< prev index next > src/hotspot/share/classfile/fieldLayoutBuilder.cpp
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*/
#include "precompiled.hpp"
#include "classfile/classFileParser.hpp"
#include "classfile/fieldLayoutBuilder.hpp"
+ #include "classfile/systemDictionary.hpp"
+ #include "classfile/vmSymbols.hpp"
#include "jvm.h"
#include "memory/resourceArea.hpp"
#include "oops/array.hpp"
#include "oops/fieldStreams.inline.hpp"
#include "oops/instanceMirrorKlass.hpp"
#include "oops/instanceKlass.inline.hpp"
#include "oops/klass.inline.hpp"
+ #include "oops/inlineKlass.inline.hpp"
#include "runtime/fieldDescriptor.inline.hpp"
+ #include "utilities/powerOfTwo.hpp"
+ static LayoutKind field_layout_selection(FieldInfo field_info, Array<InlineLayoutInfo>* inline_layout_info_array,
+ bool use_atomic_flat) {
+
+ if (field_info.field_flags().is_injected()) {
+ // don't flatten injected fields
+ return LayoutKind::REFERENCE;
+ }
+
+ if (inline_layout_info_array == nullptr || inline_layout_info_array->adr_at(field_info.index())->klass() == nullptr) {
+ // field's type is not a known value class, using a reference
+ return LayoutKind::REFERENCE;
+ }
+
+ InlineLayoutInfo* inline_field_info = inline_layout_info_array->adr_at(field_info.index());
+ InlineKlass* vk = inline_field_info->klass();
+
+ if (field_info.field_flags().is_null_free_inline_type()) {
+ assert(vk->is_implicitly_constructible(), "null-free fields must be implicitly constructible");
+ if (vk->must_be_atomic() || field_info.access_flags().is_volatile() || AlwaysAtomicAccesses) {
+ if (vk->is_naturally_atomic() && vk->has_non_atomic_layout()) return LayoutKind::NON_ATOMIC_FLAT;
+ return (vk->has_atomic_layout() && use_atomic_flat) ? LayoutKind::ATOMIC_FLAT : LayoutKind::REFERENCE;
+ } else {
+ return vk->has_non_atomic_layout() ? LayoutKind::NON_ATOMIC_FLAT : LayoutKind::REFERENCE;
+ }
+ } else {
+ if (NullableFieldFlattening && vk->has_nullable_layout()) {
+ return use_atomic_flat ? LayoutKind::NULLABLE_ATOMIC_FLAT : LayoutKind::REFERENCE;
+ } else {
+ return LayoutKind::REFERENCE;
+ }
+ }
+ }
+
+ static void get_size_and_alignment(InlineKlass* vk, LayoutKind kind, int* size, int* alignment) {
+ switch(kind) {
+ case LayoutKind::NON_ATOMIC_FLAT:
+ *size = vk->non_atomic_size_in_bytes();
+ *alignment = vk->non_atomic_alignment();
+ break;
+ case LayoutKind::ATOMIC_FLAT:
+ *size = vk->atomic_size_in_bytes();
+ *alignment = *size;
+ break;
+ case LayoutKind::NULLABLE_ATOMIC_FLAT:
+ *size = vk->nullable_size_in_bytes();
+ *alignment = *size;
+ break;
+ default:
+ ShouldNotReachHere();
+ }
+ }
LayoutRawBlock::LayoutRawBlock(Kind kind, int size) :
_next_block(nullptr),
_prev_block(nullptr),
- _kind(kind),
+ _inline_klass(nullptr),
+ _block_kind(kind),
_offset(-1),
_alignment(1),
_size(size),
- _field_index(-1),
- _is_reference(false) {
- assert(kind == EMPTY || kind == RESERVED || kind == PADDING || kind == INHERITED,
+ _field_index(-1) {
+ assert(kind == EMPTY || kind == RESERVED || kind == PADDING || kind == INHERITED || kind == NULL_MARKER,
"Otherwise, should use the constructor with a field index argument");
assert(size > 0, "Sanity check");
}
- LayoutRawBlock::LayoutRawBlock(int index, Kind kind, int size, int alignment, bool is_reference) :
+ LayoutRawBlock::LayoutRawBlock(int index, Kind kind, int size, int alignment) :
_next_block(nullptr),
_prev_block(nullptr),
- _kind(kind),
+ _inline_klass(nullptr),
+ _block_kind(kind),
_offset(-1),
_alignment(alignment),
_size(size),
- _field_index(index),
- _is_reference(is_reference) {
- assert(kind == REGULAR || kind == FLATTENED || kind == INHERITED,
+ _field_index(index) {
+ assert(kind == REGULAR || kind == FLAT || kind == INHERITED,
"Other kind do not have a field index");
assert(size > 0, "Sanity check");
assert(alignment > 0, "Sanity check");
}
return _size >= size + adjustment;
}
FieldGroup::FieldGroup(int contended_group) :
_next(nullptr),
- _primitive_fields(nullptr),
+ _small_primitive_fields(nullptr),
+ _big_primitive_fields(nullptr),
_oop_fields(nullptr),
_contended_group(contended_group), // -1 means no contended group, 0 means default contended group
_oop_count(0) {}
void FieldGroup::add_primitive_field(int idx, BasicType type) {
int size = type2aelembytes(type);
- LayoutRawBlock* block = new LayoutRawBlock(idx, LayoutRawBlock::REGULAR, size, size /* alignment == size for primitive types */, false);
- if (_primitive_fields == nullptr) {
- _primitive_fields = new GrowableArray<LayoutRawBlock*>(INITIAL_LIST_SIZE);
+ LayoutRawBlock* block = new LayoutRawBlock(idx, LayoutRawBlock::REGULAR, size, size /* alignment == size for primitive types */);
+ if (size >= oopSize) {
+ add_to_big_primitive_list(block);
+ } else {
+ add_to_small_primitive_list(block);
}
- _primitive_fields->append(block);
}
void FieldGroup::add_oop_field(int idx) {
int size = type2aelembytes(T_OBJECT);
- LayoutRawBlock* block = new LayoutRawBlock(idx, LayoutRawBlock::REGULAR, size, size /* alignment == size for oops */, true);
+ LayoutRawBlock* block = new LayoutRawBlock(idx, LayoutRawBlock::REGULAR, size, size /* alignment == size for oops */);
if (_oop_fields == nullptr) {
_oop_fields = new GrowableArray<LayoutRawBlock*>(INITIAL_LIST_SIZE);
}
_oop_fields->append(block);
_oop_count++;
}
+ void FieldGroup::add_flat_field(int idx, InlineKlass* vk, LayoutKind lk, int size, int alignment) {
+ LayoutRawBlock* block = new LayoutRawBlock(idx, LayoutRawBlock::FLAT, size, alignment);
+ block->set_inline_klass(vk);
+ block->set_layout_kind(lk);
+ if (block->size() >= oopSize) {
+ add_to_big_primitive_list(block);
+ } else {
+ add_to_small_primitive_list(block);
+ }
+ }
+
void FieldGroup::sort_by_size() {
- if (_primitive_fields != nullptr) {
- _primitive_fields->sort(LayoutRawBlock::compare_size_inverted);
+ if (_small_primitive_fields != nullptr) {
+ _small_primitive_fields->sort(LayoutRawBlock::compare_size_inverted);
+ }
+ if (_big_primitive_fields != nullptr) {
+ _big_primitive_fields->sort(LayoutRawBlock::compare_size_inverted);
}
}
- FieldLayout::FieldLayout(GrowableArray<FieldInfo>* field_info, ConstantPool* cp) :
+ void FieldGroup::add_to_small_primitive_list(LayoutRawBlock* block) {
+ if (_small_primitive_fields == nullptr) {
+ _small_primitive_fields = new GrowableArray<LayoutRawBlock*>(INITIAL_LIST_SIZE);
+ }
+ _small_primitive_fields->append(block);
+ }
+
+ void FieldGroup::add_to_big_primitive_list(LayoutRawBlock* block) {
+ if (_big_primitive_fields == nullptr) {
+ _big_primitive_fields = new GrowableArray<LayoutRawBlock*>(INITIAL_LIST_SIZE);
+ }
+ _big_primitive_fields->append(block);
+ }
+
+ FieldLayout::FieldLayout(GrowableArray<FieldInfo>* field_info, Array<InlineLayoutInfo>* inline_layout_info_array, ConstantPool* cp) :
_field_info(field_info),
+ _inline_layout_info_array(inline_layout_info_array),
_cp(cp),
_blocks(nullptr),
_start(_blocks),
- _last(_blocks) {}
+ _last(_blocks),
+ _super_first_field_offset(-1),
+ _super_alignment(-1),
+ _super_min_align_required(-1),
+ _default_value_offset(-1),
+ _null_reset_value_offset(-1),
