/** Helper: allocate a new memarea chunk of around <b>chunk_size</b> bytes. */
static memarea_chunk_t *
alloc_chunk(size_t sz, int freelist_ok)
{
tor_assert(sz < SIZE_T_CEILING);
if (freelist && freelist_ok) {
memarea_chunk_t *res = freelist;
freelist = res->next_chunk;
res->next_chunk = NULL;
--freelist_len;
CHECK_SENTINEL(res);
return res;
} else {
size_t chunk_size = freelist_ok ? CHUNK_SIZE : sz;
memarea_chunk_t *res;
chunk_size += SENTINEL_LEN;
res = tor_malloc(chunk_size);
res->next_chunk = NULL;
res->mem_size = chunk_size - CHUNK_HEADER_SIZE - SENTINEL_LEN;
res->next_mem = res->U_MEM;
tor_assert(res->next_mem+res->mem_size+SENTINEL_LEN ==
((char*)res)+chunk_size);
tor_assert(realign_pointer(res->next_mem) == res->next_mem);
SET_SENTINEL(res);
return res;
}
}
/** Return a pointer to a chunk of memory in <b>area</b> of at least <b>sz</b>
* bytes. <b>sz</b> should be significantly smaller than the area's chunk
* size, though we can deal if it isn't. */
void *
memarea_alloc(memarea_t *area, size_t sz)
{
memarea_chunk_t *chunk = area->first;
char *result;
tor_assert(chunk);
if (sz == 0)
sz = 1;
if (chunk->next_mem+sz > chunk->u.mem+chunk->mem_size) {
if (sz+CHUNK_HEADER_SIZE >= CHUNK_SIZE) {
/* This allocation is too big. Stick it in a special chunk, and put
* that chunk second in the list. */
memarea_chunk_t *new_chunk = alloc_chunk(sz+CHUNK_HEADER_SIZE, 0);
new_chunk->next_chunk = chunk->next_chunk;
chunk->next_chunk = new_chunk;
chunk = new_chunk;
} else {
memarea_chunk_t *new_chunk = alloc_chunk(CHUNK_SIZE, 1);
new_chunk->next_chunk = chunk;
area->first = chunk = new_chunk;
}
tor_assert(chunk->mem_size >= sz);
}
result = chunk->next_mem;
chunk->next_mem = chunk->next_mem + sz;
// XXXX021 remove these once bug 930 is solved.
tor_assert(chunk->next_mem >= chunk->u.mem);
tor_assert(chunk->next_mem <= chunk->u.mem+chunk->mem_size);
chunk->next_mem = realign_pointer(chunk->next_mem);
return result;
}
/** Assert that <b>area</b> is okay. */
void
memarea_assert_ok(memarea_t *area)
{
memarea_chunk_t *chunk;
tor_assert(area->first);
for (chunk = area->first; chunk; chunk = chunk->next_chunk) {
tor_assert(chunk->next_mem >= chunk->u.mem);
tor_assert(chunk->next_mem <=
(char*) realign_pointer(chunk->u.mem+chunk->mem_size));
}
}
/** Assert that <b>area</b> is okay. */
void
memarea_assert_ok(memarea_t *area)
{
memarea_chunk_t *chunk;
tor_assert(area->first);
for (chunk = area->first; chunk; chunk = chunk->next_chunk) {
CHECK_SENTINEL(chunk);
tor_assert(chunk->next_mem >= chunk->U_MEM);
tor_assert(chunk->next_mem <=
(char*) realign_pointer(chunk->U_MEM+chunk->mem_size));
}
}
/** Helper: allocate a new memarea chunk of around <b>chunk_size</b> bytes. */
static memarea_chunk_t *
alloc_chunk(size_t sz)
{
tor_assert(sz < SIZE_T_CEILING);
size_t chunk_size = sz < CHUNK_SIZE ? CHUNK_SIZE : sz;
memarea_chunk_t *res;
chunk_size += SENTINEL_LEN;
res = tor_malloc(chunk_size);
res->next_chunk = NULL;
res->mem_size = chunk_size - CHUNK_HEADER_SIZE - SENTINEL_LEN;
res->next_mem = res->U_MEM;
tor_assert(res->next_mem+res->mem_size+SENTINEL_LEN ==
((char*)res)+chunk_size);
tor_assert(realign_pointer(res->next_mem) == res->next_mem);
SET_SENTINEL(res);
return res;
}
/** Helper: allocate a new memarea chunk of around <b>chunk_size</b> bytes. */
static memarea_chunk_t *
alloc_chunk(size_t sz, int freelist_ok)
{
if (freelist && freelist_ok) {
memarea_chunk_t *res = freelist;
freelist = res->next_chunk;
res->next_chunk = NULL;
--freelist_len;
return res;
} else {
size_t chunk_size = freelist_ok ? CHUNK_SIZE : sz;
memarea_chunk_t *res = tor_malloc_roundup(&chunk_size);
res->next_chunk = NULL;
res->mem_size = chunk_size - CHUNK_HEADER_SIZE;
res->next_mem = res->u.mem;
tor_assert(res->next_mem+res->mem_size == ((char*)res)+chunk_size);
tor_assert(realign_pointer(res->next_mem) == res->next_mem);
return res;
}
}
/** Return a pointer to a chunk of memory in <b>area</b> of at least <b>sz</b>
* bytes. <b>sz</b> should be significantly smaller than the area's chunk
* size, though we can deal if it isn't. */
void *
memarea_alloc(memarea_t *area, size_t sz)
{
memarea_chunk_t *chunk = area->first;
char *result;
tor_assert(chunk);
CHECK_SENTINEL(chunk);
tor_assert(sz < SIZE_T_CEILING);
if (sz == 0)
sz = 1;
if (chunk->next_mem+sz > chunk->U_MEM+chunk->mem_size) {
if (sz+CHUNK_HEADER_SIZE >= CHUNK_SIZE) {
/* This allocation is too big. Stick it in a special chunk, and put
* that chunk second in the list. */
memarea_chunk_t *new_chunk = alloc_chunk(sz+CHUNK_HEADER_SIZE, 0);
new_chunk->next_chunk = chunk->next_chunk;
chunk->next_chunk = new_chunk;
chunk = new_chunk;
} else {
memarea_chunk_t *new_chunk = alloc_chunk(CHUNK_SIZE, 1);
new_chunk->next_chunk = chunk;
area->first = chunk = new_chunk;
}
tor_assert(chunk->mem_size >= sz);
}
result = chunk->next_mem;
chunk->next_mem = chunk->next_mem + sz;
/* Reinstate these if bug 930 ever comes back
tor_assert(chunk->next_mem >= chunk->U_MEM);
tor_assert(chunk->next_mem <= chunk->U_MEM+chunk->mem_size);
*/
chunk->next_mem = realign_pointer(chunk->next_mem);
return result;
}