st->print_cr(" waste: Small " SIZE_FORMAT " Medium " SIZE_FORMAT
" Humongous " SIZE_FORMAT,
sum_waste_in_chunks_in_use(SmallIndex),
sum_waste_in_chunks_in_use(MediumIndex),
sum_waste_in_chunks_in_use(HumongousIndex));
// block free lists
if (block_freelists() != NULL) {
st->print_cr("total in block free lists " SIZE_FORMAT,
block_freelists()->total_size());
}
}
SpaceManager::SpaceManager(Mutex* lock,
VirtualSpaceList* vs_list) :
_vs_list(vs_list),
_allocation_total(0),
_lock(lock)
{
initialize();
}
void SpaceManager::initialize() {
Metadebug::init_allocation_fail_alot_count();
for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
_chunks_in_use[i] = NULL;
}
_current_chunk = NULL;
if (TraceMetadataChunkAllocation && Verbose) {
gclog_or_tty->print_cr("SpaceManager(): " PTR_FORMAT, this);
}
}
SpaceManager::~SpaceManager() {
// This call this->_lock which can't be done while holding expand_lock()
const size_t in_use_before = sum_capacity_in_chunks_in_use();
MutexLockerEx fcl(SpaceManager::expand_lock(),
Mutex::_no_safepoint_check_flag);
ChunkManager* chunk_manager = vs_list()->chunk_manager();
chunk_manager->slow_locked_verify();
if (TraceMetadataChunkAllocation && Verbose) {
gclog_or_tty->print_cr("~SpaceManager(): " PTR_FORMAT, this);
locked_print_chunks_in_use_on(gclog_or_tty);
}
// Mangle freed memory.
NOT_PRODUCT(mangle_freed_chunks();)
// Have to update before the chunks_in_use lists are emptied
// below.
chunk_manager->inc_free_chunks_total(in_use_before,
sum_count_in_chunks_in_use());
// Add all the chunks in use by this space manager
// to the global list of free chunks.
// Follow each list of chunks-in-use and add them to the
// free lists. Each list is NULL terminated.
for (ChunkIndex i = ZeroIndex; i < HumongousIndex; i = next_chunk_index(i)) {
if (TraceMetadataChunkAllocation && Verbose) {
gclog_or_tty->print_cr("returned %d %s chunks to freelist",
sum_count_in_chunks_in_use(i),
chunk_size_name(i));
}
Metachunk* chunks = chunks_in_use(i);
chunk_manager->free_chunks(i)->add_at_head(chunks);
set_chunks_in_use(i, NULL);
if (TraceMetadataChunkAllocation && Verbose) {
gclog_or_tty->print_cr("updated freelist count %d %s",
chunk_manager->free_chunks(i)->sum_list_count(),
chunk_size_name(i));
}
assert(i != HumongousIndex, "Humongous chunks are handled explicitly later");
}
// The medium chunk case may be optimized by passing the head and
// tail of the medium chunk list to add_at_head(). The tail is often
// the current chunk but there are probably exceptions.
// Humongous chunks
if (TraceMetadataChunkAllocation && Verbose) {
gclog_or_tty->print_cr("returned %d %s humongous chunks to dictionary",
sum_count_in_chunks_in_use(HumongousIndex),
chunk_size_name(HumongousIndex));
gclog_or_tty->print("Humongous chunk dictionary: ");
}
// Humongous chunks are never the current chunk.
