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ladybird/Userland/Libraries/LibJS/Heap/Heap.h

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LibJS: Add a basic mark&sweep garbage collector :^) Objects can now be allocated via the interpreter's heap. Objects that are allocated in this way will need to be provably reachable from at least one of the known object graph roots. The roots are currently determined by Heap::collect_roots(). Anything that wants be collectable garbage should inherit from Cell, the fundamental atom of the GC heap. This is pretty neat! :^)
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/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
*
Everything: Move to SPDX license identifiers in all files. SPDX License Identifiers are a more compact / standardized way of representing file license information. See: https://spdx.dev/resources/use/#identifiers This was done with the `ambr` search and replace tool. ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
2021-04-22 01:24:48 -07:00
* SPDX-License-Identifier: BSD-2-Clause
LibJS: Add a basic mark&sweep garbage collector :^) Objects can now be allocated via the interpreter's heap. Objects that are allocated in this way will need to be provably reachable from at least one of the known object graph roots. The roots are currently determined by Heap::collect_roots(). Anything that wants be collectable garbage should inherit from Cell, the fundamental atom of the GC heap. This is pretty neat! :^)
2020-03-08 19:23:58 +01:00
*/
#pragma once
LibJS: Avoid pointless transitions and metadata lookups in storage_set() - Replace the misleading abuse of the m_transitions_enabled flag for the fast path without lookup with a new m_initialized boolean that's set either by Heap::allocate() after calling the Object's initialize(), or by the GlobalObject in its special initialize_global_object(). This makes it work regardless of the shape's uniqueness. - When we're adding a new property past the initialization phase, there's no need to do a second metadata lookup to retrieve the storage value offset - it's known to always be the shape's property count minus one. Also, instead of doing manual storage resizing and assignment via indexing, just use Vector::append(). - When we didn't add a new property but are overwriting an existing one, the property count and therefore storage value offset doesn't change, so we don't have to retrieve it either. As a result, Object::set_shape() is now solely responsible for updating the m_shape pointer and is not resizing storage anymore, so I moved it into the header.
2021-08-28 17:12:14 +01:00
#include <AK/Badge.h>
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
#include <AK/HashTable.h>
LibJS: Use IntrusiveList for keeping track of HandleImpls This allows us to remove a HashTable from heap and cuts down on some of the malloc traffic when creating handles.
2021-07-21 19:45:21 +02:00
#include <AK/IntrusiveList.h>
LibJS: Add a basic mark&sweep garbage collector :^) Objects can now be allocated via the interpreter's heap. Objects that are allocated in this way will need to be provably reachable from at least one of the known object graph roots. The roots are currently determined by Heap::collect_roots(). Anything that wants be collectable garbage should inherit from Cell, the fundamental atom of the GC heap. This is pretty neat! :^)
2020-03-08 19:23:58 +01:00
#include <AK/Noncopyable.h>
#include <AK/NonnullOwnPtr.h>
#include <AK/Types.h>
#include <AK/Vector.h>
LibJS: Add API for doing GC with a little debug log report at end You can now pass print_report=true to Heap::collect_garbage() and it will print out a little summary of the time spent, and counts of live vs freed cells and blocks.
2020-08-16 20:33:56 +02:00
#include <LibCore/Forward.h>
LibJS: Add a basic mark&sweep garbage collector :^) Objects can now be allocated via the interpreter's heap. Objects that are allocated in this way will need to be provably reachable from at least one of the known object graph roots. The roots are currently determined by Heap::collect_roots(). Anything that wants be collectable garbage should inherit from Cell, the fundamental atom of the GC heap. This is pretty neat! :^)
2020-03-08 19:23:58 +01:00
#include <LibJS/Forward.h>
LibJS: Recycle up to 64 HeapBlocks to improve performance :^) This patch adds a BlockAllocator to the GC heap where we now cache up to 64 HeapBlock-sized mmap's that get recycled when allocating HeapBlocks. This improves test-js runtime performance by ~35%, pretty cool! :^)
2021-05-27 19:01:26 +02:00
#include <LibJS/Heap/BlockAllocator.h>
LibJS: Move Cell.{cpp,h} from Runtime/ to Heap/
2021-05-17 19:50:20 +02:00
#include <LibJS/Heap/Cell.h>
LibJS: Rename Allocator => CellAllocator Now that we have a BlockAllocator as well, it seems appropriate to name the allocator-that-allocates-cells something more specific to match.
