RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-25 23:37:35 +00:00
Code Issues Activity Actions

LibJS: Delete fully-empty HeapBlocks after garbage collection

Browse source 
We now deallocate GC blocks when they are found to have no live cells
inside them.
This commit is contained in:
Andreas Kling 2020-03-21 11:45:50 +01:00
parent bc002f807a
commit 2106dafd62
2 changed files with 23 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

8
Base/home/anon/js/gc-strings.js Normal file
View file

@ -0,0 +1,8 @@
function foo() {
var a = [];
for (var i = 0; i < 4000; ++i) {
a.push("string" + i);
}
}
foo();

15
Libraries/LibJS/Heap/Heap.cpp
View file

@ -185,7 +185,10 @@ void Heap::sweep_dead_cells()
#ifdef HEAP_DEBUG #ifdef HEAP_DEBUG
dbg() << "sweep_dead_cells:"; dbg() << "sweep_dead_cells:";
#endif #endif
Vector<HeapBlock*, 32> empty_blocks;
for (auto& block : m_blocks) { for (auto& block : m_blocks) {
bool block_has_live_cells = false;
block->for_each_cell([&](Cell* cell) { block->for_each_cell([&](Cell* cell) {
if (cell->is_live()) { if (cell->is_live()) {
if (!cell->is_marked()) { if (!cell->is_marked()) {
@ -195,9 +198,21 @@ void Heap::sweep_dead_cells()
block->deallocate(cell); block->deallocate(cell);
} else { } else {
cell->set_marked(false); cell->set_marked(false);
block_has_live_cells = true;
} }
} }
}); });
if (!block_has_live_cells)
empty_blocks.append(block);
}
for (auto* block : empty_blocks) {
dbg() << " - Reclaim HeapBlock @ " << block << ": cell_size=" << block->cell_size();
m_blocks.remove_first_matching([block](auto& entry) { return entry == block; });
}
for (auto& block : m_blocks) {
dbg() << " > Live HeapBlock @ " << block << ": cell_size=" << block->cell_size();
} }
} }