+ _super_has_fields(false),
+ _has_inherited_fields(false) {}
void FieldLayout::initialize_static_layout() {
_blocks = new LayoutRawBlock(LayoutRawBlock::EMPTY, INT_MAX);
_blocks->set_offset(0);
_last = _blocks;
_blocks->set_offset(0);
_last = _blocks;
_start = _blocks;
insert(first_empty_block(), new LayoutRawBlock(LayoutRawBlock::RESERVED, instanceOopDesc::base_offset_in_bytes()));
} else {
- bool has_fields = reconstruct_layout(super_klass);
+ _super_has_fields = reconstruct_layout(super_klass);
fill_holes(super_klass);
- if (!super_klass->has_contended_annotations() || !has_fields) {
+ if ((!super_klass->has_contended_annotations()) || !_super_has_fields) {
_start = _blocks; // start allocating fields from the first empty block
} else {
_start = _last; // append fields at the end of the reconstructed layout
}
}
}
LayoutRawBlock* FieldLayout::first_field_block() {
- LayoutRawBlock* block = _start;
- while (block->kind() != LayoutRawBlock::INHERITED && block->kind() != LayoutRawBlock::REGULAR
- && block->kind() != LayoutRawBlock::FLATTENED && block->kind() != LayoutRawBlock::PADDING) {
+ LayoutRawBlock* block = _blocks;
+ while (block != nullptr
+ && block->block_kind() != LayoutRawBlock::INHERITED
+ && block->block_kind() != LayoutRawBlock::REGULAR
+ && block->block_kind() != LayoutRawBlock::FLAT
+ && block->block_kind() != LayoutRawBlock::NULL_MARKER) {
block = block->next_block();
}
return block;
}
-
- // Insert a set of fields into a layout using a best-fit strategy.
- // For each field, search for the smallest empty slot able to fit the field
+ // Insert a set of fields into a layout.
+ // For each field, search for an empty slot able to fit the field
// (satisfying both size and alignment requirements), if none is found,
// add the field at the end of the layout.
// Fields cannot be inserted before the block specified in the "start" argument
void FieldLayout::add(GrowableArray<LayoutRawBlock*>* list, LayoutRawBlock* start) {
if (list == nullptr) return;
int last_alignment = 0;
for (int i = 0; i < list->length(); i ++) {
LayoutRawBlock* b = list->at(i);
LayoutRawBlock* cursor = nullptr;
LayoutRawBlock* candidate = nullptr;
-
// if start is the last block, just append the field
if (start == last_block()) {
candidate = last_block();
}
// Before iterating over the layout to find an empty slot fitting the field's requirements,
last_size = b->size();
last_alignment = b->alignment();
cursor = last_block()->prev_block();
assert(cursor != nullptr, "Sanity check");
last_search_success = true;
+
while (cursor != start) {
- if (cursor->kind() == LayoutRawBlock::EMPTY && cursor->fit(b->size(), b->alignment())) {
+ if (cursor->block_kind() == LayoutRawBlock::EMPTY && cursor->fit(b->size(), b->alignment())) {
if (candidate == nullptr || cursor->size() < candidate->size()) {
candidate = cursor;
}
}
cursor = cursor->prev_block();
if (candidate == nullptr) {
candidate = last_block();
last_search_success = false;
}
assert(candidate != nullptr, "Candidate must not be null");
- assert(candidate->kind() == LayoutRawBlock::EMPTY, "Candidate must be an empty block");
+ assert(candidate->block_kind() == LayoutRawBlock::EMPTY, "Candidate must be an empty block");
assert(candidate->fit(b->size(), b->alignment()), "Candidate must be able to store the block");
}
-
insert_field_block(candidate, b);
}
}
// Used for classes with hard coded field offsets, insert a field at the specified offset */
}
LayoutRawBlock* slot = start;
while (slot != nullptr) {
if ((slot->offset() <= block->offset() && (slot->offset() + slot->size()) > block->offset()) ||
slot == _last){
- assert(slot->kind() == LayoutRawBlock::EMPTY, "Matching slot must be an empty slot");
- assert(slot->size() >= block->offset() + block->size() ,"Matching slot must be big enough");
+ assert(slot->block_kind() == LayoutRawBlock::EMPTY, "Matching slot must be an empty slot");
+ assert(slot->size() >= block->offset() - slot->offset() + block->size() ,"Matching slot must be big enough");
if (slot->offset() < block->offset()) {
int adjustment = block->offset() - slot->offset();
LayoutRawBlock* adj = new LayoutRawBlock(LayoutRawBlock::EMPTY, adjustment);
insert(slot, adj);
}
insert(slot, block);
if (slot->size() == 0) {
remove(slot);
}
- _field_info->adr_at(block->field_index())->set_offset(block->offset());
+ if (block->block_kind() == LayoutRawBlock::REGULAR || block->block_kind() == LayoutRawBlock::FLAT) {
+ _field_info->adr_at(block->field_index())->set_offset(block->offset());
+ }
return;
}
slot = slot->next_block();
}
fatal("Should have found a matching slot above, corrupted layout or invalid offset");
if (start == last_block()) {
candidate = last_block();
} else {
LayoutRawBlock* first = list->at(0);
candidate = last_block()->prev_block();
- while (candidate->kind() != LayoutRawBlock::EMPTY || !candidate->fit(size, first->alignment())) {
+ while (candidate->block_kind() != LayoutRawBlock::EMPTY || !candidate->fit(size, first->alignment())) {
if (candidate == start) {
candidate = last_block();
break;
}
candidate = candidate->prev_block();
}
assert(candidate != nullptr, "Candidate must not be null");
- assert(candidate->kind() == LayoutRawBlock::EMPTY, "Candidate must be an empty block");
+ assert(candidate->block_kind() == LayoutRawBlock::EMPTY, "Candidate must be an empty block");
assert(candidate->fit(size, first->alignment()), "Candidate must be able to store the whole contiguous block");
}
for (int i = 0; i < list->length(); i++) {
LayoutRawBlock* b = list->at(i);
assert((candidate->offset() % b->alignment() == 0), "Contiguous blocks must be naturally well aligned");
}
}
LayoutRawBlock* FieldLayout::insert_field_block(LayoutRawBlock* slot, LayoutRawBlock* block) {
- assert(slot->kind() == LayoutRawBlock::EMPTY, "Blocks can only be inserted in empty blocks");
+ assert(slot->block_kind() == LayoutRawBlock::EMPTY, "Blocks can only be inserted in empty blocks");
if (slot->offset() % block->alignment() != 0) {
int adjustment = block->alignment() - (slot->offset() % block->alignment());
LayoutRawBlock* adj = new LayoutRawBlock(LayoutRawBlock::EMPTY, adjustment);
insert(slot, adj);
}
+ assert(block->size() >= block->size(), "Enough space must remain after adjustment");
insert(slot, block);
if (slot->size() == 0) {
remove(slot);
}
- _field_info->adr_at(block->field_index())->set_offset(block->offset());
+ // NULL_MARKER blocks are not real fields, so they don't have an entry in the FieldInfo array
+ if (block->block_kind() != LayoutRawBlock::NULL_MARKER) {
+ _field_info->adr_at(block->field_index())->set_offset(block->offset());
+ if (_field_info->adr_at(block->field_index())->name(_cp) == vmSymbols::default_value_name()) {
+ _default_value_offset = block->offset();
+ }
+ if (_field_info->adr_at(block->field_index())->name(_cp) == vmSymbols::null_reset_value_name()) {
+ _null_reset_value_offset = block->offset();
+ }
+ }
+ if (block->block_kind() == LayoutRawBlock::FLAT && block->layout_kind() == LayoutKind::NULLABLE_ATOMIC_FLAT) {
