--- libmalloc/libmalloc-166.251.2/src/magazine_rack.h
+++ libmalloc/libmalloc-792.80.2/src/magazine_rack.h
@@ -24,23 +24,27 @@
 #ifndef __MAGAZINE_RACK_H
 #define __MAGAZINE_RACK_H
 
+#include <malloc/_ptrcheck.h>
+__ptrcheck_abi_assume_single()
+
 /*******************************************************************************
  * Definitions for region hash
  ******************************************************************************/
 
-typedef void *region_t;
-typedef region_t *rgnhdl_t; /* A pointer into hashed_regions array. */
+typedef void * __single region_t;
+typedef region_t * __single rgnhdl_t; /* A pointer into hashed_regions array. */
+typedef struct region_trailer region_trailer_t;
 
 #define INITIAL_NUM_REGIONS_SHIFT 6							 // log2(INITIAL_NUM_REGIONS)
 #define INITIAL_NUM_REGIONS (1 << INITIAL_NUM_REGIONS_SHIFT) // Must be a power of 2!
 #define HASHRING_OPEN_ENTRY ((region_t)0)					 // Initial value and sentinel marking end of collision chain
-#define HASHRING_REGION_DEALLOCATED ((region_t)-1)			 // Region at this slot reclaimed by OS
+#define HASHRING_REGION_DEALLOCATED __unsafe_forge_single(void *, ~0UL)			 // Region at this slot reclaimed by OS
 #define HASH_BLOCKS_ALIGN TINY_BLOCKS_ALIGN					 // MIN( TINY_BLOCKS_ALIGN, SMALL_BLOCKS_ALIGN, ... )
 
 typedef struct region_hash_generation {
 	size_t num_regions_allocated;
 	size_t num_regions_allocated_shift; // log2(num_regions_allocated)
-	region_t *hashed_regions;			// hashed by location
+	region_t * __counted_by(num_regions_allocated) hashed_regions;			// hashed by location
 	struct region_hash_generation *nextgen;
 } region_hash_generation_t;
 
@@ -78,7 +82,6 @@
 	uintptr_t last_madvise;
 } rack_t;
 
-
 MALLOC_NOEXPORT
 void
 rack_init(rack_t *rack, rack_type_t type, uint32_t num_magazines, uint32_t debug_flags);
@@ -95,4 +98,31 @@
 void
 rack_region_insert(rack_t *rack, region_t region);
 
+MALLOC_NOEXPORT
+bool
+rack_region_remove(rack_t *rack, region_t region, region_trailer_t *trailer);
+
+MALLOC_NOEXPORT
+bool
+rack_region_maybe_dispose(rack_t *rack, region_t region, size_t region_size,
+		region_trailer_t *trailer);
+
+MALLOC_NOEXPORT
+unsigned int
+rack_get_thread_index(rack_t *rack);
+
+MALLOC_NOEXPORT MALLOC_ALWAYS_INLINE MALLOC_INLINE
+static void
+rack_region_lock(rack_t *rack)
+{
+	_malloc_lock_lock(&rack->region_lock);
+}
+
+MALLOC_NOEXPORT MALLOC_ALWAYS_INLINE MALLOC_INLINE
+static void
+rack_region_unlock(rack_t *rack)
+{
+	_malloc_lock_unlock(&rack->region_lock);
+}
+
 #endif // __MAGAZINE_RACK_H