diff options
| -rw-r--r-- | fnlz_mlc.c | 33 |
1 files changed, 18 insertions, 15 deletions
@@ -28,13 +28,10 @@ STATIC int GC_finalized_kind = 0; STATIC int GC_CALLBACK GC_finalized_disclaim(void *obj) { - void **fc_addr; - const struct GC_finalizer_closure *fc; + word fc_word = *(word *)obj; - fc_addr = &((void **)obj)[GC_size(obj) / sizeof(void *) - 1]; - fc = *fc_addr; - if (fc != NULL) { - /* [1] The disclaim function may be passed fragments from the */ + if ((fc_word & 1) != 0) { + /* The disclaim function may be passed fragments from the */ /* free-list, on which it should not run finalization. */ /* To recognize this case, we use the fact that the first word */ /* on such fragments are always even (a link to the next */ @@ -42,8 +39,8 @@ STATIC int GC_CALLBACK GC_finalized_disclaim(void *obj) /* which does not use the first word for storing finalization */ /* info, GC_reclaim_with_finalization must be extended to clear */ /* fragments so that the assumption holds for the selected word. */ - (*fc->proc)(obj, fc->cd); - *fc_addr = NULL; + const struct GC_finalizer_closure *fc = (void *)(fc_word & ~(word)1); + (*fc->proc)((word *)obj + 1, fc->cd); } return 0; } @@ -62,6 +59,13 @@ GC_API void GC_CALL GC_init_finalized_malloc(void) } done_init = TRUE; + /* The finalizer closure is placed in the first word in order to */ + /* use the lower bits to distinguish live objects from objects on */ + /* the free list. The downside of this is that we need one-word */ + /* offset interior pointers, and that GC_base does not return the */ + /* start of the user region. */ + GC_register_displacement_inner(sizeof(word)); + GC_finalized_objfreelist = (ptr_t *)GC_new_free_list_inner(); GC_finalized_kind = GC_new_kind_inner((void **)GC_finalized_objfreelist, GC_DS_LENGTH, TRUE, TRUE); @@ -89,7 +93,7 @@ GC_API void GC_CALL GC_register_disclaim_proc(int kind, GC_disclaim_proc proc, word lg; DCL_LOCK_STATE; - lb += sizeof(void *); + lb += sizeof(word); GC_ASSERT(done_init); if (SMALL_OBJ(lb)) { GC_DBG_COLLECT_AT_MALLOC(lb); @@ -110,7 +114,6 @@ GC_API void GC_CALL GC_register_disclaim_proc(int kind, GC_disclaim_proc proc, UNLOCK(); } GC_ASSERT(lg > 0); - ((const void **)op)[GRANULES_TO_WORDS(lg) - 1] = fclos; } else { size_t op_sz; @@ -119,16 +122,16 @@ GC_API void GC_CALL GC_register_disclaim_proc(int kind, GC_disclaim_proc proc, return NULL; op_sz = GC_size(op); GC_ASSERT(op_sz >= lb); - ((const void **)op)[op_sz / sizeof(void *) - 1] = fclos; } - return GC_clear_stack(op); + *(word *)op = (word)fclos | 1; + return GC_clear_stack((word *)op + 1); } #ifdef THREAD_LOCAL_ALLOC GC_API GC_ATTR_MALLOC void * GC_CALL GC_finalized_malloc(size_t client_lb, const struct GC_finalizer_closure *fclos) { - size_t lb = client_lb + sizeof(void *); + size_t lb = client_lb + sizeof(word); size_t lg = ROUNDED_UP_GRANULES(lb); GC_tlfs tsd; void *result; @@ -161,9 +164,9 @@ GC_API void GC_CALL GC_register_disclaim_proc(int kind, GC_disclaim_proc proc, result = (void *)my_entry; *my_fl = next; obj_link(result) = 0; - ((const void **)result)[GRANULES_TO_WORDS(lg) - 1] = fclos; + *(word *)result = (word)fclos | 1; PREFETCH_FOR_WRITE(next); - return result; + return (word *)result + 1; } #endif /* THREAD_LOCAL_ALLOC */ |