STATIC void gc_sweep(void) {
#if MICROPY_PY_GC_COLLECT_RETVAL
MP_STATE_MEM(gc_collected) = 0;
#endif
// free unmarked heads and their tails
int free_tail = 0;
for (size_t block = 0; block < MP_STATE_MEM(gc_alloc_table_byte_len) * BLOCKS_PER_ATB; block++) {
switch (ATB_GET_KIND(block)) {
case AT_HEAD:
#if MICROPY_ENABLE_FINALISER
if (FTB_GET(block)) {
mp_obj_base_t *obj = (mp_obj_base_t*)PTR_FROM_BLOCK(block);
if (obj->type != NULL) {
// if the object has a type then see if it has a __del__ method
mp_obj_t dest[2];
mp_load_method_maybe(MP_OBJ_FROM_PTR(obj), MP_QSTR___del__, dest);
if (dest[0] != MP_OBJ_NULL) {
// load_method returned a method, execute it in a protected environment
#if MICROPY_ENABLE_SCHEDULER
mp_sched_lock();
#endif
mp_call_function_1_protected(dest[0], dest[1]);
#if MICROPY_ENABLE_SCHEDULER
mp_sched_unlock();
#endif
}
}
// clear finaliser flag
FTB_CLEAR(block);
}
#endif
free_tail = 1;
DEBUG_printf("gc_sweep(%p)\n", PTR_FROM_BLOCK(block));
#if MICROPY_PY_GC_COLLECT_RETVAL
MP_STATE_MEM(gc_collected)++;
#endif
// fall through to free the head
case AT_TAIL:
if (free_tail) {
ATB_ANY_TO_FREE(block);
#if CLEAR_ON_SWEEP
memset((void*)PTR_FROM_BLOCK(block), 0, BYTES_PER_BLOCK);
#endif
}
break;
case AT_MARK:
ATB_MARK_TO_HEAD(block);
free_tail = 0;
break;
}
}
}
STATIC void gc_sweep(void) {
mp_uint_t block;
#if MICROPY_PY_GC_COLLECT_RETVAL
gc_collected = 0;
#endif
// free unmarked heads and their tails
int free_tail = 0;
for (block = 0; block < gc_alloc_table_byte_len * BLOCKS_PER_ATB; block++) {
switch (ATB_GET_KIND(block)) {
case AT_HEAD:
#if MICROPY_ENABLE_FINALISER
if (FTB_GET(block)) {
mp_obj_t obj = (mp_obj_t)PTR_FROM_BLOCK(block);
if (((mp_obj_base_t*)obj)->type != MP_OBJ_NULL) {
// if the object has a type then see if it has a __del__ method
mp_obj_t dest[2];
mp_load_method_maybe(obj, MP_QSTR___del__, dest);
if (dest[0] != MP_OBJ_NULL) {
// load_method returned a method
mp_call_method_n_kw(0, 0, dest);
}
}
// clear finaliser flag
FTB_CLEAR(block);
}
#endif
free_tail = 1;
#if MICROPY_PY_GC_COLLECT_RETVAL
gc_collected++;
#endif
// fall through to free the head
// no break - disable eclipse static analyzer warning - intentional fall through
case AT_TAIL:
if (free_tail) {
DEBUG_printf("gc_sweep(%p)\n",PTR_FROM_BLOCK(block));
ATB_ANY_TO_FREE(block);
}
break;
case AT_MARK:
ATB_MARK_TO_HEAD(block);
free_tail = 0;
break;
}
}
}
STATIC void gc_sweep(void) {
// free unmarked heads and their tails
int free_tail = 0;
for (machine_uint_t block = 0; block < gc_alloc_table_byte_len * BLOCKS_PER_ATB; block++) {
switch (ATB_GET_KIND(block)) {
case AT_HEAD:
#if MICROPY_ENABLE_FINALISER
if (FTB_GET(block)) {
mp_obj_t obj = (mp_obj_t)PTR_FROM_BLOCK(block);
if (((mp_obj_base_t*)obj)->type != MP_OBJ_NULL) {
// if the object has a type then see if it has a __del__ method
mp_obj_t dest[2];
mp_load_method_maybe(obj, MP_QSTR___del__, dest);
if (dest[0] != MP_OBJ_NULL) {
// load_method returned a method
mp_call_method_n_kw(0, 0, dest);
}
}
// clear finaliser flag
FTB_CLEAR(block);
}
#endif
free_tail = 1;
// fall through to free the head
case AT_TAIL:
