From c61ccd9769c9c83dcdf5f7693af2ca0a605b6e19 Mon Sep 17 00:00:00 2001 From: Kaz Kylheku Date: Sat, 29 Mar 2014 11:44:52 -0700 Subject: 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, 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, --- syslog.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'syslog.c') diff --git a/syslog.c b/syslog.c index 3d8670ce..f45f29cb 100644 --- a/syslog.c +++ b/syslog.c @@ -141,7 +141,7 @@ static val syslog_put_string(val stream, val str) strstream = make_string_output_stream(); } - set(*cdr_l(cell), strstream); + set(cdr_l(cell), strstream); return t; } @@ -157,7 +157,7 @@ static val syslog_put_char(val stream, val ch) put_char(ch, strstream); } - set(*cdr_l(cell), strstream); + set(cdr_l(cell), strstream); return t; } @@ -173,7 +173,7 @@ static val syslog_put_byte(val stream, int ch) put_byte(num(ch), strstream); } - set(*cdr_l(cell), strstream); + set(cdr_l(cell), strstream); return t; } @@ -192,7 +192,7 @@ static val syslog_set_prop(val stream, val ind, val prop) { if (ind == prio_k) { val cell = (val) stream->co.handle; - set(*car_l(cell), prop); + set(car_l(cell), prop); return t; } return nil; -- cgit v1.2.3