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serenity/Libraries/LibJS/Heap/Heap.h
Andreas Kling a119b61782 LibJS: Add Handle<T>, a strong C++ handle for keeping GC objects alive
This is pretty heavy and unoptimized, but it will do the trick for now.
Basically, Heap now has a HashTable<HandleImpl*> and you can call
JS::make_handle(T*) to construct a Handle<T> that guarantees that the
pointee will always survive GC until the Handle<T> is destroyed.
2020-03-18 20:03:17 +01:00

83 lines
2.8 KiB
C++

/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <AK/HashTable.h>
#include <AK/Noncopyable.h>
#include <AK/NonnullOwnPtr.h>
#include <AK/Types.h>
#include <AK/Vector.h>
#include <LibJS/Forward.h>
#include <LibJS/Heap/Handle.h>
#include <LibJS/Runtime/Cell.h>
namespace JS {
class Heap {
AK_MAKE_NONCOPYABLE(Heap);
AK_MAKE_NONMOVABLE(Heap);
public:
explicit Heap(Interpreter&);
~Heap();
template<typename T, typename... Args>
T* allocate(Args&&... args)
{
auto* memory = allocate_cell(sizeof(T));
new (memory) T(forward<Args>(args)...);
return static_cast<T*>(memory);
}
void collect_garbage();
Interpreter& interpreter() { return m_interpreter; }
bool should_collect_on_every_allocation() const { return m_should_collect_on_every_allocation; }
void set_should_collect_on_every_allocation(bool b) { m_should_collect_on_every_allocation = b; }
void did_create_handle(Badge<HandleImpl>, HandleImpl&);
void did_destroy_handle(Badge<HandleImpl>, HandleImpl&);
private:
Cell* allocate_cell(size_t);
void gather_roots(HashTable<Cell*>&);
void gather_conservative_roots(HashTable<Cell*>&);
void mark_live_cells(const HashTable<Cell*>& live_cells);
void sweep_dead_cells();
Cell* cell_from_possible_pointer(FlatPtr);
bool m_should_collect_on_every_allocation { false };
Interpreter& m_interpreter;
Vector<NonnullOwnPtr<HeapBlock>> m_blocks;
HashTable<HandleImpl*> m_handles;
};
}