void flower_check(Flower *flower) {
eventTree_check(flower_getEventTree(flower));
Flower_GroupIterator *groupIterator = flower_getGroupIterator(flower);
Group *group;
while ((group = flower_getNextGroup(groupIterator)) != NULL) {
group_check(group);
}
flower_destructGroupIterator(groupIterator);
Flower_ChainIterator *chainIterator = flower_getChainIterator(flower);
Chain *chain;
while ((chain = flower_getNextChain(chainIterator)) != NULL) {
chain_check(chain);
}
flower_destructCapIterator(chainIterator);
//We check built trees in here.
Flower_EndIterator *endIterator = flower_getEndIterator(flower);
End *end;
while ((end = flower_getNextEnd(endIterator)) != NULL) {
end_check(end);
end_check(end_getReverse(end)); //We will test everything backwards also.
}
flower_destructEndIterator(endIterator);
if (flower_builtFaces(flower)) {
Flower_FaceIterator *faceIterator = flower_getFaceIterator(flower);
Face *face;
while ((face = flower_getNextFace(faceIterator)) != NULL) {
face_check(face);
}
flower_destructFaceIterator(faceIterator);
face_checkFaces(flower);
} else {
cactusCheck(flower_getFaceNumber(flower) == 0);
}
if (flower_builtBlocks(flower)) { //Note that a flower for which the blocks are not yet built must be a leaf.
Flower_BlockIterator *blockIterator = flower_getBlockIterator(flower);
Block *block;
while ((block = flower_getNextBlock(blockIterator)) != NULL) {
block_check(block);
block_check(block_getReverse(block)); //We will test everything backwards also.
}
flower_destructBlockIterator(blockIterator);
} else {
cactusCheck(flower_isLeaf(flower)); //Defensive
cactusCheck(flower_isTerminal(flower)); //Checks that a flower without built blocks is a leaf and does not
//contain any blocks.
}
Flower_SequenceIterator *sequenceIterator = flower_getSequenceIterator(flower);
Sequence *sequence;
while ((sequence = flower_getNextSequence(sequenceIterator)) != NULL) {
sequence_check(sequence);
}
flower_destructSequenceIterator(sequenceIterator);
}
/** Free a memory block
*
* @param addr The address of the block.
*
*/
void free(const void *addr)
{
if (addr == NULL)
return;
futex_down(&malloc_futex);
/* Calculate the position of the header. */
heap_block_head_t *head
= (heap_block_head_t *) (addr - sizeof(heap_block_head_t));
block_check(head);
malloc_assert(!head->free);
heap_area_t *area = head->area;
area_check(area);
malloc_assert((void *) head >= (void *) AREA_FIRST_BLOCK_HEAD(area));
malloc_assert((void *) head < area->end);
/* Mark the block itself as free. */
head->free = true;
/* Look at the next block. If it is free, merge the two. */
heap_block_head_t *next_head
= (heap_block_head_t *) (((void *) head) + head->size);
if ((void *) next_head < area->end) {
block_check(next_head);
if (next_head->free)
block_init(head, head->size + next_head->size, true, area);
}
/* Look at the previous block. If it is free, merge the two. */
if ((void *) head > (void *) AREA_FIRST_BLOCK_HEAD(area)) {
heap_block_foot_t *prev_foot =
(heap_block_foot_t *) (((void *) head) - sizeof(heap_block_foot_t));
heap_block_head_t *prev_head =
(heap_block_head_t *) (((void *) head) - prev_foot->size);
block_check(prev_head);
if (prev_head->free)
block_init(prev_head, prev_head->size + head->size, true,
area);
}
heap_shrink(area);
futex_up(&malloc_futex);
}
static struct block *block_find(const void *ptr)
{
struct block *block;
LOG(("block_find; ptr=0x%x\n", ptr));
assert(ptr);
/* locate block based on pointer, then check whether it is valid */
block = (struct block *) page_round_down(
(unsigned long) ((struct block *) __UNCONST(ptr) - 1));
block_check(block);
LOG(("block_find; block=0x%x\n", block));
return block;
}
/** Reallocate memory block
*
* @param addr Already allocated memory or NULL.
* @param size New size of the memory block.
*
* @return Reallocated memory or NULL.
*
*/
void *realloc(const void *addr, const size_t size)
{
if (addr == NULL)
return malloc(size);
futex_down(&malloc_futex);
/* Calculate the position of the header. */
heap_block_head_t *head =
(heap_block_head_t *) (addr - sizeof(heap_block_head_t));
block_check(head);
malloc_assert(!head->free);
heap_area_t *area = head->area;
area_check(area);
malloc_assert((void *) head >= (void *) AREA_FIRST_BLOCK_HEAD(area));
malloc_assert((void *) head < area->end);
void *ptr = NULL;
bool reloc = false;
size_t real_size = GROSS_SIZE(ALIGN_UP(size, BASE_ALIGN));
size_t orig_size = head->size;
if (orig_size > real_size) {
/* Shrink */
if (orig_size - real_size >= STRUCT_OVERHEAD) {
/*
* Split the original block to a full block
* and a trailing free block.
*/
block_init((void *) head, real_size, false, area);
block_init((void *) head + real_size,
orig_size - real_size, true, area);
heap_shrink(area);
}
ptr = ((void *) head) + sizeof(heap_block_head_t);
} else {
/*
* Look at the next block. If it is free and the size is
* sufficient then merge the two. Otherwise just allocate
* a new block, copy the original data into it and
* free the original block.
*/
heap_block_head_t *next_head =
(heap_block_head_t *) (((void *) head) + head->size);
if (((void *) next_head < area->end) &&
(head->size + next_head->size >= real_size) &&
(next_head->free)) {
block_check(next_head);
block_init(head, head->size + next_head->size, false, area);
split_mark(head, real_size);
ptr = ((void *) head) + sizeof(heap_block_head_t);
next_fit = NULL;
} else
reloc = true;
}
futex_up(&malloc_futex);
if (reloc) {
ptr = malloc(size);
if (ptr != NULL) {
memcpy(ptr, addr, NET_SIZE(orig_size));
free(addr);
}
}
return ptr;
}
/** Allocate memory from heap area starting from given block
*
* Should be called only inside the critical section.
* As a side effect this function also sets the current
* pointer on successful allocation.
*
* @param area Heap area where to allocate from.
* @param first_block Starting heap block.
* @param final_block Heap block where to finish the search
* (may be NULL).
* @param real_size Gross number of bytes to allocate.
* @param falign Physical alignment of the block.
*
* @return Address of the allocated block or NULL on not enough memory.
*
*/
static void *malloc_area(heap_area_t *area, heap_block_head_t *first_block,
heap_block_head_t *final_block, size_t real_size, size_t falign)
{
area_check((void *) area);
malloc_assert((void *) first_block >= (void *) AREA_FIRST_BLOCK_HEAD(area));
malloc_assert((void *) first_block < area->end);
for (heap_block_head_t *cur = first_block; (void *) cur < area->end;
cur = (heap_block_head_t *) (((void *) cur) + cur->size)) {
block_check(cur);
/* Finish searching on the final block */
if ((final_block != NULL) && (cur == final_block))
break;
/* Try to find a block that is free and large enough. */
if ((cur->free) && (cur->size >= real_size)) {
/*
* We have found a suitable block.
* Check for alignment properties.
*/
void *addr = (void *)
((uintptr_t) cur + sizeof(heap_block_head_t));
void *aligned = (void *)
ALIGN_UP((uintptr_t) addr, falign);
if (addr == aligned) {
/* Exact block start including alignment. */
split_mark(cur, real_size);
next_fit = cur;
return addr;
} else {
/* Block start has to be aligned */
size_t excess = (size_t) (aligned - addr);
if (cur->size >= real_size + excess) {
/*
* The current block is large enough to fit
* data in (including alignment).
*/
if ((void *) cur > (void *) AREA_FIRST_BLOCK_HEAD(area)) {
/*
* There is a block before the current block.
* This previous block can be enlarged to
* compensate for the alignment excess.
