| /** |
| * @file |
| * Dynamic memory manager |
| * |
| * This is a lightweight replacement for the standard C library malloc(). |
| * |
| * If you want to use the standard C library malloc() instead, define |
| * MEM_LIBC_MALLOC to 1 in your lwipopts.h |
| * |
| * To let mem_malloc() use pools (prevents fragmentation and is much faster than |
| * a heap but might waste some memory), define MEM_USE_POOLS to 1, define |
| * MEM_USE_CUSTOM_POOLS to 1 and create a file "lwippools.h" that includes a list |
| * of pools like this (more pools can be added between _START and _END): |
| * |
| * Define three pools with sizes 256, 512, and 1512 bytes |
| * LWIP_MALLOC_MEMPOOL_START |
| * LWIP_MALLOC_MEMPOOL(20, 256) |
| * LWIP_MALLOC_MEMPOOL(10, 512) |
| * LWIP_MALLOC_MEMPOOL(5, 1512) |
| * LWIP_MALLOC_MEMPOOL_END |
| */ |
| |
| /* |
| * Copyright (c) 2001-2004 Swedish Institute of Computer Science. |
| * 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. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. |
| * |
| * This file is part of the lwIP TCP/IP stack. |
| * |
| * Author: Adam Dunkels <adam@sics.se> |
| * Simon Goldschmidt |
| * |
| */ |
| |
| #include "lwip/opt.h" |
| |
| #if !MEM_LIBC_MALLOC /* don't build if not configured for use in lwipopts.h */ |
| |
| #include "lwip/def.h" |
| #include "lwip/mem.h" |
| #include "lwip/sys.h" |
| #include "lwip/stats.h" |
| #include "lwip/err.h" |
| |
| #include <string.h> |
| |
| #if MEM_USE_POOLS |
| /* lwIP head implemented with different sized pools */ |
| |
| /** |
| * Allocate memory: determine the smallest pool that is big enough |
| * to contain an element of 'size' and get an element from that pool. |
| * |
| * @param size the size in bytes of the memory needed |
| * @return a pointer to the allocated memory or NULL if the pool is empty |
| */ |
| void * |
| mem_malloc(mem_size_t size) |
| { |
| struct memp_malloc_helper *element; |
| memp_t poolnr; |
| mem_size_t required_size = size + sizeof(struct memp_malloc_helper); |
| |
| for (poolnr = MEMP_POOL_FIRST; poolnr <= MEMP_POOL_LAST; poolnr = (memp_t)(poolnr + 1)) { |
| #if MEM_USE_POOLS_TRY_BIGGER_POOL |
| again: |
| #endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */ |
| /* is this pool big enough to hold an element of the required size |
| plus a struct memp_malloc_helper that saves the pool this element came from? */ |
| if (required_size <= memp_sizes[poolnr]) { |
| break; |
| } |
| } |
| if (poolnr > MEMP_POOL_LAST) { |
| LWIP_ASSERT("mem_malloc(): no pool is that big!", 0); |
| return NULL; |
| } |
| element = (struct memp_malloc_helper*)memp_malloc(poolnr); |
| if (element == NULL) { |
| /* No need to DEBUGF or ASSERT: This error is already |
| taken care of in memp.c */ |
| #if MEM_USE_POOLS_TRY_BIGGER_POOL |
| /** Try a bigger pool if this one is empty! */ |
| if (poolnr < MEMP_POOL_LAST) { |
| poolnr++; |
| goto again; |
| } |
| #endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */ |
| return NULL; |
| } |
| |
| /* save the pool number this element came from */ |
| element->poolnr = poolnr; |
| /* and return a pointer to the memory directly after the struct memp_malloc_helper */ |
| element++; |
| |
| return element; |
| } |
| |
| /** |
| * Free memory previously allocated by mem_malloc. Loads the pool number |
| * and calls memp_free with that pool number to put the element back into |
| * its pool |
| * |
| * @param rmem the memory element to free |
| */ |
| void |
| mem_free(void *rmem) |
| { |
| struct memp_malloc_helper *hmem = (struct memp_malloc_helper*)rmem; |
| |
| LWIP_ASSERT("rmem != NULL", (rmem != NULL)); |
| LWIP_ASSERT("rmem == MEM_ALIGN(rmem)", (rmem == LWIP_MEM_ALIGN(rmem))); |
| |
