/* * Copyright (c) 2006-2021, RT-Thread Development Team * * SPDX-License-Identifier: Apache-2.0 * * Change Logs: * Date Author Notes * 2012-04-10 Bernard first implementation * 2012-10-16 Bernard add the mutex lock for heap object. * 2012-12-29 Bernard memheap can be used as system heap. * change mutex lock to semaphore lock. * 2013-04-10 Bernard add rt_lwp_memheap_realloc function. * 2013-05-24 Bernard fix the rt_lwp_memheap_realloc issue. * 2013-07-11 Grissiom fix the memory block splitting issue. * 2013-07-15 Grissiom optimize rt_lwp_memheap_realloc */ #include #include #include /* dynamic pool magic and mask */ #define RT_MEMHEAP_MAGIC 0x1ea01ea0 #define RT_MEMHEAP_MASK 0xfffffffe #define RT_MEMHEAP_USED 0x01 #define RT_MEMHEAP_FREED 0x00 #define RT_MEMHEAP_IS_USED(i) ((i)->magic & RT_MEMHEAP_USED) #define RT_MEMHEAP_MINIALLOC 12 #define RT_MEMHEAP_SIZE RT_ALIGN(sizeof(struct rt_lwp_memheap_item), RT_ALIGN_SIZE) #define MEMITEM_SIZE(item) ((rt_uint32_t)item->next - (rt_uint32_t)item - RT_MEMHEAP_SIZE) /* * The initialized memory pool will be: * +-----------------------------------+--------------------------+ * | whole freed memory block | Used Memory Block Tailer | * +-----------------------------------+--------------------------+ * * block_list --> whole freed memory block * * The length of Used Memory Block Tailer is 0, * which is prevents block merging across list */ rt_err_t rt_lwp_memheap_init(struct rt_lwp_memheap *memheap, const char *name, void *start_addr, rt_uint32_t size) { struct rt_lwp_memheap_item *item; RT_ASSERT(memheap != RT_NULL); /* initialize pool object */ memheap->start_addr = start_addr; memheap->pool_size = RT_ALIGN_DOWN(size, RT_ALIGN_SIZE); memheap->available_size = memheap->pool_size - (2 * RT_MEMHEAP_SIZE); memheap->max_used_size = memheap->pool_size - memheap->available_size; /* initialize the free list header */ item = &(memheap->free_header); item->magic = RT_MEMHEAP_MAGIC; item->pool_ptr = memheap; item->next = RT_NULL; item->prev = RT_NULL; item->next_free = item; item->prev_free = item; /* set the free list to free list header */ memheap->free_list = item; /* initialize the first big memory block */ item = (struct rt_lwp_memheap_item *)start_addr; item->magic = RT_MEMHEAP_MAGIC; item->pool_ptr = memheap; item->next = RT_NULL; item->prev = RT_NULL; item->next_free = item; item->prev_free = item; item->next = (struct rt_lwp_memheap_item *) ((rt_uint8_t *)item + memheap->available_size + RT_MEMHEAP_SIZE); item->prev = item->next; /* block list header */ memheap->block_list = item; /* place the big memory block to free list */ item->next_free = memheap->free_list->next_free; item->prev_free = memheap->free_list; memheap->free_list->next_free->prev_free = item; memheap->free_list->next_free = item; /* move to the end of memory pool to build a small tailer block, * which prevents block merging */ item = item->next; /* it's a used memory block */ item->magic = RT_MEMHEAP_MAGIC | RT_MEMHEAP_USED; item->pool_ptr = memheap; item->next = (struct rt_lwp_memheap_item *)start_addr; item->prev = (struct rt_lwp_memheap_item *)start_addr; /* not in free list */ item->next_free = item->prev_free = RT_NULL; /* initialize semaphore lock */ rt_sem_init(&(memheap->lock), name, 1, RT_IPC_FLAG_FIFO); RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("memory heap: start addr 0x%08x, size %d, free list header 0x%08x\n", start_addr, size, &(memheap->free_header))); return RT_EOK; } void *rt_lwp_memheap_alloc(struct rt_lwp_memheap *heap, rt_uint32_t size) { rt_err_t result; rt_uint32_t free_size; struct rt_lwp_memheap_item *header_ptr; RT_ASSERT(heap != RT_NULL); /* align allocated size */ size = RT_ALIGN(size, RT_ALIGN_SIZE); if (size < RT_MEMHEAP_MINIALLOC) size = RT_MEMHEAP_MINIALLOC; RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("allocate %d on heap:%8.