Commit 32bef315 authored by Damien George's avatar Damien George
Browse files

py, gc: Only zero out the extra bytes at the end of the heap chunk.

This is a small optimisation to zero out only the additional bytes that
the caller did not ask for.
parent dbc81df5
...@@ -366,17 +366,17 @@ found: ...@@ -366,17 +366,17 @@ found:
// get pointer to first block // get pointer to first block
void *ret_ptr = (void*)(gc_pool_start + start_block * WORDS_PER_BLOCK); void *ret_ptr = (void*)(gc_pool_start + start_block * WORDS_PER_BLOCK);
// zero out the newly allocated blocks // zero out the additional bytes of the newly allocated blocks
// This is needed because the blocks may have previously held pointers // This is needed because the blocks may have previously held pointers
// to the heap and will not be set to something else if the caller // to the heap and will not be set to something else if the caller
// doesn't actually use the entire block. As such they will continue // doesn't actually use the entire block. As such they will continue
// to point to the heap and may prevent other blocks from being reclaimed. // to point to the heap and may prevent other blocks from being reclaimed.
memset(ret_ptr, 0, (end_block - start_block + 1) * BYTES_PER_BLOCK); memset(ret_ptr + n_bytes, 0, (end_block - start_block + 1) * BYTES_PER_BLOCK - n_bytes);
#if MICROPY_ENABLE_FINALISER #if MICROPY_ENABLE_FINALISER
if (has_finaliser) { if (has_finaliser) {
// clear type pointer in case it is never set (now done above in memset) // clear type pointer in case it is never set
//((mp_obj_base_t*)ret_ptr)->type = MP_OBJ_NULL; ((mp_obj_base_t*)ret_ptr)->type = MP_OBJ_NULL;
// set mp_obj flag only if it has a finaliser // set mp_obj flag only if it has a finaliser
FTB_SET(start_block); FTB_SET(start_block);
} }
...@@ -534,8 +534,8 @@ void *gc_realloc(void *ptr_in, machine_uint_t n_bytes) { ...@@ -534,8 +534,8 @@ void *gc_realloc(void *ptr_in, machine_uint_t n_bytes) {
ATB_FREE_TO_TAIL(bl); ATB_FREE_TO_TAIL(bl);
} }
// zero out the newly allocated blocks (see comment above in gc_alloc) // zero out the additional bytes of the newly allocated blocks (see comment above in gc_alloc)
memset(ptr_in + n_blocks * BYTES_PER_BLOCK, 0, (new_blocks - n_blocks) * BYTES_PER_BLOCK); memset(ptr_in + n_bytes, 0, new_blocks * BYTES_PER_BLOCK - n_bytes);
return ptr_in; return ptr_in;
} }
......
...@@ -88,13 +88,9 @@ void *m_malloc_with_finaliser(int num_bytes) { ...@@ -88,13 +88,9 @@ void *m_malloc_with_finaliser(int num_bytes) {
void *m_malloc0(int num_bytes) { void *m_malloc0(int num_bytes) {
void *ptr = m_malloc(num_bytes); void *ptr = m_malloc(num_bytes);
#if MICROPY_ENABLE_GC
// the GC already zeros out all memory
#else
if (ptr != NULL) { if (ptr != NULL) {
memset(ptr, 0, num_bytes); memset(ptr, 0, num_bytes);
} }
#endif
return ptr; return ptr;
} }
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment