improve mempool implementation

Wed, 28 Jun 2023 20:07:52 +0200

author
Mike Becker <universe@uap-core.de>
date
Wed, 28 Jun 2023 20:07:52 +0200
changeset 727
d92a59f5d261
parent 726
44986c0e2b05
child 728
71c4ac35c1ce

improve mempool implementation

docs/src/features.md file | annotate | diff | comparison | revisions
src/CMakeLists.txt file | annotate | diff | comparison | revisions
src/basic_mempool.c file | annotate | diff | comparison | revisions
src/cx/basic_mempool.h file | annotate | diff | comparison | revisions
src/cx/mempool.h file | annotate | diff | comparison | revisions
src/mempool.c file | annotate | diff | comparison | revisions
tests/CMakeLists.txt file | annotate | diff | comparison | revisions
tests/test_basic_mempool.cpp file | annotate | diff | comparison | revisions
tests/test_mempool.cpp file | annotate | diff | comparison | revisions
--- a/docs/src/features.md	Wed Jun 28 19:18:01 2023 +0200
+++ b/docs/src/features.md	Wed Jun 28 20:07:52 2023 +0200
@@ -30,7 +30,7 @@
 struct my_allocator_state {
     size_t total;
     size_t avail;
-    char[] mem;
+    char mem[];
 };
 
 static cx_allocator_class my_allocator_class = {
@@ -91,10 +91,6 @@
 
 *Header file:* [mempool.h](api/mempool_8h.html)
 
-### Basic Memory Pool
-
-*Header file:* [basic_mempool.h](api/basic__mempool_8h.html)
-
 ## Iterator
 
 *Header file:* [iterator.h](api/iterator_8h.html)
--- a/src/CMakeLists.txt	Wed Jun 28 19:18:01 2023 +0200
+++ b/src/CMakeLists.txt	Wed Jun 28 20:07:52 2023 +0200
@@ -9,7 +9,7 @@
         map.c
         hash_key.c
         hash_map.c
-        basic_mempool.c
+        mempool.c
         printf.c
         compare.c
 )
@@ -28,7 +28,6 @@
         cx/hash_key.h
         cx/hash_map.h
         cx/mempool.h
-        cx/basic_mempool.h
         cx/printf.h
         cx/compare.h
         )
--- a/src/basic_mempool.c	Wed Jun 28 19:18:01 2023 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,235 +0,0 @@
-/*
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
- *
- * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- *   1. Redistributions of source code must retain the above copyright
- *      notice, this list of conditions and the following disclaimer.
- *
- *   2. Redistributions in binary form must reproduce the above copyright
- *      notice, this list of conditions and the following disclaimer in the
- *      documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "cx/basic_mempool.h"
-#include "cx/utils.h"
-#include <string.h>
-
-#define of_chk_(n) if (SIZE_MAX - sizeof(cx_destructor_func) < (n)) return NULL
-
-/** Internal structure for denoting pooled memory. */
-typedef struct {
-    /** The destructor. */
-    cx_destructor_func destructor;
-    /**
-     * Access to the first byte of the polled memory.
