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lwip/core/mem.c
- Committer:
- segundo
- Date:
- 2010-11-09
- Revision:
- 0:ac1725ba162c
File content as of revision 0:ac1725ba162c:
#pragma diag_remark 177 /** * @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] MEM_POSITION; #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 */