+ int nm_offset = block->inline_klass()->null_marker_offset() - block->inline_klass()->first_field_offset() + block->offset();
+ _field_info->adr_at(block->field_index())->set_null_marker_offset(nm_offset);
+ _inline_layout_info_array->adr_at(block->field_index())->set_null_marker_offset(nm_offset);
+ }
+
return block;
}
bool FieldLayout::reconstruct_layout(const InstanceKlass* ik) {
bool has_instance_fields = false;
+ if (ik->is_abstract() && !ik->is_identity_class()) {
+ _super_alignment = type2aelembytes(BasicType::T_LONG);
+ }
GrowableArray<LayoutRawBlock*>* all_fields = new GrowableArray<LayoutRawBlock*>(32);
while (ik != nullptr) {
for (AllFieldStream fs(ik->fieldinfo_stream(), ik->constants()); !fs.done(); fs.next()) {
BasicType type = Signature::basic_type(fs.signature());
// distinction between static and non-static fields is missing
if (fs.access_flags().is_static()) continue;
has_instance_fields = true;
- int size = type2aelembytes(type);
- // INHERITED blocks are marked as non-reference because oop_maps are handled by their holder class
- LayoutRawBlock* block = new LayoutRawBlock(fs.index(), LayoutRawBlock::INHERITED, size, size, false);
+ _has_inherited_fields = true;
+ if (_super_first_field_offset == -1 || fs.offset() < _super_first_field_offset) _super_first_field_offset = fs.offset();
+ LayoutRawBlock* block;
+ if (fs.is_flat()) {
+ InlineLayoutInfo layout_info = ik->inline_layout_info(fs.index());
+ InlineKlass* vk = layout_info.klass();
+ block = new LayoutRawBlock(fs.index(), LayoutRawBlock::INHERITED,
+ vk->layout_size_in_bytes(layout_info.kind()),
+ vk->layout_alignment(layout_info.kind()));
+ assert(_super_alignment == -1 || _super_alignment >= vk->payload_alignment(), "Invalid value alignment");
+ _super_min_align_required = _super_min_align_required > vk->payload_alignment() ? _super_min_align_required : vk->payload_alignment();
+ } else {
+ int size = type2aelembytes(type);
+ // INHERITED blocks are marked as non-reference because oop_maps are handled by their holder class
+ block = new LayoutRawBlock(fs.index(), LayoutRawBlock::INHERITED, size, size);
+ // For primitive types, the alignment is equal to the size
+ assert(_super_alignment == -1 || _super_alignment >= size, "Invalid value alignment");
+ _super_min_align_required = _super_min_align_required > size ? _super_min_align_required : size;
+ }
block->set_offset(fs.offset());
all_fields->append(block);
}
ik = ik->super() == nullptr ? nullptr : InstanceKlass::cast(ik->super());
}
-
all_fields->sort(LayoutRawBlock::compare_offset);
_blocks = new LayoutRawBlock(LayoutRawBlock::RESERVED, instanceOopDesc::base_offset_in_bytes());
_blocks->set_offset(0);
_last = _blocks;
-
for(int i = 0; i < all_fields->length(); i++) {
LayoutRawBlock* b = all_fields->at(i);
_last->set_next_block(b);
b->set_prev_block(_last);
_last = b;
LayoutRawBlock::Kind filling_type = super_klass->has_contended_annotations() ? LayoutRawBlock::PADDING: LayoutRawBlock::EMPTY;
LayoutRawBlock* b = _blocks;
while (b->next_block() != nullptr) {
if (b->next_block()->offset() > (b->offset() + b->size())) {
int size = b->next_block()->offset() - (b->offset() + b->size());
+ // FIXME it would be better if initial empty block where tagged as PADDING for value classes
LayoutRawBlock* empty = new LayoutRawBlock(filling_type, size);
empty->set_offset(b->offset() + b->size());
empty->set_next_block(b->next_block());
b->next_block()->set_prev_block(empty);
b->set_next_block(empty);
empty->set_prev_block(b);
}
b = b->next_block();
}
assert(b->next_block() == nullptr, "Invariant at this point");
- assert(b->kind() != LayoutRawBlock::EMPTY, "Sanity check");
-
+ assert(b->block_kind() != LayoutRawBlock::EMPTY, "Sanity check");
// If the super class has @Contended annotation, a padding block is
// inserted at the end to ensure that fields from the subclasses won't share
// the cache line of the last field of the contended class
if (super_klass->has_contended_annotations() && ContendedPaddingWidth > 0) {
LayoutRawBlock* p = new LayoutRawBlock(LayoutRawBlock::PADDING, ContendedPaddingWidth);
last->set_prev_block(b);
_last = last;
}
LayoutRawBlock* FieldLayout::insert(LayoutRawBlock* slot, LayoutRawBlock* block) {
- assert(slot->kind() == LayoutRawBlock::EMPTY, "Blocks can only be inserted in empty blocks");
+ assert(slot->block_kind() == LayoutRawBlock::EMPTY, "Blocks can only be inserted in empty blocks");
assert(slot->offset() % block->alignment() == 0, "Incompatible alignment");
block->set_offset(slot->offset());
slot->set_offset(slot->offset() + block->size());
assert((slot->size() - block->size()) < slot->size(), "underflow checking");
assert(slot->size() - block->size() >= 0, "no negative size allowed");
block->prev_block()->set_next_block(block);
}
if (_blocks == slot) {
_blocks = block;
}
+ if (_start == slot) {
+ _start = block;
+ }
return block;
}
void FieldLayout::remove(LayoutRawBlock* block) {
assert(block != nullptr, "Sanity check");
if (block == _start) {
_start = block->prev_block();
}
}
- void FieldLayout::print(outputStream* output, bool is_static, const InstanceKlass* super) {
+ void FieldLayout::shift_fields(int shift) {
+ LayoutRawBlock* b = first_field_block();
+ LayoutRawBlock* previous = b->prev_block();
+ if (previous->block_kind() == LayoutRawBlock::EMPTY) {
+ previous->set_size(previous->size() + shift);
+ } else {
+ LayoutRawBlock* nb = new LayoutRawBlock(LayoutRawBlock::PADDING, shift);
+ nb->set_offset(b->offset());
+ previous->set_next_block(nb);
+ nb->set_prev_block(previous);
+ b->set_prev_block(nb);
+ nb->set_next_block(b);
+ }
+ while (b != nullptr) {
+ b->set_offset(b->offset() + shift);
+ if (b->block_kind() == LayoutRawBlock::REGULAR || b->block_kind() == LayoutRawBlock::FLAT) {
+ _field_info->adr_at(b->field_index())->set_offset(b->offset());
+ if (b->layout_kind() == LayoutKind::NULLABLE_ATOMIC_FLAT) {
+ int new_nm_offset = _field_info->adr_at(b->field_index())->null_marker_offset() + shift;
+ _field_info->adr_at(b->field_index())->set_null_marker_offset(new_nm_offset);
+ _inline_layout_info_array->adr_at(b->field_index())->set_null_marker_offset(new_nm_offset);
+
+ }
+ }
+ assert(b->block_kind() == LayoutRawBlock::EMPTY || b->offset() % b->alignment() == 0, "Must still be correctly aligned");
+ b = b->next_block();
+ }
+ }
+
+ LayoutRawBlock* FieldLayout::find_null_marker() {
+ LayoutRawBlock* b = _blocks;
+ while (b != nullptr) {
+ if (b->block_kind() == LayoutRawBlock::NULL_MARKER) {
+ return b;
+ }
+ b = b->next_block();
+ }
+ ShouldNotReachHere();
+ }
+
+ void FieldLayout::remove_null_marker() {
+ LayoutRawBlock* b = first_field_block();
+ while (b != nullptr) {
+ if (b->block_kind() == LayoutRawBlock::NULL_MARKER) {
+ if (b->next_block()->block_kind() == LayoutRawBlock::EMPTY) {
+ LayoutRawBlock* n = b->next_block();
+ remove(b);
+ n->set_offset(b->offset());
+ n->set_size(n->size() + b->size());
+ } else {
+ b->set_block_kind(LayoutRawBlock::EMPTY);
+ }
+ return;
+ }
+ b = b->next_block();
+ }
+ ShouldNotReachHere(); // if we reach this point, the null marker was not found!