| /* get the original struct memp_malloc_helper */ |
| hmem--; |
| |
| LWIP_ASSERT("hmem != NULL", (hmem != NULL)); |
| LWIP_ASSERT("hmem == MEM_ALIGN(hmem)", (hmem == LWIP_MEM_ALIGN(hmem))); |
| LWIP_ASSERT("hmem->poolnr < MEMP_MAX", (hmem->poolnr < MEMP_MAX)); |
| |
| /* and put it in the pool we saved earlier */ |
| memp_free(hmem->poolnr, hmem); |
| } |
| |
| #else /* MEM_USE_POOLS */ |
| /* lwIP replacement for your libc malloc() */ |
| |
| /** |
| * The heap is made up as a list of structs of this type. |
| * This does not have to be aligned since for getting its size, |
| * we only use the macro SIZEOF_STRUCT_MEM, which automatically alignes. |
| */ |
| struct mem { |
| /** index (-> ram[next]) of the next struct */ |
| mem_size_t next; |
| /** index (-> ram[prev]) of the previous struct */ |
| mem_size_t prev; |
| /** 1: this area is used; 0: this area is unused */ |
| u8_t used; |
| }; |
| |
| /** All allocated blocks will be MIN_SIZE bytes big, at least! |
| * MIN_SIZE can be overridden to suit your needs. Smaller values save space, |
| * larger values could prevent too small blocks to fragment the RAM too much. */ |
| #ifndef MIN_SIZE |
| #define MIN_SIZE 12 |
| #endif /* MIN_SIZE */ |
| /* some alignment macros: we define them here for better source code layout */ |
| #define MIN_SIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(MIN_SIZE) |
| #define SIZEOF_STRUCT_MEM LWIP_MEM_ALIGN_SIZE(sizeof(struct mem)) |
| #define MEM_SIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(MEM_SIZE) |
| |
| /** If you want to relocate the heap to external memory, simply define |
| * LWIP_RAM_HEAP_POINTER as a void-pointer to that location. |
| * If so, make sure the memory at that location is big enough (see below on |
| * how that space is calculated). */ |
| #ifndef LWIP_RAM_HEAP_POINTER |
| /** the heap. we need one struct mem at the end and some room for alignment */ |
| u8_t ram_heap[MEM_SIZE_ALIGNED + (2*SIZEOF_STRUCT_MEM) + MEM_ALIGNMENT]; |
| #define LWIP_RAM_HEAP_POINTER ram_heap |
| #endif /* LWIP_RAM_HEAP_POINTER */ |
| |
| /** pointer to the heap (ram_heap): for alignment, ram is now a pointer instead of an array */ |
| static u8_t *ram; |
| /** the last entry, always unused! */ |
| static struct mem *ram_end; |
| /** pointer to the lowest free block, this is used for faster search */ |
| static struct mem *lfree; |
| |
| /** concurrent access protection */ |
| static sys_mutex_t mem_mutex; |
| |
| #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT |
| |
| static volatile u8_t mem_free_count; |
| |
| /* Allow mem_free from other (e.g. interrupt) context */ |
| #define LWIP_MEM_FREE_DECL_PROTECT() SYS_ARCH_DECL_PROTECT(lev_free) |
| #define LWIP_MEM_FREE_PROTECT() SYS_ARCH_PROTECT(lev_free) |
| #define LWIP_MEM_FREE_UNPROTECT() SYS_ARCH_UNPROTECT(lev_free) |
| #define LWIP_MEM_ALLOC_DECL_PROTECT() SYS_ARCH_DECL_PROTECT(lev_alloc) |
| #define LWIP_MEM_ALLOC_PROTECT() SYS_ARCH_PROTECT(lev_alloc) |
| #define LWIP_MEM_ALLOC_UNPROTECT() SYS_ARCH_UNPROTECT(lev_alloc) |
| |
| #else /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */ |
| |
| /* Protect the heap only by using a semaphore */ |
| #define LWIP_MEM_FREE_DECL_PROTECT() |
| #define LWIP_MEM_FREE_PROTECT() sys_mutex_lock(&mem_mutex) |
| #define LWIP_MEM_FREE_UNPROTECT() sys_mutex_unlock(&mem_mutex) |
| /* mem_malloc is protected using semaphore AND LWIP_MEM_ALLOC_PROTECT */ |
| #define LWIP_MEM_ALLOC_DECL_PROTECT() |
| #define LWIP_MEM_ALLOC_PROTECT() |
| #define LWIP_MEM_ALLOC_UNPROTECT() |
| |
| #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */ |
| |
| |
| /** |
| * "Plug holes" by combining adjacent empty struct mems. |
| * After this function is through, there should not exist |
