serenity/Libraries/LibJS/Heap/Heap.h
Andreas Kling f7a1696087 LibJS: Add MarkedValueList and use it for argument passing
A MarkedValueList is basically a Vector<JS::Value> that registers with
the Heap and makes sure that the stored values don't get GC'd.

Before this change, we were unsafely keeping Vector<JS::Value> in some
places, which is out-of-reach for the live reference finding logic
since Vector puts its elements on the heap by default.

We now pass all the JavaScript tests even when running with "js -g",
which does a GC on every heap allocation.
2020-04-19 17:34:33 +02:00

102 lines
3.4 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);
}
enum class CollectionType {
CollectGarbage,
CollectEverything,
};
void collect_garbage(CollectionType = CollectionType::CollectGarbage);
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&);
void did_create_marked_value_list(Badge<MarkedValueList>, MarkedValueList&);
void did_destroy_marked_value_list(Badge<MarkedValueList>, MarkedValueList&);
void defer_gc(Badge<DeferGC>);
void undefer_gc(Badge<DeferGC>);
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);
size_t m_max_allocations_between_gc { 10000 };
size_t m_allocations_since_last_gc { false };
bool m_should_collect_on_every_allocation { false };
Interpreter& m_interpreter;
Vector<NonnullOwnPtr<HeapBlock>> m_blocks;
HashTable<HandleImpl*> m_handles;
HashTable<MarkedValueList*> m_marked_value_lists;
size_t m_gc_deferrals { 0 };
bool m_should_gc_when_deferral_ends { false };
};
}