if (free_tail) {
ATB_ANY_TO_FREE(block);
}
break;
case AT_MARK:
ATB_MARK_TO_HEAD(block);
free_tail = 0;
break;
}
}
}
// old, simple realloc that didn't expand memory in place
void *gc_realloc(void *ptr, machine_uint_t n_bytes) {
machine_uint_t n_existing = gc_nbytes(ptr);
if (n_bytes <= n_existing) {
return ptr;
} else {
bool has_finaliser;
if (ptr == NULL) {
has_finaliser = false;
} else {
#if MICROPY_ENABLE_FINALISER
has_finaliser = FTB_GET(BLOCK_FROM_PTR((machine_uint_t)ptr));
#else
has_finaliser = false;
#endif
}
void *ptr2 = gc_alloc(n_bytes, has_finaliser);
if (ptr2 == NULL) {
return ptr2;
}
memcpy(ptr2, ptr, n_existing);
gc_free(ptr);
return ptr2;
}
}
void *gc_realloc(void *ptr_in, machine_uint_t n_bytes) {
if (gc_lock_depth > 0) {
return NULL;
}
// check for pure allocation
if (ptr_in == NULL) {
return gc_alloc(n_bytes, false);
}
machine_uint_t ptr = (machine_uint_t)ptr_in;
// sanity check the ptr
if (!VERIFY_PTR(ptr)) {
return NULL;
}
// get first block
machine_uint_t block = BLOCK_FROM_PTR(ptr);
// sanity check the ptr is pointing to the head of a block
if (ATB_GET_KIND(block) != AT_HEAD) {
return NULL;
}
// compute number of new blocks that are requested
machine_uint_t new_blocks = (n_bytes + BYTES_PER_BLOCK - 1) / BYTES_PER_BLOCK;
// get the number of consecutive tail blocks and
// the number of free blocks after last tail block
// stop if we reach (or are at) end of heap
machine_uint_t n_free = 0;
machine_uint_t n_blocks = 1; // counting HEAD block
machine_uint_t max_block = gc_alloc_table_byte_len * BLOCKS_PER_ATB;
while (block + n_blocks + n_free < max_block) {
if (n_blocks + n_free >= new_blocks) {
// stop as soon as we find enough blocks for n_bytes
break;
}
byte block_type = ATB_GET_KIND(block + n_blocks + n_free);
switch (block_type) {
case AT_FREE: n_free++; continue;
case AT_TAIL: n_blocks++; continue;
case AT_MARK: assert(0);
}
break;
}
// return original ptr if it already has the requested number of blocks
if (new_blocks == n_blocks) {
return ptr_in;
}
// check if we can shrink the allocated area
if (new_blocks < n_blocks) {
// free unneeded tail blocks
for (machine_uint_t bl = block + new_blocks; ATB_GET_KIND(bl) == AT_TAIL; bl++) {
ATB_ANY_TO_FREE(bl);
}
return ptr_in;
}
// check if we can expand in place
if (new_blocks <= n_blocks + n_free) {
// mark few more blocks as used tail
for (machine_uint_t bl = block + n_blocks; bl < block + new_blocks; bl++) {
assert(ATB_GET_KIND(bl) == AT_FREE);
ATB_FREE_TO_TAIL(bl);
}
// zero out the additional bytes of the newly allocated blocks (see comment above in gc_alloc)
memset((byte*)ptr_in + n_bytes, 0, new_blocks * BYTES_PER_BLOCK - n_bytes);
return ptr_in;
}
// can't resize inplace; try to find a new contiguous chain
void *ptr_out = gc_alloc(n_bytes,
#if MICROPY_ENABLE_FINALISER
FTB_GET(block)
#else
false
#endif
);
// check that the alloc succeeded
if (ptr_out == NULL) {
return NULL;
}
DEBUG_printf("gc_realloc(%p -> %p)\n", ptr_in, ptr_out);
memcpy(ptr_out, ptr_in, n_blocks * BYTES_PER_BLOCK);
gc_free(ptr_in);
return ptr_out;
}
void *gc_realloc(void *ptr_in, size_t n_bytes, bool allow_move) {