+ }
+
+ static const char* layout_kind_to_string(LayoutKind lk) {
+ switch(lk) {
+ case LayoutKind::REFERENCE:
+ return "REFERENCE";
+ case LayoutKind::NON_ATOMIC_FLAT:
+ return "NON_ATOMIC_FLAT";
+ case LayoutKind::ATOMIC_FLAT:
+ return "ATOMIC_FLAT";
+ case LayoutKind::NULLABLE_ATOMIC_FLAT:
+ return "NULLABLE_ATOMIC_FLAT";
+ case LayoutKind::UNKNOWN:
+ return "UNKNOWN";
+ default:
+ ShouldNotReachHere();
+ }
+ }
+
+ void FieldLayout::print(outputStream* output, bool is_static, const InstanceKlass* super, Array<InlineLayoutInfo>* inline_fields) {
ResourceMark rm;
LayoutRawBlock* b = _blocks;
while(b != _last) {
- switch(b->kind()) {
+ switch(b->block_kind()) {
case LayoutRawBlock::REGULAR: {
FieldInfo* fi = _field_info->adr_at(b->field_index());
- output->print_cr(" @%d \"%s\" %s %d/%d %s",
+ output->print_cr(" @%d %s %d/%d \"%s\" %s",
b->offset(),
- fi->name(_cp)->as_C_string(),
- fi->signature(_cp)->as_C_string(),
+ "REGULAR",
b->size(),
b->alignment(),
- "REGULAR");
+ fi->name(_cp)->as_C_string(),
+ fi->signature(_cp)->as_C_string());
break;
}
- case LayoutRawBlock::FLATTENED: {
+ case LayoutRawBlock::FLAT: {
FieldInfo* fi = _field_info->adr_at(b->field_index());
- output->print_cr(" @%d \"%s\" %s %d/%d %s",
+ InlineKlass* ik = inline_fields->adr_at(fi->index())->klass();
+ assert(ik != nullptr, "");
+ output->print_cr(" @%d %s %d/%d \"%s\" %s %s@%p %s",
b->offset(),
- fi->name(_cp)->as_C_string(),
- fi->signature(_cp)->as_C_string(),
+ "FLAT",
b->size(),
b->alignment(),
- "FLATTENED");
+ fi->name(_cp)->as_C_string(),
+ fi->signature(_cp)->as_C_string(),
+ ik->name()->as_C_string(),
+ ik->class_loader_data(), layout_kind_to_string(b->layout_kind()));
break;
}
case LayoutRawBlock::RESERVED: {
- output->print_cr(" @%d %d/- %s",
+ output->print_cr(" @%d %s %d/-",
b->offset(),
- b->size(),
- "RESERVED");
+ "RESERVED",
+ b->size());
break;
}
case LayoutRawBlock::INHERITED: {
assert(!is_static, "Static fields are not inherited in layouts");
assert(super != nullptr, "super klass must be provided to retrieve inherited fields info");
bool found = false;
const InstanceKlass* ik = super;
while (!found && ik != nullptr) {
for (AllFieldStream fs(ik->fieldinfo_stream(), ik->constants()); !fs.done(); fs.next()) {
- if (fs.offset() == b->offset()) {
- output->print_cr(" @%d \"%s\" %s %d/%d %s",
+ if (fs.offset() == b->offset() && fs.access_flags().is_static() == is_static) {
+ output->print_cr(" @%d %s %d/%d \"%s\" %s",
b->offset(),
- fs.name()->as_C_string(),
- fs.signature()->as_C_string(),
+ "INHERITED",
b->size(),
- b->size(), // so far, alignment constraint == size, will change with Valhalla
- "INHERITED");
+ b->size(), // so far, alignment constraint == size, will change with Valhalla => FIXME
+ fs.name()->as_C_string(),
+ fs.signature()->as_C_string());
found = true;
break;
}
- }
- ik = ik->java_super();
}
- break;
+ ik = ik->java_super();
}
- case LayoutRawBlock::EMPTY:
- output->print_cr(" @%d %d/1 %s",
- b->offset(),
- b->size(),
- "EMPTY");
- break;
- case LayoutRawBlock::PADDING:
- output->print_cr(" @%d %d/1 %s",
- b->offset(),
- b->size(),
- "PADDING");
- break;
+ break;
+ }
+ case LayoutRawBlock::EMPTY:
+ output->print_cr(" @%d %s %d/1",
+ b->offset(),
+ "EMPTY",
+ b->size());
+ break;
+ case LayoutRawBlock::PADDING:
+ output->print_cr(" @%d %s %d/1",
+ b->offset(),
+ "PADDING",
+ b->size());
+ break;
+ case LayoutRawBlock::NULL_MARKER:
+ {
+ output->print_cr(" @%d %s %d/1 ",
+ b->offset(),
+ "NULL_MARKER",
+ b->size());
+ break;
+ }
+ default:
+ fatal("Unknown block type");
}
b = b->next_block();
}
}
- FieldLayoutBuilder::FieldLayoutBuilder(const Symbol* classname, const InstanceKlass* super_klass, ConstantPool* constant_pool,
- GrowableArray<FieldInfo>* field_info, bool is_contended, FieldLayoutInfo* info) :
+ FieldLayoutBuilder::FieldLayoutBuilder(const Symbol* classname, ClassLoaderData* loader_data, const InstanceKlass* super_klass, ConstantPool* constant_pool,
+ GrowableArray<FieldInfo>* field_info, bool is_contended, bool is_inline_type,bool is_abstract_value,
+ bool must_be_atomic, FieldLayoutInfo* info, Array<InlineLayoutInfo>* inline_layout_info_array) :
_classname(classname),
+ _loader_data(loader_data),
_super_klass(super_klass),
_constant_pool(constant_pool),
_field_info(field_info),
_info(info),
+ _inline_layout_info_array(inline_layout_info_array),
_root_group(nullptr),
_contended_groups(GrowableArray<FieldGroup*>(8)),
_static_fields(nullptr),
_layout(nullptr),
_static_layout(nullptr),
_nonstatic_oopmap_count(0),
- _alignment(-1),
+ _payload_alignment(-1),
+ _first_field_offset(-1),
+ _null_marker_offset(-1),
+ _payload_size_in_bytes(-1),
+ _non_atomic_layout_size_in_bytes(-1),
+ _non_atomic_layout_alignment(-1),
+ _atomic_layout_size_in_bytes(-1),
+ _nullable_layout_size_in_bytes(-1),
+ _fields_size_sum(0),
+ _declared_non_static_fields_count(0),
+ _has_non_naturally_atomic_fields(false),
+ _is_naturally_atomic(false),
+ _must_be_atomic(must_be_atomic),
_has_nonstatic_fields(false),
- _is_contended(is_contended) {}
-
+ _has_inline_type_fields(false),
+ _is_contended(is_contended),
+ _is_inline_type(is_inline_type),
+ _is_abstract_value(is_abstract_value),
+ _has_flattening_information(is_inline_type),
+ _is_empty_inline_class(false) {}
FieldGroup* FieldLayoutBuilder::get_or_create_contended_group(int g) {
assert(g > 0, "must only be called for named contended groups");
FieldGroup* fg = nullptr;
for (int i = 0; i < _contended_groups.length(); i++) {
_contended_groups.append(fg);
return fg;
}
void FieldLayoutBuilder::prologue() {
- _layout = new FieldLayout(_field_info, _constant_pool);
+ _layout = new FieldLayout(_field_info, _inline_layout_info_array, _constant_pool);
const InstanceKlass* super_klass = _super_klass;
_layout->initialize_instance_layout(super_klass);
+ _nonstatic_oopmap_count = super_klass == nullptr ? 0 : super_klass->nonstatic_oop_map_count();
if (super_klass != nullptr) {
_has_nonstatic_fields = super_klass->has_nonstatic_fields();
}
- _static_layout = new FieldLayout(_field_info, _constant_pool);
+ _static_layout = new FieldLayout(_field_info, _inline_layout_info_array, _constant_pool);
_static_layout->initialize_static_layout();
_static_fields = new FieldGroup();
_root_group = new FieldGroup();
}
- // Field sorting for regular classes:
+ // Field sorting for regular (non-inline) classes:
// - fields are sorted in static and non-static fields
// - non-static fields are also sorted according to their contention group
// (support of the @Contended annotation)
// - @Contended annotation is ignored for static fields
+ // - field flattening decisions are taken in this method
void FieldLayoutBuilder::regular_field_sorting() {
int idx = 0;
