From 5f2106f5128314cc392881718d8c1794c9f117fa Mon Sep 17 00:00:00 2001
From: Jonas 'Sortie' Termansen <sortie@maxsi.org>
Date: Thu, 15 May 2014 19:45:51 +0200
Subject: [PATCH] Maintain size of allocated memory in the heap.

---
 libc/stdlib/heap.cpp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/libc/stdlib/heap.cpp b/libc/stdlib/heap.cpp
index af5dd0ec..ca0a9e74 100644
--- a/libc/stdlib/heap.cpp
+++ b/libc/stdlib/heap.cpp
@@ -221,6 +221,9 @@ size_t heapmaxsize = SIZE_MAX;
 // excludes the wilderness.
 size_t heapsize = 0;
 
+// How many bytes of actual storage the heap contains.
+size_t heapstorage = 0;
+
 // bins[N] contain a linked list of chunks that are at least 2^(N+1)
 // bytes, but less than 2^(N+2) bytes. By selecting the proper bin in
 // constant time, we can allocate chunks in constant time.
@@ -502,6 +505,8 @@ extern "C" void* malloc(size_t size)
 		chunk->magic = MAGIC;
 		chunk->GetTrailer()->magic = MAGIC;
 
+		heapstorage += chunk->size;
+
 		#if 3 <= PARANOIA
 		assert(ValidateHeap());
 		#endif
@@ -546,6 +551,8 @@ extern "C" void* malloc(size_t size)
 	chunk->magic = MAGIC;
 	trailer->magic = MAGIC;
 
+	heapstorage += chunk->size;
+
 	#if 3 <= PARANOIA
 	assert(ValidateHeap());
 	#endif
@@ -671,6 +678,8 @@ extern "C" void free(void* addr)
 	assert(chunk->IsUsed());
 	assert(chunk->IsSane());
 
+	heapstorage -= chunk->size;
+
 	UnifyNeighbors(&chunk);
 
 	bool nexttowilderness = IsRightmostChunk(chunk);