2021-05-27 19:03:41 +02:00
#include <LibJS/Heap/CellAllocator.h>
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
#include <LibJS/Heap/Handle.h>
LibJS: Prevent object shape transitions during runtime object buildup While initialization common runtime objects like functions, prototypes, etc, we don't really care about tracking transitions for each and every property added to them. This patch puts objects into a "disable transitions" mode while we call initialize() on them. After that, adding more properties will cause new transitions to be generated and added to the chain. This gives a ~10% speed-up on test-js. :^)
2020-10-05 20:08:14 +02:00
#include <LibJS/Runtime/Object.h>
LibJS: Use IntrusiveList for keeping track of WeakContainers
2021-07-21 19:57:41 +02:00
#include <LibJS/Runtime/WeakContainer.h>
LibJS: Add a basic mark&sweep garbage collector :^) Objects can now be allocated via the interpreter's heap. Objects that are allocated in this way will need to be provably reachable from at least one of the known object graph roots. The roots are currently determined by Heap::collect_roots(). Anything that wants be collectable garbage should inherit from Cell, the fundamental atom of the GC heap. This is pretty neat! :^)
2020-03-08 19:23:58 +01:00
namespace JS {
class Heap {
AK_MAKE_NONCOPYABLE(Heap);
AK_MAKE_NONMOVABLE(Heap);
public:
LibJS+Clients: Add JS::VM object, separate Heap from Interpreter Taking a big step towards a world of multiple global object, this patch adds a new JS::VM object that houses the JS::Heap. This means that the Heap moves out of Interpreter, and the same Heap can now be used by multiple Interpreters, and can also outlive them. The VM keeps a stack of Interpreter pointers. We push/pop on this stack when entering/exiting execution with a given Interpreter. This allows us to make this change without disturbing too much of the existing code. There is still a 1-to-1 relationship between Interpreter and the global object. This will change in the future. Ultimately, the goal here is to make Interpreter a transient object that only needs to exist while you execute some code. Getting there will take a lot more work though. :^) Note that in LibWeb, the global JS::VM is called main_thread_vm(), to distinguish it from future worker VM's.
2020-09-20 19:24:44 +02:00
explicit Heap(VM&);
LibJS: Add a basic mark&sweep garbage collector :^) Objects can now be allocated via the interpreter's heap. Objects that are allocated in this way will need to be provably reachable from at least one of the known object graph roots. The roots are currently determined by Heap::collect_roots(). Anything that wants be collectable garbage should inherit from Cell, the fundamental atom of the GC heap. This is pretty neat! :^)
2020-03-08 19:23:58 +01:00
~Heap();
template<typename T, typename... Args>
LibJS: Move native objects towards two-pass construction To make sure that everything is set up correctly in objects before we start adding properties to them, we split cell allocation into 3 steps: 1. Allocate a cell of appropriate size from the Heap 2. Call the C++ constructor on the cell 3. Call initialize() on the constructed object The job of initialize() is to define all the initial properties. Doing it in a second pass guarantees that the Object has a valid Shape and can find its own GlobalObject.
2020-06-20 15:40:48 +02:00
T* allocate_without_global_object(Args&&... args)
LibJS: Add a basic mark&sweep garbage collector :^) Objects can now be allocated via the interpreter's heap. Objects that are allocated in this way will need to be provably reachable from at least one of the known object graph roots. The roots are currently determined by Heap::collect_roots(). Anything that wants be collectable garbage should inherit from Cell, the fundamental atom of the GC heap. This is pretty neat! :^)
2020-03-08 19:23:58 +01:00
{
auto* memory = allocate_cell(sizeof(T));
new (memory) T(forward<Args>(args)...);
return static_cast<T*>(memory);
}
LibJS: Move native objects towards two-pass construction To make sure that everything is set up correctly in objects before we start adding properties to them, we split cell allocation into 3 steps: 1. Allocate a cell of appropriate size from the Heap 2. Call the C++ constructor on the cell 3. Call initialize() on the constructed object The job of initialize() is to define all the initial properties. Doing it in a second pass guarantees that the Object has a valid Shape and can find its own GlobalObject.