| * one empty struct mem pointing to another empty struct mem. |
| * |
| * @param mem this points to a struct mem which just has been freed |
| * @internal this function is only called by mem_free() and mem_trim() |
| * |
| * This assumes access to the heap is protected by the calling function |
| * already. |
| */ |
| static void |
| plug_holes(struct mem *mem) |
| { |
| struct mem *nmem; |
| struct mem *pmem; |
| |
| LWIP_ASSERT("plug_holes: mem >= ram", (u8_t *)mem >= ram); |
| LWIP_ASSERT("plug_holes: mem < ram_end", (u8_t *)mem < (u8_t *)ram_end); |
| LWIP_ASSERT("plug_holes: mem->used == 0", mem->used == 0); |
| |
| /* plug hole forward */ |
| LWIP_ASSERT("plug_holes: mem->next <= MEM_SIZE_ALIGNED", mem->next <= MEM_SIZE_ALIGNED); |
| |
| nmem = (struct mem *)(void *)&ram[mem->next]; |
| if (mem != nmem && nmem->used == 0 && (u8_t *)nmem != (u8_t *)ram_end) { |
| /* if mem->next is unused and not end of ram, combine mem and mem->next */ |
| if (lfree == nmem) { |
| lfree = mem; |
| } |
| mem->next = nmem->next; |
| ((struct mem *)(void *)&ram[nmem->next])->prev = (mem_size_t)((u8_t *)mem - ram); |
| } |
| |
| /* plug hole backward */ |
| pmem = (struct mem *)(void *)&ram[mem->prev]; |
| if (pmem != mem && pmem->used == 0) { |
| /* if mem->prev is unused, combine mem and mem->prev */ |
| if (lfree == mem) { |
| lfree = pmem; |
| } |
| pmem->next = mem->next; |
| ((struct mem *)(void *)&ram[mem->next])->prev = (mem_size_t)((u8_t *)pmem - ram); |
| } |
| } |
| |
| /** |
| * Zero the heap and initialize start, end and lowest-free |
| */ |
| void |
| mem_init(void) |
| { |
| struct mem *mem; |
| |
| LWIP_ASSERT("Sanity check alignment", |
| (SIZEOF_STRUCT_MEM & (MEM_ALIGNMENT-1)) == 0); |
| |
| /* align the heap */ |
| ram = (u8_t *)LWIP_MEM_ALIGN(LWIP_RAM_HEAP_POINTER); |
| /* initialize the start of the heap */ |
| mem = (struct mem *)(void *)ram; |
| mem->next = MEM_SIZE_ALIGNED; |
| mem->prev = 0; |
| mem->used = 0; |
| /* initialize the end of the heap */ |
| ram_end = (struct mem *)(void *)&ram[MEM_SIZE_ALIGNED]; |
| ram_end->used = 1; |
| ram_end->next = MEM_SIZE_ALIGNED; |
| ram_end->prev = MEM_SIZE_ALIGNED; |
| |
| /* initialize the lowest-free pointer to the start of the heap */ |
| lfree = (struct mem *)(void *)ram; |
| |
| MEM_STATS_AVAIL(avail, MEM_SIZE_ALIGNED); |
| |
| if(sys_mutex_new(&mem_mutex) != ERR_OK) { |
| LWIP_ASSERT("failed to create mem_mutex", 0); |
| } |
| } |
| |
| /** |
| * Put a struct mem back on the heap |
| * |
| * @param rmem is the data portion of a struct mem as returned by a previous |
| * call to mem_malloc() |
| */ |
| void |
| mem_free(void *rmem) |
| { |
| struct mem *mem; |
| LWIP_MEM_FREE_DECL_PROTECT(); |
| |
| if (rmem == NULL) { |
| LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("mem_free(p == NULL) was called.\n")); |
| return; |
| } |
| LWIP_ASSERT("mem_free: sanity check alignment", (((mem_ptr_t)rmem) & (MEM_ALIGNMENT-1)) == 0); |
| |
| LWIP_ASSERT("mem_free: legal memory", (u8_t *)rmem >= (u8_t *)ram && |
| (u8_t *)rmem < (u8_t *)ram_end); |
| |
| if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) { |
| SYS_ARCH_DECL_PROTECT(lev); |
| LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_free: illegal memory\n")); |
| /* protect mem stats from concurrent access */ |
| SYS_ARCH_PROTECT(lev); |
| MEM_STATS_INC(illegal); |
| SYS_ARCH_UNPROTECT(lev); |
| return; |
| } |
| /* protect the heap from concurrent access */ |
| LWIP_MEM_FREE_PROTECT(); |
| /* Get the corresponding struct mem ... */ |
| mem = (struct mem *)(void *)((u8_t *)rmem - SIZEOF_STRUCT_MEM); |
| /* ... which has to be in a used state ... */ |
| LWIP_ASSERT("mem_free: mem->used", mem->used); |
| /* ... and is now unused. */ |