-     */
-    char c;
-} cx_basic_mempool_memory;
-
-static int cx_basic_mempool_chcap(
-        struct cx_basic_mempool_s *pool,
-        size_t newcap
-) {
-    if (newcap < pool->ndata) {
-        return 1;
-    }
-
-    size_t newcapsz;
-    if (cx_szmul(newcap, sizeof(void *), &newcapsz)) {
-        return 1;
-    }
-
-    void **data = realloc(pool->data, newcapsz);
-    if (data) {
-        pool->data = data;
-        pool->size = newcap;
-        return 0;
-    } else {
-        return 1;
-    }
-}
-
-void *cx_malloc_basic_mempool(
-        void *data,
-        size_t n
-) {
-    of_chk_(n);
-    struct cx_basic_mempool_s *pool = data;
-
-    if (pool->ndata >= pool->size) {
-        size_t newcap = pool->size * 2;
-        if (newcap < pool->size || cx_basic_mempool_chcap(pool, newcap)) {
-            return NULL;
-        }
-    }
-
-    cx_basic_mempool_memory *mem = malloc(sizeof(cx_destructor_func) + n);
-    if (mem == NULL) {
-        return NULL;
-    }
-
-    mem->destructor = NULL;
-    pool->data[pool->ndata] = mem;
-    pool->ndata++;
-
-    return &(mem->c);
-}
-
-void *cx_calloc_basic_mempool(
-        void *data,
-        size_t nelem,
-        size_t elsize
-) {
-    size_t msz;
-    if (cx_szmul(nelem, elsize, &msz)) {
-        return NULL;
-    }
-    void *ptr = cx_malloc_basic_mempool(data, msz);
-    if (ptr == NULL) {
-        return NULL;
-    }
-    memset(ptr, 0, nelem * elsize);
-    return ptr;
-}
-
-void *cx_realloc_basic_mempool(
-        void *data,
-        void *ptr,
-        size_t n
-) {
-    of_chk_(n);
-    struct cx_basic_mempool_s *pool = data;
-
-    char *mem = ((char *) ptr) - sizeof(cx_destructor_func);
-    char *newm = (char *) realloc(mem, n + sizeof(cx_destructor_func));
-    if (newm == NULL) {
-        return NULL;
-    }
-    if (mem != newm) {
-        cx_for_n(i, pool->ndata) {
-            if (pool->data[i] == mem) {
-                pool->data[i] = newm;
-                return newm + sizeof(cx_destructor_func);
-            }
-        }
-        abort();
-    } else {
-        return newm + sizeof(cx_destructor_func);
-    }
-}
-
-void cx_free_basic_mempool(
-        void *data,
-        void *ptr
-) {
-    struct cx_basic_mempool_s *pool = data;
-
-    cx_basic_mempool_memory *mem = (cx_basic_mempool_memory *)
-            ((char *) ptr - sizeof(cx_destructor_func));
-    cx_for_n(i, pool->ndata) {
-        if (mem == pool->data[i]) {
-            if (mem->destructor != NULL) {
-                mem->destructor(&(mem->c));
-            }
-            free(mem);
-            size_t last_index = pool->ndata - 1;
-            if (i != last_index) {
-                pool->data[i] = pool->data[last_index];
-                pool->data[last_index] = NULL;
-            }
-            pool->ndata--;
-            return;
-        }
-    }
-    abort();
-}
-
-void cx_basic_mempool_destroy(CxMempool *p) {
-    struct cx_basic_mempool_s *pool = (struct cx_basic_mempool_s *) p;
-    cx_basic_mempool_memory *mem;
-    cx_for_n(i, pool->ndata) {
-        mem = (cx_basic_mempool_memory *) pool->data[i];
-        if (mem) {
-            if (mem->destructor) {
-                mem->destructor(&(mem->c));
-            }
-            free(mem);
-        }
-    }
-    free(pool->data);
-    free((void *) p->allocator);
-    free(pool);
-}
-
-void cx_basic_mempool_set_destr(
-        __attribute__((__unused__)) CxMempool *pool,
-        void *ptr,
-        cx_destructor_func func
-) {
-    *(cx_destructor_func *) ((char *) ptr - sizeof(cx_destructor_func)) = func;
-}
-
-static cx_allocator_class cx_basic_mempool_allocator_class = {
-        cx_malloc_basic_mempool,
-        cx_realloc_basic_mempool,
-        cx_calloc_basic_mempool,
-        cx_free_basic_mempool
-};
-
-static cx_mempool_class cx_basic_mempool_class = {
-        cx_basic_mempool_destroy,
-        cx_basic_mempool_set_destr,
-};
-
-CxMempool *cxBasicMempoolCreate(size_t capacity) {
-    size_t poolsize;
-    if (cx_szmul(capacity, sizeof(void *), &poolsize)) {
-        return NULL;
-    }
-
-    struct cx_basic_mempool_s *pool =
-            malloc(sizeof(struct cx_basic_mempool_s));
-    if (pool == NULL) {
-        return NULL;
-    }
-
-
-    CxAllocator *provided_allocator = malloc(sizeof(CxAllocator));
-    if (!provided_allocator) {
-        free(pool);
-        return NULL;
-    }
-    provided_allocator->cl = &cx_basic_mempool_allocator_class;
-    provided_allocator->data = pool;
-
-    pool->base.cl = &cx_basic_mempool_class;
-    pool->base.allocator = provided_allocator;
-
-    pool->data = malloc(poolsize);
-    if (pool->data == NULL) {
-        free(provided_allocator);
-        free(pool);
-        return NULL;
-    }
-
-    pool->ndata = 0;
-    pool->size = capacity;
-
-    return (CxMempool *) pool;
-}
--- a/src/cx/basic_mempool.h	Wed Jun 28 19:18:01 2023 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,76 +0,0 @@
-/*
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
- *
- * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- *   1. Redistributions of source code must retain the above copyright
- *      notice, this list of conditions and the following disclaimer.