*s", size, RT_NAME_MAX, heap->parent.name)); if (size < heap->available_size) { /* search on free list */ free_size = 0; /* lock memheap */ result = rt_sem_take(&(heap->lock), RT_WAITING_FOREVER); if (result != RT_EOK) { rt_set_errno(result); return RT_NULL; } /* get the first free memory block */ header_ptr = heap->free_list->next_free; while (header_ptr != heap->free_list && free_size < size) { /* get current freed memory block size */ free_size = MEMITEM_SIZE(header_ptr); if (free_size < size) { /* move to next free memory block */ header_ptr = header_ptr->next_free; } } /* determine if the memory is available. */ if (free_size >= size) { /* a block that satisfies the request has been found. */ /* determine if the block needs to be split. */ if (free_size >= (size + RT_MEMHEAP_SIZE + RT_MEMHEAP_MINIALLOC)) { struct rt_lwp_memheap_item *new_ptr; /* split the block. */ new_ptr = (struct rt_lwp_memheap_item *) (((rt_uint8_t *)header_ptr) + size + RT_MEMHEAP_SIZE); RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("split: block[0x%08x] nextm[0x%08x] prevm[0x%08x] to new[0x%08x]\n", header_ptr, header_ptr->next, header_ptr->prev, new_ptr)); /* mark the new block as a memory block and freed. */ new_ptr->magic = RT_MEMHEAP_MAGIC; /* put the pool pointer into the new block. */ new_ptr->pool_ptr = heap; /* break down the block list */ new_ptr->prev = header_ptr; new_ptr->next = header_ptr->next; header_ptr->next->prev = new_ptr; header_ptr->next = new_ptr; /* remove header ptr from free list */ header_ptr->next_free->prev_free = header_ptr->prev_free; header_ptr->prev_free->next_free = header_ptr->next_free; header_ptr->next_free = RT_NULL; header_ptr->prev_free = RT_NULL; /* insert new_ptr to free list */ new_ptr->next_free = heap->free_list->next_free; new_ptr->prev_free = heap->free_list; heap->free_list->next_free->prev_free = new_ptr; heap->free_list->next_free = new_ptr; RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("new ptr: next_free 0x%08x, prev_free 0x%08x\n", new_ptr->next_free, new_ptr->prev_free)); /* decrement the available byte count. */ heap->available_size = heap->available_size - size - RT_MEMHEAP_SIZE; if (heap->pool_size - heap->available_size > heap->max_used_size) heap->max_used_size = heap->pool_size - heap->available_size; } else { /* decrement the entire free size from the available bytes count. */ heap->available_size = heap->available_size - free_size; if (heap->pool_size - heap->available_size > heap->max_used_size) heap->max_used_size = heap->pool_size - heap->available_size; /* remove header_ptr from free list */ RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("one block: block[0x%08x], next_free 0x%08x, prev_free 0x%08x\n", header_ptr, header_ptr->next_free, header_ptr->prev_free)); header_ptr->next_free->prev_free = header_ptr->prev_free; header_ptr->prev_free->next_free = header_ptr->next_free; header_ptr->next_free = RT_NULL; header_ptr->prev_free = RT_NULL; } /* Mark the allocated block as not available. */ header_ptr->magic |= RT_MEMHEAP_USED; /* release lock */ rt_sem_release(&(heap->lock)); /* Return a memory address to the caller. */ RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("alloc mem: memory[0x%08x], heap[0x%08x], size: %d\n", (void *)((rt_uint8_t *)header_ptr + RT_MEMHEAP_SIZE), header_ptr, size)); return (void *)((rt_uint8_t *)header_ptr + RT_MEMHEAP_SIZE); } /* release lock */ rt_sem_release(&(heap->lock)); } RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("allocate memory: failed\n")); /* Return the completion status. */ return RT_NULL; } void *rt_lwp_memheap_realloc(struct rt_lwp_memheap *heap, void *ptr, rt_size_t newsize) { rt_err_t result; rt_size_t oldsize; struct rt_lwp_memheap_item *header_ptr; struct rt_lwp_memheap_item *new_ptr; if (newsize == 0) { rt_lwp_memheap_free(ptr); return RT_NULL; } /* align allocated size */ newsize = RT_ALIGN(newsize, RT_ALIGN_SIZE); if (newsize < RT_MEMHEAP_MINIALLOC) newsize = RT_MEMHEAP_MINIALLOC; if (ptr == RT_NULL) { return rt_lwp_memheap_alloc(heap, newsize); } /* get memory block header and get the size of memory block */ header_ptr = (struct rt_lwp_memheap_item *) ((rt_uint8_t *)ptr - RT_MEMHEAP_SIZE); oldsize = MEMITEM_SIZE(header_ptr); /* re-allocate memory */ if (newsize > oldsize) { void *new_ptr; struct rt_lwp_memheap_item *next_ptr; /* lock memheap */ result = rt_sem_take(&(heap->lock), RT_WAITING_FOREVER); if (result != RT_EOK) { rt_set_errno(result); return RT_NULL; } next_ptr = header_ptr->next; /* header_ptr should not be the tail */ RT_ASSERT(next_ptr > header_ptr); /* check whether the following free space is enough to expand */ if (!RT_MEMHEAP_IS_USED(next_ptr)) { rt_int32_t nextsize; nextsize = MEMITEM_SIZE(next_ptr); RT_ASSERT(next_ptr > 0); /* Here is the ASCII art of the situation that we can make use of * the next free node without alloc/memcpy, |*| is the control * block: * * oldsize free node * |*|-----------|*|----------------------|*| * newsize >= minialloc * |*|----------------|*|-----------------|*| */ if (nextsize + oldsize > newsize + RT_MEMHEAP_MINIALLOC) { /* decrement the entire free size from the available bytes count. */ heap->available_size = heap->available_size - (newsize - oldsize); if (heap->pool_size - heap->available_size > heap->max_used_size) heap->max_used_size = heap->pool_size - heap->available_size; /* remove next_ptr from free list */ RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("remove block: block[0x%08x], next_free 0x%08x, prev_free 0x%08x", next_ptr, next_ptr->next_free, next_ptr->prev_free)); next_ptr->next_free->prev_free = next_ptr->prev_free; next_ptr->prev_free->next_free = next_ptr->next_free; next_ptr->next->prev = next_ptr->prev; next_ptr->prev->next = next_ptr->next; /* build a new one on the right place */ next_ptr = (struct rt_lwp_memheap_item *)((char *)ptr + newsize); RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("new free block: block[0x%08x] nextm[0x%08x] prevm[0x%08x]", next_ptr, next_ptr->next, next_ptr->prev)); /* mark the new block as a memory block and freed. */ next_ptr->magic = RT_MEMHEAP_MAGIC; /* put the pool pointer into the new block. */ next_ptr->pool_ptr = heap; next_ptr->prev = header_ptr; next_ptr->next = header_ptr->next; header_ptr->next->prev = next_ptr; header_ptr->next = next_ptr; /* insert next_ptr to free list */ next_ptr->next_free = heap->free_list->next_free; next_ptr->prev_free = heap->free_list; heap->free_list->next_free->prev_free = next_ptr; heap->free_list->next_free = next_ptr; RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("new ptr: next_free 0x%08x, prev_free 0x%08x", next_ptr->next_free, next_ptr->prev_free)); /* release lock */ rt_sem_release(&(heap->lock)); return ptr; } } /* release lock */ rt_sem_release(&(heap->lock)); /* re-allocate a memory block */ new_ptr = (void *)rt_lwp_memheap_alloc(heap, newsize); if (new_ptr != RT_NULL) { rt_memcpy(new_ptr, ptr, oldsize < newsize ? oldsize : newsize); rt_lwp_memheap_free(ptr); } return new_ptr; } /* don't split when there is less than one node space left */ if (newsize + RT_MEMHEAP_SIZE + RT_MEMHEAP_MINIALLOC >= oldsize) return ptr; /* lock memheap */ result = rt_sem_take(&(heap->lock), RT_WAITING_FOREVER); if (result != RT_EOK) { rt_set_errno(result); return RT_NULL; } /* split the block. */ new_ptr = (struct rt_lwp_memheap_item *) (((rt_uint8_t *)header_ptr) + newsize + RT_MEMHEAP_SIZE); RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("split: block[0x%08x] nextm[0x%08x] prevm[0x%08x] to new[0x%08x]\n", header_ptr, header_ptr->next, header_ptr->prev, new_ptr)); /* mark the new block as a memory block and freed. */ new_ptr->magic = RT_MEMHEAP_MAGIC; /* put the pool pointer into the new block. */ new_ptr->pool_ptr = heap; /* break down the block list */ new_ptr->prev = header_ptr; new_ptr->next = header_ptr->next; header_ptr->next->prev = new_ptr; header_ptr->next = new_ptr; /* determine if the block can be merged with the next neighbor. */ if (!RT_MEMHEAP_IS_USED(new_ptr->next)) { struct rt_lwp_memheap_item *free_ptr; /* merge block with next neighbor. */ free_ptr = new_ptr->next; heap->available_size = heap->available_size - MEMITEM_SIZE(free_ptr); RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("merge: right node 0x%08x, next_free 0x%08x, prev_free 0x%08x\n", header_ptr, header_ptr->next_free, header_ptr->prev_free)); free_ptr->next->prev = new_ptr; new_ptr->next = free_ptr->next; /* remove free ptr from free list */ free_ptr->next_free->prev_free = free_ptr->prev_free; free_ptr->prev_free->next_free = free_ptr->next_free; } /* insert the split block to free list */ new_ptr->next_free = heap->free_list->next_free; new_ptr->prev_free = heap->free_list; heap->free_list->next_free->prev_free = new_ptr; heap->free_list->next_free = new_ptr; RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("new free ptr: next_free 0x%08x, prev_free 0x%08x\n", new_ptr->next_free, new_ptr->prev_free)); /* increment the available byte count. */ heap->available_size = heap->available_size + MEMITEM_SIZE(new_ptr); /* release lock */ rt_sem_release(&(heap->lock)); /* return the old memory block */ return ptr; } void rt_lwp_memheap_free(void *ptr) { rt_err_t result; struct rt_lwp_memheap *heap; struct rt_lwp_memheap_item *header_ptr, *new_ptr; rt_uint32_t insert_header; /* NULL check */ if (ptr == RT_NULL) return; /* set initial status as OK */ insert_header = 1; new_ptr = RT_NULL; header_ptr = (struct rt_lwp_memheap_item *) ((rt_uint8_t *)ptr - RT_MEMHEAP_SIZE); RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("free memory: memory[0x%08x], block[0x%08x]\n", ptr, header_ptr)); /* check magic */ RT_ASSERT((header_ptr->magic & RT_MEMHEAP_MASK) == RT_MEMHEAP_MAGIC); RT_ASSERT(header_ptr->magic & RT_MEMHEAP_USED); /* check whether this block of memory has been over-written. */ RT_ASSERT((header_ptr->next->magic & RT_MEMHEAP_MASK) == RT_MEMHEAP_MAGIC); /* get pool ptr */ heap = header_ptr->pool_ptr; /* lock memheap */ result = rt_sem_take(&(heap->lock), RT_WAITING_FOREVER); if (result != RT_EOK) { rt_set_errno(result); return ; } /* Mark the memory as available. */ header_ptr->magic &= ~RT_MEMHEAP_USED; /* Adjust the available number of bytes. */ heap->available_size = heap->available_size + MEMITEM_SIZE(header_ptr); /* Determine if the block can be merged with the previous neighbor. */ if (!RT_MEMHEAP_IS_USED(header_ptr->prev)) { RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("merge: left node 0x%08x\n", header_ptr->prev)); /* adjust the available number of bytes. */ heap->available_size = heap->available_size + RT_MEMHEAP_SIZE; /* yes, merge block with previous neighbor. */ (header_ptr->prev)->next = header_ptr->next; (header_ptr->next)->prev = header_ptr->prev; /* move header pointer to previous. */ header_ptr = header_ptr->prev; /* don't insert header to free list */ insert_header = 0; } /* determine if the block can be merged with the next neighbor. */ if (!RT_MEMHEAP_IS_USED(header_ptr->next)) { /* adjust the available number of bytes. */ heap->available_size = heap->available_size + RT_MEMHEAP_SIZE; /* merge block with next neighbor. */ new_ptr = header_ptr->next; RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("merge: right node 0x%08x, next_free 0x%08x, prev_free 0x%08x\n", new_ptr, new_ptr->next_free, new_ptr->prev_free)); new_ptr->next->prev = header_ptr; header_ptr->next = new_ptr->next; /* remove new ptr from free list */ new_ptr->next_free->prev_free = new_ptr->prev_free; new_ptr->prev_free->next_free = new_ptr->next_free; } if (insert_header) { /* no left merge, insert to free list */ header_ptr->next_free = heap->free_list->next_free; header_ptr->prev_free = heap->free_list; heap->free_list->next_free->prev_free = header_ptr; heap->free_list->next_free = header_ptr; RT_DEBUG_LOG(RT_DEBUG_MEMHEAP, ("insert to free list: next_free 0x%08x, prev_free 0x%08x\n", header_ptr->next_free, header_ptr->prev_free)); } /* release lock */ rt_sem_release(&(heap->lock)); } rt_bool_t rt_lwp_memheap_is_empty(struct rt_lwp_memheap *memheap) { RT_ASSERT(memheap != RT_NULL); return (memheap->available_size + 2 * sizeof(struct rt_lwp_memheap_item)) == memheap->pool_size; } rt_bool_t rt_lwp_memheap_unavailable_size_get(void) { return 2 * RT_MEMHEAP_SIZE + 3; }