Metachunk* humongous_chunks = chunks_in_use(HumongousIndex);
while (humongous_chunks != NULL) {
#ifdef ASSERT
humongous_chunks->set_is_free(true);
#endif
if (TraceMetadataChunkAllocation && Verbose) {
gclog_or_tty->print(PTR_FORMAT " (" SIZE_FORMAT ") ",
humongous_chunks,
humongous_chunks->word_size());
}
assert(humongous_chunks->word_size() == (size_t)
align_size_up(humongous_chunks->word_size(),
HumongousChunkGranularity),
err_msg("Humongous chunk size is wrong: word size " SIZE_FORMAT
" granularity %d",
humongous_chunks->word_size(), HumongousChunkGranularity));
Metachunk* next_humongous_chunks = humongous_chunks->next();
chunk_manager->humongous_dictionary()->return_chunk(humongous_chunks);
humongous_chunks = next_humongous_chunks;
}
if (TraceMetadataChunkAllocation && Verbose) {
gclog_or_tty->print_cr("");
gclog_or_tty->print_cr("updated dictionary count %d %s",
chunk_manager->humongous_dictionary()->total_count(),
chunk_size_name(HumongousIndex));
}
set_chunks_in_use(HumongousIndex, NULL);
chunk_manager->slow_locked_verify();
}
const char* SpaceManager::chunk_size_name(ChunkIndex index) const {
switch (index) {
case SpecializedIndex:
return "Specialized";
case SmallIndex:
return "Small";
case MediumIndex:
return "Medium";
case HumongousIndex:
return "Humongous";
default:
return NULL;
}
}
ChunkIndex ChunkManager::list_index(size_t size) {
switch (size) {
case SpecializedChunk:
assert(SpecializedChunk == ClassSpecializedChunk,
"Need branch for ClassSpecializedChunk");
return SpecializedIndex;
case SmallChunk:
case ClassSmallChunk:
return SmallIndex;
case MediumChunk:
case ClassMediumChunk:
return MediumIndex;
default:
assert(size > MediumChunk || size > ClassMediumChunk,
"Not a humongous chunk");
return HumongousIndex;
}
}
void SpaceManager::deallocate(MetaWord* p, size_t word_size) {
assert_lock_strong(_lock);
size_t min_size = TreeChunk<Metablock, FreeList>::min_size();
assert(word_size >= min_size,
err_msg("Should not deallocate dark matter " SIZE_FORMAT, word_size));
block_freelists()->return_block(p, word_size);
}
// Adds a chunk to the list of chunks in use.
void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) {
assert(new_chunk != NULL, "Should not be NULL");
assert(new_chunk->next() == NULL, "Should not be on a list");
new_chunk->reset_empty();
// Find the correct list and and set the current
// chunk for that list.
ChunkIndex index = ChunkManager::list_index(new_chunk->word_size());
if (index != HumongousIndex) {
set_current_chunk(new_chunk);
new_chunk->set_next(chunks_in_use(index));
set_chunks_in_use(index, new_chunk);
} else {
// For null class loader data and DumpSharedSpaces, the first chunk isn't
// small, so small will be null. Link this first chunk as the current
// chunk.
if (make_current) {
// Set as the current chunk but otherwise treat as a humongous chunk.
set_current_chunk(new_chunk);
}
// Link at head. The _current_chunk only points to a humongous chunk for
// the null class loader metaspace (class and data virtual space managers)
// any humongous chunks so will not point to the tail
// of the humongous chunks list.
new_chunk->set_next(chunks_in_use(HumongousIndex));
set_chunks_in_use(HumongousIndex, new_chunk);
assert(new_chunk->word_size() > medium_chunk_size(), "List inconsistency");
}
assert(new_chunk->is_empty(), "Not ready for reuse");
if (TraceMetadataChunkAllocation && Verbose) {
gclog_or_tty->print("SpaceManager::add_chunk: %d) ",
sum_count_in_chunks_in_use());
new_chunk->print_on(gclog_or_tty);
vs_list()->chunk_manager()->locked_print_free_chunks(tty);
}
}
Metachunk* SpaceManager::get_new_chunk(size_t word_size,
size_t grow_chunks_by_words) {
Metachunk* next = vs_list()->get_new_chunk(word_size,
grow_chunks_by_words,
medium_chunk_bunch());
if (TraceMetadataHumongousAllocation &&
SpaceManager::is_humongous(next->word_size())) {
gclog_or_tty->print_cr(" new humongous chunk word size " PTR_FORMAT,
next->word_size());
}
return next;
}
MetaWord* SpaceManager::allocate(size_t word_size) {
MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
// If only the dictionary is going to be used (i.e., no
// indexed free list), then there is a minimum size requirement.