- *
- *   2. Redistributions in binary form must reproduce the above copyright
- *      notice, this list of conditions and the following disclaimer in the
- *      documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-/**
- * \file basic_mempool.h
- * \brief Implementation of a basic memory pool.
- * \author Mike Becker
- * \author Olaf Wintermann
- * \version 3.0
- * \copyright 2-Clause BSD License
- */
-
-#ifndef UCX_BASIC_MEMPOOL_H
-#define UCX_BASIC_MEMPOOL_H
-
-#include "mempool.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/**
- * Basic array-based memory pool.
- */
-struct cx_basic_mempool_s {
-    /** Inherit base structure members. */
-    CxMempool base;
-
-    /** List of pointers to pooled memory. */
-    void **data;
-
-    /** Number of pooled memory items. */
-    size_t ndata;
-
-    /** Memory pool size. */
-    size_t size;
-};
-
-/**
- * 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__))
-CxMempool *cxBasicMempoolCreate(size_t capacity);
-
-#ifdef __cplusplus
-} // extern "C"
-#endif
-
-#endif // UCX_BASIC_MEMPOOL_H
--- a/src/cx/mempool.h	Wed Jun 28 19:18:01 2023 +0200
+++ b/src/cx/mempool.h	Wed Jun 28 20:07:52 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;
 };
 
 /**
@@ -70,22 +77,27 @@
 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);
+__attribute__((__warn_unused_result__))
+CxMempool *cxMempoolCreate(size_t capacity, cx_destructor_func destr);
 
-    /** Member function for setting a destructor. */
-    __attribute__((__nonnull__))
-    void (*set_destructor)(
-            CxMempool *pool,
-            void *memory,
-            cx_destructor_func fnc
-    );
-};
-
+/**
+ * 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 including their contents.
@@ -93,27 +105,42 @@
  * @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"
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/mempool.c	Wed Jun 28 20:07:52 2023 +0200
@@ -0,0 +1,232 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *
+ *   2. Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "cx/mempool.h"
+#include "cx/utils.h"
+#include <string.h>
+
+struct cx_mempool_memory_s {
+    /** The destructor. */
+    cx_destructor_func destructor;
+    /** The actual memory. */
+    char c[];
+};
+
+static void *cx_mempool_malloc(
+        void *p,
+        size_t n
+) {
+    struct cx_mempool_s *pool = p;
+
+    if (pool->size >= pool->capacity) {
+        size_t newcap = pool->capacity - (pool->capacity % 16) + 16;
+        struct cx_mempool_memory_s **newdata = realloc(pool->data, newcap*sizeof(struct cx_mempool_memory_s*));
+        if (newdata == NULL) {
+            return NULL;
+        }
+        pool->data = newdata;
+        pool->capacity = newcap;
+    }
+
+    struct cx_mempool_memory_s *mem = malloc(sizeof(cx_destructor_func) + n);
+    if (mem == NULL) {
+        return NULL;
+    }
+
+    mem->destructor = pool->auto_destr;
+    pool->data[pool->size] = mem;
+    pool->size++;
+
+    return mem->c;
+}
+
+static void *cx_mempool_calloc(
+        void *p,
+        size_t nelem,
+        size_t elsize
+) {
+    size_t msz;
+    if (cx_szmul(nelem, elsize, &msz)) {
+        return NULL;
+    }
+    void *ptr = cx_mempool_malloc(p, msz);
+    if (ptr == NULL) {
+        return NULL;
+    }
+    memset(ptr, 0, nelem * elsize);
+    return ptr;
+}
+
+static void *cx_mempool_realloc(
+        void *p,
+        void *ptr,
+        size_t n
+) {
+    struct cx_mempool_s *pool = p;
+
+    struct cx_mempool_memory_s *mem, *newm;
+    mem = (struct cx_mempool_memory_s*)(((char *) ptr) - sizeof(cx_destructor_func));
+    newm = realloc(mem, n + sizeof(cx_destructor_func));
+
+    if (newm == NULL) {
+        return NULL;
+    }
+    if (mem != newm) {
+        cx_for_n(i, pool->size) {
+            if (pool->data[i] == mem) {
+                pool->data[i] = newm;