for (GrowableArrayIterator<FieldInfo> it = _field_info->begin(); it != _field_info->end(); ++it, ++idx) {
- FieldInfo ctrl = _field_info->at(0);
FieldGroup* group = nullptr;
FieldInfo fieldinfo = *it;
if (fieldinfo.access_flags().is_static()) {
group = _static_fields;
} else {
}
}
assert(group != nullptr, "invariant");
BasicType type = Signature::basic_type(fieldinfo.signature(_constant_pool));
switch(type) {
- case T_BYTE:
- case T_CHAR:
- case T_DOUBLE:
- case T_FLOAT:
- case T_INT:
- case T_LONG:
- case T_SHORT:
- case T_BOOLEAN:
- group->add_primitive_field(idx, type);
- break;
- case T_OBJECT:
- case T_ARRAY:
+ case T_BYTE:
+ case T_CHAR:
+ case T_DOUBLE:
+ case T_FLOAT:
+ case T_INT:
+ case T_LONG:
+ case T_SHORT:
+ case T_BOOLEAN:
+ group->add_primitive_field(idx, type);
+ break;
+ case T_OBJECT:
+ case T_ARRAY:
+ {
+ LayoutKind lk = field_layout_selection(fieldinfo, _inline_layout_info_array, true);
+ if (fieldinfo.field_flags().is_null_free_inline_type() || lk != LayoutKind::REFERENCE
+ || (!fieldinfo.field_flags().is_injected()
+ && _inline_layout_info_array != nullptr && _inline_layout_info_array->adr_at(fieldinfo.index())->klass() != nullptr
+ && !_inline_layout_info_array->adr_at(fieldinfo.index())->klass()->is_identity_class())) {
+ _has_inline_type_fields = true;
+ _has_flattening_information = true;
+ }
+ if (lk == LayoutKind::REFERENCE) {
if (group != _static_fields) _nonstatic_oopmap_count++;
group->add_oop_field(idx);
- break;
- default:
- fatal("Something wrong?");
+ } else {
+ _has_flattening_information = true;
+ InlineKlass* vk = _inline_layout_info_array->adr_at(fieldinfo.index())->klass();
+ int size, alignment;
+ get_size_and_alignment(vk, lk, &size, &alignment);
+ group->add_flat_field(idx, vk, lk, size, alignment);
+ _inline_layout_info_array->adr_at(fieldinfo.index())->set_kind(lk);
+ _nonstatic_oopmap_count += vk->nonstatic_oop_map_count();
+ _field_info->adr_at(idx)->field_flags_addr()->update_flat(true);
+ _field_info->adr_at(idx)->set_layout_kind(lk);
+ // no need to update _must_be_atomic if vk->must_be_atomic() is true because current class is not an inline class
+ }
+ break;
+ }
+ default:
+ fatal("Something wrong?");
}
}
_root_group->sort_by_size();
_static_fields->sort_by_size();
if (!_contended_groups.is_empty()) {
_contended_groups.at(i)->sort_by_size();
}
}
}
+ /* Field sorting for inline classes:
+ * - because inline classes are immutable, the @Contended annotation is ignored
+ * when computing their layout (with only read operation, there's no false
+ * sharing issue)
+ * - this method also records the alignment of the field with the most
+ * constraining alignment, this value is then used as the alignment
+ * constraint when flattening this inline type into another container
+ * - field flattening decisions are taken in this method (those decisions are
+ * currently only based in the size of the fields to be flattened, the size
+ * of the resulting instance is not considered)
+ */
+ void FieldLayoutBuilder::inline_class_field_sorting() {
+ assert(_is_inline_type || _is_abstract_value, "Should only be used for inline classes");
+ int alignment = -1;
+ int idx = 0;
+ for (GrowableArrayIterator<FieldInfo> it = _field_info->begin(); it != _field_info->end(); ++it, ++idx) {
+ FieldGroup* group = nullptr;
+ FieldInfo fieldinfo = *it;
+ int field_alignment = 1;
+ if (fieldinfo.access_flags().is_static()) {
+ group = _static_fields;
+ } else {
+ _has_nonstatic_fields = true;
+ _declared_non_static_fields_count++;
+ group = _root_group;
+ }
+ assert(group != nullptr, "invariant");
+ BasicType type = Signature::basic_type(fieldinfo.signature(_constant_pool));
+ switch(type) {
+ case T_BYTE:
+ case T_CHAR:
+ case T_DOUBLE:
+ case T_FLOAT:
+ case T_INT:
+ case T_LONG:
+ case T_SHORT:
+ case T_BOOLEAN:
+ if (group != _static_fields) {
+ field_alignment = type2aelembytes(type); // alignment == size for primitive types
+ }
+ group->add_primitive_field(fieldinfo.index(), type);
+ break;
+ case T_OBJECT:
+ case T_ARRAY:
+ {
+ bool use_atomic_flat = _must_be_atomic; // flatten atomic fields only if the container is itself atomic
+ LayoutKind lk = field_layout_selection(fieldinfo, _inline_layout_info_array, use_atomic_flat);
+ if (fieldinfo.field_flags().is_null_free_inline_type() || lk != LayoutKind::REFERENCE
+ || (!fieldinfo.field_flags().is_injected()
+ && _inline_layout_info_array != nullptr && _inline_layout_info_array->adr_at(fieldinfo.index())->klass() != nullptr
+ && !_inline_layout_info_array->adr_at(fieldinfo.index())->klass()->is_identity_class())) {
+ _has_inline_type_fields = true;
+ _has_flattening_information = true;
+ }
+ if (lk == LayoutKind::REFERENCE) {
+ if (group != _static_fields) {
+ _nonstatic_oopmap_count++;
+ field_alignment = type2aelembytes(type); // alignment == size for oops
+ }
+ group->add_oop_field(idx);
+ } else {
+ _has_flattening_information = true;
+ InlineKlass* vk = _inline_layout_info_array->adr_at(fieldinfo.index())->klass();
+ if (!vk->is_naturally_atomic()) _has_non_naturally_atomic_fields = true;
+ int size, alignment;
+ get_size_and_alignment(vk, lk, &size, &alignment);
+ group->add_flat_field(idx, vk, lk, size, alignment);
+ _inline_layout_info_array->adr_at(fieldinfo.index())->set_kind(lk);
+ _nonstatic_oopmap_count += vk->nonstatic_oop_map_count();
+ field_alignment = alignment;
+ _field_info->adr_at(idx)->field_flags_addr()->update_flat(true);
+ _field_info->adr_at(idx)->set_layout_kind(lk);
+ }
+ break;
+ }
+ default:
+ fatal("Unexpected BasicType");
+ }
+ if (!fieldinfo.access_flags().is_static() && field_alignment > alignment) alignment = field_alignment;
+ }
+ _payload_alignment = alignment;
+ assert(_has_nonstatic_fields || _is_abstract_value, "Concrete value types do not support zero instance size yet");
+ }
+
void FieldLayoutBuilder::insert_contended_padding(LayoutRawBlock* slot) {
if (ContendedPaddingWidth > 0) {
LayoutRawBlock* padding = new LayoutRawBlock(LayoutRawBlock::PADDING, ContendedPaddingWidth);
_layout->insert(slot, padding);
}
}
- // Computation of regular classes layout is an evolution of the previous default layout
- // (FieldAllocationStyle 1):
- // - primitive fields are allocated first (from the biggest to the smallest)
- // - then oop fields are allocated, either in existing gaps or at the end of
- // the layout
+ /* Computation of regular classes layout is an evolution of the previous default layout
+ * (FieldAllocationStyle 1):
+ * - primitive fields (both primitive types and flat inline types) are allocated
+ * first, from the biggest to the smallest
+ * - then oop fields are allocated (to increase chances to have contiguous oops and
+ * a simpler oopmap).