2020-06-20 15:40:48 +02:00
template<typename T, typename... Args>
T* allocate(GlobalObject& global_object, Args&&... args)
{
auto* memory = allocate_cell(sizeof(T));
new (memory) T(forward<Args>(args)...);
auto* cell = static_cast<T*>(memory);
AK+Everywhere: Make StdLibExtras templates less wrapper-y This commit makes the user-facing StdLibExtras templates and utilities arguably more nice-looking by removing the need to reach into the wrapper structs generated by them to get the value/type needed. The C++ standard library had to invent `_v` and `_t` variants (likely because of backwards compat), but we don't need to cater to any codebase except our own, so might as well have good things for free. :^)
2021-04-10 18:29:06 +04:30
constexpr bool is_object = IsBaseOf<Object, T>;
LibJS: Prevent object shape transitions during runtime object buildup While initialization common runtime objects like functions, prototypes, etc, we don't really care about tracking transitions for each and every property added to them. This patch puts objects into a "disable transitions" mode while we call initialize() on them. After that, adding more properties will cause new transitions to be generated and added to the chain. This gives a ~10% speed-up on test-js. :^)
2020-10-05 20:08:14 +02:00
if constexpr (is_object)
static_cast<Object*>(cell)->disable_transitions();
LibJS: Simplify Cell::initialize() Remove the Interpreter& argument and pass only GlobalObject&. We can find everything we need via the global object anyway.
2020-07-22 17:50:18 +02:00
cell->initialize(global_object);
LibJS: Avoid pointless transitions and metadata lookups in storage_set() - Replace the misleading abuse of the m_transitions_enabled flag for the fast path without lookup with a new m_initialized boolean that's set either by Heap::allocate() after calling the Object's initialize(), or by the GlobalObject in its special initialize_global_object(). This makes it work regardless of the shape's uniqueness. - When we're adding a new property past the initialization phase, there's no need to do a second metadata lookup to retrieve the storage value offset - it's known to always be the shape's property count minus one. Also, instead of doing manual storage resizing and assignment via indexing, just use Vector::append(). - When we didn't add a new property but are overwriting an existing one, the property count and therefore storage value offset doesn't change, so we don't have to retrieve it either. As a result, Object::set_shape() is now solely responsible for updating the m_shape pointer and is not resizing storage anymore, so I moved it into the header.
2021-08-28 17:12:14 +01:00
if constexpr (is_object) {
LibJS: Prevent object shape transitions during runtime object buildup While initialization common runtime objects like functions, prototypes, etc, we don't really care about tracking transitions for each and every property added to them. This patch puts objects into a "disable transitions" mode while we call initialize() on them. After that, adding more properties will cause new transitions to be generated and added to the chain. This gives a ~10% speed-up on test-js. :^)
2020-10-05 20:08:14 +02:00
static_cast<Object*>(cell)->enable_transitions();
LibJS: Avoid pointless transitions and metadata lookups in storage_set() - Replace the misleading abuse of the m_transitions_enabled flag for the fast path without lookup with a new m_initialized boolean that's set either by Heap::allocate() after calling the Object's initialize(), or by the GlobalObject in its special initialize_global_object(). This makes it work regardless of the shape's uniqueness. - When we're adding a new property past the initialization phase, there's no need to do a second metadata lookup to retrieve the storage value offset - it's known to always be the shape's property count minus one. Also, instead of doing manual storage resizing and assignment via indexing, just use Vector::append(). - When we didn't add a new property but are overwriting an existing one, the property count and therefore storage value offset doesn't change, so we don't have to retrieve it either. As a result, Object::set_shape() is now solely responsible for updating the m_shape pointer and is not resizing storage anymore, so I moved it into the header.
2021-08-28 17:12:14 +01:00
static_cast<Object*>(cell)->set_initialized(Badge<Heap> {});
}
LibJS: Move native objects towards two-pass construction To make sure that everything is set up correctly in objects before we start adding properties to them, we split cell allocation into 3 steps: 1. Allocate a cell of appropriate size from the Heap 2. Call the C++ constructor on the cell 3. Call initialize() on the constructed object The job of initialize() is to define all the initial properties. Doing it in a second pass guarantees that the Object has a valid Shape and can find its own GlobalObject.
2020-06-20 15:40:48 +02:00
return cell;
}
LibJS: Always collect all garbage when destroying Heap When the Heap is going down, it's our last chance to run destructors, so add a separate collector mode where we simply skip over the marking phase and go directly to sweeping. This causes everything to get swept and all live cells get destroyed. This way, valgrind reports 0 leaks on exit. :^)
2020-03-23 14:11:19 +01:00
enum class CollectionType {
CollectGarbage,
CollectEverything,
};
LibJS: Add API for doing GC with a little debug log report at end You can now pass print_report=true to Heap::collect_garbage() and it will print out a little summary of the time spent, and counts of live vs freed cells and blocks.