+                return ((char*)newm) + sizeof(cx_destructor_func);
+            }
+        }
+        abort();
+    } else {
+        return ptr;
+    }
+}
+
+static void cx_mempool_free(
+        void *p,
+        void *ptr
+) {
+    struct cx_mempool_s *pool = p;
+
+    struct cx_mempool_memory_s *mem = (struct cx_mempool_memory_s *)
+            ((char *) ptr - sizeof(cx_destructor_func));
+
+    cx_for_n(i, pool->size) {
+        if (mem == pool->data[i]) {
+            if (mem->destructor) {
+                mem->destructor(mem->c);
+            }
+            free(mem);
+            size_t last_index = pool->size - 1;
+            if (i != last_index) {
+                pool->data[i] = pool->data[last_index];
+                pool->data[last_index] = NULL;
+            }
+            pool->size--;
+            return;
+        }
+    }
+    abort();
+}
+
+void cxMempoolDestroy(CxMempool *pool) {
+    struct cx_mempool_memory_s *mem;
+    cx_for_n(i, pool->size) {
+        mem = pool->data[i];
+        if (mem->destructor) {
+            mem->destructor(mem->c);
+        }
+        free(mem);
+    }
+    free(pool->data);
+    free((void*) pool->allocator);
+    free(pool);
+}
+
+void cxMempoolSetDestructor(
+        void *ptr,
+        cx_destructor_func func
+) {
+    *(cx_destructor_func *) ((char *) ptr - sizeof(cx_destructor_func)) = func;
+}
+
+struct cx_mempool_foreign_mem_s {
+    cx_destructor_func destr;
+    void* mem;
+};
+
+static void cx_mempool_destr_foreign_mem(void* ptr) {
+    struct cx_mempool_foreign_mem_s *fm = ptr;
+    fm->destr(fm->mem);
+}
+
+int cxMempoolRegister(
+        CxMempool *pool,
+        void *memory,
+        cx_destructor_func destr
+) {
+    struct cx_mempool_foreign_mem_s *fm = cx_mempool_malloc(
+            pool,
+            sizeof(struct cx_mempool_foreign_mem_s)
+    );
+    if (fm == NULL) return 1;
+
+    fm->mem = memory;
+    fm->destr = destr;
+    *(cx_destructor_func *) ((char *) fm - sizeof(cx_destructor_func)) = cx_mempool_destr_foreign_mem;
+
+    return 0;
+}
+
+static cx_allocator_class cx_mempool_allocator_class = {
+        cx_mempool_malloc,
+        cx_mempool_realloc,
+        cx_mempool_calloc,
+        cx_mempool_free
+};
+
+CxMempool *cxMempoolCreate(
+        size_t capacity,
+        cx_destructor_func destr
+) {
+    size_t poolsize;
+    if (cx_szmul(capacity, sizeof(struct cx_mempool_memory_s*), &poolsize)) {
+        return NULL;
+    }
+
+    struct cx_mempool_s *pool =
+            malloc(sizeof(struct cx_mempool_s));
+    if (pool == NULL) {
+        return NULL;
+    }
+
+    CxAllocator *provided_allocator = malloc(sizeof(CxAllocator));
+    if (provided_allocator == NULL) {
+        free(pool);
+        return NULL;
+    }
+    provided_allocator->cl = &cx_mempool_allocator_class;
+    provided_allocator->data = pool;
+
+    pool->allocator = provided_allocator;
+
+    pool->data = malloc(poolsize);
+    if (pool->data == NULL) {
+        free(provided_allocator);
+        free(pool);
+        return NULL;
+    }
+
+    pool->size = 0;
+    pool->capacity = capacity;
+    pool->auto_destr = destr;
+
+    return (CxMempool *) pool;
+}
--- a/tests/CMakeLists.txt	Wed Jun 28 19:18:01 2023 +0200
+++ b/tests/CMakeLists.txt	Wed Jun 28 20:07:52 2023 +0200
@@ -26,7 +26,7 @@
         test_hash_key.cpp
         test_map.cpp
         test_map_generics.c
-        test_basic_mempool.cpp
+        test_mempool.cpp
         test_printf.cpp
         selftest.cpp
         util_allocator.cpp
--- a/tests/test_basic_mempool.cpp	Wed Jun 28 19:18:01 2023 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,154 +0,0 @@
-/*
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
- *
- * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- *   1. Redistributions of source code must retain the above copyright
- *      notice, this list of conditions and the following disclaimer.
