diff options
Diffstat (limited to 'gc.c')
| -rw-r--r-- | gc.c | 23 |
1 files changed, 15 insertions, 8 deletions
@@ -44,7 +44,7 @@ typedef struct heap { } heap_t; int opt_gc_debug; -obj_t **gc_stack_top; +static obj_t **gc_stack_bottom; static obj_t **prot_stack[PROT_STACK_SIZE]; static obj_t ***prot_stack_limit = prot_stack + PROT_STACK_SIZE; @@ -274,7 +274,7 @@ static void mark_mem_region(obj_t **bottom, obj_t **top) static void mark(void) { - obj_t *gc_stack_bottom; + obj_t *gc_stack_top; obj_t ***rootloc; /* @@ -286,14 +286,13 @@ static void mark(void) mark_obj(**rootloc); } - mark_mem_region(&gc_stack_bottom, gc_stack_top); + mark_mem_region(&gc_stack_top, gc_stack_bottom); } static void sweep(void) { heap_t *heap; int dbg = opt_gc_debug; - long freed = 0; for (heap = heap_list; heap != 0; heap = heap->next) { obj_t *block, *end; @@ -316,6 +315,13 @@ static void sweep(void) } finalize(block); block->t.type |= FREE; + /* If debugging is turned on, we want to catch instances + where a reachable object is wrongly freed. This is difficult + to do if the object is recycled soon after. + So when debugging is on, the free list is FIFO + rather than LIFO, which increases our chances that the + code which is still using the object will trip on + the freed object before it is recycled. */ if (dbg) { *free_tail = block; block->t.next = nil; @@ -324,12 +330,8 @@ static void sweep(void) block->t.next = free_list; free_list = block; } - freed++; } } - - if (dbg) - fprintf(stderr, "%s: gc freed %ld blocks\n", progname, freed); } void gc(void) @@ -349,6 +351,11 @@ int gc_state(int enabled) return old; } +void gc_init(obj_t **stack_bottom) +{ + gc_stack_bottom = stack_bottom; +} + /* * Useful functions for gdb'ing. */ |