2020-08-16 20:33:56 +02:00
void collect_garbage(CollectionType = CollectionType::CollectGarbage, bool print_report = false);
LibJS: Add a basic mark&sweep garbage collector :^) Objects can now be allocated via the interpreter's heap. Objects that are allocated in this way will need to be provably reachable from at least one of the known object graph roots. The roots are currently determined by Heap::collect_roots(). Anything that wants be collectable garbage should inherit from Cell, the fundamental atom of the GC heap. This is pretty neat! :^)
2020-03-08 19:23:58 +01:00
LibJS+Clients: Add JS::VM object, separate Heap from Interpreter Taking a big step towards a world of multiple global object, this patch adds a new JS::VM object that houses the JS::Heap. This means that the Heap moves out of Interpreter, and the same Heap can now be used by multiple Interpreters, and can also outlive them. The VM keeps a stack of Interpreter pointers. We push/pop on this stack when entering/exiting execution with a given Interpreter. This allows us to make this change without disturbing too much of the existing code. There is still a 1-to-1 relationship between Interpreter and the global object. This will change in the future. Ultimately, the goal here is to make Interpreter a transient object that only needs to exist while you execute some code. Getting there will take a lot more work though. :^) Note that in LibWeb, the global JS::VM is called main_thread_vm(), to distinguish it from future worker VM's.
2020-09-20 19:24:44 +02:00
VM& vm() { return m_vm; }
LibJS: Add Cell::interpreter() convenience helper This allows you to go from any Cell* to the Interpreter.
2020-03-15 15:08:27 +01:00
LibJS+js: Add a debug option (js -g) to GC after every allocation This is very useful for discovering collector bugs.
2020-03-16 19:18:46 +01:00
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; }
LibJS+js+test-js: Add GC debug mode that keeps cells "alive" as zombies This patch adds a `-z` option to js and test-js. When run in this mode, garbage cells are never actually destroyed. We instead keep them around in a special zombie state. This allows us to validate that zombies don't get marked in future GC scans (since there were not supposed to be any more references!) :^) Cells get notified when they become a zombie (via did_become_zombie()) and this is used by WeakContainer cells to deregister themselves from the heap.
2021-09-11 16:44:40 +02:00
void set_zombify_dead_cells(bool b) { m_zombify_dead_cells = b; }
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
void did_create_handle(Badge<HandleImpl>, HandleImpl&);
void did_destroy_handle(Badge<HandleImpl>, HandleImpl&);
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 17:24:56 +02:00
void did_create_marked_value_list(Badge<MarkedValueList>, MarkedValueList&);
void did_destroy_marked_value_list(Badge<MarkedValueList>, MarkedValueList&);
LibJS: Generify the garbage collector's weak container notifications This will allow us to use the same interface for other JS weak containers like the WeakMap & WeakRef.
2021-06-12 05:23:33 +03:00
void did_create_weak_container(Badge<WeakContainer>, WeakContainer&);
void did_destroy_weak_container(Badge<WeakContainer>, WeakContainer&);
LibJS: Notify WeakSets when heap cells are sweeped This is an implementation of the following optional optimization: https://tc39.es/ecma262/#sec-weakref-execution
2021-06-09 20:10:47 +03:00
LibJS: Add DeferGC, a RAII way to prevent GC temporarily
2020-04-19 11:30:47 +02:00
void defer_gc(Badge<DeferGC>);
void undefer_gc(Badge<DeferGC>);
LibJS: Recycle up to 64 HeapBlocks to improve performance :^) This patch adds a BlockAllocator to the GC heap where we now cache up to 64 HeapBlock-sized mmap's that get recycled when allocating HeapBlocks. This improves test-js runtime performance by ~35%, pretty cool! :^)
2021-05-27 19:01:26 +02:00
BlockAllocator& block_allocator() { return m_block_allocator; }
test-js: Add a mark_as_garbage method to force GC to collect that object This should fix the flaky tests of test-js. It also fixes the tests when running with the -g flag since the values will not be garbage collected too soon.
