From 9aaf19f4de1ba1f1bd7278f35d5b3c9e56d860da Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Mon, 6 Apr 2020 12:36:49 +0200
Subject: [PATCH] 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. :^)
---
 Libraries/LibJS/Heap/Heap.cpp | 8 +++++++-
 Libraries/LibJS/Heap/Heap.h   | 3 +++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/Libraries/LibJS/Heap/Heap.cpp b/Libraries/LibJS/Heap/Heap.cpp
index c75702bd35..3dd3902ca5 100644
--- a/Libraries/LibJS/Heap/Heap.cpp
+++ b/Libraries/LibJS/Heap/Heap.cpp
@@ -58,8 +58,14 @@ Heap::~Heap()
 
 Cell* Heap::allocate_cell(size_t size)
 {
-    if (should_collect_on_every_allocation())
+    if (should_collect_on_every_allocation()) {
         collect_garbage();
+    } else if (m_allocations_since_last_gc > m_max_allocations_between_gc) {
+        m_allocations_since_last_gc = 0;
+        collect_garbage();
+    } else {
+        ++m_allocations_since_last_gc;
+    }
 
     for (auto& block : m_blocks) {
         if (size > block->cell_size())
diff --git a/Libraries/LibJS/Heap/Heap.h b/Libraries/LibJS/Heap/Heap.h
index 8ed4d55b87..afaacada13 100644
--- a/Libraries/LibJS/Heap/Heap.h
+++ b/Libraries/LibJS/Heap/Heap.h
@@ -78,6 +78,9 @@ private:
 
     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;