--- /dev/null
+/*\r
+ LUFA Library\r
+ Copyright (C) Dean Camera, 2009.\r
+ \r
+ dean [at] fourwalledcubicle [dot] com\r
+ www.fourwalledcubicle.com\r
+*/\r
+\r
+/*\r
+ Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com)\r
+\r
+ Permission to use, copy, modify, and distribute this software\r
+ and its documentation for any purpose and without fee is hereby\r
+ granted, provided that the above copyright notice appear in all\r
+ copies and that both that the copyright notice and this\r
+ permission notice and warranty disclaimer appear in supporting\r
+ documentation, and that the name of the author not be used in\r
+ advertising or publicity pertaining to distribution of the\r
+ software without specific, written prior permission.\r
+\r
+ The author disclaim all warranties with regard to this\r
+ software, including all implied warranties of merchantability\r
+ and fitness. In no event shall the author be liable for any\r
+ special, indirect or consequential damages or any damages\r
+ whatsoever resulting from loss of use, data or profits, whether\r
+ in an action of contract, negligence or other tortious action,\r
+ arising out of or in connection with the use or performance of\r
+ this software.\r
+*/\r
+\r
+/** \file\r
+ *\r
+ * Dynamic, auto-defragmenting block memory allocator library. This library provides a convenient replacement for\r
+ * the standard avr-libc dynamic memory allocation routines. Memory is handed out in block chunks, to reduce the\r
+ * management memory overhead.\r
+ *\r
+ * Unlike the normal memory allocation routines, this library gives out handles to memory which must be dereferenced\r
+ * at the exact time of use, rather than handing back direct memory pointers. By using library managed handles\r
+ * instead of pointers, allocated memory blocks can be shifted around as needed transparently to defragment the\r
+ * memory as more blocks are requested.\r
+ *\r
+ * The memory heap is static, thus the total memory usage of the compiled application (as reported by the avr-size\r
+ * tool of the AVR-GCC toolchain) includes the dynamic memory heap.\r
+ *\r
+ * The constants NUM_BLOCKS, BLOCK_SIZE and NUM_HANDLES must be defined in the project makefile (and passed to the\r
+ * preprocessor via the -D GCC switch) for this library to compile.\r
+ *\r
+ * NUM_BLOCKS indicates the number of memory blocks in the memory psudoheap which can be chaned together and handed\r
+ * to the application via a memory handle. NUM_HANDLES is the maximum number of memory handles (pointing to one or\r
+ * more chained memory blocks) which can be handed out simultaneously before requring a handle (and its associated\r
+ * memory) to be freed. BLOCK_SIZE gives the number of bytes in each memory block.\r
+ */\r
+\r
+#ifndef __DYN_ALLOC__\r
+#define __DYN_ALLOC__\r
+\r
+ /* Includes : */\r
+ #include <avr/io.h>\r
+ #include <stdbool.h>\r
+ #include <string.h>\r
+ \r
+ /* Preprocessor Checks: */\r
+ #if (!defined(NUM_BLOCKS) || !defined(BLOCK_SIZE) || !defined(NUM_HANDLES))\r
+ #error NUM_BLOCKS, BLOCK_SIZE and NUM_HANDLES must be defined before use via makefile.\r
+ #endif\r
+\r
+ /* Public Interface - May be used in end-application: */\r
+ /* Macros: */\r
+ /** Macro to dereference a given memory handle into the given type. The given type should be a pointer\r
+ * if the memory is to contain an array of items, or should be a standard type (such as a primative or\r
+ * structure) if the memory is to hold a single item of a single type. */\r
+ #define DEREF(handle, type) (*(type*)handle)\r
+ \r
+ /** Constant, giving the total heap size in bytes. */\r
+ #define ALLOCABLE_BYTES (1UL * NUM_BLOCKS * BLOCK_SIZE)\r
+ \r
+ /* Type Defines: */\r
+ /** Memory handle type, used to store handles given by the library functions. */\r
+ typedef const void** Mem_Handle_t;\r
+ \r
+ #if (ALLOCABLE_BYTES > 0xFFFF) || defined(__DOXYGEN__)\r
+ /** Type define for the size (in bytes) for an allocation for passing to the library functions.\r
+ * The exact type width varies depending on the value of ALLOCABLE_BYTES to ensure that a single\r
+ * allocation can request the entire heap if needed.\r
+ */\r