if (MP_STATE_MEM(gc_lock_depth) > 0) {
return NULL;
}
// check for pure allocation
if (ptr_in == NULL) {
return gc_alloc(n_bytes, false);
}
// check for pure free
if (n_bytes == 0) {
gc_free(ptr_in);
return NULL;
}
void *ptr = ptr_in;
// sanity check the ptr
if (!VERIFY_PTR(ptr)) {
return NULL;
}
// get first block
size_t block = BLOCK_FROM_PTR(ptr);
// sanity check the ptr is pointing to the head of a block
if (ATB_GET_KIND(block) != AT_HEAD) {
return NULL;
}
// compute number of new blocks that are requested
size_t new_blocks = (n_bytes + BYTES_PER_BLOCK - 1) / BYTES_PER_BLOCK;
// Get the total number of consecutive blocks that are already allocated to
// this chunk of memory, and then count the number of free blocks following
// it. Stop if we reach the end of the heap, or if we find enough extra
// free blocks to satisfy the realloc. Note that we need to compute the
// total size of the existing memory chunk so we can correctly and
// efficiently shrink it (see below for shrinking code).
size_t n_free = 0;
size_t n_blocks = 1; // counting HEAD block
size_t max_block = MP_STATE_MEM(gc_alloc_table_byte_len) * BLOCKS_PER_ATB;
for (size_t bl = block + n_blocks; bl < max_block; bl++) {
byte block_type = ATB_GET_KIND(bl);
if (block_type == AT_TAIL) {
n_blocks++;
continue;
}
if (block_type == AT_FREE) {
n_free++;
if (n_blocks + n_free >= new_blocks) {
// stop as soon as we find enough blocks for n_bytes
break;
}
continue;
}
break;
}
// return original ptr if it already has the requested number of blocks
if (new_blocks == n_blocks) {
return ptr_in;
}
// check if we can shrink the allocated area
if (new_blocks < n_blocks) {
// free unneeded tail blocks
for (size_t bl = block + new_blocks, count = n_blocks - new_blocks; count > 0; bl++, count--) {
ATB_ANY_TO_FREE(bl);
}
// set the last_free pointer to end of this block if it's earlier in the heap
if ((block + new_blocks) / BLOCKS_PER_ATB < MP_STATE_MEM(gc_last_free_atb_index)) {
MP_STATE_MEM(gc_last_free_atb_index) = (block + new_blocks) / BLOCKS_PER_ATB;
}
#if EXTENSIVE_HEAP_PROFILING
gc_dump_alloc_table();
#endif
return ptr_in;
}
// check if we can expand in place
if (new_blocks <= n_blocks + n_free) {
// mark few more blocks as used tail
for (size_t bl = block + n_blocks; bl < block + new_blocks; bl++) {
assert(ATB_GET_KIND(bl) == AT_FREE);
ATB_FREE_TO_TAIL(bl);
}
// zero out the bytes of the newly allocated blocks (see comment above in gc_alloc)
memset((byte*)ptr_in + n_blocks * BYTES_PER_BLOCK, 0, (new_blocks - n_blocks) * BYTES_PER_BLOCK);
#if EXTENSIVE_HEAP_PROFILING
gc_dump_alloc_table();
#endif
return ptr_in;
}
if (!allow_move) {
// not allowed to move memory block so return failure
return NULL;
}
// can't resize inplace; try to find a new contiguous chain
void *ptr_out = gc_alloc(n_bytes,
#if MICROPY_ENABLE_FINALISER
FTB_GET(block)
#else
false
#endif
);
// check that the alloc succeeded
if (ptr_out == NULL) {
return NULL;
}
DEBUG_printf("gc_realloc(%p -> %p)\n", ptr_in, ptr_out);
memcpy(ptr_out, ptr_in, n_blocks * BYTES_PER_BLOCK);
gc_free(ptr_in);
return ptr_out;
}