- *
- *   2. Redistributions in binary form must reproduce the above copyright
- *      notice, this list of conditions and the following disclaimer in the
- *      documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "cx/basic_mempool.h"
-#include "util_allocator.h"
-#include <gtest/gtest.h>
-
-class CxBasicMempool : public ::testing::Test {
-protected:
-    CxMempool *pool = nullptr;
-
-    void TearDown() override {
-        if (pool != nullptr) {
-            cxMempoolDestroy(pool);
-        }
-    }
-};
-
-TEST_F(CxBasicMempool, Create) {
-    pool = cxBasicMempoolCreate(16);
-    ASSERT_NE(pool->allocator, nullptr);
-    ASSERT_NE(pool->cl, nullptr);
-    EXPECT_NE(pool->cl->destroy, nullptr);
-    ASSERT_NE(pool->allocator->cl, nullptr);
-    EXPECT_EQ(pool->allocator->data, pool);
-    EXPECT_NE(pool->allocator->cl->malloc, nullptr);
-    EXPECT_NE(pool->allocator->cl->calloc, nullptr);
-    EXPECT_NE(pool->allocator->cl->realloc, nullptr);
-    EXPECT_NE(pool->allocator->cl->free, nullptr);
-
-    auto basic_pool = reinterpret_cast<cx_basic_mempool_s *>(pool);
-    EXPECT_EQ(basic_pool->size, 16);
-    EXPECT_EQ(basic_pool->ndata, 0);
-    EXPECT_NE(basic_pool->data, nullptr);
-}
-
-TEST_F(CxBasicMempool, malloc) {
-    pool = cxBasicMempoolCreate(4);
-    auto basic_pool = reinterpret_cast<cx_basic_mempool_s *>(pool);
-    EXPECT_NE(cxMalloc(pool->allocator, sizeof(int)), nullptr);
-    EXPECT_NE(cxMalloc(pool->allocator, sizeof(int)), nullptr);
-    EXPECT_EQ(basic_pool->ndata, 2);
-    EXPECT_EQ(basic_pool->size, 4);
-    EXPECT_NE(cxMalloc(pool->allocator, sizeof(int)), nullptr);
-    EXPECT_NE(cxMalloc(pool->allocator, sizeof(int)), nullptr);
-    EXPECT_EQ(basic_pool->ndata, 4);
-    EXPECT_EQ(basic_pool->size, 4);
-    EXPECT_NE(cxMalloc(pool->allocator, sizeof(int)), nullptr);
-    EXPECT_NE(cxMalloc(pool->allocator, sizeof(int)), nullptr);
-    EXPECT_EQ(basic_pool->ndata, 6);
-    EXPECT_GE(basic_pool->size, 6);
-}
-
-TEST_F(CxBasicMempool, calloc) {
-    pool = cxBasicMempoolCreate(4);
-
-    auto test = (int *) cxCalloc(pool->allocator, 2, sizeof(int));
-    ASSERT_NE(test, nullptr);
-    EXPECT_EQ(test[0], 0);
-    EXPECT_EQ(test[1], 0);
-}
-
-static unsigned test_destructor_called = 0;
-
-static void test_destructor([[maybe_unused]] void *mem) {
-    test_destructor_called++;
-}
-
-TEST_F(CxBasicMempool, destructor) {
-    pool = cxBasicMempoolCreate(4);
-    auto data = cxMalloc(pool->allocator, sizeof(int));
-    *((int *) data) = 13;
-    cxMempoolSetDestructor(pool, data, test_destructor);
-    EXPECT_EQ(*((int *) data), 13);
-    test_destructor_called = 0;
-    cxFree(pool->allocator, data);
-    EXPECT_EQ(test_destructor_called, 1);
-    data = cxMalloc(pool->allocator, sizeof(int));
-    cxMempoolSetDestructor(pool, data, test_destructor);