// MinChunkSize is a placeholder for the real minimum size JJJ
size_t byte_size = word_size * BytesPerWord;
size_t byte_size_with_overhead = byte_size + Metablock::overhead();
size_t raw_bytes_size = MAX2(byte_size_with_overhead,
Metablock::min_block_byte_size());
raw_bytes_size = ARENA_ALIGN(raw_bytes_size);
size_t raw_word_size = raw_bytes_size / BytesPerWord;
assert(raw_word_size * BytesPerWord == raw_bytes_size, "Size problem");
BlockFreelist* fl = block_freelists();
MetaWord* p = NULL;
// Allocation from the dictionary is expensive in the sense that
// the dictionary has to be searched for a size. Don't allocate
// from the dictionary until it starts to get fat. Is this
// a reasonable policy? Maybe an skinny dictionary is fast enough
// for allocations. Do some profiling. JJJ
if (fl->total_size() > allocation_from_dictionary_limit) {
p = fl->get_block(raw_word_size);
}
if (p == NULL) {
p = allocate_work(raw_word_size);
}
Metadebug::deallocate_block_a_lot(this, raw_word_size);
return p;
}
// Returns the address of spaced allocated for "word_size".
// This methods does not know about blocks (Metablocks)
MetaWord* SpaceManager::allocate_work(size_t word_size) {
assert_lock_strong(_lock);
#ifdef ASSERT
if (Metadebug::test_metadata_failure()) {
return NULL;
}
#endif
// Is there space in the current chunk?
MetaWord* result = NULL;
// For DumpSharedSpaces, only allocate out of the current chunk which is
// never null because we gave it the size we wanted. Caller reports out
// of memory if this returns null.
if (DumpSharedSpaces) {
assert(current_chunk() != NULL, "should never happen");
inc_allocation_total(word_size);
return current_chunk()->allocate(word_size); // caller handles null result
}
if (current_chunk() != NULL) {
result = current_chunk()->allocate(word_size);
}
if (result == NULL) {
result = grow_and_allocate(word_size);
}
if (result > 0) {
inc_allocation_total(word_size);
assert(result != (MetaWord*) chunks_in_use(MediumIndex),
"Head of the list is being allocated");
}
return result;
}
void SpaceManager::verify() {
// If there are blocks in the dictionary, then
// verfication of chunks does not work since
// being in the dictionary alters a chunk.
if (block_freelists()->total_size() == 0) {
for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
Metachunk* curr = chunks_in_use(i);
while (curr != NULL) {
curr->verify();
verify_chunk_size(curr);
curr = curr->next();
}
}
}
}
void SpaceManager::verify_chunk_size(Metachunk* chunk) {
assert(is_humongous(chunk->word_size()) ||
chunk->word_size() == medium_chunk_size() ||
chunk->word_size() == small_chunk_size() ||
chunk->word_size() == specialized_chunk_size(),
"Chunk size is wrong");
return;
}
#ifdef ASSERT
void SpaceManager::verify_allocation_total() {
// Verification is only guaranteed at a safepoint.
if (SafepointSynchronize::is_at_safepoint()) {
gclog_or_tty->print_cr("Chunk " PTR_FORMAT " allocation_total " SIZE_FORMAT
" sum_used_in_chunks_in_use " SIZE_FORMAT,
this,
allocation_total(),
sum_used_in_chunks_in_use());
}
MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
assert(allocation_total() == sum_used_in_chunks_in_use(),
err_msg("allocation total is not consistent " SIZE_FORMAT
" vs " SIZE_FORMAT,
allocation_total(), sum_used_in_chunks_in_use()));
}
#endif
void SpaceManager::dump(outputStream* const out) const {
size_t curr_total = 0;
size_t waste = 0;
uint i = 0;
size_t used = 0;
size_t capacity = 0;
// Add up statistics for all chunks in this SpaceManager.
for (ChunkIndex index = ZeroIndex;
index < NumberOfInUseLists;
index = next_chunk_index(index)) {
for (Metachunk* curr = chunks_in_use(index);
curr != NULL;
curr = curr->next()) {
out->print("%d) ", i++);
curr->print_on(out);
if (TraceMetadataChunkAllocation && Verbose) {
block_freelists()->print_on(out);
}
curr_total += curr->word_size();
used += curr->used_word_size();
capacity += curr->capacity_word_size();
waste += curr->free_word_size() + curr->overhead();;
}
}
size_t free = current_chunk() == NULL ? 0 : current_chunk()->free_word_size();
// Free space isn't wasted.