+ */
void FieldLayoutBuilder::compute_regular_layout() {
bool need_tail_padding = false;
prologue();
regular_field_sorting();
-
if (_is_contended) {
_layout->set_start(_layout->last_block());
// insertion is currently easy because the current strategy doesn't try to fill holes
// in super classes layouts => the _start block is by consequence the _last_block
insert_contended_padding(_layout->start());
need_tail_padding = true;
}
- _layout->add(_root_group->primitive_fields());
+ _layout->add(_root_group->big_primitive_fields());
+ _layout->add(_root_group->small_primitive_fields());
_layout->add(_root_group->oop_fields());
if (!_contended_groups.is_empty()) {
for (int i = 0; i < _contended_groups.length(); i++) {
FieldGroup* cg = _contended_groups.at(i);
LayoutRawBlock* start = _layout->last_block();
insert_contended_padding(start);
- _layout->add(cg->primitive_fields(), start);
+ _layout->add(cg->big_primitive_fields());
+ _layout->add(cg->small_primitive_fields(), start);
_layout->add(cg->oop_fields(), start);
need_tail_padding = true;
}
}
if (need_tail_padding) {
insert_contended_padding(_layout->last_block());
}
- _static_layout->add_contiguously(this->_static_fields->oop_fields());
- _static_layout->add(this->_static_fields->primitive_fields());
+ // Warning: IntanceMirrorKlass expects static oops to be allocated first
+ _static_layout->add_contiguously(_static_fields->oop_fields());
+ _static_layout->add(_static_fields->big_primitive_fields());
+ _static_layout->add(_static_fields->small_primitive_fields());
epilogue();
}
- void FieldLayoutBuilder::epilogue() {
- // Computing oopmaps
- int super_oop_map_count = (_super_klass == nullptr) ? 0 :_super_klass->nonstatic_oop_map_count();
- int max_oop_map_count = super_oop_map_count + _nonstatic_oopmap_count;
+ /* Computation of inline classes has a slightly different strategy than for
+ * regular classes. Regular classes have their oop fields allocated at the end
+ * of the layout to increase GC performances. Unfortunately, this strategy
+ * increases the number of empty slots inside an instance. Because the purpose
+ * of inline classes is to be embedded into other containers, it is critical
+ * to keep their size as small as possible. For this reason, the allocation
+ * strategy is:
+ * - big primitive fields (primitive types and flat inline type smaller
+ * than an oop) are allocated first (from the biggest to the smallest)
+ * - then oop fields
+ * - then small primitive fields (from the biggest to the smallest)
+ */
+ void FieldLayoutBuilder::compute_inline_class_layout() {
- OopMapBlocksBuilder* nonstatic_oop_maps =
- new OopMapBlocksBuilder(max_oop_map_count);
- if (super_oop_map_count > 0) {
- nonstatic_oop_maps->initialize_inherited_blocks(_super_klass->start_of_nonstatic_oop_maps(),
- _super_klass->nonstatic_oop_map_count());
+ // Test if the concrete inline class is an empty class (no instance fields)
+ // and insert a dummy field if needed
+ if (!_is_abstract_value) {
+ bool declares_non_static_fields = false;
+ for (GrowableArrayIterator<FieldInfo> it = _field_info->begin(); it != _field_info->end(); ++it) {
+ FieldInfo fieldinfo = *it;
+ if (!fieldinfo.access_flags().is_static()) {
+ declares_non_static_fields = true;
+ break;
+ }
+ }
+ if (!declares_non_static_fields) {
+ bool has_inherited_fields = false;
+ const InstanceKlass* super = _super_klass;
+ while(super != nullptr) {
+ if (super->has_nonstatic_fields()) {
+ has_inherited_fields = true;
+ break;
+ }
+ super = super->super() == nullptr ? nullptr : InstanceKlass::cast(super->super());
+ }
+
+ if (!has_inherited_fields) {
+ // Inject ".empty" dummy field
+ _is_empty_inline_class = true;
+ FieldInfo::FieldFlags fflags(0);
+ fflags.update_injected(true);
+ AccessFlags aflags;
+ FieldInfo fi(aflags,
+ (u2)vmSymbols::as_int(VM_SYMBOL_ENUM_NAME(empty_marker_name)),
+ (u2)vmSymbols::as_int(VM_SYMBOL_ENUM_NAME(byte_signature)),
+ 0,
+ fflags);
+ int idx = _field_info->append(fi);
+ _field_info->adr_at(idx)->set_index(idx);
+ }
+ }
+ }
+
+ prologue();
+ inline_class_field_sorting();
+
+ assert(_layout->start()->block_kind() == LayoutRawBlock::RESERVED, "Unexpected");
+
+ if (_layout->super_has_fields() && !_is_abstract_value) { // non-static field layout
+ if (!_has_nonstatic_fields) {
+ assert(_is_abstract_value, "Concrete value types have at least one field");
+ // Nothing to do
+ } else {
+ // decide which alignment to use, then set first allowed field offset
+
+ assert(_layout->super_alignment() >= _payload_alignment, "Incompatible alignment");
+ assert(_layout->super_alignment() % _payload_alignment == 0, "Incompatible alignment");
+
+ if (_payload_alignment < _layout->super_alignment()) {
+ int new_alignment = _payload_alignment > _layout->super_min_align_required() ? _payload_alignment : _layout->super_min_align_required();
+ assert(new_alignment % _payload_alignment == 0, "Must be");
+ assert(new_alignment % _layout->super_min_align_required() == 0, "Must be");
+ _payload_alignment = new_alignment;
+ }
+ _layout->set_start(_layout->first_field_block());
+ }
+ } else {
+ if (_is_abstract_value && _has_nonstatic_fields) {
+ _payload_alignment = type2aelembytes(BasicType::T_LONG);
+ }
+ assert(_layout->start()->next_block()->block_kind() == LayoutRawBlock::EMPTY || !UseCompressedClassPointers, "Unexpected");
+ LayoutRawBlock* first_empty = _layout->start()->next_block();
+ if (first_empty->offset() % _payload_alignment != 0) {
+ LayoutRawBlock* padding = new LayoutRawBlock(LayoutRawBlock::PADDING, _payload_alignment - (first_empty->offset() % _payload_alignment));
+ _layout->insert(first_empty, padding);
+ if (first_empty->size() == 0) {
+ _layout->remove(first_empty);
+ }
+ _layout->set_start(padding);
+ }
+ }
+
+ _layout->add(_root_group->big_primitive_fields());
+ _layout->add(_root_group->oop_fields());
+ _layout->add(_root_group->small_primitive_fields());
+
+ LayoutRawBlock* first_field = _layout->first_field_block();
+ if (first_field != nullptr) {
+ _first_field_offset = _layout->first_field_block()->offset();
+ _payload_size_in_bytes = _layout->last_block()->offset() - _layout->first_field_block()->offset();
+ } else {
+ assert(_is_abstract_value, "Concrete inline types must have at least one field");
+ _first_field_offset = _layout->blocks()->size();
+ _payload_size_in_bytes = 0;
+ }
+
+ // Determining if the value class is naturally atomic:
+ if ((!_layout->super_has_fields() && _declared_non_static_fields_count <= 1 && !_has_non_naturally_atomic_fields)
+ || (_layout->super_has_fields() && _super_klass->is_naturally_atomic() && _declared_non_static_fields_count == 0)) {
+ _is_naturally_atomic = true;
+ }
+
+ // At this point, the characteristics of the raw layout (used in standalone instances) are known.
+ // From this, additional layouts will be computed: atomic and nullable layouts
+ // Once those additional layouts are computed, the raw layout might need some adjustments
+
+ if (!_is_abstract_value) { // Flat layouts are only for concrete value classes
+ // Validation of the non atomic layout
+ if ((InlineFieldMaxFlatSize < 0 || _payload_size_in_bytes * BitsPerByte <= InlineFieldMaxFlatSize)
+ && (!_must_be_atomic || _is_naturally_atomic)) {
+ _non_atomic_layout_size_in_bytes = _payload_size_in_bytes;
+ _non_atomic_layout_alignment = _payload_alignment;
+ }
+
+ // Next step is to compute the characteristics for a layout enabling atomic updates
+ if (AtomicFieldFlattening) {
+ int atomic_size = _payload_size_in_bytes == 0 ? 0 : round_up_power_of_2(_payload_size_in_bytes);
+ if ( atomic_size <= (int)MAX_ATOMIC_OP_SIZE
+ && (InlineFieldMaxFlatSize < 0 || atomic_size * BitsPerByte <= InlineFieldMaxFlatSize)) {
+ _atomic_layout_size_in_bytes = atomic_size;
+ }
+ }
+
+ // Next step is the nullable layout: the layout must include a null marker and must also be atomic
+ if (NullableFieldFlattening) {
+ // Looking if there's an empty slot inside the layout that could be used to store a null marker
+ // FIXME: could it be possible to re-use the .empty field as a null marker for empty values?
+ LayoutRawBlock* b = _layout->first_field_block();
+ assert(b != nullptr, "A concrete value class must have at least one (possible dummy) field");
+ int null_marker_offset = -1;
+ if (_is_empty_inline_class) {
+ // Reusing the dummy field as a field marker
+ assert(_field_info->adr_at(b->field_index())->name(_constant_pool) == vmSymbols::empty_marker_name(), "b must be the dummy field");
+ null_marker_offset = b->offset();
+ } else {
+ while (b != _layout->last_block()) {
+ if (b->block_kind() == LayoutRawBlock::EMPTY) {
+ break;
+ }
+ b = b->next_block();
+ }
+ if (b != _layout->last_block()) {
+ // found an empty slot, register its offset from the beginning of the payload
+ null_marker_offset = b->offset();
+ LayoutRawBlock* marker = new LayoutRawBlock(LayoutRawBlock::NULL_MARKER, 1);
+ _layout->add_field_at_offset(marker, b->offset());
+ }
+ if (null_marker_offset == -1) { // no empty slot available to store the null marker, need to inject one
+ int last_offset = _layout->last_block()->offset();
+ LayoutRawBlock* marker = new LayoutRawBlock(LayoutRawBlock::NULL_MARKER, 1);
+ _layout->insert_field_block(_layout->last_block(), marker);
+ assert(marker->offset() == last_offset, "Null marker should have been inserted at the end");
+ null_marker_offset = marker->offset();
+ }
+ }
+
+ // Now that the null marker is there, the size of the nullable layout must computed (remember, must be atomic too)
+ int new_raw_size = _layout->last_block()->offset() - _layout->first_field_block()->offset();
+ int nullable_size = round_up_power_of_2(new_raw_size);
+ if (nullable_size <= (int)MAX_ATOMIC_OP_SIZE
+ && (InlineFieldMaxFlatSize < 0 || nullable_size * BitsPerByte <= InlineFieldMaxFlatSize)) {
+ _nullable_layout_size_in_bytes = nullable_size;
+ _null_marker_offset = null_marker_offset;
+ } else {
+ // If the nullable layout is rejected, the NULL_MARKER block should be removed
+ // from the layout, otherwise it will appear anyway if the layout is printer
+ _layout->remove_null_marker();
+ _null_marker_offset = -1;
+ }
+ }
+ // If the inline class has an atomic or nullable (which is also atomic) layout,
+ // we want the raw layout to have the same alignment as those atomic layouts so access codes
+ // could remain simple (single instruction without intermediate copy). This might required
+ // to shift all fields in the raw layout, but this operation is possible only if the class
+ // doesn't have inherited fields (offsets of inherited fields cannot be changed). If a
+ // field shift is needed but not possible, all atomic layouts are disabled and only reference
+ // and loosely consistent are supported.
+ int required_alignment = _payload_alignment;
+ if (has_atomic_layout() && _payload_alignment < atomic_layout_size_in_bytes()) {
+ required_alignment = atomic_layout_size_in_bytes();
+ }
+ if (has_nullable_layout() && _payload_alignment < nullable_layout_size_in_bytes()) {
+ required_alignment = nullable_layout_size_in_bytes();
+ }
+ int shift = first_field->offset() % required_alignment;
+ if (shift != 0) {
+ if (required_alignment > _payload_alignment && !_layout->has_inherited_fields()) {
+ assert(_layout->first_field_block() != nullptr, "A concrete value class must have at least one (possible dummy) field");
+ _layout->shift_fields(shift);
+ _first_field_offset = _layout->first_field_block()->offset();
+ if (has_nullable_layout()) {
+ assert(!_is_empty_inline_class, "Should not get here with empty values");
+ _null_marker_offset = _layout->find_null_marker()->offset();
+ }
+ _payload_alignment = required_alignment;
+ } else {
+ _atomic_layout_size_in_bytes = -1;
+ if (has_nullable_layout() && !_is_empty_inline_class) { // empty values don't have a dedicated NULL_MARKER block
+ _layout->remove_null_marker();
+ }
+ _nullable_layout_size_in_bytes = -1;
+ _null_marker_offset = -1;
+ }
+ } else {
+ _payload_alignment = required_alignment;
+ }
+
+ // If the inline class has a nullable layout, the layout used in heap allocated standalone
+ // instances must also be the nullable layout, in order to be able to set the null marker to
+ // non-null before copying the payload to other containers.
