diff -r aeaf7db26fac -r c094afcdfb27 src/ucx/cx/mempool.h
--- a/src/ucx/cx/mempool.h	Sun Jul 09 15:14:26 2023 +0200
+++ b/src/ucx/cx/mempool.h	Mon Jul 10 18:39:24 2023 +0200
@@ -44,24 +44,31 @@
 extern "C" {
 #endif
 
-/**
- * Memory pool class type.
- */
-typedef struct cx_mempool_class_s cx_mempool_class;
+/** Internal structure for pooled memory. */
+struct cx_mempool_memory_s;
 
 /**
  * The basic structure of a memory pool.
  * Should be the first member of an actual memory pool implementation.
  */
 struct cx_mempool_s {
+    /** The provided allocator. */
+    CxAllocator const *allocator;
+
     /**
-     * The pool class definition.
+     * A destructor that shall be automatically registered for newly allocated memory.
+     * This destructor MUST NOT free the memory.
      */
-    cx_mempool_class *cl;
-    /**
-     * The provided allocator.
-     */
-    CxAllocator const *allocator;
+    cx_destructor_func auto_destr;
+
+    /** Array of pooled memory. */
+    struct cx_mempool_memory_s **data;
+
+    /** Number of pooled memory items. */
+    size_t size;
+
+    /** Memory pool capacity. */
+    size_t capacity;
 };
 
 /**
@@ -70,50 +77,70 @@
 typedef struct cx_mempool_s CxMempool;
 
 /**
- * The class definition for a memory pool.
+ * Creates an array-based memory pool with a shared destructor function.
+ *
+ * This destructor MUST NOT free the memory.
+ *
+ * @param capacity the initial capacity of the pool
+ * @param destr the destructor function to use for allocated memory
+ * @return the created memory pool or \c NULL if allocation failed
  */
-struct cx_mempool_class_s {
-    /** Member function for destroying the pool. */
-    __attribute__((__nonnull__))
-    void (*destroy)(CxMempool *pool);
-
-    /** Member function for setting a destructor. */
-    __attribute__((__nonnull__))
-    void (*set_destructor)(
-            CxMempool *pool,
-            void *memory,
-            cx_destructor_func fnc
-    );
-};
-
+__attribute__((__warn_unused_result__))
+CxMempool *cxMempoolCreate(size_t capacity, cx_destructor_func destr);
 
 /**
- * Destroys a memory pool including their contents.
+ * Creates a basic array-based memory pool.
+ *
+ * @param capacity the initial capacity of the pool
+ * @return the created memory pool or \c NULL if allocation failed
+ */
+__attribute__((__warn_unused_result__))
+static inline CxMempool *cxBasicMempoolCreate(size_t capacity) {
+    return cxMempoolCreate(capacity, NULL);
+}
+
+/**
+ * Destroys a memory pool and frees the managed memory.
  *
  * @param pool the memory pool to destroy
  */
 __attribute__((__nonnull__))
-static inline void cxMempoolDestroy(CxMempool *pool) {
-    pool->cl->destroy(pool);
-}
+void cxMempoolDestroy(CxMempool *pool);
 
 /**
- * Sets a destructor function for an allocated memory object.
+ * Sets the destructor function for a specific allocated memory object.
  *
- * If the memory is not managed by the pool, the behavior is undefined.
+ * If the memory is not managed by a UCX memory pool, the behavior is undefined.
+ * The destructor MUST NOT free the memory.
  *
- * @param pool the pool
- * @param memory the objected allocated in the pool
+ * @param memory the object allocated in the pool
  * @param fnc the destructor function
  */
 __attribute__((__nonnull__))
-static inline void cxMempoolSetDestructor(
-        CxMempool *pool,
+void cxMempoolSetDestructor(
         void *memory,
         cx_destructor_func fnc
-) {
-    pool->cl->set_destructor(pool, memory, fnc);
-}
+);
+
+/**
+ * Registers foreign memory with this pool.
+ *
+ * The destructor, in contrast to memory allocated by the pool, MUST free the memory.
+ *
+ * A small portion of memory will be allocated to register the information in the pool.
+ * If that allocation fails, this function will return non-zero.
+ *
+ * @param pool the pool
+ * @param memory the object allocated in the pool
+ * @param destr the destructor function
+ * @return zero on success, non-zero on failure
+ */
+__attribute__((__nonnull__))
+int cxMempoolRegister(
+        CxMempool *pool,
+        void *memory,
+        cx_destructor_func destr
+);
 
 #ifdef __cplusplus
 } // extern "C"