2021-09-07 17:14:05 +02:00
void uproot_cell(Cell* cell);
LibJS: Add a basic mark&sweep garbage collector :^) Objects can now be allocated via the interpreter's heap. Objects that are allocated in this way will need to be provably reachable from at least one of the known object graph roots. The roots are currently determined by Heap::collect_roots(). Anything that wants be collectable garbage should inherit from Cell, the fundamental atom of the GC heap. This is pretty neat! :^)
2020-03-08 19:23:58 +01:00
private:
Cell* allocate_cell(size_t);
LibJS: Rename collect_roots() => gather_roots() Since this is about finding the things we should *not* garabge collect, it seemed wrong to call it "collect_something" :^)
2020-03-15 15:12:34 +01:00
void gather_roots(HashTable<Cell*>&);
LibJS: Implement basic conservative garbage collection We now scan the stack and CPU registers for potential pointers into the GC heap, and include any valid Cell pointers in the set of roots. This works pretty well but we'll also need to solve marking of things passed to native functions, since those are currently in Vector<Value> and the Vector storage is on the heap (not scanned.)
2020-03-16 19:08:59 +01:00
void gather_conservative_roots(HashTable<Cell*>&);
LibJS: Add a basic mark&sweep garbage collector :^) Objects can now be allocated via the interpreter's heap. Objects that are allocated in this way will need to be provably reachable from at least one of the known object graph roots. The roots are currently determined by Heap::collect_roots(). Anything that wants be collectable garbage should inherit from Cell, the fundamental atom of the GC heap. This is pretty neat! :^)
2020-03-08 19:23:58 +01:00
void mark_live_cells(const HashTable<Cell*>& live_cells);
LibJS: Add API for doing GC with a little debug log report at end You can now pass print_report=true to Heap::collect_garbage() and it will print out a little summary of the time spent, and counts of live vs freed cells and blocks.
2020-08-16 20:33:56 +02:00
void sweep_dead_cells(bool print_report, const Core::ElapsedTimer&);
LibJS: Add a basic mark&sweep garbage collector :^) Objects can now be allocated via the interpreter's heap. Objects that are allocated in this way will need to be provably reachable from at least one of the known object graph roots. The roots are currently determined by Heap::collect_roots(). Anything that wants be collectable garbage should inherit from Cell, the fundamental atom of the GC heap. This is pretty neat! :^)
2020-03-08 19:23:58 +01:00
LibJS: Rename Allocator => CellAllocator Now that we have a BlockAllocator as well, it seems appropriate to name the allocator-that-allocates-cells something more specific to match.
2021-05-27 19:03:41 +02:00
CellAllocator& allocator_for_size(size_t);
LibJS: Split Heap into per-cell-size allocators Instead of keeping all the HeapBlocks in one big list, we now split it into two levels: - Heap has a set of Allocators, each with a specific cell size. - Allocators have two lists of blocks, "full" and "usable". Allocating a new cell no longer has to scan the entire set of blocks, but instead just needs to find the right allocator and then pop a cell from its freelist. If all the blocks in the allocator are full, a new block will be created. Blocks are moved from the "full" to "usable" list after sweeping has determined that they are not completely empty and not completely full. There are certainly many ways we can improve on this. This patch is mostly about getting the new allocator architecture in place. :^)
2020-10-06 18:50:47 +02:00
template<typename Callback>
void for_each_block(Callback callback)
{
for (auto& allocator : m_allocators) {
if (allocator->for_each_block(callback) == IterationDecision::Break)
return;
}
}
LibJS: Increase time between garbage collections This patch ups the max number of heap allocations between each GC from 10'000 to 100'000. This is still relatively aggressive but already does a good job of cutting down on time spent in GC.
2021-09-17 15:21:40 +02:00
size_t m_max_allocations_between_gc { 100000 };
LibJS: Fix m_allocations_since_last_gc initialization value
2021-03-28 18:22:54 +02:00
size_t m_allocations_since_last_gc { 0 };
LibJS: Do a garbage collection every N allocations (N=10'000) To prevent the heap from growing infinitely large, we now do a full GC every 10'000 allocations. :^)
2020-04-06 12:36:49 +02:00
LibJS+js: Add a debug option (js -g) to GC after every allocation This is very useful for discovering collector bugs.