+ if (has_nullable_layout() && payload_layout_size_in_bytes() < nullable_layout_size_in_bytes()) {
+ _payload_size_in_bytes = nullable_layout_size_in_bytes();
+ }
+ }
+ // Warning:: InstanceMirrorKlass expects static oops to be allocated first
+ _static_layout->add_contiguously(_static_fields->oop_fields());
+ _static_layout->add(_static_fields->big_primitive_fields());
+ _static_layout->add(_static_fields->small_primitive_fields());
+
+ epilogue();
+ }
+
+ void FieldLayoutBuilder::add_flat_field_oopmap(OopMapBlocksBuilder* nonstatic_oop_maps,
+ InlineKlass* vklass, int offset) {
+ int diff = offset - vklass->first_field_offset();
+ const OopMapBlock* map = vklass->start_of_nonstatic_oop_maps();
+ const OopMapBlock* last_map = map + vklass->nonstatic_oop_map_count();
+ while (map < last_map) {
+ nonstatic_oop_maps->add(map->offset() + diff, map->count());
+ map++;
}
+ }
- if (_root_group->oop_fields() != nullptr) {
- for (int i = 0; i < _root_group->oop_fields()->length(); i++) {
- LayoutRawBlock* b = _root_group->oop_fields()->at(i);
+ void FieldLayoutBuilder::register_embedded_oops_from_list(OopMapBlocksBuilder* nonstatic_oop_maps, GrowableArray<LayoutRawBlock*>* list) {
+ if (list == nullptr) return;
+ for (int i = 0; i < list->length(); i++) {
+ LayoutRawBlock* f = list->at(i);
+ if (f->block_kind() == LayoutRawBlock::FLAT) {
+ InlineKlass* vk = f->inline_klass();
+ assert(vk != nullptr, "Should have been initialized");
+ if (vk->contains_oops()) {
+ add_flat_field_oopmap(nonstatic_oop_maps, vk, f->offset());
+ }
+ }
+ }
+ }
+
+ void FieldLayoutBuilder::register_embedded_oops(OopMapBlocksBuilder* nonstatic_oop_maps, FieldGroup* group) {
+ if (group->oop_fields() != nullptr) {
+ for (int i = 0; i < group->oop_fields()->length(); i++) {
+ LayoutRawBlock* b = group->oop_fields()->at(i);
nonstatic_oop_maps->add(b->offset(), 1);
}
}
+ register_embedded_oops_from_list(nonstatic_oop_maps, group->big_primitive_fields());
+ register_embedded_oops_from_list(nonstatic_oop_maps, group->small_primitive_fields());
+ }
+ void FieldLayoutBuilder::epilogue() {
+ // Computing oopmaps
+ OopMapBlocksBuilder* nonstatic_oop_maps =
+ new OopMapBlocksBuilder(_nonstatic_oopmap_count);
+ int super_oop_map_count = (_super_klass == nullptr) ? 0 :_super_klass->nonstatic_oop_map_count();
+ if (super_oop_map_count > 0) {
+ nonstatic_oop_maps->initialize_inherited_blocks(_super_klass->start_of_nonstatic_oop_maps(),
+ _super_klass->nonstatic_oop_map_count());
+ }
+ register_embedded_oops(nonstatic_oop_maps, _root_group);
if (!_contended_groups.is_empty()) {
for (int i = 0; i < _contended_groups.length(); i++) {
FieldGroup* cg = _contended_groups.at(i);
if (cg->oop_count() > 0) {
assert(cg->oop_fields() != nullptr && cg->oop_fields()->at(0) != nullptr, "oop_count > 0 but no oop fields found");
- nonstatic_oop_maps->add(cg->oop_fields()->at(0)->offset(), cg->oop_count());
+ register_embedded_oops(nonstatic_oop_maps, cg);
}
}
}
-
nonstatic_oop_maps->compact();
int instance_end = align_up(_layout->last_block()->offset(), wordSize);
int static_fields_end = align_up(_static_layout->last_block()->offset(), wordSize);
int static_fields_size = (static_fields_end -
_info->oop_map_blocks = nonstatic_oop_maps;
_info->_instance_size = align_object_size(instance_end / wordSize);
_info->_static_field_size = static_fields_size;
_info->_nonstatic_field_size = (nonstatic_field_end - instanceOopDesc::base_offset_in_bytes()) / heapOopSize;
_info->_has_nonstatic_fields = _has_nonstatic_fields;
+ _info->_has_inline_fields = _has_inline_type_fields;
+ _info->_is_naturally_atomic = _is_naturally_atomic;
+ if (_is_inline_type) {
+ _info->_must_be_atomic = _must_be_atomic;
+ _info->_payload_alignment = _payload_alignment;
+ _info->_first_field_offset = _first_field_offset;
+ _info->_payload_size_in_bytes = _payload_size_in_bytes;
+ _info->_non_atomic_size_in_bytes = _non_atomic_layout_size_in_bytes;
+ _info->_non_atomic_alignment = _non_atomic_layout_alignment;
+ _info->_atomic_layout_size_in_bytes = _atomic_layout_size_in_bytes;
+ _info->_nullable_layout_size_in_bytes = _nullable_layout_size_in_bytes;
+ _info->_null_marker_offset = _null_marker_offset;
+ _info->_default_value_offset = _static_layout->default_value_offset();
+ _info->_null_reset_value_offset = _static_layout->null_reset_value_offset();
+ _info->_is_empty_inline_klass = _is_empty_inline_class;
+ }
+
+ // This may be too restrictive, since if all the fields fit in 64
+ // bits we could make the decision to align instances of this class
+ // to 64-bit boundaries, and load and store them as single words.
+ // And on machines which supported larger atomics we could similarly
+ // allow larger values to be atomic, if properly aligned.
+
+ #ifdef ASSERT
+ // Tests verifying integrity of field layouts are using the output of -XX:+PrintFieldLayout
+ // which prints the details of LayoutRawBlocks used to compute the layout.
+ // The code below checks that offsets in the _field_info meta-data match offsets
+ // in the LayoutRawBlocks
+ LayoutRawBlock* b = _layout->blocks();
+ while(b != _layout->last_block()) {
+ if (b->block_kind() == LayoutRawBlock::REGULAR || b->block_kind() == LayoutRawBlock::FLAT) {
+ if (_field_info->adr_at(b->field_index())->offset() != (u4)b->offset()) {
+ tty->print_cr("Offset from field info = %d, offset from block = %d", (int)_field_info->adr_at(b->field_index())->offset(), b->offset());
+ }
+ assert(_field_info->adr_at(b->field_index())->offset() == (u4)b->offset()," Must match");
+ }
+ b = b->next_block();
+ }
+ b = _static_layout->blocks();
+ while(b != _static_layout->last_block()) {
+ if (b->block_kind() == LayoutRawBlock::REGULAR || b->block_kind() == LayoutRawBlock::FLAT) {
+ assert(_field_info->adr_at(b->field_index())->offset() == (u4)b->offset()," Must match");
+ }
+ b = b->next_block();
+ }
+ #endif // ASSERT
+
+ static bool first_layout_print = true;
- if (PrintFieldLayout) {
+
+ if (PrintFieldLayout || (PrintInlineLayout && _has_flattening_information)) {
ResourceMark rm;
- tty->print_cr("Layout of class %s", _classname->as_C_string());
- tty->print_cr("Instance fields:");
- _layout->print(tty, false, _super_klass);
- tty->print_cr("Static fields:");
- _static_layout->print(tty, true, nullptr);
- tty->print_cr("Instance size = %d bytes", _info->_instance_size * wordSize);
- tty->print_cr("---");
+ stringStream st;
+ if (first_layout_print) {
+ st.print_cr("Field layout log format: @offset size/alignment [name] [signature] [comment]");
+ st.print_cr("Heap oop size = %d", heapOopSize);
+ first_layout_print = false;
+ }
+ if (_super_klass != nullptr) {
+ st.print_cr("Layout of class %s@%p extends %s@%p", _classname->as_C_string(),
+ _loader_data, _super_klass->name()->as_C_string(), _super_klass->class_loader_data());
+ } else {
+ st.print_cr("Layout of class %s@%p", _classname->as_C_string(), _loader_data);
+ }
+ st.print_cr("Instance fields:");
+ _layout->print(&st, false, _super_klass, _inline_layout_info_array);
+ st.print_cr("Static fields:");
+ _static_layout->print(&st, true, nullptr, _inline_layout_info_array);
+ st.print_cr("Instance size = %d bytes", _info->_instance_size * wordSize);
+ if (_is_inline_type) {
+ st.print_cr("First field offset = %d", _first_field_offset);
+ st.print_cr("Payload layout: %d/%d", _payload_size_in_bytes, _payload_alignment);
+ if (has_non_atomic_flat_layout()) {
+ st.print_cr("Non atomic flat layout: %d/%d", _non_atomic_layout_size_in_bytes, _non_atomic_layout_alignment);
+ } else {
+ st.print_cr("Non atomic flat layout: -/-");
+ }
+ if (has_atomic_layout()) {
+ st.print_cr("Atomic flat layout: %d/%d", _atomic_layout_size_in_bytes, _atomic_layout_size_in_bytes);
+ } else {
+ st.print_cr("Atomic flat layout: -/-");
+ }
+ if (has_nullable_layout()) {
+ st.print_cr("Nullable flat layout: %d/%d", _nullable_layout_size_in_bytes, _nullable_layout_size_in_bytes);
+ } else {
+ st.print_cr("Nullable flat layout: -/-");
+ }
+ if (_null_marker_offset != -1) {
+ st.print_cr("Null marker offset = %d", _null_marker_offset);
+ }
+ }
+ st.print_cr("---");
+ // Print output all together.
+ tty->print_raw(st.as_string());
}
}
void FieldLayoutBuilder::build_layout() {
- compute_regular_layout();
+ if (_is_inline_type || _is_abstract_value) {
+ compute_inline_class_layout();
+ } else {
+ compute_regular_layout();
+ }
}
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