ucx/cx/allocator.h

branch
newapi
changeset 174
0358f1d9c506
child 187
24ce2c326d85
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ucx/cx/allocator.h	Mon May 22 16:17:26 2023 +0200
@@ -0,0 +1,225 @@
+/*
+ * 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 allocator.h
+ * Interface for custom allocators.
+ */
+
+#ifndef UCX_ALLOCATOR_H
+#define UCX_ALLOCATOR_H
+
+#include "common.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * The class definition for an allocator.
+ */
+typedef struct {
+    /**
+     * The allocator's malloc() implementation.
+     */
+    void *(*malloc)(
+            void *data,
+            size_t n
+    );
+
+    /**
+     * The allocator's realloc() implementation.
+     */
+    void *(*realloc)(
+            void *data,
+            void *mem,
+            size_t n
+    )
+    __attribute__((__warn_unused_result__));
+
+    /**
+     * The allocator's calloc() implementation.
+     */
+    void *(*calloc)(
+            void *data,
+            size_t nelem,
+            size_t n
+    );
+
+    /**
+     * The allocator's free() implementation.
+     */
+    void (*free)(
+            void *data,
+            void *mem
+    )
+    __attribute__((__nonnull__));
+} cx_allocator_class;
+
+/**
+ * Structure holding the data for an allocator.
+ */
+struct cx_allocator_s {
+    /**
+     * A pointer to the instance of the allocator class.
+     */
+    cx_allocator_class *cl;
+    /**
+     * A pointer to the data this allocator uses.
+     */
+    void *data;
+};
+
+/**
+ * High-Level type alias for the allocator type.
+ */
+typedef struct cx_allocator_s CxAllocator;
+
+/**
+ * A default allocator using standard library malloc() etc.
+ */
+extern CxAllocator *cxDefaultAllocator;
+
+/**
+ * Function pointer type for destructor functions.
+ *
+ * A destructor function deallocates possible contents and MAY free the memory
+ * pointed to by \p memory. Read the documentation of the respective function
+ * pointer to learn if a destructor SHALL, MAY, or MUST NOT free the memory in that
+ * particular implementation.
+ *
+ * @param memory a pointer to the object to destruct
+  */
+typedef void (*cx_destructor_func)(void *memory) __attribute__((__nonnull__));
+
+/**
+ * Function pointer type for destructor functions.
+ *
+ * A destructor function deallocates possible contents and MAY free the memory
+ * pointed to by \p memory. Read the documentation of the respective function
+ * pointer to learn if a destructor SHALL, MAY, or MUST NOT free the memory in that
+ * particular implementation.
+ *
+ * @param data an optional pointer to custom data
+ * @param memory a pointer to the object to destruct
+  */
+typedef void (*cx_destructor_func2)(
+        void *data,
+        void *memory
+) __attribute__((__nonnull__(2)));
+
+/**
+ * Allocate \p n bytes of memory.
+ *
+ * @param allocator the allocator
+ * @param n the number of bytes
+ * @return a pointer to the allocated memory
+ */
+void *cxMalloc(
+        CxAllocator const *allocator,
+        size_t n
+)
+__attribute__((__malloc__))
+__attribute__((__alloc_size__(2)));
+
+/**
+ * Re-allocate the previously allocated block in \p mem, making the new block \p n bytes long.
+ * This function may return the same pointer that was passed to it, if moving the memory
+ * was not necessary.
+ *
+ * \note Re-allocating a block allocated by a different allocator is undefined.
+ *
+ * @param allocator the allocator
+ * @param mem pointer to the previously allocated block
+ * @param n the new size in bytes
+ * @return a pointer to the re-allocated memory
+ */
+void *cxRealloc(
+        CxAllocator const *allocator,
+        void *mem,
+        size_t n
+)
+__attribute__((__warn_unused_result__))
+__attribute__((__alloc_size__(3)));
+
+/**
+ * Re-allocate a previously allocated block and changes the pointer in-place, if necessary.
+ * This function acts like cxRealloc() using the pointer pointed to by \p mem.
+ * On success, the pointer is changed to the new location (in case the
+ *
+ * \note Re-allocating a block allocated by a different allocator is undefined.
+ *
+ * \par Error handling
+ * \c errno will be set, if the underlying realloc function does so.
+ *
+ * @param allocator the allocator
+ * @param mem pointer to the pointer to allocated block
+ * @param n the new size in bytes
+ * @return zero on success, non-zero on failure
+ */
+int cxReallocate(
+        CxAllocator const *allocator,
+        void **mem,
+        size_t n
+)
+__attribute__((__nonnull__));
+
+/**
+ * Allocate \p nelem elements of \p n bytes each, all initialized to zero.
+ *
+ * @param allocator the allocator
+ * @param nelem the number of elements
+ * @param n the size of each element in bytes
+ * @return a pointer to the allocated memory
+ */
+void *cxCalloc(
+        CxAllocator const *allocator,
+        size_t nelem,
+        size_t n
+)
+__attribute__((__malloc__))
+__attribute__((__alloc_size__(2, 3)));
+
+/**
+ * Free a block allocated by this allocator.
+ *
+ * \note Freeing a block of a different allocator is undefined.
+ *
+ * @param allocator the allocator
+ * @param mem a pointer to the block to free
+ */
+void cxFree(
+        CxAllocator const *allocator,
+        void *mem
+)
+__attribute__((__nonnull__));
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif // UCX_ALLOCATOR_H

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