| mem->used = 0; |
| |
| if (mem < lfree) { |
| /* the newly freed struct is now the lowest */ |
| lfree = mem; |
| } |
| |
| MEM_STATS_DEC_USED(used, mem->next - (mem_size_t)(((u8_t *)mem - ram))); |
| |
| /* finally, see if prev or next are free also */ |
| plug_holes(mem); |
| #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT |
| mem_free_count = 1; |
| #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */ |
| LWIP_MEM_FREE_UNPROTECT(); |
| } |
| |
| /** |
| * Shrink memory returned by mem_malloc(). |
| * |
| * @param rmem pointer to memory allocated by mem_malloc the is to be shrinked |
| * @param newsize required size after shrinking (needs to be smaller than or |
| * equal to the previous size) |
| * @return for compatibility reasons: is always == rmem, at the moment |
| * or NULL if newsize is > old size, in which case rmem is NOT touched |
| * or freed! |
| */ |
| void * |
| mem_trim(void *rmem, mem_size_t newsize) |
| { |
| mem_size_t size; |
| mem_size_t ptr, ptr2; |
| struct mem *mem, *mem2; |
| /* use the FREE_PROTECT here: it protects with sem OR SYS_ARCH_PROTECT */ |
| LWIP_MEM_FREE_DECL_PROTECT(); |
| |
| /* Expand the size of the allocated memory region so that we can |
| adjust for alignment. */ |
| newsize = LWIP_MEM_ALIGN_SIZE(newsize); |
| |
| if(newsize < MIN_SIZE_ALIGNED) { |
| /* every data block must be at least MIN_SIZE_ALIGNED long */ |
| newsize = MIN_SIZE_ALIGNED; |
| } |
| |
| if (newsize > MEM_SIZE_ALIGNED) { |
| return NULL; |
| } |
| |
| LWIP_ASSERT("mem_trim: legal memory", (u8_t *)rmem >= (u8_t *)ram && |
| (u8_t *)rmem < (u8_t *)ram_end); |
| |
| if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) { |
| SYS_ARCH_DECL_PROTECT(lev); |
| LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_trim: illegal memory\n")); |
| /* protect mem stats from concurrent access */ |
| SYS_ARCH_PROTECT(lev); |
| MEM_STATS_INC(illegal); |
| SYS_ARCH_UNPROTECT(lev); |
| return rmem; |
| } |
| /* Get the corresponding struct mem ... */ |
| mem = (struct mem *)(void *)((u8_t *)rmem - SIZEOF_STRUCT_MEM); |
| /* ... and its offset pointer */ |
| ptr = (mem_size_t)((u8_t *)mem - ram); |
| |
| size = mem->next - ptr - SIZEOF_STRUCT_MEM; |
| LWIP_ASSERT("mem_trim can only shrink memory", newsize <= size); |
| if (newsize > size) { |
| /* not supported */ |
| return NULL; |
| } |
| if (newsize == size) { |
| /* No change in size, simply return */ |
| return rmem; |
| } |
| |
| /* protect the heap from concurrent access */ |
| LWIP_MEM_FREE_PROTECT(); |
| |
| mem2 = (struct mem *)(void *)&ram[mem->next]; |
| if(mem2->used == 0) { |
| /* The next struct is unused, we can simply move it at little */ |
| mem_size_t next; |
| /* remember the old next pointer */ |
| next = mem2->next; |
| /* create new struct mem which is moved directly after the shrinked mem */ |
| ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize; |
| if (lfree == mem2) { |
| lfree = (struct mem *)(void *)&ram[ptr2]; |
| } |
| mem2 = (struct mem *)(void *)&ram[ptr2]; |
| mem2->used = 0; |
| /* restore the next pointer */ |
| mem2->next = next; |
| /* link it back to mem */ |
| mem2->prev = ptr; |
| /* link mem to it */ |
| mem->next = ptr2; |
| /* last thing to restore linked list: as we have moved mem2, |
| * let 'mem2->next->prev' point to mem2 again. but only if mem2->next is not |
| * the end of the heap */ |
| if (mem2->next != MEM_SIZE_ALIGNED) { |
| ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2; |
| } |
| MEM_STATS_DEC_USED(used, (size - newsize)); |
| /* no need to plug holes, we've already done that */ |
| } else if (newsize + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED <= size) { |
| /* Next struct is used but there's room for another struct mem with |