*/
heap_block_foot_t *prev_foot = (heap_block_foot_t *)
((void *) cur - sizeof(heap_block_foot_t));
heap_block_head_t *prev_head = (heap_block_head_t *)
((void *) cur - prev_foot->size);
block_check(prev_head);
size_t reduced_size = cur->size - excess;
heap_block_head_t *next_head = ((void *) cur) + excess;
if ((!prev_head->free) &&
(excess >= STRUCT_OVERHEAD)) {
/*
* The previous block is not free and there
* is enough free space left to fill in
* a new free block between the previous
* and current block.
*/
block_init(cur, excess, true, area);
} else {
/*
* The previous block is free (thus there
* is no need to induce additional
* fragmentation to the heap) or the
* excess is small. Therefore just enlarge
* the previous block.
*/
block_init(prev_head, prev_head->size + excess,
prev_head->free, area);
}
block_init(next_head, reduced_size, true, area);
split_mark(next_head, real_size);
next_fit = next_head;
return aligned;
} else {
/*
* The current block is the first block
* in the heap area. We have to make sure
* that the alignment excess is large enough
* to fit a new free block just before the
* current block.
*/
while (excess < STRUCT_OVERHEAD) {
aligned += falign;
excess += falign;
}
/* Check for current block size again */
if (cur->size >= real_size + excess) {
size_t reduced_size = cur->size - excess;
cur = (heap_block_head_t *)
(AREA_FIRST_BLOCK_HEAD(area) + excess);
block_init((void *) AREA_FIRST_BLOCK_HEAD(area),
excess, true, area);
block_init(cur, reduced_size, true, area);
split_mark(cur, real_size);
next_fit = cur;
return aligned;
}
}
}
}
}
}
return NULL;
}
/** Try to shrink heap
*
* Should be called only inside the critical section.
* In all cases the next pointer is reset.
*
* @param area Last modified heap area.
*
*/
static void heap_shrink(heap_area_t *area)
{
area_check(area);
heap_block_foot_t *last_foot =
(heap_block_foot_t *) AREA_LAST_BLOCK_FOOT(area);
heap_block_head_t *last_head = BLOCK_HEAD(last_foot);
block_check((void *) last_head);
malloc_assert(last_head->area == area);
if (last_head->free) {
/*
* The last block of the heap area is
* unused. The area might be potentially
* shrunk.
*/
heap_block_head_t *first_head =
(heap_block_head_t *) AREA_FIRST_BLOCK_HEAD(area);
block_check((void *) first_head);
malloc_assert(first_head->area == area);
size_t shrink_size = ALIGN_DOWN(last_head->size, PAGE_SIZE);
if (first_head == last_head) {
/*
* The entire heap area consists of a single
* free heap block. This means we can get rid
* of it entirely.
*/
heap_area_t *prev = area->prev;
heap_area_t *next = area->next;
if (prev != NULL) {
area_check(prev);
prev->next = next;
} else
first_heap_area = next;
if (next != NULL) {
area_check(next);
next->prev = prev;
} else
last_heap_area = prev;
as_area_destroy(area->start);
} else if (shrink_size >= SHRINK_GRANULARITY) {
/*
* Make sure that we always shrink the area
* by a multiple of page size and update
* the block layout accordingly.
*/
size_t asize = (size_t) (area->end - area->start) - shrink_size;
void *end = (void *) ((uintptr_t) area->start + asize);
/* Resize the address space area */
int ret = as_area_resize(area->start, asize, 0);
if (ret != EOK)
abort();
/* Update heap area parameters */
area->end = end;
size_t excess = ((size_t) area->end) - ((size_t) last_head);
if (excess > 0) {
if (excess >= STRUCT_OVERHEAD) {
/*
* The previous block cannot be free and there
* is enough free space left in the area to
* create a new free block.
*/
block_init((void *) last_head, excess, true, area);
} else {
/*
* The excess is small. Therefore just enlarge
* the previous block.
*/
heap_block_foot_t *prev_foot = (heap_block_foot_t *)
(((uintptr_t) last_head) - sizeof(heap_block_foot_t));
heap_block_head_t *prev_head = BLOCK_HEAD(prev_foot);
block_check((void *) prev_head);
block_init(prev_head, prev_head->size + excess,
prev_head->free, area);
}
}
}
}
next_fit = NULL;
}