-    cxMempoolDestroy(pool);
-    pool = nullptr;
-    EXPECT_EQ(test_destructor_called, 2);
-}
-
-TEST_F(CxBasicMempool, realloc) {
-    pool = cxBasicMempoolCreate(4);
-    auto data = cxMalloc(pool->allocator, sizeof(int));
-    *((int *) data) = 13;
-    cxMempoolSetDestructor(pool, data, test_destructor);
-
-    void *rdata = data;
-    unsigned n = 1;
-    while (rdata == data) {
-        n <<= 1;
-        ASSERT_LT(n, 65536); // eventually the memory should be moved elsewhere
-        rdata = cxRealloc(pool->allocator, data, n * sizeof(intptr_t));
-    }
-
-    EXPECT_EQ(*((int *) rdata), 13);
-    // test if destructor is still intact
-    test_destructor_called = 0;
-    cxFree(pool->allocator, rdata);
-    EXPECT_EQ(test_destructor_called, 1);
-}
-
-
-TEST_F(CxBasicMempool, free) {
-    pool = cxBasicMempoolCreate(4);
-    auto basic_pool = reinterpret_cast<cx_basic_mempool_s *>(pool);
-
-    void *mem1;
-    void *mem2;
-
-    mem1 = cxMalloc(pool->allocator, 16);
-    cxFree(pool->allocator, mem1);
-    EXPECT_EQ(basic_pool->ndata, 0);
-
-    cxMalloc(pool->allocator, 16);
-    cxMalloc(pool->allocator, 16);
-    mem1 = cxMalloc(pool->allocator, 16);
-    cxMalloc(pool->allocator, 16);
-    mem2 = cxMalloc(pool->allocator, 16);
-
-    EXPECT_EQ(basic_pool->ndata, 5);
-    cxFree(pool->allocator, mem1);
-    EXPECT_EQ(basic_pool->ndata, 4);
-    cxFree(pool->allocator, mem2);
-    EXPECT_EQ(basic_pool->ndata, 3);
-}
\ No newline at end of file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test_mempool.cpp	Wed Jun 28 20:07:52 2023 +0200
@@ -0,0 +1,153 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *
+ *   2. Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "cx/mempool.h"
+#include "util_allocator.h"
+#include <gtest/gtest.h>
+
+TEST(Mempool, Create) {
+    auto pool = cxBasicMempoolCreate(16);
+    ASSERT_EQ(pool->auto_destr, nullptr);
+    ASSERT_NE(pool->allocator, nullptr);
+    ASSERT_NE(pool->allocator->cl, nullptr);
+    EXPECT_EQ(pool->allocator->data, pool);
+    EXPECT_NE(pool->allocator->cl->malloc, nullptr);
+    EXPECT_NE(pool->allocator->cl->calloc, nullptr);
+    EXPECT_NE(pool->allocator->cl->realloc, nullptr);
+    EXPECT_NE(pool->allocator->cl->free, nullptr);
+    EXPECT_EQ(pool->capacity, 16);
+    EXPECT_EQ(pool->size, 0);
+    EXPECT_NE(pool->data, nullptr);
+    cxMempoolDestroy(pool);
+}
+
+TEST(Mempool, malloc) {
+    auto pool = cxBasicMempoolCreate(4);
+    EXPECT_NE(cxMalloc(pool->allocator, sizeof(int)), nullptr);
+    EXPECT_NE(cxMalloc(pool->allocator, sizeof(int)), nullptr);
+    EXPECT_EQ(pool->size, 2);
+    EXPECT_EQ(pool->capacity, 4);
+    EXPECT_NE(cxMalloc(pool->allocator, sizeof(int)), nullptr);
+    EXPECT_NE(cxMalloc(pool->allocator, sizeof(int)), nullptr);
+    EXPECT_EQ(pool->size, 4);
+    EXPECT_EQ(pool->capacity, 4);