waste -= free;
out->print_cr("total of all chunks " SIZE_FORMAT " used " SIZE_FORMAT
" free " SIZE_FORMAT " capacity " SIZE_FORMAT
" waste " SIZE_FORMAT, curr_total, used, free, capacity, waste);
}
#ifndef PRODUCT
void SpaceManager::mangle_freed_chunks() {
for (ChunkIndex index = ZeroIndex;
index < NumberOfInUseLists;
index = next_chunk_index(index)) {
for (Metachunk* curr = chunks_in_use(index);
curr != NULL;
curr = curr->next()) {
curr->mangle();
}
}
}
#endif // PRODUCT
// MetaspaceAux
size_t MetaspaceAux::used_in_bytes(Metaspace::MetadataType mdtype) {
size_t used = 0;
ClassLoaderDataGraphMetaspaceIterator iter;
while (iter.repeat()) {
Metaspace* msp = iter.get_next();
// Sum allocation_total for each metaspace
if (msp != NULL) {
used += msp->used_words(mdtype);
}
}
return used * BytesPerWord;
}
size_t MetaspaceAux::free_in_bytes(Metaspace::MetadataType mdtype) {
size_t free = 0;
ClassLoaderDataGraphMetaspaceIterator iter;
while (iter.repeat()) {
Metaspace* msp = iter.get_next();
if (msp != NULL) {
free += msp->free_words(mdtype);
}
}
return free * BytesPerWord;
}
size_t MetaspaceAux::capacity_in_bytes(Metaspace::MetadataType mdtype) {
size_t capacity = free_chunks_total(mdtype);
ClassLoaderDataGraphMetaspaceIterator iter;
while (iter.repeat()) {
Metaspace* msp = iter.get_next();
if (msp != NULL) {
capacity += msp->capacity_words(mdtype);
}
}
return capacity * BytesPerWord;
}
size_t MetaspaceAux::reserved_in_bytes(Metaspace::MetadataType mdtype) {
size_t reserved = (mdtype == Metaspace::ClassType) ?
Metaspace::class_space_list()->virtual_space_total() :
Metaspace::space_list()->virtual_space_total();
return reserved * BytesPerWord;
}
size_t MetaspaceAux::min_chunk_size() { return Metaspace::first_chunk_word_size(); }
size_t MetaspaceAux::free_chunks_total(Metaspace::MetadataType mdtype) {
ChunkManager* chunk = (mdtype == Metaspace::ClassType) ?
Metaspace::class_space_list()->chunk_manager() :
Metaspace::space_list()->chunk_manager();
chunk->slow_verify();
return chunk->free_chunks_total();
}
size_t MetaspaceAux::free_chunks_total_in_bytes(Metaspace::MetadataType mdtype) {
return free_chunks_total(mdtype) * BytesPerWord;
}
void MetaspaceAux::print_metaspace_change(size_t prev_metadata_used) {
gclog_or_tty->print(", [Metaspace:");
if (PrintGCDetails && Verbose) {
gclog_or_tty->print(" " SIZE_FORMAT
"->" SIZE_FORMAT
"(" SIZE_FORMAT "/" SIZE_FORMAT ")",
prev_metadata_used,
used_in_bytes(),
capacity_in_bytes(),
reserved_in_bytes());
} else {
gclog_or_tty->print(" " SIZE_FORMAT "K"
"->" SIZE_FORMAT "K"
"(" SIZE_FORMAT "K/" SIZE_FORMAT "K)",
prev_metadata_used / K,
used_in_bytes()/ K,
capacity_in_bytes()/K,
reserved_in_bytes()/ K);
}
gclog_or_tty->print("]");
}
// This is printed when PrintGCDetails
void MetaspaceAux::print_on(outputStream* out) {
Metaspace::MetadataType ct = Metaspace::ClassType;
Metaspace::MetadataType nct = Metaspace::NonClassType;
out->print_cr(" Metaspace total "
SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
" reserved " SIZE_FORMAT "K",
capacity_in_bytes()/K, used_in_bytes()/K, reserved_in_bytes()/K);
out->print_cr(" data space "
SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
" reserved " SIZE_FORMAT "K",
capacity_in_bytes(nct)/K, used_in_bytes(nct)/K, reserved_in_bytes(nct)/K);
out->print_cr(" class space "
SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
" reserved " SIZE_FORMAT "K",
capacity_in_bytes(ct)/K, used_in_bytes(ct)/K, reserved_in_bytes(ct)/K);
}
// Print information for class space and data space separately.
