/** * 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) { void *ret; struct memp_malloc_helper *element; memp_t poolnr; mem_size_t required_size = size + LWIP_MEM_ALIGN_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_pools[poolnr]->size) { break; } } if (poolnr > MEMP_POOL_LAST) { LWIP_ASSERT("mem_malloc(): no pool is that big!", 0); MEM_STATS_INC(err); 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 */ MEM_STATS_INC(err); 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 */ ret = (u8_t*)element + LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper)); #if MEMP_OVERFLOW_CHECK || (LWIP_STATS && MEM_STATS) /* truncating to u16_t is safe because struct memp_desc::size is u16_t */ element->size = (u16_t)size; MEM_STATS_INC_USED(used, element->size); #endif /* MEMP_OVERFLOW_CHECK || (LWIP_STATS && MEM_STATS) */ #if MEMP_OVERFLOW_CHECK /* initialize unused memory (diff between requested size and selected pool's size) */ memset((u8_t*)ret + size, 0xcd, memp_pools[poolnr]->size - size); #endif /* MEMP_OVERFLOW_CHECK */ return ret; }
void mem_free(void *rmem) { struct mem *mem; //printf("mem_free %p\n", rmem); 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(); }
/** * 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 must always be aligned (as defined by MEM_ALIGNMENT). */ void * mem_malloc(mem_size_t size) { void* ret = mem_clib_malloc(size + MEM_LIBC_STATSHELPER_SIZE); if (ret == NULL) { MEM_STATS_INC(err); } else { LWIP_ASSERT("malloc() must return aligned memory", LWIP_MEM_ALIGN(ret) == ret); #if LWIP_STATS && MEM_STATS *(mem_size_t*)ret = size; ret = (u8_t*)ret + MEM_LIBC_STATSHELPER_SIZE; MEM_STATS_INC_USED(used, size); #endif } return ret; }
/** * 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 or mem_trim */ 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 or mem_trim to run */ LWIP_MEM_ALLOC_PROTECT(); if (mem_free_count != 0) { /* If mem_free or mem_trim have run, we have to restart since they could have altered our current struct mem. */ local_mem_free_count = 1; break; } #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 LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT mem_malloc_adjust_lfree: #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */ if (mem == lfree) { struct mem *cur = lfree; /* Find next free block after mem and update lowest free pointer */ while (cur->used && cur != ram_end) { #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT mem_free_count = 0; LWIP_MEM_ALLOC_UNPROTECT(); /* prevent high interrupt latency... */ LWIP_MEM_ALLOC_PROTECT(); if (mem_free_count != 0) { /* If mem_free or mem_trim have run, we have to restart since they could have altered our current struct mem or lfree. */ goto mem_malloc_adjust_lfree; } #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */ cur = (struct mem *)(void *)&ram[cur->next]; } lfree = cur; 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; }
/** * 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; }