| * at least MIN_SIZE_ALIGNED of data. |
| * Old size ('size') must be big enough to contain at least 'newsize' plus a struct mem |
| * ('SIZEOF_STRUCT_MEM') with some data ('MIN_SIZE_ALIGNED'). |
| * @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty |
| * region that couldn't hold data, but when mem->next gets freed, |
| * the 2 regions would be combined, resulting in more free memory */ |
| ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize; |
| mem2 = (struct mem *)(void *)&ram[ptr2]; |
| if (mem2 < lfree) { |
| lfree = mem2; |
| } |
| mem2->used = 0; |
| mem2->next = mem->next; |
| mem2->prev = ptr; |
| mem->next = ptr2; |
| if (mem2->next != MEM_SIZE_ALIGNED) { |
| ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2; |
| } |
| MEM_STATS_DEC_USED(used, (size - newsize)); |
| /* the original mem->next is used, so no need to plug holes! */ |
| } |
| /* else { |
| next struct mem is used but size between mem and mem2 is not big enough |
| to create another struct mem |
| -> don't do anyhting. |
| -> the remaining space stays unused since it is too small |
| } */ |
| #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT |
| mem_free_count = 1; |
| #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */ |
| LWIP_MEM_FREE_UNPROTECT(); |
| return rmem; |
| } |
| |
| /** |
| * Adam's mem_malloc() plus solution for bug #17922 |
| * Allocate a block of memory with a minimum of 'size' bytes. |
| * |
| * @param size is the minimum size of the requested block in bytes. |
| * @return pointer to allocated memory or NULL if no free memory was found. |
| * |
| * Note that the returned value will always be aligned (as defined by MEM_ALIGNMENT). |
| */ |
| void * |
| mem_malloc(mem_size_t size) |
| { |
| mem_size_t ptr, ptr2; |
| struct mem *mem, *mem2; |
| #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT |
| u8_t local_mem_free_count = 0; |
| #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */ |
| LWIP_MEM_ALLOC_DECL_PROTECT(); |
| |
| if (size == 0) { |
| return NULL; |
| } |
| |
| /* Expand the size of the allocated memory region so that we can |
| adjust for alignment. */ |
| size = LWIP_MEM_ALIGN_SIZE(size); |
| |
| if(size < MIN_SIZE_ALIGNED) { |
| /* every data block must be at least MIN_SIZE_ALIGNED long */ |
| size = MIN_SIZE_ALIGNED; |
| } |
| |
| if (size > MEM_SIZE_ALIGNED) { |
| return NULL; |
| } |
| |
| /* protect the heap from concurrent access */ |
| sys_mutex_lock(&mem_mutex); |
| LWIP_MEM_ALLOC_PROTECT(); |
| #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT |
| /* run as long as a mem_free disturbed mem_malloc */ |
| do { |
| local_mem_free_count = 0; |
| #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */ |
| |
| /* Scan through the heap searching for a free block that is big enough, |
| * beginning with the lowest free block. |
| */ |
| for (ptr = (mem_size_t)((u8_t *)lfree - ram); ptr < MEM_SIZE_ALIGNED - size; |
| ptr = ((struct mem *)(void *)&ram[ptr])->next) { |
| mem = (struct mem *)(void *)&ram[ptr]; |
| #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT |
| mem_free_count = 0; |
| LWIP_MEM_ALLOC_UNPROTECT(); |
| /* allow mem_free to run */ |
| LWIP_MEM_ALLOC_PROTECT(); |
| if (mem_free_count != 0) { |
| local_mem_free_count = mem_free_count; |
| } |
| mem_free_count = 0; |
| #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */ |
| |
| if ((!mem->used) && |
| (mem->next - (ptr + SIZEOF_STRUCT_MEM)) >= size) { |
| /* mem is not used and at least perfect fit is possible: |
| * mem->next - (ptr + SIZEOF_STRUCT_MEM) gives us the 'user data size' of mem */ |
| |
| if (mem->next - (ptr + SIZEOF_STRUCT_MEM) >= (size + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED)) { |