2020-03-16 19:18:46 +01:00
bool m_should_collect_on_every_allocation { false };
LibJS+Clients: Add JS::VM object, separate Heap from Interpreter Taking a big step towards a world of multiple global object, this patch adds a new JS::VM object that houses the JS::Heap. This means that the Heap moves out of Interpreter, and the same Heap can now be used by multiple Interpreters, and can also outlive them. The VM keeps a stack of Interpreter pointers. We push/pop on this stack when entering/exiting execution with a given Interpreter. This allows us to make this change without disturbing too much of the existing code. There is still a 1-to-1 relationship between Interpreter and the global object. This will change in the future. Ultimately, the goal here is to make Interpreter a transient object that only needs to exist while you execute some code. Getting there will take a lot more work though. :^) Note that in LibWeb, the global JS::VM is called main_thread_vm(), to distinguish it from future worker VM's.
2020-09-20 19:24:44 +02:00
VM& m_vm;
LibJS: Split Heap into per-cell-size allocators Instead of keeping all the HeapBlocks in one big list, we now split it into two levels: - Heap has a set of Allocators, each with a specific cell size. - Allocators have two lists of blocks, "full" and "usable". Allocating a new cell no longer has to scan the entire set of blocks, but instead just needs to find the right allocator and then pop a cell from its freelist. If all the blocks in the allocator are full, a new block will be created. Blocks are moved from the "full" to "usable" list after sweeping has determined that they are not completely empty and not completely full. There are certainly many ways we can improve on this. This patch is mostly about getting the new allocator architecture in place. :^)
2020-10-06 18:50:47 +02:00
LibJS: Rename Allocator => CellAllocator Now that we have a BlockAllocator as well, it seems appropriate to name the allocator-that-allocates-cells something more specific to match.
2021-05-27 19:03:41 +02:00
Vector<NonnullOwnPtr<CellAllocator>> m_allocators;
LibJS: Use IntrusiveList for keeping track of HandleImpls This allows us to remove a HashTable from heap and cuts down on some of the malloc traffic when creating handles.
2021-07-21 19:45:21 +02:00
HandleImpl::List m_handles;
LibJS: Add DeferGC, a RAII way to prevent GC temporarily
2020-04-19 11:30:47 +02:00
LibJS: Use IntrusiveList for keeping track of MarkedValueLists
2021-07-21 19:51:19 +02:00
MarkedValueList::List m_marked_value_lists;
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 17:24:56 +02:00
LibJS: Use IntrusiveList for keeping track of WeakContainers
2021-07-21 19:57:41 +02:00
WeakContainer::List m_weak_containers;
LibJS: Notify WeakSets when heap cells are sweeped This is an implementation of the following optional optimization: https://tc39.es/ecma262/#sec-weakref-execution
2021-06-09 20:10:47 +03:00
test-js: Add a mark_as_garbage method to force GC to collect that object This should fix the flaky tests of test-js. It also fixes the tests when running with the -g flag since the values will not be garbage collected too soon.
2021-09-07 17:14:05 +02:00
Vector<Cell*> m_uprooted_cells;
LibJS: Recycle up to 64 HeapBlocks to improve performance :^) This patch adds a BlockAllocator to the GC heap where we now cache up to 64 HeapBlock-sized mmap's that get recycled when allocating HeapBlocks. This improves test-js runtime performance by ~35%, pretty cool! :^)
2021-05-27 19:01:26 +02:00
BlockAllocator m_block_allocator;
LibJS: Add DeferGC, a RAII way to prevent GC temporarily
2020-04-19 11:30:47 +02:00
size_t m_gc_deferrals { 0 };
bool m_should_gc_when_deferral_ends { false };
LibJS: Assert if garbage collection is restarted while ongoing We can't GC while we're already in GC. Assert if this happens.
2020-09-21 14:35:19 +02:00
bool m_collecting_garbage { false };
LibJS+js+test-js: Add GC debug mode that keeps cells "alive" as zombies This patch adds a `-z` option to js and test-js. When run in this mode, garbage cells are never actually destroyed. We instead keep them around in a special zombie state. This allows us to validate that zombies don't get marked in future GC scans (since there were not supposed to be any more references!) :^) Cells get notified when they become a zombie (via did_become_zombie()) and this is used by WeakContainer cells to deregister themselves from the heap.
2021-09-11 16:44:40 +02:00
bool m_zombify_dead_cells { false };
LibJS: Add a basic mark&sweep garbage collector :^) Objects can now be allocated via the interpreter's heap. Objects that are allocated in this way will need to be provably reachable from at least one of the known object graph roots. The roots are currently determined by Heap::collect_roots(). Anything that wants be collectable garbage should inherit from Cell, the fundamental atom of the GC heap. This is pretty neat! :^)
2020-03-08 19:23:58 +01:00
};
}
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