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Diffstat (limited to 'ChangeLog')
| -rw-r--r-- | ChangeLog | 117 |
1 files changed, 117 insertions, 0 deletions
@@ -1,5 +1,122 @@ 2014-03-29 Kaz Kylheku <kaz@kylheku.com> + Change to how locations are passed around, for the sake of generational + GC. The issue being solved here is the accuracy of the gc_set function. + The existing impelmentation is too conservative. It has no generation + information about the memory location being stored, and so it assumes + the worst: that it is a location in the middle of a gen 1 object. + This is sub-optimal, creating unacceptable pressure against the + checkobj array and, worse, as a consequence causing unreachable gen 0 + objects to be tenured into gen 1. + + To solve this problem, we replace "val *" pointers with a structure + of type "loc" which keeps track of the object too, which lets us + discover the generation. + + I tried another approach: using just a pointer with a bitfield + indicating the generation. This turned out to have a serious issue: + such a bitfield goes stale when the object is moved to a different + generation. The object holding the memory location is in gen 1, but the + annotated pointer still indicates gen 0. The gc_set function then + makes the wrong decision, and premature reclamation takes place. + + * combi.c (perm_init_common, comb_gen_fun_common, + rcomb_gen_fun_common, rcomb_list_gen_fun): Update to new interfaces + for managing mutation. + + * debug.c (debug): Update to new interfaces for managing mutation. + Avoid loc variable name. + + * eval.c (env_fbind, env_fbind): Update to new interfaces + for managing mutation. + (lookup_var_l, dwim_loc): Return loc type and update to new interfaces. + (apply_frob_args, op_modplace, op_dohash, transform_op, mapcarv, + mappendv, repeat_infinite_func, repeat_times_func): Update to new + interfaces for managing mutation. + + * eval.h (lookup_var_l): Declaration updated. + + * filter.c (trie_add, trie_compress, trie_compress_intrinsic, + * build_filter, built_filter_from_list, filter_init): Update to new + * interfaces. + + * gc.c (gc_set): Rewritten to use loc type which provides the exact + generation. We do not need the in_malloc_range hack any more, since + we have the backpointer to the object. + (gc_push): Take loc rather than raw pointer. + + * gc.h (gc_set, gc_push): Declarations updated. + + * hash.c (struct hash): The acons* functions use loc instead + of val * now. + (hash_equal_op, copy_hash, gethash_c, inhash, gethash_n, pushhash, + remhash, set_hash_userdata, hash_next, group_by, hash_keys, + hash_values, hash_pairs, hash_uni, hash_isec, hash_update, + hash_update_1): Updated to new interfaces for managing mutation. + (hash_grow): Needs hash table argument to call the new form of set. + (hash_process_weak): We need to use valptr to recover the val * + from the loc that we receive from some functions now. + + * hash.h (gethash_c, gethash_f): Declarations updated. + (gethash_l): Inline function's prototype changes. + + * lib.c (rplaca, rplacd, car_l, cdr_l, listref_l, tail, lastcons, last, + ltail, list_collect, list_collect_nconc, list_collect_append, nreverse, + lazy_appendv_func, lazy_appendv): Update to new interfaces. + (malloc_low_bound, malloc_high_bound): Static variables removed. + (adjust_bounds): Static function removed. + (chk_malloc, chk_malloc_gc_more, chk_calloc, chk_realloc): + Calls to adjust_bounds removed. + (in_malloc_range): Function removed. + (get_plist_f, string_extend, length_str, replace_str, make_sym, + delete_package, intern, rehome_sym, get_user_package, + get_system_package, get_keyword_package, func_get_env, vec_set_length, + vecref, vecref_l, vec_push, simple_lazy_stream_func, lazy_stream_func, + lazy_str, lazy_str_force, lazy_str_force_upto, acons_new, acons_new_c, + aconsql_new, aconsql_new_c, alist_nremove, alist_nremove1, merge, + sort_list, refset, obj_init): Update to new interfaces. + + * lib.h (loc): New typedef. + (gc_set): Interface change. + (mkloc_fun): New inline function. + (mkloc, mkcloc, nulloc, nullocp, deref, valptr): New macros + (set): Interface change: takes loc as first argument, + rather than lvalue expression. + (mpush): Interface change: second argument is loc, rather + than lvalue. + (keyword_package, user_package, system_package, gensym_counter): Use + deref rather than dereference operator. + (in_malloc_range): Declaration removed. + (car_l, cdr_l, listref_l, tail, lastcons, ltail, getplist_f, + get_user_package, get_system_pckage, get_keyword_package, + vecref_l, acons_new_c, aconsql_new_c): Declarations updated. + (list_collect_decl): Updated to follow new interfaces. + + * match.c (dest_set, h_coll, v_gather, v_collect, v_cat, v_output, + v_filter): Updated to follow new interfaces. + + * parser.y (expand_meta, rlset): Updated to follow new interfaces. + + * rand.h (random_state): Use deref. + + * stream.c (string_in_get_line, string_in_get_char, + string_in_unget_char, strlist_out_put_string, strlist_out_put_char): + Updated to follow new interfaces. + + * stream.h (std_input, std_output, std_debug, std_error, + std_null): Use deref macro. + (lookup_var_l): Declaration updated. + + * syslog.c (syslog_put_string, syslog_put_char, syslog_put_byte, + syslog_set_prop): Updated to follow new interfaces. + + * unwind.c (uw_register_subtype): Updated to follow + new interfaces. + +2014-03-29 Kaz Kylheku <kaz@kylheku.com> + + Generational GC tweaks. + * gc.c (make_obj): If we have room in the freshobj array, but are out of objects, then call more. Without this, we don't take proper advantage of this nursing area. |