LibJS: Make WeakContainer pruning do less work

Instead of iterating *all* swept cells when pruning weak containers,
only iterate the cells actually *in* the container.

Also, instead of compiling a list of all swept cells, we can simply
check the Cell::state() flag to know if something should be pruned.

1 files changed, 1 insertions, 5 deletions

diff --git a/Userland/Libraries/LibJS/Heap/Heap.cpp b/Userland/Libraries/LibJS/Heap/Heap.cpp
index 43a8d41b87..a3aef36e0e 100644
--- a/Userland/Libraries/LibJS/Heap/Heap.cpp
+++ b/Userland/Libraries/LibJS/Heap/Heap.cpp
@@ -216,22 +216,18 @@ void Heap::sweep_dead_cells(bool print_report, const Core::ElapsedTimer& measure
     dbgln_if(HEAP_DEBUG, "sweep_dead_cells:");
     Vector<HeapBlock*, 32> empty_blocks;
     Vector<HeapBlock*, 32> full_blocks_that_became_usable;
-    Vector<Cell*> swept_cells;
 
     size_t collected_cells = 0;
     size_t live_cells = 0;
     size_t collected_cell_bytes = 0;
     size_t live_cell_bytes = 0;
 
-    auto should_store_swept_cells = !m_weak_containers.is_empty();
     for_each_block([&](auto& block) {
         bool block_has_live_cells = false;
         bool block_was_full = block.is_full();
         block.template for_each_cell_in_state<Cell::State::Live>([&](Cell* cell) {
             if (!cell->is_marked()) {
                 dbgln_if(HEAP_DEBUG, "  ~ {}", cell);
-                if (should_store_swept_cells)
-                    swept_cells.append(cell);
 #ifdef JS_TRACK_ZOMBIE_CELLS
                 if (m_zombify_dead_cells) {
                     cell->set_state(Cell::State::Zombie);
@@ -269,7 +265,7 @@ void Heap::sweep_dead_cells(bool print_report, const Core::ElapsedTimer& measure
     }
 
     for (auto& weak_container : m_weak_containers)
-        weak_container.remove_swept_cells({}, swept_cells.span());
+        weak_container.remove_dead_cells({});
 
     if constexpr (HEAP_DEBUG) {
         for_each_block([&](auto& block) {