| /* (in addition to the above, we test if another struct mem (SIZEOF_STRUCT_MEM) containing |
| * at least MIN_SIZE_ALIGNED of data also fits in the 'user data space' of 'mem') |
| * -> split large block, create empty remainder, |
| * remainder must be large enough to contain MIN_SIZE_ALIGNED data: if |
| * mem->next - (ptr + (2*SIZEOF_STRUCT_MEM)) == size, |
| * struct mem would fit in but no data between mem2 and mem2->next |
| * @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty |
| * region that couldn't hold data, but when mem->next gets freed, |
| * the 2 regions would be combined, resulting in more free memory |
| */ |
| ptr2 = ptr + SIZEOF_STRUCT_MEM + size; |
| /* create mem2 struct */ |
| mem2 = (struct mem *)(void *)&ram[ptr2]; |
| mem2->used = 0; |
| mem2->next = mem->next; |
| mem2->prev = ptr; |
| /* and insert it between mem and mem->next */ |
| mem->next = ptr2; |
| mem->used = 1; |
| |
| if (mem2->next != MEM_SIZE_ALIGNED) { |
| ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2; |
| } |
| MEM_STATS_INC_USED(used, (size + SIZEOF_STRUCT_MEM)); |
| } else { |
| /* (a mem2 struct does no fit into the user data space of mem and mem->next will always |
| * be used at this point: if not we have 2 unused structs in a row, plug_holes should have |
| * take care of this). |
| * -> near fit or excact fit: do not split, no mem2 creation |
| * also can't move mem->next directly behind mem, since mem->next |
| * will always be used at this point! |
| */ |
| mem->used = 1; |
| MEM_STATS_INC_USED(used, mem->next - (mem_size_t)((u8_t *)mem - ram)); |
| } |
| |
| if (mem == lfree) { |
| /* Find next free block after mem and update lowest free pointer */ |
| while (lfree->used && lfree != ram_end) { |
| LWIP_MEM_ALLOC_UNPROTECT(); |
| /* prevent high interrupt latency... */ |
| LWIP_MEM_ALLOC_PROTECT(); |
| lfree = (struct mem *)(void *)&ram[lfree->next]; |
| } |
| LWIP_ASSERT("mem_malloc: !lfree->used", ((lfree == ram_end) || (!lfree->used))); |
| } |
| LWIP_MEM_ALLOC_UNPROTECT(); |
| sys_mutex_unlock(&mem_mutex); |
| LWIP_ASSERT("mem_malloc: allocated memory not above ram_end.", |
| (mem_ptr_t)mem + SIZEOF_STRUCT_MEM + size <= (mem_ptr_t)ram_end); |
| LWIP_ASSERT("mem_malloc: allocated memory properly aligned.", |
| ((mem_ptr_t)mem + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT == 0); |
| LWIP_ASSERT("mem_malloc: sanity check alignment", |
| (((mem_ptr_t)mem) & (MEM_ALIGNMENT-1)) == 0); |
| |
| return (u8_t *)mem + SIZEOF_STRUCT_MEM; |
| } |
| } |
| #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT |
| /* if we got interrupted by a mem_free, try again */ |
| } while(local_mem_free_count != 0); |
| #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */ |
| LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("mem_malloc: could not allocate %"S16_F" bytes\n", (s16_t)size)); |
| MEM_STATS_INC(err); |
| LWIP_MEM_ALLOC_UNPROTECT(); |
| sys_mutex_unlock(&mem_mutex); |
| return NULL; |
| } |
| |
| #endif /* MEM_USE_POOLS */ |
| /** |
| * Contiguously allocates enough space for count objects that are size bytes |
| * of memory each and returns a pointer to the allocated memory. |
| * |
| * The allocated memory is filled with bytes of value zero. |
| * |
| * @param count number of objects to allocate |
| * @param size size of the objects to allocate |
| * @return pointer to allocated memory / NULL pointer if there is an error |
| */ |
| void *mem_calloc(mem_size_t count, mem_size_t size) |
| { |
| void *p; |
| |
| /* allocate 'count' objects of size 'size' */ |
| p = mem_malloc(count * size); |
| if (p) { |
| /* zero the memory */ |
| memset(p, 0, count * size); |
| } |
| return p; |
| } |
| |
| #endif /* !MEM_LIBC_MALLOC */ |