// This is almost the same as above.
void MetaspaceAux::print_on(outputStream* out, Metaspace::MetadataType mdtype) {
size_t free_chunks_capacity_bytes = free_chunks_total_in_bytes(mdtype);
size_t capacity_bytes = capacity_in_bytes(mdtype);
size_t used_bytes = used_in_bytes(mdtype);
size_t free_bytes = free_in_bytes(mdtype);
size_t used_and_free = used_bytes + free_bytes +
free_chunks_capacity_bytes;
out->print_cr(" Chunk accounting: used in chunks " SIZE_FORMAT
"K + unused in chunks " SIZE_FORMAT "K + "
" capacity in free chunks " SIZE_FORMAT "K = " SIZE_FORMAT
"K capacity in allocated chunks " SIZE_FORMAT "K",
used_bytes / K,
free_bytes / K,
free_chunks_capacity_bytes / K,
used_and_free / K,
capacity_bytes / K);
// Accounting can only be correct if we got the values during a safepoint
assert(!SafepointSynchronize::is_at_safepoint() || used_and_free == capacity_bytes, "Accounting is wrong");
}
// Print total fragmentation for class and data metaspaces separately
void MetaspaceAux::print_waste(outputStream* out) {
size_t specialized_waste = 0, small_waste = 0, medium_waste = 0, large_waste = 0;
size_t specialized_count = 0, small_count = 0, medium_count = 0, large_count = 0;
size_t cls_specialized_waste = 0, cls_small_waste = 0, cls_medium_waste = 0, cls_large_waste = 0;
size_t cls_specialized_count = 0, cls_small_count = 0, cls_medium_count = 0, cls_large_count = 0;
ClassLoaderDataGraphMetaspaceIterator iter;
while (iter.repeat()) {
Metaspace* msp = iter.get_next();
if (msp != NULL) {
specialized_waste += msp->vsm()->sum_waste_in_chunks_in_use(SpecializedIndex);
specialized_count += msp->vsm()->sum_count_in_chunks_in_use(SpecializedIndex);
small_waste += msp->vsm()->sum_waste_in_chunks_in_use(SmallIndex);
small_count += msp->vsm()->sum_count_in_chunks_in_use(SmallIndex);
medium_waste += msp->vsm()->sum_waste_in_chunks_in_use(MediumIndex);
medium_count += msp->vsm()->sum_count_in_chunks_in_use(MediumIndex);
large_waste += msp->vsm()->sum_waste_in_chunks_in_use(HumongousIndex);
large_count += msp->vsm()->sum_count_in_chunks_in_use(HumongousIndex);
cls_specialized_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SpecializedIndex);
cls_specialized_count += msp->class_vsm()->sum_count_in_chunks_in_use(SpecializedIndex);
cls_small_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SmallIndex);
cls_small_count += msp->class_vsm()->sum_count_in_chunks_in_use(SmallIndex);
cls_medium_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(MediumIndex);
cls_medium_count += msp->class_vsm()->sum_count_in_chunks_in_use(MediumIndex);
cls_large_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(HumongousIndex);
cls_large_count += msp->class_vsm()->sum_count_in_chunks_in_use(HumongousIndex);
}
}
out->print_cr("Total fragmentation waste (words) doesn't count free space");
out->print_cr(" data: " SIZE_FORMAT " specialized(s) " SIZE_FORMAT ", "
SIZE_FORMAT " small(s) " SIZE_FORMAT ", "
SIZE_FORMAT " medium(s) " SIZE_FORMAT,
specialized_count, specialized_waste, small_count,
small_waste, medium_count, medium_waste);
out->print_cr(" class: " SIZE_FORMAT " specialized(s) " SIZE_FORMAT ", "
SIZE_FORMAT " small(s) " SIZE_FORMAT,
cls_specialized_count, cls_specialized_waste,
cls_small_count, cls_small_waste);
}
