diff options
Diffstat (limited to 'gc.c')
| -rw-r--r-- | gc.c | 39 |
1 files changed, 30 insertions, 9 deletions
@@ -47,6 +47,7 @@ #define PROT_STACK_SIZE 1024 #define HEAP_SIZE 16384 #define CHECKOBJ_VEC_SIZE (2 * HEAP_SIZE) +#define MUTOBJ_VEC_SIZE (HEAP_SIZE / 4) #define FULL_GC_INTERVAL 40 #define FRESHOBJ_VEC_SIZE (2 * HEAP_SIZE) @@ -82,6 +83,8 @@ int gc_enabled = 1; #if CONFIG_GEN_GC static val checkobj[CHECKOBJ_VEC_SIZE]; static int checkobj_idx; +static val mutobj[MUTOBJ_VEC_SIZE]; +static int mutobj_idx; static val freshobj[FRESHOBJ_VEC_SIZE]; static int freshobj_idx; static int full_gc; @@ -253,14 +256,14 @@ tail_call: t = obj->t.type; + if ((t & REACHABLE) != 0) + return; + #if CONFIG_GEN_GC if (!full_gc && obj->t.gen > 0) return; #endif - if ((t & REACHABLE) != 0) - return; - if ((t & FREE) != 0) abort(); @@ -404,6 +407,8 @@ static void mark(mach_context_t *pmc, val *gc_stack_top) int i; for (i = 0; i < checkobj_idx; i++) mark_obj(checkobj[i]); + for (i = 0; i < mutobj_idx; i++) + mark_obj(mutobj[i]); } #endif @@ -502,6 +507,12 @@ static int_ptr_t sweep(void) for (i = 0; i < freshobj_idx; i++) free_count += sweep_one(freshobj[i]); + /* Generation 1 objects that were indicated for dangerous + mutation must have their REACHABLE flag flipped off, + and must be returned to gen 1. */ + for (i = 0; i < mutobj_idx; i++) + sweep_one(mutobj[i]); + return free_count; } #endif @@ -564,6 +575,7 @@ void gc(void) #if CONFIG_GEN_GC checkobj_idx = 0; + mutobj_idx = 0; freshobj_idx = 0; full_gc = 0; #endif @@ -609,9 +621,10 @@ int gc_is_reachable(val obj) val gc_set(val *ptr, val obj) { - if (in_malloc_range((mem_t *) ptr) && is_ptr(obj) && obj->t.gen == 0) { - if (checkobj_idx >= CHECKOBJ_VEC_SIZE) - gc(); + if (checkobj_idx >= CHECKOBJ_VEC_SIZE) { + gc(); + /* obj can't be in gen 0 because there are no baby objects after gc */ + } else if (in_malloc_range((mem_t *) ptr) && is_ptr(obj) && obj->t.gen == 0) { obj->t.gen = -1; checkobj[checkobj_idx++] = obj; } @@ -621,12 +634,20 @@ val gc_set(val *ptr, val obj) val gc_mutated(val obj) { - if (checkobj_idx >= CHECKOBJ_VEC_SIZE) - gc(); + /* We care only about mature generation objects that have not + already been noted. */ + if (obj->t.gen <= 0) + return obj; obj->t.gen = -1; - return checkobj[checkobj_idx++] = obj; + /* Store in mutobj array *before* triggering gc, otherwise + baby objects referenced by obj could be reclaimed! */ + mutobj[mutobj_idx++] = obj; + if (mutobj_idx >= MUTOBJ_VEC_SIZE) + gc(); + return obj; } + val gc_push(val obj, val *plist) { return gc_set(plist, cons(obj, *plist)); |