heap_block_size

2 files changed, 12 insertions, 0 deletions

diff --git a/qstd/memory.c b/qstd/memory.c
index f245289..6ea43f7 100644
--- a/qstd/memory.c
+++ b/qstd/memory.c
@@ -209,6 +209,17 @@ void heap_free(
 	heap_free_aligned(h, p);
 }
 
+int heap_block_size(void* ptr) {
+	unsigned char* a;
+	int f = ~((unsigned)-1 >> 1);
+	ptrdiff_t shift;
+	a = ptr;
+	shift = a[-1];
+	shift += 256 * shift == 0;
+	a -= shift;
+	return ((int*)a)[-1] & ~f;
+}
+
 /*
 void print_blocks(Heap* h) {
 	int i, o;
diff --git a/qstd/memory.h b/qstd/memory.h
index 26c0382..842cb49 100644
--- a/qstd/memory.h
+++ b/qstd/memory.h
@@ -53,4 +53,5 @@ void heap_free(
 	void* p
 );
 void heap_defrag(Heap* h);
+int heap_block_size(void* ptr);
 #endif