853c17a966
- Use backticks to create cross-refs (https://chromium.googlesource.com/chromium/src/+/master/styleguide/c++/c++-dos-and-donts.md#comment-style) - More API docs Change-Id: Ia90641a532aa84c51bbf4cf96d9ab1c6c1505de5 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2484403 Reviewed-by: Omer Katz <omerkatz@chromium.org> Commit-Queue: Michael Lippautz <mlippautz@chromium.org> Cr-Commit-Position: refs/heads/master@{#70602}
144 lines
4.1 KiB
C++
144 lines
4.1 KiB
C++
// 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_HEAP_H_
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#define INCLUDE_CPPGC_HEAP_H_
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#include <memory>
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#include <vector>
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#include "cppgc/common.h"
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#include "cppgc/custom-space.h"
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#include "cppgc/platform.h"
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#include "v8config.h" // NOLINT(build/include_directory)
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/**
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* cppgc - A C++ garbage collection library.
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*/
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namespace cppgc {
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class AllocationHandle;
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/**
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* Implementation details of cppgc. Those details are considered internal and
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* may change at any point in time without notice. Users should never rely on
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* the contents of this namespace.
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*/
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namespace internal {
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class Heap;
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} // namespace internal
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class V8_EXPORT Heap {
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public:
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/**
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* Specifies the stack state the embedder is in.
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*/
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using StackState = EmbedderStackState;
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/**
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* Specifies whether conservative stack scanning is supported.
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*/
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enum class StackSupport : uint8_t {
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/**
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* Conservative stack scan is supported.
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*/
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kSupportsConservativeStackScan,
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/**
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* Conservative stack scan is not supported. Embedders may use this option
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* when using custom infrastructure that is unsupported by the library.
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*/
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kNoConservativeStackScan,
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};
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/**
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* Constraints for a Heap setup.
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*/
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struct ResourceConstraints {
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/**
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* Allows the heap to grow to some initial size in bytes before triggering
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* garbage collections. This is useful when it is known that applications
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* need a certain minimum heap to run to avoid repeatedly invoking the
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* garbage collector when growing the heap.
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*/
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size_t initial_heap_size_bytes = 0;
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};
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/**
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* Options specifying Heap properties (e.g. custom spaces) when initializing a
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* heap through `Heap::Create()`.
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*/
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struct HeapOptions {
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/**
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* Creates reasonable defaults for instantiating a Heap.
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*
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* \returns the HeapOptions that can be passed to `Heap::Create()`.
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*/
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static HeapOptions Default() { return {}; }
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/**
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* Custom spaces added to heap are required to have indices forming a
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* numbered sequence starting at 0, i.e., their `kSpaceIndex` must
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* correspond to the index they reside in the vector.
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*/
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std::vector<std::unique_ptr<CustomSpaceBase>> custom_spaces;
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/**
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* Specifies whether conservative stack scan is supported. When conservative
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* stack scan is not supported, the collector may try to invoke
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* garbage collections using non-nestable task, which are guaranteed to have
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* no interesting stack, through the provided Platform. If such tasks are
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* not supported by the Platform, the embedder must take care of invoking
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* the GC through `ForceGarbageCollectionSlow()`.
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*/
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StackSupport stack_support = StackSupport::kSupportsConservativeStackScan;
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/**
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* Resource constraints specifying various properties that the internal
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* GC scheduler follows.
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*/
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ResourceConstraints resource_constraints;
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};
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/**
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* Creates a new heap that can be used for object allocation.
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*
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* \param platform implemented and provided by the embedder.
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* \param options HeapOptions specifying various properties for the Heap.
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* \returns a new Heap instance.
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*/
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static std::unique_ptr<Heap> Create(
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std::shared_ptr<Platform> platform,
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HeapOptions options = HeapOptions::Default());
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virtual ~Heap() = default;
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/**
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* Forces garbage collection.
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*
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* \param source String specifying the source (or caller) triggering a
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* forced garbage collection.
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* \param reason String specifying the reason for the forced garbage
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* collection.
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* \param stack_state The embedder stack state, see StackState.
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*/
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void ForceGarbageCollectionSlow(
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const char* source, const char* reason,
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StackState stack_state = StackState::kMayContainHeapPointers);
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/**
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* \returns the opaque handle for allocating objects using
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* `MakeGarbageCollected()`.
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*/
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AllocationHandle& GetAllocationHandle();
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private:
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Heap() = default;
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friend class internal::Heap;
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};
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} // namespace cppgc
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#endif // INCLUDE_CPPGC_HEAP_H_
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