// Dump global metaspace things from the end of ClassLoaderDataGraph
void MetaspaceAux::dump(outputStream* out) {
out->print_cr("All Metaspace:");
out->print("data space: "); print_on(out, Metaspace::NonClassType);
out->print("class space: "); print_on(out, Metaspace::ClassType);
print_waste(out);
}
void MetaspaceAux::verify_free_chunks() {
Metaspace::space_list()->chunk_manager()->verify();
Metaspace::class_space_list()->chunk_manager()->verify();
}
// Metaspace methods
size_t Metaspace::_first_chunk_word_size = 0;
size_t Metaspace::_first_class_chunk_word_size = 0;
Metaspace::Metaspace(Mutex* lock, MetaspaceType type) {
initialize(lock, type);
}
Metaspace::~Metaspace() {
delete _vsm;
delete _class_vsm;
}
VirtualSpaceList* Metaspace::_space_list = NULL;
VirtualSpaceList* Metaspace::_class_space_list = NULL;
#define VIRTUALSPACEMULTIPLIER 2
void Metaspace::global_initialize() {
// Initialize the alignment for shared spaces.
int max_alignment = os::vm_page_size();
MetaspaceShared::set_max_alignment(max_alignment);
if (DumpSharedSpaces) {
SharedReadOnlySize = align_size_up(SharedReadOnlySize, max_alignment);
SharedReadWriteSize = align_size_up(SharedReadWriteSize, max_alignment);
SharedMiscDataSize = align_size_up(SharedMiscDataSize, max_alignment);
SharedMiscCodeSize = align_size_up(SharedMiscCodeSize, max_alignment);
// Initialize with the sum of the shared space sizes. The read-only
// and read write metaspace chunks will be allocated out of this and the
// remainder is the misc code and data chunks.
size_t total = align_size_up(SharedReadOnlySize + SharedReadWriteSize +
SharedMiscDataSize + SharedMiscCodeSize,
os::vm_allocation_granularity());
size_t word_size = total/wordSize;
_space_list = new VirtualSpaceList(word_size);
} else {
// If using shared space, open the file that contains the shared space
// and map in the memory before initializing the rest of metaspace (so
// the addresses don't conflict)
if (UseSharedSpaces) {
FileMapInfo* mapinfo = new FileMapInfo();
memset(mapinfo, 0, sizeof(FileMapInfo));
// Open the shared archive file, read and validate the header. If
// initialization fails, shared spaces [UseSharedSpaces] are
// disabled and the file is closed.
// Map in spaces now also
if (mapinfo->initialize() && MetaspaceShared::map_shared_spaces(mapinfo)) {
FileMapInfo::set_current_info(mapinfo);
} else {
assert(!mapinfo->is_open() && !UseSharedSpaces,
"archive file not closed or shared spaces not disabled.");
}
}
// Initialize these before initializing the VirtualSpaceList
_first_chunk_word_size = InitialBootClassLoaderMetaspaceSize / BytesPerWord;
_first_chunk_word_size = align_word_size_up(_first_chunk_word_size);
// Make the first class chunk bigger than a medium chunk so it's not put
// on the medium chunk list. The next chunk will be small and progress
// from there. This size calculated by -version.
_first_class_chunk_word_size = MIN2((size_t)MediumChunk*6,
(ClassMetaspaceSize/BytesPerWord)*2);
_first_class_chunk_word_size = align_word_size_up(_first_class_chunk_word_size);
// Arbitrarily set the initial virtual space to a multiple
// of the boot class loader size.
size_t word_size = VIRTUALSPACEMULTIPLIER * first_chunk_word_size();
// Initialize the list of virtual spaces.
