#include <stdlib.h>
#include "malloc.h"
-static struct free_arena_header *
-__free_block(struct free_arena_header *ah)
+static struct free_arena_header *__free_block(struct free_arena_header *ah)
{
- struct free_arena_header *pah, *nah;
+ struct free_arena_header *pah, *nah;
- pah = ah->a.prev;
- nah = ah->a.next;
- if ( pah->a.type == ARENA_TYPE_FREE &&
- (char *)pah+pah->a.size == (char *)ah ) {
- /* Coalesce into the previous block */
- pah->a.size += ah->a.size;
- pah->a.next = nah;
- nah->a.prev = pah;
+ pah = ah->a.prev;
+ nah = ah->a.next;
+ if (pah->a.type == ARENA_TYPE_FREE &&
+ (char *)pah + pah->a.size == (char *)ah) {
+ /* Coalesce into the previous block */
+ pah->a.size += ah->a.size;
+ pah->a.next = nah;
+ nah->a.prev = pah;
#ifdef DEBUG_MALLOC
- ah->a.type = ARENA_TYPE_DEAD;
+ ah->a.type = ARENA_TYPE_DEAD;
#endif
- ah = pah;
- pah = ah->a.prev;
- } else {
- /* Need to add this block to the free chain */
- ah->a.type = ARENA_TYPE_FREE;
-
- ah->next_free = __malloc_head.next_free;
- ah->prev_free = &__malloc_head;
- __malloc_head.next_free = ah;
- ah->next_free->prev_free = ah;
- }
-
- /* In either of the previous cases, we might be able to merge
- with the subsequent block... */
- if ( nah->a.type == ARENA_TYPE_FREE &&
- (char *)ah+ah->a.size == (char *)nah ) {
- ah->a.size += nah->a.size;
-
- /* Remove the old block from the chains */
- nah->next_free->prev_free = nah->prev_free;
- nah->prev_free->next_free = nah->next_free;
- ah->a.next = nah->a.next;
- nah->a.next->a.prev = ah;
+ ah = pah;
+ pah = ah->a.prev;
+ } else {
+ /* Need to add this block to the free chain */
+ ah->a.type = ARENA_TYPE_FREE;
+
+ ah->next_free = __malloc_head.next_free;
+ ah->prev_free = &__malloc_head;
+ __malloc_head.next_free = ah;
+ ah->next_free->prev_free = ah;
+ }
+
+ /* In either of the previous cases, we might be able to merge
+ with the subsequent block... */
+ if (nah->a.type == ARENA_TYPE_FREE &&
+ (char *)ah + ah->a.size == (char *)nah) {
+ ah->a.size += nah->a.size;
+
+ /* Remove the old block from the chains */
+ nah->next_free->prev_free = nah->prev_free;
+ nah->prev_free->next_free = nah->next_free;
+ ah->a.next = nah->a.next;
+ nah->a.next->a.prev = ah;
#ifdef DEBUG_MALLOC
- nah->a.type = ARENA_TYPE_DEAD;
+ nah->a.type = ARENA_TYPE_DEAD;
#endif
- }
+ }
- /* Return the block that contains the called block */
- return ah;
+ /* Return the block that contains the called block */
+ return ah;
}
/*
*/
void __inject_free_block(struct free_arena_header *ah)
{
- struct free_arena_header *nah;
- size_t a_end = (size_t)ah + ah->a.size;
- size_t n_end;
+ struct free_arena_header *nah;
+ size_t a_end = (size_t) ah + ah->a.size;
+ size_t n_end;
- for (nah = __malloc_head.a.next; nah->a.type != ARENA_TYPE_HEAD;
- nah = nah->a.next) {
- n_end = (size_t)nah + nah->a.size;
+ for (nah = __malloc_head.a.next; nah->a.type != ARENA_TYPE_HEAD;
+ nah = nah->a.next) {
+ n_end = (size_t) nah + nah->a.size;
- /* Is nah entirely beyond this block? */
- if ((size_t)nah >= a_end)
- break;
+ /* Is nah entirely beyond this block? */
+ if ((size_t) nah >= a_end)
+ break;
- /* Is this block entirely beyond nah? */
- if ((size_t)ah >= n_end)
- continue;
+ /* Is this block entirely beyond nah? */
+ if ((size_t) ah >= n_end)
+ continue;
- /* Otherwise we have some sort of overlap - reject this block */
- return;
- }
+ /* Otherwise we have some sort of overlap - reject this block */
+ return;
+ }
- /* Now, nah should point to the successor block */
- ah->a.next = nah;
- ah->a.prev = nah->a.prev;
- nah->a.prev = ah;
- ah->a.prev->a.next = ah;
+ /* Now, nah should point to the successor block */
+ ah->a.next = nah;
+ ah->a.prev = nah->a.prev;
+ nah->a.prev = ah;
+ ah->a.prev->a.next = ah;
- __free_block(ah);
+ __free_block(ah);
}
void free(void *ptr)
{
- struct free_arena_header *ah;
+ struct free_arena_header *ah;
- if ( !ptr )
- return;
+ if (!ptr)
+ return;
- ah = (struct free_arena_header *)
- ((struct arena_header *)ptr - 1);
+ ah = (struct free_arena_header *)
+ ((struct arena_header *)ptr - 1);
#ifdef DEBUG_MALLOC
- assert( ah->a.type == ARENA_TYPE_USED );
+ assert(ah->a.type == ARENA_TYPE_USED);
#endif
- __free_block(ah);
+ __free_block(ah);
- /* Here we could insert code to return memory to the system. */
+ /* Here we could insert code to return memory to the system. */
}