From fd8b6bcf5572b342b1e61f4f3737a2a650659166 Mon Sep 17 00:00:00 2001
From: Damien <damien.p.george@gmail.com>
Date: Tue, 22 Oct 2013 20:26:36 +0100
Subject: [PATCH] Add gc_free function to force a block to be freed.
---
py/gc.c | 35 ++++++++++++++++++++++++-----------
py/gc.h | 3 ++-
2 files changed, 26 insertions(+), 12 deletions(-)
diff --git a/py/gc.c b/py/gc.c
index 48e792266..0c9c56086 100644
--- a/py/gc.c
+++ b/py/gc.c
@@ -52,7 +52,6 @@ void gc_init(void *start, void *end) {
printf(" alloc table at %p, length %u bytes\n", gc_alloc_table_start, gc_alloc_table_byte_len);
printf(" pool at %p, length %u blocks = %u words = %u bytes\n", gc_pool_start, gc_pool_block_len, gc_pool_word_len, gc_pool_word_len * BYTES_PER_WORD);
*/
- printf("GC: %u bytes\n", gc_pool_word_len * BYTES_PER_WORD);
}
// ATB = allocation table byte
@@ -89,13 +88,15 @@ void gc_init(void *start, void *end) {
#define PTR_FROM_BLOCK(block) (((block) * BYTES_PER_BLOCK + (machine_uint_t)gc_pool_start))
#define ATB_FROM_BLOCK(bl) ((bl) / BLOCKS_PER_ATB)
+#define VERIFY_PTR(ptr) ( \
+ (ptr & (BYTES_PER_BLOCK - 1)) == 0 /* must be aligned on a block */ \
+ && ptr >= (machine_uint_t)gc_pool_start /* must be above start of pool */ \
+ && ptr < (machine_uint_t)gc_pool_end /* must be below end of pool */ \
+ )
+
#define VERIFY_MARK_AND_PUSH(ptr) \
do { \
- if ( \
- (ptr & (BYTES_PER_BLOCK - 1)) == 0 /* must be aligned on a block */ \
- && ptr >= (machine_uint_t)gc_pool_start /* must be above start of pool */ \
- && ptr < (machine_uint_t)gc_pool_end /* must be below end of pool */ \
- ) { \
+ if (VERIFY_PTR(ptr)) { \
machine_uint_t _block = BLOCK_FROM_PTR(ptr); \
if (ATB_GET_KIND(_block) == AT_HEAD) { \
/* an unmarked head, mark it, and push it on gc stack */ \
@@ -283,14 +284,26 @@ found:
return (void*)(gc_pool_start + start_block * WORDS_PER_BLOCK);
}
+// force the freeing of a piece of memory
+void gc_free(void *ptr_in) {
+ machine_uint_t ptr = (machine_uint_t)ptr_in;
+
+ if (VERIFY_PTR(ptr)) {
+ machine_uint_t block = BLOCK_FROM_PTR(ptr);
+ if (ATB_GET_KIND(block) == AT_HEAD) {
+ // free head and all of its tail blocks
+ do {
+ ATB_ANY_TO_FREE(block);
+ block += 1;
+ } while (ATB_GET_KIND(block) == AT_TAIL);
+ }
+ }
+}
+
machine_uint_t gc_nbytes(void *ptr_in) {
machine_uint_t ptr = (machine_uint_t)ptr_in;
- if (
- (ptr & (BYTES_PER_BLOCK - 1)) == 0 // must be aligned on a block
- && ptr >= (machine_uint_t)gc_pool_start // must be above start of pool
- && ptr < (machine_uint_t)gc_pool_end // must be below end of pool
- ) {
+ if (VERIFY_PTR(ptr)) {
machine_uint_t block = BLOCK_FROM_PTR(ptr);
if (ATB_GET_KIND(block) == AT_HEAD) {
// work out number of consecutive blocks in the chain starting with this on
diff --git a/py/gc.h b/py/gc.h
index 4fe87b830..d5b5fcc91 100644
--- a/py/gc.h
+++ b/py/gc.h
@@ -4,7 +4,8 @@ void gc_collect_root(void **ptrs, machine_uint_t len);
void gc_collect_end();
void gc_collect();
void *gc_alloc(machine_uint_t n_bytes);
-machine_uint_t gc_nbytes(void *ptr_in);
+void gc_free(void *ptr);
+machine_uint_t gc_nbytes(void *ptr);
void *gc_realloc(void *ptr, machine_uint_t n_bytes);
typedef struct _gc_info_t {
--
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