_space_list = new VirtualSpaceList(word_size);
}
}
// For UseCompressedKlassPointers the class space is reserved as a piece of the
// Java heap because the compression algorithm is the same for each. The
// argument passed in is at the top of the compressed space
void Metaspace::initialize_class_space(ReservedSpace rs) {
// The reserved space size may be bigger because of alignment, esp with UseLargePages
assert(rs.size() >= ClassMetaspaceSize,
err_msg(SIZE_FORMAT " != " UINTX_FORMAT, rs.size(), ClassMetaspaceSize));
_class_space_list = new VirtualSpaceList(rs);
}
void Metaspace::initialize(Mutex* lock,
MetaspaceType type) {
assert(space_list() != NULL,
"Metadata VirtualSpaceList has not been initialized");
_vsm = new SpaceManager(lock, space_list());
if (_vsm == NULL) {
return;
}
size_t word_size;
size_t class_word_size;
vsm()->get_initial_chunk_sizes(type,
&word_size,
&class_word_size);
assert(class_space_list() != NULL,
"Class VirtualSpaceList has not been initialized");
// Allocate SpaceManager for classes.
_class_vsm = new SpaceManager(lock, class_space_list());
if (_class_vsm == NULL) {
return;
}
MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
// Allocate chunk for metadata objects
Metachunk* new_chunk =
space_list()->get_initialization_chunk(word_size,
vsm()->medium_chunk_bunch());
assert(!DumpSharedSpaces || new_chunk != NULL, "should have enough space for both chunks");
if (new_chunk != NULL) {
// Add to this manager's list of chunks in use and current_chunk().
vsm()->add_chunk(new_chunk, true);
}
// Allocate chunk for class metadata objects
Metachunk* class_chunk =
class_space_list()->get_initialization_chunk(class_word_size,
class_vsm()->medium_chunk_bunch());
if (class_chunk != NULL) {
class_vsm()->add_chunk(class_chunk, true);
}
}
size_t Metaspace::align_word_size_up(size_t word_size) {
size_t byte_size = word_size * wordSize;
return ReservedSpace::allocation_align_size_up(byte_size) / wordSize;
}
MetaWord* Metaspace::allocate(size_t word_size, MetadataType mdtype) {
// DumpSharedSpaces doesn't use class metadata area (yet)
if (mdtype == ClassType && !DumpSharedSpaces) {
return class_vsm()->allocate(word_size);
} else {
return vsm()->allocate(word_size);
}
}
MetaWord* Metaspace::expand_and_allocate(size_t word_size, MetadataType mdtype) {
MetaWord* result;
MetaspaceGC::set_expand_after_GC(true);
size_t before_inc = MetaspaceGC::capacity_until_GC();
size_t delta_words = MetaspaceGC::delta_capacity_until_GC(word_size);
MetaspaceGC::inc_capacity_until_GC(delta_words);
if (PrintGCDetails && Verbose) {
gclog_or_tty->print_cr("Increase capacity to GC from " SIZE_FORMAT
" to " SIZE_FORMAT, before_inc, MetaspaceGC::capacity_until_GC());
}
result = allocate(word_size, mdtype);
return result;
}
// Space allocated in the Metaspace. This may
// be across several metadata virtual spaces.
char* Metaspace::bottom() const {
assert(DumpSharedSpaces, "only useful and valid for dumping shared spaces");
return (char*)vsm()->current_chunk()->bottom();
}
size_t Metaspace::used_words(MetadataType mdtype) const {
// return vsm()->allocation_total();
return mdtype == ClassType ? class_vsm()->sum_used_in_chunks_in_use() :
vsm()->sum_used_in_chunks_in_use(); // includes overhead!
}
size_t Metaspace::free_words(MetadataType mdtype) const {
return mdtype == ClassType ? class_vsm()->sum_free_in_chunks_in_use() :
vsm()->sum_free_in_chunks_in_use();
}
// Space capacity in the Metaspace. It includes
// space in the list of chunks from which allocations
// have been made. Don't include space in the global freelist and
// in the space available in the dictionary which
// is already counted in some chunk.
size_t Metaspace::capacity_words(MetadataType mdtype) const {
return mdtype == ClassType ? class_vsm()->sum_capacity_in_chunks_in_use() :
vsm()->sum_capacity_in_chunks_in_use();
}
void Metaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
if (SafepointSynchronize::is_at_safepoint()) {
assert(Thread::current()->is_VM_thread(), "should be the VM thread");
// Don't take Heap_lock
MutexLocker ml(vsm()->lock());
if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
// Dark matter. Too small for dictionary.
