Commit eefcc790 authored by Damien's avatar Damien
Browse files

Clear ATBs on gc_init; better gc_info.

parent 3f69aca2
......@@ -33,6 +33,8 @@ static machine_uint_t *gc_sp;
void gc_init(void *start, void *end) {
// align end pointer on block boundary
end = (void*)((machine_uint_t)end & (~(BYTES_PER_BLOCK - 1)));
// calculate parameters for GC
machine_uint_t total_word_len = (machine_uint_t*)end - (machine_uint_t*)start;
gc_alloc_table_byte_len = total_word_len * BYTES_PER_WORD / (1 + BITS_PER_BYTE / 2 * BYTES_PER_BLOCK);
gc_alloc_table_start = (byte*)start;
......@@ -42,6 +44,9 @@ void gc_init(void *start, void *end) {
gc_pool_start = (machine_uint_t*)end - gc_pool_word_len;
gc_pool_end = end;
// clear ATBs
memset(gc_alloc_table_start, 0, gc_alloc_table_byte_len);
/*
printf("GC layout:\n");
printf(" alloc table at %p, length %u bytes\n", gc_alloc_table_start, gc_alloc_table_byte_len);
......@@ -80,19 +85,6 @@ void gc_init(void *start, void *end) {
#define ATB_HEAD_TO_MARK(block) do { gc_alloc_table_start[(block) / BLOCKS_PER_ATB] |= (AT_MARK << BLOCK_SHIFT(block)); } while (0)
#define ATB_MARK_TO_HEAD(block) do { gc_alloc_table_start[(block) / BLOCKS_PER_ATB] &= (~(AT_TAIL << BLOCK_SHIFT(block))); } while (0)
void gc_dump_at() {
for (machine_uint_t bl = 0; bl < gc_alloc_table_byte_len * BLOCKS_PER_ATB; bl++) {
printf("block % 6u ", bl);
switch (ATB_GET_KIND(bl)) {
case AT_FREE: printf("FREE"); break;
case AT_HEAD: printf("HEAD"); break;
case AT_TAIL: printf("TAIL"); break;
default: printf("MARK"); break;
}
printf("\n");
}
}
#define BLOCK_FROM_PTR(ptr) (((ptr) - (machine_uint_t)gc_pool_start) / BYTES_PER_BLOCK)
#define PTR_FROM_BLOCK(block) (((block) * BYTES_PER_BLOCK + (machine_uint_t)gc_pool_start))
#define ATB_FROM_BLOCK(bl) ((bl) / BLOCKS_PER_ATB)
......@@ -122,7 +114,7 @@ static void gc_drain_stack() {
// pop the next block off the stack
machine_uint_t block = *--gc_sp;
// work out number of consecutive blocks in the chain starting with this on
// work out number of consecutive blocks in the chain starting with this one
machine_uint_t n_blocks = 0;
do {
n_blocks += 1;
......@@ -192,26 +184,51 @@ void gc_collect_root(void **ptrs, machine_uint_t len) {
void gc_collect_end() {
gc_deal_with_stack_overflow();
gc_sweep();
}
machine_uint_t n_free = 0;
machine_uint_t n_used = 0;
for (machine_uint_t block = 0; block < gc_alloc_table_byte_len * BLOCKS_PER_ATB; block++) {
switch (ATB_GET_KIND(block)) {
void gc_info(gc_info_t *info) {
info->total = (gc_pool_end - gc_pool_start) * sizeof(machine_uint_t);
info->used = 0;
info->free = 0;
info->num_1block = 0;
info->num_2block = 0;
info->max_block = 0;
for (machine_uint_t block = 0, len = 0; block < gc_alloc_table_byte_len * BLOCKS_PER_ATB; block++) {
machine_uint_t kind = ATB_GET_KIND(block);
if (kind == AT_FREE || kind == AT_HEAD) {
if (len == 1) {
info->num_1block += 1;
} else if (len == 2) {
info->num_2block += 1;
}
if (len > info->max_block) {
info->max_block = len;
}
}
switch (kind) {
case AT_FREE:
n_free += 1;
info->free += 1;
len = 0;
break;
case AT_HEAD:
info->used += 1;
len = 1;
break;
case AT_TAIL:
n_used += 1;
info->used += 1;
len += 1;
break;
case AT_MARK:
// shouldn't happen
break;
}
}
printf("GC %u/%u\n", n_used * BYTES_PER_BLOCK, (n_free + n_used) * BYTES_PER_BLOCK);
info->used *= BYTES_PER_BLOCK;
info->free *= BYTES_PER_BLOCK;
}
void *gc_alloc(machine_uint_t n_bytes) {
......@@ -301,6 +318,19 @@ void *gc_realloc(void *ptr, machine_uint_t n_bytes) {
}
/*
static void gc_dump_at() {
for (machine_uint_t bl = 0; bl < gc_alloc_table_byte_len * BLOCKS_PER_ATB; bl++) {
printf("block % 6u ", bl);
switch (ATB_GET_KIND(bl)) {
case AT_FREE: printf("FREE"); break;
case AT_HEAD: printf("HEAD"); break;
case AT_TAIL: printf("TAIL"); break;
default: printf("MARK"); break;
}
printf("\n");
}
}
int main() {
machine_uint_t len = 1000;
machine_uint_t *heap = malloc(len);
......
......@@ -6,3 +6,14 @@ void gc_collect();
void *gc_alloc(machine_uint_t n_bytes);
machine_uint_t gc_nbytes(void *ptr_in);
void *gc_realloc(void *ptr, machine_uint_t n_bytes);
typedef struct _gc_info_t {
machine_uint_t total;
machine_uint_t used;
machine_uint_t free;
machine_uint_t num_1block;
machine_uint_t num_2block;
machine_uint_t max_block;
} gc_info_t;
void gc_info(gc_info_t *info);
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