+    EXPECT_NE(cxMalloc(pool->allocator, sizeof(int)), nullptr);
+    EXPECT_NE(cxMalloc(pool->allocator, sizeof(int)), nullptr);
+    EXPECT_EQ(pool->size, 6);
+    EXPECT_GE(pool->capacity, 6);
+    cxMempoolDestroy(pool);
+}
+
+TEST(Mempool, calloc) {
+    auto pool = cxBasicMempoolCreate(4);
+
+    auto test = (int *) cxCalloc(pool->allocator, 2, sizeof(int));
+    ASSERT_NE(test, nullptr);
+    EXPECT_EQ(test[0], 0);
+    EXPECT_EQ(test[1], 0);
+    cxMempoolDestroy(pool);
+}
+
+static unsigned test_destructor_called;
+
+static void test_destructor([[maybe_unused]] void *mem) {
+    test_destructor_called++;
+}
+
+TEST(Mempool, realloc) {
+    auto pool = cxMempoolCreate(4, test_destructor);
+    ASSERT_EQ(pool->auto_destr, test_destructor);
+    auto data = cxMalloc(pool->allocator, sizeof(int));
+    *((int *) data) = 13;
+
+    void *rdata = data;
+    unsigned n = 1;
+    while (rdata == data) {
+        n <<= 1;
+        ASSERT_LT(n, 65536); // eventually the memory should be moved elsewhere
+        rdata = cxRealloc(pool->allocator, data, n * sizeof(intptr_t));
+    }
+
+    EXPECT_EQ(*((int *) rdata), 13);
+    // test if destructor is still intact
+    test_destructor_called = 0;
+    cxFree(pool->allocator, rdata);
+    EXPECT_EQ(test_destructor_called, 1);
+    cxMempoolDestroy(pool);
+}
+
+
+TEST(Mempool, free) {
+    auto pool = cxBasicMempoolCreate(4);
+
+    void *mem1;
+    void *mem2;
+
+    mem1 = cxMalloc(pool->allocator, 16);
+    cxFree(pool->allocator, mem1);
+    EXPECT_EQ(pool->size, 0);
+
+    cxMalloc(pool->allocator, 16);
+    cxMalloc(pool->allocator, 16);
+    mem1 = cxMalloc(pool->allocator, 16);
+    cxMalloc(pool->allocator, 16);
+    mem2 = cxMalloc(pool->allocator, 16);
+
+    EXPECT_EQ(pool->size, 5);
+    cxFree(pool->allocator, mem1);
+    EXPECT_EQ(pool->size, 4);
+    cxFree(pool->allocator, mem2);
+    EXPECT_EQ(pool->size, 3);
+    cxMempoolDestroy(pool);
+}
+
+TEST(Mempool, Destroy) {
+    auto pool = cxBasicMempoolCreate(4);
+    auto data = cxMalloc(pool->allocator, sizeof(int));
+    *((int *) data) = 13;
+    cxMempoolSetDestructor(data, test_destructor);
+    EXPECT_EQ(*((int *) data), 13);
+    test_destructor_called = 0;
+    cxFree(pool->allocator, data);
+    EXPECT_EQ(test_destructor_called, 1);
+    data = cxMalloc(pool->allocator, sizeof(int));
+    cxMempoolSetDestructor(data, test_destructor);
+    cxMempoolDestroy(pool);
+    EXPECT_EQ(test_destructor_called, 2);
+}
+
+TEST(Mempool, Register) {
+    auto pool = cxBasicMempoolCreate(4);
+    auto data = cxMalloc(pool->allocator, sizeof(int));
+    test_destructor_called = 0;
+    cxMempoolSetDestructor(data, test_destructor);
+    int donotfree = 0;
+    cxMempoolRegister(pool, &donotfree, test_destructor);
+    cxMempoolDestroy(pool);
+    EXPECT_EQ(test_destructor_called, 2);
+}

mercurial