#ifdef ASSERT
Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
#endif
return;
}
if (is_class) {
class_vsm()->deallocate(ptr, word_size);
} else {
vsm()->deallocate(ptr, word_size);
}
} else {
MutexLocker ml(vsm()->lock());
if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
// Dark matter. Too small for dictionary.
#ifdef ASSERT
Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
#endif
return;
}
if (is_class) {
class_vsm()->deallocate(ptr, word_size);
} else {
vsm()->deallocate(ptr, word_size);
}
}
}
Metablock* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
bool read_only, MetadataType mdtype, TRAPS) {
if (HAS_PENDING_EXCEPTION) {
assert(false, "Should not allocate with exception pending");
return NULL; // caller does a CHECK_NULL too
}
// SSS: Should we align the allocations and make sure the sizes are aligned.
MetaWord* result = NULL;
assert(loader_data != NULL, "Should never pass around a NULL loader_data. "
"ClassLoaderData::the_null_class_loader_data() should have been used.");
// Allocate in metaspaces without taking out a lock, because it deadlocks
// with the SymbolTable_lock. Dumping is single threaded for now. We'll have
// to revisit this for application class data sharing.
if (DumpSharedSpaces) {
if (read_only) {
result = loader_data->ro_metaspace()->allocate(word_size, NonClassType);
} else {
result = loader_data->rw_metaspace()->allocate(word_size, NonClassType);
}
if (result == NULL) {
report_out_of_shared_space(read_only ? SharedReadOnly : SharedReadWrite);
}
return Metablock::initialize(result, word_size);
}
result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
if (result == NULL) {
// Try to clean out some memory and retry.
result =
Universe::heap()->collector_policy()->satisfy_failed_metadata_allocation(
loader_data, word_size, mdtype);
// If result is still null, we are out of memory.
if (result == NULL) {
if (Verbose && TraceMetadataChunkAllocation) {
gclog_or_tty->print_cr("Metaspace allocation failed for size "
SIZE_FORMAT, word_size);
if (loader_data->metaspace_or_null() != NULL) loader_data->metaspace_or_null()->dump(gclog_or_tty);
MetaspaceAux::dump(gclog_or_tty);
}
// -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
report_java_out_of_memory("Metadata space");
if (JvmtiExport::should_post_resource_exhausted()) {
JvmtiExport::post_resource_exhausted(
JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
"Metadata space");
}
THROW_OOP_0(Universe::out_of_memory_error_perm_gen());
}
}
return Metablock::initialize(result, word_size);
}
void Metaspace::print_on(outputStream* out) const {
// Print both class virtual space counts and metaspace.
if (Verbose) {
vsm()->print_on(out);
class_vsm()->print_on(out);
}
}
bool Metaspace::contains(const void * ptr) {
if (MetaspaceShared::is_in_shared_space(ptr)) {
return true;
}
// This is checked while unlocked. As long as the virtualspaces are added
// at the end, the pointer will be in one of them. The virtual spaces
// aren't deleted presently. When they are, some sort of locking might
// be needed. Note, locking this can cause inversion problems with the
// caller in MetaspaceObj::is_metadata() function.
return space_list()->contains(ptr) || class_space_list()->contains(ptr);
}
void Metaspace::verify() {
vsm()->verify();
class_vsm()->verify();
}
void Metaspace::dump(outputStream* const out) const {
if (UseMallocOnly) {
// Just print usage for now
out->print_cr("usage %d", used_words(Metaspace::NonClassType));
}
out->print_cr("\nVirtual space manager: " INTPTR_FORMAT, vsm());
vsm()->dump(out);
out->print_cr("\nClass space manager: " INTPTR_FORMAT, class_vsm());
class_vsm()->dump(out);
}