+ typedef uint32_t Alloc_Size_t;\r
+ #elif (ALLOCABLE_BYTES > 0xFF)\r
+ typedef uint16_t Alloc_Size_t;\r
+ #else \r
+ typedef uint8_t Alloc_Size_t;\r
+ #endif\r
+\r
+ #if (NUM_BLOCKS > 0xFFFF) || defined(__DOXYGEN__)\r
+ /** Type define for a block number in the heap. The exact type width varies depending on the\r
+ * value of NUM_BLOCKS to ensure that the type can store an index to any block in the block pool.\r
+ */\r
+ typedef uint32_t Block_Number_t;\r
+ #elif (NUM_BLOCKS > 0xFF)\r
+ typedef uint16_t Block_Number_t;\r
+ #else\r
+ typedef uint8_t Block_Number_t;\r
+ #endif\r
+\r
+ #if (NUM_HANDLES > 0xFFFF) || defined(__DOXYGEN__)\r
+ /** Type define for a handle number. The exact type width varies depending on the value of NUM_HANDLES\r
+ * to ensure that the type can store the index of any handle in the handle pool.\r
+ */\r
+ typedef uint32_t Handle_Number_t;\r
+ #elif (NUM_HANDLES > 0xFF)\r
+ typedef uint16_t Handle_Number_t;\r
+ #else \r
+ typedef uint8_t Handle_Number_t;\r
+ #endif\r
+ \r
+ /* Function Prototypes: */\r
+ /** Allocates a given number of blocks from the heap (calculated from the requested number of bytes) and\r
+ * returns a handle to the newly allocated memory.\r
+ *\r
+ * \param Bytes The number of bytes requested to be allocated from the heap\r
+ *\r
+ * \return NULL handle if the allocation fails, or handle to the allocated memory if the allocation succeeds\r
+ */\r
+ Mem_Handle_t Mem_Alloc(const Alloc_Size_t Bytes);\r
+ \r
+ /** Allocates a given number of blocks from the heap (calculated from the requested number of bytes) and\r
+ * returns a handle to the newly allocated memory. Calloced memory is automatically cleared to all 0x00\r
+ * values at the time of allocation.\r
+ *\r
+ * \param Bytes The number of pre-cleared bytes requested to be allocated from the heap\r
+ *\r
+ * \return NULL handle if the allocation fails, or handle to the allocated memory if the allocation succeeds\r
+ */\r
+ Mem_Handle_t Mem_Calloc(const Alloc_Size_t Bytes);\r
+\r
+ /** Deallocates a given memory handle, and attempts to allocates the given number of blocks from the heap\r
+ * (calculated from the requested number of bytes) immediately following the deallocation. The new memory\r
+ * may be located in the same area as the previous memory, but this is not guaranteed.\r
+ *\r
+ * \param CurrAllocHdl Handle to an already allocated section of memory in the heap to deallocate\r
+ * \param Bytes The number of bytes requested to be allocated from the heap following the\r
+ * deallocation\r
+ *\r
+ * \return NULL handle if the allocation fails, or handle to the allocated memory if the allocation succeeds\r
+ *\r
+ * \warning Even if the allocation fails, the deallocation will still occur. Care should be taken to ensure\r
+ * that the previously allocated memory is not used following an unsuccessful realloc().\r
+ */\r
+ Mem_Handle_t Mem_Realloc(Mem_Handle_t CurrAllocHdl, const Alloc_Size_t Bytes);\r
+ \r
+ /** Deallocates a given previously allocated section of memory from the heap.\r
+ *\r
+ * \param CurrAllocHdl Handle to a previously allocated section of memory in the heap\r
+ */\r
+ void Mem_Free(Mem_Handle_t CurrAllocHdl);\r
+ \r
+ /** Returns the total number of unallocated blocks in the heap.\r
+ *\r
+ * \return Number of free blocks in the heap, as a Block_Number_t integer\r
+ */\r
+ Block_Number_t Mem_TotalFreeBlocks(void);\r
+\r
+ /** Returns the total number of unallocated handles in the handle pool.\r
+ *\r
+ * \return Number of free handles in the handle pool, as a Handle_Number_t integer\r
+ */\r
+ Handle_Number_t Mem_TotalFreeHandles(void);\r
+ \r
+ /* Private Interface - For use in library only: */\r
+ #if !defined(__DOXYGEN__)\r
+ /* Macros: */\r
+ #define BLOCK_USED_MASK (1 << 0)\r
+ #define BLOCK_LINKED_MASK (1 << 1)\r
+ \r
+ /* Function Prototypes: */\r
+ #if defined(INCLUDE_FROM_DYNALLOC_C)\r
+ static uint8_t Mem_GetBlockFlags(const Block_Number_t BlockNum);\r
+ static void Mem_SetBlockFlags(const Block_Number_t BlockNum, const uint8_t Flags);\r
+ static void Mem_Defrag(void);\r
+ #endif\r
+ #endif\r
+ \r
+#endif\r
projects / pub / lufa.git / blobdiff