v8
10.1.124 (node 18.2.0)
V8 is Google's open source JavaScript engine
caged-heap-local-data.h
Go to the documentation of this file.
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// Copyright 2020 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#
ifndef
INCLUDE_CPPGC_INTERNAL_CAGED_HEAP_LOCAL_DATA_H_
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#
define
INCLUDE_CPPGC_INTERNAL_CAGED_HEAP_LOCAL_DATA_H_
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#
include
<
array
>
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#
include
"cppgc/internal/api-constants.h"
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#
include
"cppgc/internal/logging.h"
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#
include
"cppgc/platform.h"
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#
include
"v8config.h"
// NOLINT(build/include_directory)
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namespace
cppgc
{
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namespace
internal
{
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class
HeapBase;
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#
if
defined
(
CPPGC_YOUNG_GENERATION
)
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// AgeTable contains entries that correspond to 4KB memory regions. Each entry
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// can be in one of three states: kOld, kYoung or kUnknown.
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class
AgeTable
final
{
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static
constexpr
size_t
kGranularityBits
= 12;
// 4KiB per byte.
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public
:
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enum
class
Age
:
uint8_t
{
kOld
,
kYoung
,
kUnknown
};
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static
constexpr
size_t
kEntrySizeInBytes
= 1 <<
kGranularityBits
;
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Age
&
operator
[](
uintptr_t
offset
) {
return
table_
[
entry
(
offset
)]; }
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Age
operator
[](
uintptr_t
offset
)
const
{
return
table_
[
entry
(
offset
)]; }
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void
Reset
(
PageAllocator
*
allocator
);
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private
:
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static
constexpr
size_t
kAgeTableSize
=
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api_constants
::
kCagedHeapReservationSize
>>
kGranularityBits
;
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size_t
entry
(
uintptr_t
offset
)
const
{
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const
size_t
entry
=
offset
>>
kGranularityBits
;
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CPPGC_DCHECK
(
table_
.
size
() >
entry
);
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return
entry
;
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}
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std
::
array
<
Age
,
kAgeTableSize
>
table_
;
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};
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static_assert
(
sizeof
(
AgeTable
) == 1 *
api_constants
::
kMB
,
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"Size of AgeTable is 1MB"
);
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#
endif
// CPPGC_YOUNG_GENERATION
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struct
CagedHeapLocalData
final
{
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CagedHeapLocalData
(HeapBase&, PageAllocator&);
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bool
is_incremental_marking_in_progress
=
false
;
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HeapBase&
heap_base
;
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#
if
defined
(
CPPGC_YOUNG_GENERATION
)
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AgeTable age_table;
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#
endif
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};
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}
// namespace internal
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}
// namespace cppgc
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#
endif
// INCLUDE_CPPGC_INTERNAL_CAGED_HEAP_LOCAL_DATA_H_
include
cppgc
internal
caged-heap-local-data.h
Generated on Tue May 24 2022 19:28:53 for v8 by
1.9.1